阅读说明：本技术 无损检测单晶体或定向结晶体内部晶体取向差异和晶界缺陷的方法及装置 (Method and device for nondestructive detection of crystal orientation difference and crystal boundary defects in single crystal or oriented crystal ) 是由 郑林 窦世涛 张津 车路长 陈新 封先河 唐伦科 张伦武 王成章 伍太宾 赵方超 于 2020-05-27 设计创作，主要内容包括：本发明提供了无损检测单晶体或定向结晶体内部晶体取向差异和晶界缺陷的方法及装置,方法步骤包括：采用透射的短波长特征X射线衍射,无损测定样品内部某一方向(h-(1)k-(1)l-(1))晶面的晶体取向角(ϑ-(1),κ-(1)),并判定该样品晶面取向角是否超差；在该晶面的(ϑ-(1),κ-(1))方向上,平移样品扫描测量被测样品各部位的(h-(1)k-(1)l-(1))晶面衍射强度及其分布,根据测量结果判定被测样品内部是否存在晶界缺陷、亚晶界缺陷。装置包括样品台、X射线照射系统和X射线探测系统及用于改变入射X射线束与样品夹角的转动机构等。采用本发明,解决了不能快速准确地无损测定单晶体和定向结晶体内部晶体取向差异、亚晶界、晶界等晶体缺陷的难题。(The invention provides a method and a device for nondestructive detection of crystal orientation difference and grain boundary defects in single crystals or oriented crystals, wherein the method comprises the following steps: nondestructive measurement of a certain direction (h) within a sample using transmitted short wavelength characteristic X-ray diffraction 1 k 1 l 1 ) Crystal orientation angle of crystal plane (ϑ) 1 ，κ 1 ) Judging whether the crystal plane orientation angle of the sample is out of tolerance; at (ϑ) of the crystal face 1 ，κ 1 ) In the direction, the sample is translated to scan and measure (h) of each part of the measured sample 1 k 1 l 1 ) And judging whether the grain boundary defect and the subgrain boundary defect exist in the tested sample according to the measurement result of the diffraction intensity and the distribution of the crystal face. The device comprises a sample table, an X-ray irradiation system, an X-ray detection system, a rotating mechanism and the like, wherein the rotating mechanism is used for changing an included angle between an incident X-ray beam and a sample. By adopting the invention, the problem thatThe method can rapidly and accurately determine the crystal defects such as crystal orientation difference, subgrain boundary, crystal boundary and the like in the single crystal and the oriented crystal without damage.)

1. The method for nondestructively detecting crystal orientation difference and grain boundary defects in the single crystal or oriented crystal is characterized by comprising the following steps of:

selecting short wavelength characteristic X-ray and wavelength of a heavy metal target for diffraction, and selecting a strong diffraction crystal face (h) of a main phase of a sample to be detected₁k₁l₁) As the measured diffraction crystal face, the (h) is calculated and determined by the BRAGG equation₁k₁l₁) Diffraction angle 2 theta of crystal plane₁；

Nondestructively measuring the diffraction plane (h)₁k₁l₁) Angle of crystal orientation ofAccording to the nondestructive measurement result and the requirement of product qualityJudging whether the crystal plane orientation angle of the measured monocrystal or oriented crystal sample is out of tolerance;

at the crystal plane orientation angleIn the direction, every part (h) of the tested sample is measured₁k₁l₁) Scanning and measuring the diffraction intensity of the short-wavelength characteristic X-ray diffracted by the crystal face to obtain the intensity and the distribution of the short-wavelength characteristic X-ray diffracted by each part of the monocrystal or oriented crystal, or: diffraction coefficients and distribution of each part of the monocrystal or oriented crystal;

and judging crystal orientation difference, grain boundary defects and subgrain boundary defects inside the single crystal or the oriented crystal according to the difference of the short-wavelength characteristic X-ray diffraction intensity or diffraction coefficient of each part and the distribution thereof and the requirement of product quality.

2. The method of claim 1, wherein the steps comprise:

step 1, selecting a short-wavelength characteristic X ray of a certain heavy metal target material for diffraction to determine the wavelength of the heavy metal target material;

step 2, selecting a certain strong diffraction crystal face (h) of the main phase of the sample to be detected₁k₁l₁) As the measured diffraction face, the (h) is calculated and determined₁k₁l₁) Diffraction angle 2 theta of crystal plane₁；

Step 3, nondestructively measuring the crystal face orientation angle of the diffraction crystal face of the sample to be measuredAccording to the (h) of the product₁k₁l₁) Angle of orientation of crystal planeJudging whether the orientation angle of the crystal face of the measured monocrystal or oriented crystal sample is out of tolerance or not;

step 4, scanning and measuring the diffraction crystal face in the direction of the orientation angle of the determined crystal on each part of the measured sample to obtain the intensity and distribution of short-wavelength characteristic X-rays diffracted by each part of the monocrystal or directional crystal;

step 5, obtaining the short-wavelength characteristic X-ray diffraction intensity of each part of the tested sample and a distribution diagram thereof according to a theoretical calculation mode of diffraction intensity correction;

or: adopting a direct correction mode of correcting diffraction intensity by taking a qualified sample as a standard sample to obtain short-wavelength characteristic X-ray diffraction coefficients and distribution maps of the short-wavelength characteristic X-ray diffraction coefficients of all parts of the tested sample;

and 6, judging the orientation difference of the crystal face, the grain boundary defect and the subgrain boundary defect in the detected single crystal sample or judging the orientation difference of the crystal face, the grain boundary defect and the subgrain boundary defect in the detected single crystal sample according to the obtained difference of the short-wavelength characteristic X-ray diffraction intensity distribution or diffraction coefficient distribution and the requirement of the product quality.

3. The method according to claim 2, characterized in that the method further comprises the step 7:

selecting a strong diffraction crystal face (h) in the other direction₂k₂l₂) After having measuredRepeating the step 2 to the step 3 at the same position, and nondestructively measuring the crystal plane orientation angle of the selected crystal plane in the directionAccording to the crystal plane orientation angles of crystal planes in different directions measured at the same positionAnd calculating the theoretical orientation relationship of the crystal planes in the two directions to obtain the crystal orientation angle of the phase measured at the measured part Judging whether the crystal orientation angle of the tested monocrystal or oriented crystal sample at the position is out of tolerance or not according to the crystal orientation angle requirement of the product;

repeating the step 4 to the step 6 to obtain the crystal face (h)₂k₂l₂) In thatAnd judging whether orientation difference exists in the detected single crystal or oriented crystal sample or not according to the obtained difference of the diffraction intensity distribution or the diffraction coefficient distribution and the requirement of product quality, and judging whether other grain boundary defects and subboundary defects exist in the detected single crystal or oriented crystal sample or not.

4. A method according to claim 2 or 3, characterized in that said step 3 further comprises:

when theta is 0 degree and K is 0 degree, a sample is arranged on a sample table of a diffraction device, so that the ideal growth direction of the sample crystal is parallel to the direction of a first translation axis of the sample table which is perpendicular to an incident ray at the moment, and on the plane of a diffractometer circle, the width direction of the sample which is perpendicular to the crystal growth direction is parallel to the direction of a second translation axis which is parallel to rotating shafts theta and 2 theta on the sample table, and the third translation axis is parallel to the thickness direction of the sample;

then, adjusting a translation mechanism of a sample stage of the diffraction device, and translating the measured part of the sample to the circle center of a diffractometer of the diffraction device; at the same position, nondestructively measuring the crystal orientation angle of the diffraction crystal face of the sample to be measuredOr

5. The method of claim 4, wherein the step 3 further comprises: nondestructively measuring the orientation angle of the crystal face by adopting one of the following first method and second methodOr/and

the first method comprises the following steps:

adjusting a 2 theta angle rotating mechanism of a diffraction device to rotate an X-ray detection system to 2 theta₁Or 2 theta₂；

Rotating theta angle, scanning and measuring the measured part of the sample at the center of the circle of the diffractometer with X-ray detection system to obtain short wavelength characteristic X-ray diffraction intensities and distribution thereof at different theta angles, and determining peak to obtain maximum diffraction intensityOr

Rotating the theta angle of the diffraction device toOrRotating the K angle of the sample stage, scanning and measuring the measured part of the sample at the center of the circle of the diffractometer by an X-ray detection system to obtain the diffraction intensity and distribution of short wavelength characteristic X-rays with different K angles, and determining the peak to obtain the kappa with the maximum diffraction intensity₁Or kappa₂。

The second method comprises the following steps:

placing the two-dimensional planar array detection system in an X-ray irradiation system opposite the diffraction device and allowing incidence through the sampleThe X-ray beam is vertically incident to the two-dimensional planar array detection system and can detect the transmitted diffraction pattern of the sample, and the distance from the sample to the two-dimensional planar array detection system is known; rotating theta angle, detecting the diffraction patterns and distribution of the diffraction patterns in different theta angle directions of the tested part of the sample at the center of the diffractometer, and fixing peak to obtain (h)₁k₁l₁) Orientation angle of maximum diffraction intensity direction of crystal faceAnd peak determination to obtain (h)₂k₂l₂) Orientation angle of maximum diffraction intensity direction of crystal face

6. The method according to claim 2 or 3, characterized in that said step 4 comprises in particular:

step 3-1, adjusting a translation mechanism of a sample stage of the diffraction device, and translating the thickness center of the measured part of the sample to the center of a circle of a diffractometer of the diffraction device or a certain position near the center of the circle;

step 3-2, adjusting the sample rotating mechanism to enable the sample to be tested (h)₁k₁l₁) Orientation of diffraction planesOrRotating an X-ray detection system to 2 θ₁Or 2 theta₂Translating the sample on the determined sampleOrScanning in the direction to measure different parts (h)₁k₁l₁) Crystal face or (h)₂k₂l₂) Short wavelength characteristic X-ray intensity of crystal plane diffraction and its distribution.

7. The method according to claim 2 or 3, wherein the direct correction of the diffraction intensity in step 5 is:

selecting qualified sample without grain boundary defect and subboundary defect as standard sample, and nondestructively measuring the measured part (h) of the standard sample₁k₁l₁) Angle of orientation of crystal planeFor scanning measuring standardsIn the direction (h)₁k₁l₁) The short wavelength characteristic X-ray intensity and distribution of the diffraction of the crystal face at different positions of the standard sample respectively take the measured value of the diffraction intensity of each position of the standard sample as denominator and the measured value of the diffraction intensity of the corresponding position of the measured sample as numerator to calculate the diffraction coefficient of each position of the measured sample and obtain the diffraction coefficient of each position (h) of the measured sample₁k₁l₁) Crystal plane at orientation angleThe diffraction coefficients in the direction and the distribution diagram thereof; similarly, each part (h) of the sample to be measured can be obtained₂k₂l₂) Crystal plane at orientation angleThe diffraction coefficients in the directions and their distribution.

8. The method according to claim 3, wherein the step 7 specifically comprises:

step 7-1, selecting another strong diffraction crystal face (h) of the main phase₂k₂l₂) As measuredDiffraction crystal face, diffraction angle 2 theta of sample is determined by calculation of bragg formula₂，

Or selecting the diffraction crystal face (h) in the other direction₁k₁l₁) As the measured diffraction crystal plane, the measured diffraction crystal plane is defined as (h)₂k₂l₂) The diffraction angle of the crystal plane is correspondingly defined as 2 theta₂；

Step 7-2, adjusting a rotating mechanism of the diffraction device to rotate the X-ray detection system to 2 theta₂；

7-3, adjusting a translation mechanism of a sample stage of the diffraction device to measure the sampleThe same part is translated to the center of a diffractometer circle of the diffraction device;

step 7-4, determining the position (h) of the sample at the center of the diffractometer circle of the diffractometer₂k₂l₂) Orientation angle of maximum direction of diffraction intensity of crystal face

By passing

Rotating theta angle, scanning and measuring the single crystal material at the measured position of the sample at the center of the circle by an X-ray detection system, measuring the short wavelength characteristic X-ray diffraction intensity and distribution thereof at different theta angles, and determining peak to obtainRotating the theta angle of the diffraction device toRotating the K angle of the sample stage, scanning the single crystal material at the measured part of the sample at the center of the circle by an X-ray detection system to measure the short wavelength characteristic X-ray diffraction intensity and distribution thereof at different K angles, and determining the peak to obtain kappa₂；

Or by

Will be a two-dimensional planeThe array detection system is arranged opposite to the X-ray irradiation system of the diffraction device, rotates the theta angle, detects the diffraction patterns of the tested part of the sample positioned at the circle center of the diffractometer in different theta angle directions, and performs peak fixing to obtain the diffraction patternsAnd kappa₂；

7-5, according to the crystal plane orientation angles of the crystal planes in different directions measured at the same position And calculating the theoretical orientation relationship of the crystal planes in the two directions to obtain the crystal orientation angle of the phase measured at the measured partJudging whether the crystal orientation angle of the tested monocrystal or oriented crystal sample at the position is out of tolerance or not according to the crystal orientation angle requirement of the product;

7-6, adjusting a translation mechanism of a sample stage of the diffraction device, and translating the thickness center of the measured part of the sample to a position near the center of the circle of the diffractometer of the diffraction device or near the center of the circle;

step 7-7, adjusting the sample rotating mechanism to measure (h) of the sample to be measured₂k₂l₂) Orientation of diffraction planesRotating an X-ray detection system to 2 θ₂Translating the sample on the determined sampleScanning in the direction to measure the short wavelength characteristic X-ray diffraction intensity and distribution of different parts;

and 7-8, correcting the diffraction intensity measured in a scanning nondestructive mode to obtain the short-wavelength characteristic X-ray diffraction intensity and distribution diagram and/or diffraction coefficient and distribution diagram of each part of the sample.

9. The method of claim 8, wherein: determining diffraction crystal face (h) according to theoretical orientation relation between selected crystal faces₁k₁l₁) And (h)₂k₂l₂) Then throughIs determined by angular range scan measurementsThen by at κ₁Angular range scan measurement of C to determine k₂。

10. A method according to claim 2 or 3, characterized in that: and performing three-dimensional reconstruction on the distribution condition of the obtained short-wavelength characteristic X-ray diffraction intensity or diffraction coefficient to obtain a three-dimensional distribution map of the diffraction intensity or diffraction coefficient, and judging whether the crystal face or crystal orientation difference, the crystal boundary defect and the subboundary defect exist in the measured monocrystal or oriented crystal sample or not and the three-dimensional distribution condition of the crystal face or crystal orientation difference, the crystal boundary defect and the subboundary defect exists according to the three-dimensional distribution map.

11. A method according to claim 2 or 3, characterized in that: rotating the theta angle of the sample table and the K angle of the sample table in a stepping rotating mode or a continuous mode; and measuring each part covering the whole tested sample by one or more times of scanning by using an X-ray detection system.

12. Diffraction device for use in the method according to any of claims 1-11, characterized in that: the diffraction device comprises a sample table, an X-ray irradiation system and an X-ray detection system, wherein an incident X-ray beam emitted by the X-ray irradiation system irradiates a measurement part of a sample; the X-ray detection system is used for measuring the X-ray diffraction intensity and distribution inside the sample; the X-ray diffraction line is a short-wavelength characteristic X-ray; the system comprises a theta rotating mechanism used for changing an included angle between an incident X-ray beam and a sample, and a 2 theta rotating mechanism used for changing an included angle between a sample diffraction beam and an incident X-ray beam, wherein the theta rotating mechanism and the 2 theta rotating mechanism are concentric and coaxial, and the circle center of a diffractometer circle is the center of a K-angle rotating circle of a sample table, namely the center of the diffractometer circle is positioned at the intersection point of the axes of theta and 2 theta rotating shafts and the axis of the K-angle rotating shaft; the sample stage comprises a translation mechanism and a rotating mechanism, the translation mechanism of the sample stage is arranged on the rotating mechanism of the sample stage, so that the measured part of the measured sample, which is positioned at the circle center of the diffractometer of the diffraction device, is unchanged when the rotating mechanism of the sample stage rotates K under the condition that the measured sample does not translate;

wherein the X-ray illumination system comprises a radiation source and an entrance collimator defining an X-ray divergence incident to the sample; the radiation source of the X-ray irradiation system comprises a heavy metal target X-ray tube with an atomic number larger than 55 and a high-voltage power supply with a power supply voltage of more than 160 kv;

the width range of the light through hole of the incident collimator is 0.02mm-0.20mm, the height range is 0.2mm-10.0mm, the divergence range on the circular plane of the diffractometer is 0.02-0.2 degrees, and the height direction vertical to the width of the light through hole is parallel to the rotating shafts of the theta rotating mechanism and the 2 theta rotating mechanism;

the X-ray detection system comprises a receiving collimator and a detector matched with the receiving collimator, wherein the detector only receives X photons passing through a light through hole of the receiving collimator, and the detector detects X-rays directly passing through the light through hole of the receiving collimator; the detector is an energy dispersion detector comprising an energy analyzer, and is a CdTe detector or a CdZnTe detector or a GaAs detector; the width range of the light through hole of the receiving collimator is 0.02mm-0.20mm, the divergence range of the width of the light through hole on the circular plane of the diffractometer of the diffraction device is 0.02-0.2 degrees, and the height direction vertical to the width of the light through hole is parallel to the rotating shafts of theta and 2 theta;

the shielding boxes of the incident collimator, the receiving collimator and the detector are all made of heavy metal materials with atomic numbers larger than 46;

the distance from the circular center of the diffractometer of the diffraction device to the X-ray irradiation system and the detection system is 100 mm-500 mm.

13. The diffraction device of claim 12, wherein: the X-ray detection system is an array detection system, the array detection system comprises an array collimator and an array detector matched with the receiving array collimator, and the array detection system is used for simultaneously detecting a plurality of short-wavelength characteristic X-rays diffracted by all parts on a cross section formed by an incident parallel light beam passing through a sample path and simultaneously measuring the diffraction intensity and the distribution of the short-wavelength characteristic X-rays diffracted by all parts on the internal cross section of the sample;

the specification range of each pixel of the array detector is 0.02mm-0.2 mm;

the specifications of all light through holes of the array receiving collimator are the same, the width range of each light through hole is 0.02-0.20 mm, the divergence range of the width of each light through hole on the circular plane of the diffractometer is 0.02-0.2 degrees, and the height direction vertical to the width of each light through hole is parallel to the rotating shafts of theta and 2 theta;

the array detector is a two-dimensional array detector, each pixel of the array detector only receives X photons passing through a corresponding light through hole of the receiving collimator, and each pixel of the detector detects X rays directly passing through the light through hole of the receiving collimator, namely, each pixel of the two-dimensional array detector detects the diffraction intensity and distribution of short-wavelength characteristic X rays diffracted by each part of a two-dimensional section in a sample.

14. The diffraction device of claim 13, wherein: each detection pixel of the array detector has single photon measurement.

15. The diffraction device of claim 14, wherein: one or more energy thresholds are set for each detection pixel of the array detector.

16. The apparatus of claim 15, wherein: the array detector is a CdTe array detector or a CdZnTe array detector or a GaAs array detector.

17. A diffraction device as claimed in claim 12, 13, 14, 15 or 16, wherein: a set of two-dimensional plane array detection system is arranged right opposite to the X-ray irradiation system, so that an incident X-ray beam passing through a detected sample or a standard sample is vertically incident to the two-dimensional plane array detector, diffraction patterns generated by all parts of the incident X-ray beam passing through the path of the incident X-ray beam can be detected, and the two-dimensional plane array detection system is used for nondestructively measuring the orientation angle of a diffraction crystal face

Technical Field

The invention relates to a nondestructive testing technology of crystal defects, in particular to a method and a device for nondestructive testing of crystal orientation over-tolerance and crystal boundary defects in single crystals or oriented crystals.

Background

Internal defects of single crystals and oriented crystals are generally divided into two main categories, namely defects such as air holes and inclusions, and crystallographic defects such as crystal orientation angle out-of-tolerance and grain boundaries. For the former, an X-ray transmission detection method is usually adopted to nondestructively detect such internal defects of the material/workpiece, and it detects the X-ray absorption coefficients and distribution maps of substances at different positions in the material/workpiece, and determines defects such as air holes, inclusions and the like according to the difference of the X-ray absorption coefficient distribution, for example, X-ray flaw detection and X-ray CT can nondestructively detect defects such as air holes, inclusions and the like in the material/workpiece, but it cannot detect crystallographic defects in single crystals and oriented crystals. For the latter, cutting a single crystal, orienting a crystal, corroding the cut surface, and checking whether a grain boundary exists in the cut surface, that is, detecting an internal grain boundary defect by using a destructive detection method, wherein the destructive grain boundary defect detection method detects only the grain boundary defect existing in the cut surface of the sample to be detected, and the detection result can not objectively reflect whether the grain boundary defect exists in other parts of the sample to be detected, and can not objectively reflect whether the grain boundary exists in other single crystals and other orienting crystals in the same batch as the sample to be detected, and the positions where the grain boundary exists in the interior of the other single crystals and other orienting crystals.

At present, the crystal orientation of the surface of a material, namely the crystal surface orientation, can be measured nondestructively by adopting an X-ray diffraction (XRD) detection method, and the orientation angle of a crystal or a crystal face is measured and calculated based on the different direction diffraction difference principle of crystal grains, for example, the crystal orientation of the surface of a high-temperature alloy blade is subjected to nondestructive detection. The Laue method diffracts a certain crystal face of a certain surface position of the monocrystal by using white light X-rays, and only one exposure imaging is needed to complete the collection of diffraction spots of the surface position and determine the crystal orientation angle of the surface position; the texture method uses monochromatic X-rays to diffract on a certain crystal face of a certain surface position of the monocrystal, measures the diffraction intensity distribution of the crystal face in different directions by rotating a sample, and determines the orientation angle of the crystal face of the surface position. Of course, the orientation angle is measured for each position of the surface, the grain boundary defects can be identified and judged according to the difference of the orientation angles of the measured positions of the surface of the single crystal or the oriented crystal, the large angle grain boundaries with the difference of the orientation angles of the adjacent positions being more than 10 ° and the small angle grain boundaries with the difference of the orientation angles being 2 ° to 10 °, the sub-grain boundary defects are identified and judged according to the difference of the orientation angles of the adjacent positions being the sub-grain boundaries with the difference of the orientation angles being less than 2 °, but it takes too long to detect the orientation angles of the surface of the single crystal and the oriented crystal one by one to be theoretically and practically impossible, and no prior document is disclosed about a method and a technique for nondestructively detecting the orientation angles of the inside of the single crystal and the oriented crystal and the inside grain boundary defects. Therefore, there is a need to develop a method and apparatus for non-destructive testing of crystal orientation differences and grain boundary defects within single crystals or oriented crystals.

Disclosure of Invention

For single crystals, the directions of the individual crystal planes in the macroscopic coordinate system of the single crystal are constant, i.e. the angles to the three coordinate axes are constant. If the direction of the crystal plane of a certain part in the measured single crystal sample is different from that of the other part, namely the included angle of the crystal plane and the coordinate axis is different, the part is a crystal with another orientation, and a grain boundary defect or a subgrain boundary defect is inevitably present at or near the part, so that the diffraction pattern of the part is obviously different from that of the other part.

The invention aims to provide a method and a device for nondestructively detecting crystal orientation difference and grain boundary defects (including grain boundary defects and subgrain boundary defects defined according to orientation angle difference) in a single crystal or a directional crystal.

In the present invention, the term "short wavelength characteristic X-ray of heavy metal target" is used to refer to the characteristic X-ray emitted from the X-ray tube of heavy metal target with atomic number greater than 55, the heavy metal target includes but is not limited to W, Au, Pt, U or their alloys, and the wavelength is less than 0.04 nm; the term "stronger diffraction crystal face" is used to mean a crystal face with relative diffraction intensity of more than 40% in the diffraction PDF card of the main phase of the tested sample, such as AlNi₃The (111), (200) and (420) crystal faces in the 09-0097 card.

The judgment of the grain boundary and sub-grain boundary defects of the tested monocrystal or oriented crystal sample is to judge the crystal face or crystal orientation difference or the existence of the grain boundary and sub-grain boundary defects according to the short-wavelength characteristic X-ray diffraction intensity or diffraction coefficient of each part of the tested sample and the distribution steep change thereof and the requirement of product quality, such as: if the short wavelength characteristic X-ray diffraction intensity or the diffraction coefficient of each part of the tested sample and the steep change amplitude existing in the distribution of the short wavelength characteristic X-ray diffraction intensity or the diffraction coefficient are larger than 90%, judging that a grain boundary defect exists at or near the steep change position; if the diffraction intensity or the diffraction coefficient of the short-wavelength characteristic X-ray diffracted by each part of the tested sample and the steep change amplitude existing in the distribution of the diffraction intensity or the diffraction coefficient are 20% -90%, judging that the subgrain boundary defect exists at or near the steep change position; if the short wavelength characteristic X-ray diffraction intensity or diffraction coefficient of each part of the tested sample and the steep change amplitude existing in the distribution of the short wavelength characteristic X-ray diffraction intensity or diffraction coefficient are less than 20%, judging that no grain boundary or subgrain boundary defect exists.

Diffraction angle 2 theta mentioned in the present invention₁、2θ₂、2θ_hklAnd 2 θ, both refer to the angle between the diffraction ray and the incident ray, and it is not limited to the angle between the sample and the incident ray (in this case, the X-ray tube is fixed, i.e., the direction of the incident ray is fixed) changed by directly rotating the sample by the θ angle rotation in the present invention and fig. 1 and fig. 3, or it is not limited to the angle between the sample and the incident ray (in this case, the direction of the sample is fixed) changed by directly rotating the X-ray tube by the θ angle rotation in the present invention and fig. 2.

The method for achieving the purpose adopts the following technical scheme.

The method for nondestructively detecting crystal orientation difference and grain boundary defects in the single crystal or oriented crystal is characterized by comprising the following steps of:

selecting short wavelength characteristic X-ray and wavelength of a heavy metal target for diffraction, and selecting a strong diffraction crystal face (h) of a main phase of a sample to be detected₁k₁l₁) The spacing between the measured diffraction facets is determined by calculation from the BRAGG equation₁k₁l₁) Diffraction angle 2 theta of crystal plane₁；

Nondestructively measuring the diffraction plane (h)₁k₁l₁) Angle of crystal orientation ofJudging whether the crystal plane orientation angle of the measured single crystal or oriented crystal sample is out of tolerance or not according to the nondestructive measurement result and the requirement of product quality;

at the crystal plane orientation angleIn the direction, every part (h) of the tested sample is measured₁k₁l₁) Scanning and measuring the diffraction intensity of the short-wavelength characteristic X-ray diffracted by the crystal face to obtain the intensity and the distribution of the short-wavelength characteristic X-ray diffracted by each part of the monocrystal or oriented crystal, or: diffraction coefficients and distribution of each part of the monocrystal or oriented crystal;

and judging crystal orientation difference, grain boundary defects and subgrain boundary defects inside the single crystal or the oriented crystal according to the difference of the short-wavelength characteristic X-ray diffraction intensity or diffraction coefficient of each part and the distribution thereof and the requirement of product quality.

Further, the method for nondestructive detection of crystal orientation difference and grain boundary defects in the single crystal or oriented crystal comprises the following steps:

step 1, selecting a short-wavelength characteristic X ray of a certain heavy metal target material for diffraction to determine the wavelength of the heavy metal target material;

step 2, selecting a certain strong diffraction crystal face (h) of the main phase of the sample to be detected₁k₁l₁) (h) is determined by calculation as a measured diffraction crystal plane (for example, a (200) crystal plane parallel to the growth direction of the nickel-based single-crystal blade is used as the measured diffraction crystal plane)₁k₁l₁) Diffraction angle 2 theta of crystal plane₁；

Step 3, nondestructively measuring the crystal face orientation angle of the diffraction crystal face of the sample to be measuredAccording to the (h) of the product₁k₁l₁) Angle of orientation of crystal planeJudging whether the orientation angle of the crystal face of the measured monocrystal or oriented crystal sample is out of tolerance or not;

step 4, scanning and measuring the diffraction crystal face in the direction of the orientation angle of the determined crystal on each part of the measured sample to obtain the intensity and distribution of short-wavelength characteristic X-rays diffracted by each part of the monocrystal or directional crystal;

step 5, obtaining the short wavelength characteristic X-ray diffraction intensity of each part of the tested sample and a distribution diagram thereof according to the theoretical calculation mode of the diffraction intensity correction of the shape, the structure and the like of the tested sample,

or: adopting a qualified sample (namely a single crystal without grain boundary defects and subgrain boundary defects) as a standard sample to carry out a direct correction mode of diffraction intensity correction to obtain short-wavelength characteristic X-ray diffraction coefficients and distribution maps of the short-wavelength characteristic X-ray diffraction coefficients of all parts of the tested sample;

and 6, judging the orientation difference of the crystal face, the grain boundary defect and the subgrain boundary defect in the detected single crystal sample or judging the orientation difference of the crystal face, the grain boundary defect and the subgrain boundary defect in the detected single crystal sample according to the obtained difference of the short-wavelength characteristic X-ray diffraction intensity distribution or diffraction coefficient distribution and the requirement of the product quality.

Furthermore, in order to perform overall nondestructive detection on the crystal orientation difference inside the single crystal and the oriented crystal and judge the grain boundary defects, the method further comprises the following steps of 7:

selecting a strong diffraction crystal face (h) in the other direction₂k₂l₂) After having measuredRepeating the step 2 to the step 3 at the same position, and nondestructively measuring the crystal plane orientation angle of the selected crystal plane in the directionAccording to the crystal plane orientation angles of crystal planes in different directions measured at the same positionAnd calculating the theoretical orientation relationship of the crystal planes in the two directions to obtain the crystal orientation angle of the phase measured at the measured part Judging whether the crystal orientation angle of the tested monocrystal or oriented crystal sample at the position is out of tolerance or not according to the crystal orientation angle requirement of the product;

repeating the step 4 to the step 6 to obtain the crystal face (h)₂k₂l₂) In thatShort wavelength characteristic X-ray diffraction intensity in directionAnd judging whether orientation difference exists in the tested monocrystal or oriented crystal sample or not according to the obtained diffraction intensity distribution or the difference of the diffraction coefficient distribution and the requirement of product quality, and judging whether other grain boundary defects and subgrain boundary defects exist in the tested monocrystal or oriented crystal sample or not.

As a preferable embodiment of the present invention, the step 3 further includes:

when theta is 0 degree and K is 0 degree, a fixed sample is arranged on a sample table of a diffraction device, so that the ideal growth direction of a sample crystal is parallel to the direction of a first translation axis (such as an X axis) of the sample table which is perpendicular to an incident line at the moment, and on the plane of a diffractometer circle, the width direction of the sample which is perpendicular to the crystal growth direction is parallel to the direction of a second translation axis (such as a Y axis) which is parallel to rotating axes of theta and 2 theta on the sample table, and a third translation axis (such as a Z axis) is parallel to the thickness direction of the sample, for example, the sample is a nickel-based single crystal blade, the ideal growth direction of the sample is the radial direction of the nickel-based single crystal blade, and the smaller included angle between a gamma' - (200) crystal plane and the radial direction is better;

then, adjusting a translation mechanism of a sample stage of the diffraction device, and translating the measured part of the sample to the circle center of a diffractometer of the diffraction device; at the same position, nondestructively measuring the crystal orientation angle of the diffraction crystal face of the sample to be measuredOr

As a preferable mode of the present invention, the crystal orientation angle is nondestructively measured by one of the following first and second methodsOr/and

the first method comprises the following steps:

adjusting 2 theta angle rotation of diffraction deviceThe moving mechanism rotates the X-ray detection system to 2 theta₁Or 2 theta₂；

Rotating theta angle, scanning and measuring the measured part of the sample at the center of the circle of the diffractometer with X-ray detection system to obtain short wavelength characteristic X-ray diffraction intensities and distribution thereof at different theta angles, and determining peak to obtain maximum diffraction intensityOr

Rotating the theta angle of the diffraction device toOrRotating the K angle of the sample stage, scanning and measuring the measured part of the sample at the center of the circle of the diffractometer by an X-ray detection system to obtain the diffraction intensity and distribution of short wavelength characteristic X-rays with different K angles, and determining the peak to obtain the kappa with the maximum diffraction intensity₁Or kappa₂；

The second method comprises the following steps:

placing a two-dimensional planar array detection system in an X-ray irradiation system which is opposite to a diffraction device, enabling an incident X-ray beam which penetrates through a sample to be vertically incident to the two-dimensional planar array detection system, and detecting a diffraction pattern transmitted by the sample, wherein the distance from the sample to the two-dimensional planar array detection system is known; rotating theta angle, detecting the diffraction patterns and distribution of the diffraction patterns in different theta angle directions of the tested part of the sample at the center of the diffractometer, and fixing peak to obtain (h)₁k₁l₁) Orientation angle of maximum diffraction intensity direction of crystal faceAnd peak determination to obtain (h)₂k₂l₂) Orientation angle of maximum diffraction intensity direction of crystal face

As a preferred embodiment of the present invention, the step 4 specifically includes:

step 3-1, adjusting a translation mechanism of a sample stage of the diffraction device, and translating the thickness center of the measured part of the sample to the center of a circle of a diffractometer of the diffraction device or a certain position near the center of the circle;

step 3-2, adjusting the sample rotating mechanism to enable the sample to be tested (h)₁k₁l₁) Orientation of diffraction planesAnd kappa₁OrRotating an X-ray detection system to 2 θ₁Or 2 theta₂Translating the sample on the determined sampleOrScanning in the direction to measure different parts (h)₁k₁l₁) Crystal face or (h)₂k₂l₂) Short wavelength characteristic X-ray intensity of crystal plane diffraction and its distribution.

As a preferred embodiment of the present invention, the direct correction method for the diffraction intensity correction in step 5 is:

selecting qualified sample without grain boundary defect and subboundary defect as standard sample, and measuring the measured part (h) of the standard sample₁k₁l₁) Angle of orientation of crystal planeFor scanning measuring standardsIn the direction (h)₁k₁l₁) Crystal face on the markThe short wavelength characteristic X-ray intensity and distribution of sample diffraction at different parts are calculated by taking the measured diffraction intensity of each part of the standard sample as denominator and the measured diffraction intensity of the corresponding part of the sample as numerator to obtain the diffraction coefficients of each part of the sample (h)₁k₁l₁) Crystal plane at orientation angleThe diffraction coefficients in the directions and their distribution. Similarly, each part (h) of the sample to be measured can be obtained₂k₂l₂) Crystal plane at orientation angleThe diffraction coefficients in the directions and their distribution.

As a preferred embodiment of the present invention, the step 7 specifically includes:

step 7-1, selecting another strong diffraction crystal face (h) of the main phase₂k₂l₂) As the measured diffraction crystal face, the diffraction angle 2 theta of the sample is calculated and determined by the bragg formula₂，

Or, selecting (h) in another direction₁k₁l₁) The crystal face is the measured diffraction crystal face, and for the convenience of description, it is referred to as (h) in the present invention₂k₂l₂) The angle of diffraction of a crystal plane, correspondingly called 2 theta₂；

Step 7-2, adjusting a rotating mechanism of the diffraction device to rotate the X-ray detection system to 2 theta₂；

7-3, adjusting a translation mechanism of a sample stage of the diffraction device to measure the sampleThe same part is translated to the center of a diffractometer circle of the diffraction device;

step 7-4, determining the measured part (h) of the sample₂k₂l₂) Orientation angle of maximum direction of diffraction intensity of crystal face

By passing

Adjusting the 2 theta angle rotating mechanism of the diffraction device to rotate the X-ray detection system to 2 theta₂；

Rotating theta angle, scanning and measuring the single crystal material at the measured position of the sample at the center of the circle by an X-ray detection system, measuring the short wavelength characteristic X-ray diffraction intensity and distribution thereof at different theta angles, and determining peak to obtainRotating the theta angle of the diffraction device toRotating the K angle of the sample stage, scanning the single crystal material at the measured part of the sample at the center of the circle by an X-ray detection system to measure the short wavelength characteristic X-ray diffraction intensity and distribution thereof at different K angles, and determining the peak to obtain kappa₂；

Or by

A two-dimensional plane array detector is opposite to the X-ray irradiation system of the diffraction device, the theta angle is rotated, the diffraction patterns of the tested part of the sample at the circle center of the diffractometer in different theta angle directions are detected, and the peak is fixed to obtain the diffraction patternAnd kappa₂；

7-5, according to the crystal plane orientation angles of the crystal planes in different directions measured at the same position And calculating the theoretical orientation relationship of the crystal planes in the two directions to obtain the crystal orientation angle of the phase measured at the measured partJudging whether the crystal orientation angle of the tested monocrystal or oriented crystal sample at the position is out of tolerance or not according to the crystal orientation angle requirement of the product;

7-6, adjusting a translation mechanism of a sample stage of the diffraction device, and translating the thickness center of the measured part of the sample to the center of the circle of the diffractometer of the diffraction device or a certain position near the center of the circle;

step 7-7, adjusting the sample rotating mechanism to measure (h) of the sample to be measured₂k₂l₂) Orientation of diffraction planesRotating an X-ray detection system to 2 θ₂Translating the sample on the determined sampleScanning in the direction to measure the short wavelength characteristic X-ray diffraction intensity and distribution of different parts;

and 7-8, correcting the diffraction intensity measured in a scanning nondestructive mode to obtain the short-wavelength characteristic X-ray diffraction intensity and distribution diagram and/or diffraction coefficient and distribution diagram of each part of the sample.

As a preferable embodiment of the present invention, in order to improve the detection efficiency, for a known crystal structure, the diffraction facets (h) are determined₁k₁l₁) And (h)₂k₂l₂) Then throughIs determined by angular range scan measurementsThen by at κ₁Angular range scan measurement of C to determine k₂。

Furthermore, in order to visually and conveniently represent the internal orientation distribution of the single crystal sample or the directional crystal sample, namely the grain boundary, subgrain boundary defects and the distribution thereof in the sample, the measured short-wavelength characteristic X-ray diffraction intensity distribution or diffraction coefficient distribution of the crystal faces in two different directions, the three-dimensional reconstruction is carried out on the distribution condition of the diffraction intensity or diffraction coefficient which is measured in a scanning nondestructive mode, the three-dimensional distribution diagram of the diffraction intensity or diffraction coefficient is obtained, and according to the difference and the degree of the difference, whether the grain boundary and/or subgrain boundary exist in the sample and the three-dimensional distribution condition of the existing subgrain boundary and/or subgrain boundary are judged, so that the nondestructive measurement of whether the grain boundary, subgrain boundary defects and the distribution thereof exist in the whole single crystal sample or the directional crystal sample is completed. The determination of the grain boundary and subgrain boundary defects of the single crystal or oriented crystalline sample to be tested according to the difference and the degree of the three-dimensional distribution map is described in the section of "determination of the grain boundary and subgrain boundary defects of the single crystal or oriented crystalline sample to be tested … determination of no grain boundary and subgrain boundary defects" mentioned in the present invention.

As the preferred scheme of the invention, the theta angle of the sample table and the K angle of the sample table are rotated in a stepping rotation mode or a continuous mode; and measuring each part covering the whole tested sample by one or more times of scanning by using an X-ray detection system.

The diffraction device for realizing the method adopts the following technical scheme.

In the invention, the diffraction device comprises a sample stage, an X-ray irradiation system and an X-ray detection system, wherein an incident X-ray beam emitted by the X-ray irradiation system irradiates a measurement part of a sample; the X-ray detection system is used for measuring the X-ray diffraction intensity and distribution inside the sample; the X-ray diffraction line is a short-wavelength characteristic X-ray; the system comprises a theta rotating mechanism used for changing an included angle between an incident X-ray beam and a sample, and a 2 theta rotating mechanism used for changing an included angle between a sample diffraction beam and an incident X-ray beam, wherein the theta rotating mechanism and the 2 theta rotating mechanism are concentric and coaxial, and the circle center of a diffractometer circle is the center of a K-angle rotating circle of a sample table, namely the center of the diffractometer circle is positioned at the intersection point of the axes of theta and 2 theta rotating shafts and the axis of the K-angle rotating shaft; the sample stage comprises a translation mechanism and a rotating mechanism, the translation mechanism of the sample stage is arranged on the rotating mechanism of the sample stage, so that the measured part of the measured sample, which is positioned at the circle center of the diffractometer of the diffraction device, is unchanged when the rotating mechanism of the sample stage rotates K under the condition that the measured sample does not translate;

wherein the X-ray illumination system comprises a radiation source and an entrance collimator defining an X-ray divergence incident to the sample; the radiation source of the X-ray irradiation system also comprises a heavy metal target X-ray tube of targets such as W, Au, Pt and U, and a high-voltage power supply with power supply voltage of more than 160 kv;

the width range of the light through hole of the incident collimator is 0.02mm-0.20mm, the height range of the light through hole of the incident collimator is 0.2mm-10.0mm, the divergence range on the circular plane of the diffractometer is 0.02-0.2 degrees, and the height direction vertical to the width of the light through hole is parallel to the rotating shafts of the theta rotating mechanism and the 2 theta rotating mechanism.

The X-ray detection system comprises a receiving collimator and a detector matched with the receiving collimator, wherein the detector only receives X photons passing through a light through hole of the receiving collimator, so that the interference of stray X-rays is avoided, and the detector detects the X-rays directly passing through the light through hole of the receiving collimator; the detector is an energy dispersion detector comprising an energy analyzer, is a CdTe detector or a CdZnTe detector or a GaAs detector, and not only records the number of photons, but also can analyze the energy of the photons; the width range of the light through hole of the receiving collimator is 0.02mm-0.20mm, the divergence range of the width of the light through hole on the circular plane of the diffractometer of the diffraction device is 0.02-0.2 degrees, and the height direction vertical to the width of the light through hole is parallel to the rotating shafts of theta and 2 theta.

The X-ray detection system is an array detection system, the array detection system comprises an array collimator and an array detector matched with the receiving array collimator, and the array detection system is used for simultaneously detecting a plurality of short-wavelength characteristic X-rays diffracted by all parts on a cross section formed by incident parallel beams with a certain height passing through a sample path, and simultaneously measuring the diffraction intensity and the distribution of the short-wavelength characteristic X-rays diffracted by all parts on the internal cross section of the sample.

As a preferable scheme of the invention, each detection pixel of the array detector has single photon measurement, and the specification range of each pixel of the array detector is 0.02mm-0.2 mm.

As a preferable scheme of the invention, the specifications of all the light through holes of the array receiving collimator are the same, the width of each light through hole ranges from 0.02mm to 0.20mm, the divergence degree of the width of each light through hole on the circular plane of a diffractometer of the diffraction device ranges from 0.02 degrees to 0.2 degrees, and the height direction vertical to the width of each light through hole is parallel to the rotating shafts of theta and 2 theta.

As a preferred aspect of the present invention, the array detector is a two-dimensional array detector, each pixel of the two-dimensional array detector only receives X photons passing through a corresponding light-passing hole of the receiving collimator, and each pixel of the detector detects X rays directly passing through the light-passing hole of the receiving collimator, that is, each pixel of the two-dimensional array detector detects the diffraction intensity and distribution of short-wavelength characteristic X rays diffracted by each part of the two-dimensional cross section inside the sample.

In a preferred embodiment of the present invention, one or more energy thresholds can be set for each detection pixel of the array detector. As a preferable scheme of the invention, the array detector is a CdTe detector or a CdZnTe detector or a GaAs detector.

As a preferable scheme of the invention, a set of two-dimensional plane array detection system is arranged right opposite to the X-ray irradiation system, so that an incident X-ray beam passing through a tested sample or a standard sample is vertically incident to the two-dimensional plane array detection system, diffraction patterns generated by all parts of the incident X-ray beam passing through the paths can be detected, and the two-dimensional plane array detection system is used for nondestructively measuring the orientation angle of a diffraction crystal face

In a preferred embodiment of the present invention, the distance from the center of the diffractometer circle of the diffraction device to the X-ray irradiation system, the detection system, or the array detection system is 100mm to 500 mm. The shielding boxes of the incident collimator, the receiving collimator or the receiving array collimator, the detector or the array detector are all made of heavy metal materials with atomic number larger than 46, such as tungsten, gold and alloy thereof.

Has the advantages that: the method can nondestructively detect the crystal orientation and the difference of each part in the large monocrystal (such as a monocrystal blade), solves the problems that the crystal orientation and the difference of the inside of the monocrystal blade and the directional crystallization blade cannot be nondestructively detected at present and the crystal defects such as subboundary, crystal boundary and the like in the large monocrystal cannot be accurately judged, can provide indispensable internal quality nondestructive detection means for the developed and produced monocrystal blade and the directional crystallization blade, and has the advantages of quickly, simply and reliably nondestructively detecting the crystal orientation and the crystal boundary defects of each part in the large monocrystal (such as the monocrystal blade).

Drawings

FIG. 1 is a schematic view of nondestructive testing of grain boundary defects of a single crystal sample by the method of the present invention;

FIG. 2 is a schematic illustration of the optical path diagram of FIG. 1, sample coordinates and diffraction apparatus of the present invention;

FIG. 3 is a schematic diagram of nondestructive testing of grain boundary defects of a single crystal sample by single point detection according to the present invention;

FIG. 4 is a flow chart of nondestructive testing of internal crystal orientation and grain boundary defects of a sample according to the present invention;

FIG. 5 is a partial picture of a Ni-based superalloy single crystal blade of example 1 and the corresponding non-destructive testing of the diffraction intensity distribution of the gamma' - (200) crystallographic plane in a given direction scanned at different positions along the y-direction;

FIG. 6 is a partial photograph of a sample of directionally crystallized nickel-base superalloy material of example 2, and the distribution of diffraction intensity of the gamma' - (200) crystallographic plane in the direction of (-6.0870 °, 0.4147 °) across various portions of the YZ cross-section of the sample as measured by step-and-scan Y-direction without loss;

FIG. 7 is a YZ cross section of a sample of the hollow single crystal made of a nickel-base superalloy used in example 3, and a Y-direction step scan showing the gamma' - (420) plane diffraction coefficients and their distribution measured without loss of diffraction at various positions on the YZ cross section;

in fig. 1, 2 and 3, 1-X-ray tube, 2-incidence collimator, 3-sample, 4-receiving collimator or receiving array collimator, 5-detector or array detector, 6-coaxial concentric theta and 2 theta rotation mechanism, 7-XYZ translation mechanism and K angle rotation mechanism of sample stage, 8-diffractometer circle, 9-diffractometer circle center, 10-incident line, 11-diffracted line, 12-diffracted vector direction, 13-exposure part of section, 14-defect such as miscellaneous crystal, 15-sample coordinate system, 16-defect such as miscellaneous crystal of exposure section, 21-theta, 2 theta, K, X, Y, Z driver, 22-high voltage generator, 23-high voltage controller, 24-main control computer, 25-remote operation terminal.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments, which are only used for understanding the principle and the core idea of the present invention, and are not intended to limit the scope of the present invention. It should be noted that modifications to the invention as described herein, which do not depart from the principles of the invention, are intended to be within the scope of the claims which follow.

As shown in fig. 1, 2, and 3, the diffraction device of the present invention includes: an X-ray irradiation system, wherein an incident X-ray beam emitted by a heavy metal anode target X-ray tube 1 of the X-ray irradiation system irradiates a measurement part of a sample; an incident collimator 2 for defining the divergence of the X-rays incident on the sample 3; the X-ray detector comprises a receiving collimator or receiving array collimator 4, a detector or array detector 5 and a coaxial concentric theta and 2 theta rotating mechanism 6, wherein the rotating mechanism 6 is used for changing the theta and 2 theta of an included angle between an incident X-ray beam and a sample; the sample stage comprises an X, Y, Z translation mechanism and a K-angle rotation mechanism 7, the translation mechanism of the sample stage is arranged on the sample stage rotation mechanism, so that under the condition that the sample 3 to be measured does not translate, and when the sample stage rotation mechanism rotates K, the part to be measured of the sample 3 to be measured, which is positioned at the circle center of the diffractometer of the diffraction device, is unchanged; the diffraction instrument circle 8, the diffraction instrument circle center 9, the sample coordinate system 15, a driver 21 for movement of theta, 2 theta and K, X, Y, Z, a high voltage generator 22, a high voltage controller 23, a main control computer 24 and a remote operation terminal 25.

Wherein, the central extension line of the incident collimator 2 and the central extension line of the receiving array collimator corresponding to the center of a certain detection unit in the middle of the array detector 5 or the central extension line of the receiving collimator of the detector 5 intersect at the center of the diffraction instrument circle; wherein, the X-ray composed of the heavy metal anode target X-ray tube 1, the high voltage generator 22, the high voltage controller 23, etc. is used as the X-ray source of the device; x rays (incident rays 10) emitted by the heavy metal anode target X-ray tube 1 are incident on a sample after passing through the incident collimator 2, diffraction rays 11 of the X rays are received by the receiving collimator or the receiving array collimator 4, and the X-ray diffraction intensity and distribution inside the sample are measured through the detector or the array detector 5.

Wherein, the main control computer 24 controls the driver 21 of the movement through the signal cable, controls the movement of the rotating mechanism and the translating mechanism of theta, 2 theta, K, X, Y, Z; the main control computer 24 controls the detector 5 or the array detector 5 through a signal cable, and the short wavelength characteristic X-ray diffraction counting intensity measured by each corresponding detection unit of the detector 5 or the array detector 5 enters a communication interface of the main control computer 24 through the signal cable; the high voltage controller 23 is used for starting the high voltage generator 22 and adjusting and controlling the voltage, the current and the like output to the X-ray tube 1 by the high voltage generator 22; the main control computer 24 and the remote operation terminal 25 are connected by a signal cable, and an operator can operate and control the diffraction device at the remote operation terminal 25 through the main control computer 24.

Example 1

The embodiment focuses on a method for nondestructively detecting crystal orientation difference and grain boundary defects in a single crystal, in particular to a method for nondestructively detecting crystal orientation difference and grain boundary defects of a gamma' -phase (200) crystal plane in a nickel-based superalloy single crystal blade.

In this embodiment, the diffraction device adopts a tungsten target X-ray tube, the focus size of the tungsten target X-ray tube is 5.5mm × 5.5mm, and WKa for diffraction is selected₁Its wavelength is 0.0209nm, which corresponds to a photon energy of 59.3 kev.

Wherein the diffraction device:

the X-ray detection system is a single-point detection system, and the energy resolution is better than 2%;

the incident collimator and the receiving collimator are made of tungsten alloy materials, light through holes of the incident collimator and the receiving collimator are rectangular light through holes, the height direction of the light through holes is parallel to rotating shafts of theta and 2 theta, the width of the light through holes is 0.1mm, the height of the light through holes is 10mm, and the divergence of the incident collimator and the receiving collimator on a circular plane of a diffractometer of the diffractometer (namely the width of the light through holes) is 0.11 degrees;

the detector is CdZnTe detectionThe device is provided with a single photon measurement, two thresholds of the detected photon energy are set to be 58.2kev and 60.4kev respectively, and the device is used for detecting and recording WK alpha₁Diffraction intensity, the detector adopts heavy metal material-tungsten alloy with atomic number greater than 46 to fully shield, only receives X photons passing through the light-passing hole of the receiving collimator, and avoids the interference of stray X rays;

the translation mechanism of the sample stage is arranged on the rotating mechanism of the sample stage, so that when the rotating mechanism of the sample stage rotates theta and/or K, the sample part positioned at the circle center of the diffractometer of the diffraction device cannot deviate from the circle center, and the rotating shafts of the theta and the 2 theta are coaxial and concentric; the distance from the center of the diffractometer circle of the diffraction device to the X-ray irradiation system is 300mm, and the distance from the center of the diffractometer circle to the detection system is 300 mm.

In this example, the sample is a solid nickel-based superalloy single crystal blade, as shown in fig. 5, a macroscopic broken line exists between the index 1 and the index 2, that is, a grain boundary defect exists, and a scanning test along the width direction of the blade body shows that the thickness of the blade body is 2.5mm to 3.2mm, the thickness of the blade body at the position 1 is 2.5mm, the thickness of the blade body at the position 2 is 3.0mm, and the thickness of the broken line between the connecting lines at the positions 1 and 2 is 3.2mm,

the detection steps are as follows:

selecting a (200) crystal face of a gamma' phase of a main phase of the sample as a diffraction crystal face, wherein the diffraction angle is 2 theta₂₀₀＝6.66°；

When theta is 0 DEG and K is 0 DEG, a fixed sample is arranged on a sample stage of the diffraction device, the crystal growth direction (namely the radial direction of the blade) of the sample is parallel to the X-axis direction of the sample stage which is perpendicular to the incident line at the moment, the normal line of the side surface (the bonding surface in the figure 5) of the tenon close to the convex surface side of the blade body is perpendicular to the rotating shafts theta and 2 theta as much as possible, namely the width direction of the blade which is perpendicular to the crystal growth direction is parallel to the Y-axis direction which is parallel to the rotating shafts theta and 2 theta on the sample stage as much as possible, the thickness direction of the blade is parallel to the Z-axis direction on the sample stage as much as possible, namely the radial initial direction of the sample blade is close to the directions theta 3.33 DEG and K is 0 DEG as much as possible, the X coordinates of the position 1 and the position 2 are the same, and the Y coordinates are different;

setting the tube voltage to 200kv and the tube current to 12mA, and measuring in step scanLength is 10s, and the coordinate Z at the center of the thickness of the blade body at the sample position 1 is Z₁-29.250mm, and Z-coordinate at the center of the leaf thickness at sample position 1₂＝-28.890mm；

The sample is translated in the Z direction so that the centre of leaf thickness at sample position 2 is located at the centre of the diffractometer circle of the diffraction device, at which time the sample coordinate Z ═ Z₂-28.890 mm; instructing the X-ray detection system to rotate to a diffraction angle 2 theta₂₀₀6.66 °; step theta angle scanning with step size of 0.02 degree is carried out to measure diffraction intensity of short wavelength characteristic X-ray at different theta angles, and a parabolic legal peak is adopted to obtain maximum diffraction intensity by peak fixingSend instructions to rotate the sample table, i.e. the sample, toStep-by-step K angle scanning with step length of 0.2 degree is carried out to measure the short wavelength characteristic X-ray diffraction intensity of different K angles, a parabolic legal peak is adopted, and the maximum K (kappa) of the diffraction intensity is obtained by peak fixing₂-0.1776 °; sending a command to rotate the sample table, i.e. the sample, to K ═ K₂At-0.1776 °, the stage, i.e., the sample, is translated to Z ═ Z (Z)₁+Z₂) The grain size is-29.070 mm, and theta is 2.4758 degrees at the moment, namely the direction of the gamma' - (200) crystal face to be measured of the sample is positioned atAnd K ═ K₂The X-ray detection system is also set to-0.1776 ° at a diffraction angle of 2 θ₂₀₀At 6.66 degrees, the sample is translated in the direction of (2.4758 degrees and-0.1776 degrees) to perform Y scanning measurement with the step length of 0.5mm, and the short-wavelength characteristic X-ray intensity and distribution of substance diffraction at different Y positions with unchanged X, Z coordinates are measured; from the measured distribution of the short-wavelength characteristic X-ray intensity along Y as shown in fig. 5, there was a sharp change in diffraction intensity near the fold line between positions 1 and 2, i.e., there was a grain boundary defect near Y ═ 10.5 mm;

in order to comprehensively and nondestructively detect the in-situ position of a single crystal blade sampleThe difference in internal crystal orientation between position 1 and position 2 was determined for the remaining grain boundary defects, and the center of leaf thickness at position 1 of the sample was measured in the same manner as described above (in this case, Z ═ Z-₁Orientation angle of gamma' - (200) plane of-29.250 mm)K＝κ₁0.3806 °; y-scan measurement with a step size of 0.5mm was performed in the (8.5449 °, 0.3806 °) direction of the sample, at which time the coordinate Z of the sample was (Z ═ Z₁+Z₂) 2-29.070 mm, the X-ray detection system is still at a diffraction angle 2 theta₂₀₀At 6.66 °, the distribution of the measured short-wavelength characteristic X-ray intensity along Y is as shown in fig. 5, and there is a sharp change in diffraction intensity near the fold line between positions 1 and 2, i.e., there is a grain boundary defect near Y of 5.1 mm; furthermore, there is a minimum in the diffraction intensity at 30 th of the scan measurement, i.e. there are also grain boundary defects or subgrain boundary defects at y ═ 14.5mm ± 0.5 mm.

In the above test scanning along the coordinate Y, the X, Z coordinate of the sample is unchanged.

And (3) judging the accurate position of the grain boundary defect near the broken line: since the X-ray detection system is a single-point detection system, and the light-passing holes of the incident collimator and the receiving collimator are rectangular light-passing holes, the height direction of the light-passing holes is parallel to the rotating axes of theta and 2 theta, the width of the light-passing holes is 0.1mm, the height of the light-passing holes is 10mm, the difference between the theta angle positions of the position 1 and the position 2 is 8.5449 ° -2.4758 ° -6.0691 °, and the difference between the K angle positions is 0.3806 ° - (-0.1776 °) -0.5582 °, namely, the difference between the orientation angles of the thickness centers of the position 1 and the position 2 is 6.0946 ° -degrees, and in combination with the diffraction intensities and the distribution thereof in the crystal plane directions of the position 1 and the position 2, the crystal boundary defect can be determined between the position 17 and the position 18 in the scanning measurement, namely, the crystal boundary defect near the fold line is positioned at the position y ═ 8.25mm ± 0.5 mm.

In summary, the following non-destructive testing results were obtained:

(1) the included angle of the orientation of the gamma ' - (200) plane at the center of the thickness of the blade body at the position 1 is 6.0946 degrees calculated from the orientation angle (8.5449 degrees and 0.3806 degrees) of the gamma ' - (200) plane at the center of the thickness of the blade body at the position 2 and the orientation angle (2.4758 degrees and-0.1776 degrees) of the gamma ' - (200) plane at the center of the thickness of the blade body at the position 2;

(2) the above detection results, measured by diffraction intensity scanning of the orientation angle of the γ' - (200) plane at different positions around the macroscopic grain boundary defect, confirm the correctness and utility of the method, and both the macroscopic grain boundary defect at y 8.25mm ± 0.5mm and the macroscopic grain boundary or sub-grain boundary defect at y 14.5mm ± 0.5mm (smaller difference in orientation angle) were detected in the interior between the position 1 and the position 2 of the sample.

Example 2

The present embodiment focuses on a method for nondestructive testing of crystal orientation difference and grain boundary defects inside a directional crystallization part, and specifically, the method is used for nondestructive testing of crystal orientation difference and grain boundary defects of a gamma' phase (200) crystal plane inside a nickel-based superalloy directional crystallization part.

In this embodiment, the diffraction device adopts a tungsten target X-ray tube, the focus size of the tungsten target X-ray tube is 0.4mm × 0.4mm, and WKa for diffraction is selected₁Its wavelength is 0.0209nm, which corresponds to a photon energy of 59.3 kev.

Wherein the diffraction device:

the X-ray detection system is an array detection system and comprises a one-dimensional receiving array collimator and a two-dimensional array detector;

the incident collimator and the one-dimensional receiving array collimator are made of tungsten alloy and other heavy metals and alloy materials thereof, the two-dimensional array detector is a CdTe array detector with 0.1mm multiplied by 0.1mm pixels, each pixel has single photon measurement and the energy resolution ratio is better than 5%, each pixel can be set with two energy thresholds, the two energy thresholds of each pixel are respectively set to be 53kev and 65kev and used for detecting and recording WK alpha₁The intensity of diffraction;

the array detector is fully shielded by adopting a heavy metal material-tungsten alloy with the atomic number larger than 46, only X photons passing through the light through holes of the receiving array collimator are received, each pixel of the two-dimensional array detector only detects X rays directly passing through each corresponding light through hole of the one-dimensional receiving array collimator, and the interference of stray X rays is avoided;

the light through hole of the incident collimator is a rectangular light through hole, the height direction of the light through hole is parallel to the rotating shafts of theta and 2 theta, the width of the light through hole is 0.1mm, the height of the light through hole is 5mm, and the divergence of the incident collimator on the circular plane of the diffractometer of the diffraction device (namely the width of the light through hole) is 0.11 degrees;

the one-dimensional array collimator is composed of 50 parallel rectangular light through holes with the distance of 0.1mm, the width of each light through hole is 0.05mm, the height of each light through hole is 5mm, the wall thickness between every two adjacent light through holes is 0.05mm, the materials of the light through holes are tungsten alloys, the light through holes are parallel to each other, the specifications of the light through holes are the same, the height direction of each light through hole is parallel to a rotating shaft of theta and 2 theta, the divergence of the width of each light through hole on the circular plane of a diffractometer of the diffractometer is 0.11 degrees, namely the divergence angle of an incident ray and a diffraction ray entering each pixel of the two-dimensional array detection system on the circular plane of the diffractometer is 0.11 degrees; it should be noted that, because the incident X-ray beam and the diffracted beam have a certain height, the diffraction device has a plurality of diffractometer circle centers on the rotating shafts of theta and 2 theta, and the centers are the intersections of the circle planes of the diffractometers and the rotating shafts of theta and 2 theta;

the translation mechanism of the sample stage is arranged on the rotating mechanism of the sample stage, so that when the rotating mechanism of the sample stage rotates theta and/or K, the sample part positioned at the circle center of the diffractometer of the diffraction device cannot deviate from the circle center, and the rotating shafts of theta and 2 theta are coaxial and concentric.

The distance from the center of a diffractometer circle of the diffraction device to the X-ray irradiation system is 150mm, and the distance from the center of the diffractometer circle to the array detection system is 200 mm.

In this embodiment: the nickel-based superalloy blade is molded by adopting a directional crystallization casting process, samples of about 1.8mm (thickness) × 33.0mm (width) × 10.0mm (radial length of the blade) are cut from the tenon part of the directionally crystallized nickel-based superalloy blade, different testing positions are marked, and as shown in fig. 6, different crystal growth areas visible to naked eyes exist between a mark 1 and a mark 9, namely a grain boundary defect exists; the Ni-based superalloy consists of a matrix gamma phase (Ni-based solid solution) and a gamma' precipitation phase (Ni)₃Al intermetallic compound) two phases, and a γ' phase is a main phase.

The detection steps are as follows:

selecting a (200) crystal face of a main phase gamma' phase as a diffraction crystal face, wherein the diffraction angle is 2 theta₂₀₀＝6.66°；

When theta is 0 DEG and K is 0 DEG, a fixed sample is arranged on a sample stage of the diffraction device, the crystal growth direction (namely the radial direction of the blade) of the sample is parallel to the X-axis direction of the sample stage which is perpendicular to the incident line at the moment as much as possible, the normal line of the side surface of the tenon close to the convex surface of the blade body is perpendicular to the rotating shafts theta and 2 theta as much as possible, namely the width direction of the blade which is perpendicular to the crystal growth direction is parallel to the Y-axis direction which is parallel to the rotating shafts theta and 2 theta on the sample stage as much as possible, the thickness direction of the blade is parallel to the Z-axis direction on the sample stage as much as possible, namely the initial direction of the radial direction of the sample blade is near the direction of theta 3.33 DEG and K is 0 DEG as much as possible, the X coordinates of the section where the scribing line is positioned are the same as shown in figure 6, and the Y coordinates are different from the Z coordinates;

setting the tube voltage to be 200kv, the tube current to be 8mA, and the measuring time of step scanning to be 10 s;

first, the orientation angle of the γ' - (200) crystal plane of the single crystal blade was measured, that is: adjusting a sample stage of the diffraction device, and translating the thickness center of a measured part (such as the position of 9 points) of the sample to the center of a diffractometer circle of the diffraction device; adjusting a 2 theta angle rotating mechanism of the diffraction device to rotate the X-ray detection system to a diffraction angle 2 theta which is 2 theta₂₀₀6.66 °, WK α emitted from W target₁After passing through an incident collimator, forming a parallel light beam with the height of 0.4mm to irradiate a sample; rotating the theta angle of the sample table in a 0.01-degree step scanning mode, performing theta angle scanning measurement on the single crystal material of the measured part of the sample at the circle center of the diffractometer, and measuring WKa of different theta angles₁The diffraction intensity is determined by a method such as a parabola method, and the peak is determined to obtainAdjusting a theta angle rotating mechanism of the diffraction device to-6.0870 degrees, rotating a K angle of a sample table in a step scanning mode of 0.5 degrees with delta K, carrying out K angle scanning measurement on the single crystal material of the measured part of the sample at the circle center of the diffractometer, and measuring WKa of different K angles₁The diffraction intensity is determined by a method such as a parabola method, and the peak is determined to obtain K ═ kappa₉＝0.4147°；

Then, the sample was scanned in the (-6.0870 DEG, 0.4147 DEG) direction to measure the diffraction intensity distribution of the gamma' - (200) crystal plane along the cross section taken by the scribe line shown in FIG. 6The situation is as follows: adjusting a sample stage of the diffraction device, and translating the thickness center of the sample to be close to the circular center of a diffractometer of the diffraction device; adjusting a sample rotating mechanism to position the direction of the gamma' - (200) diffraction crystal face to be detected of the sample atAnd K ═ K₉0.4147 °, at diffraction angle 2 θ, the X-ray detection system is free to operate at₂₀₀At 6.66 °, measurement was started, at which time WK α emitted from the W target₁The X-ray detection system is characterized in that a beam of parallel light beams is formed after the X-ray detection system passes through an incident collimator and irradiates a sample, due to strong penetrability of short-wavelength characteristic X-rays, diffraction occurs on all parts penetrating through the tested sample and on a path of the beam of rays, namely, all parts of a certain part of the cross section of a single crystal blade (such as a gray scale identification part of one cross section of the tested sample shown in figure 1) diffract, the X-rays scattered and diffracted at all parts enter a two-dimensional array detector after passing through a positioned receiving array collimator, and each pixel of the X-ray detection system only measures and records WK alpha incident to the two-dimensional array detector₁Measuring WK alpha of gray scale marking part of one cross section of tested blade sample in 10s₁Diffraction intensity and its distribution, as shown in the lower left corner of FIG. 1; the WK alpha of the whole YZ cross section of the sample can be measured without damage by scanning and measuring the sample by stepping 5mm in the Y direction₁Diffraction intensity and distribution thereof, and in addition, the WKa of the whole cross section can be measured without damage by sequentially stepping 4mm in the y direction for scanning measurement₁Diffraction intensity and distribution thereof, wherein 5mm-4 mm-1 mm is the overlapping part of two adjacent measurements, and is used for WK alpha₁Calculating the correction of diffraction intensity and distribution thereof;

then, WK α of the entire YZ cross section of the sample was measured nondestructively according to the above scan₁The diffraction intensities and the distribution thereof, that is, the difference of the (200) crystal plane orientation of the γ' phase of the sample in the distribution of the measured cross section is obtained, as shown in fig. 6, the diffraction intensities from the position 3 to the position 4 and from the position 8 to the right of the sample are much stronger than the rest, that is, grain boundaries exist at and near the sharp change of the diffraction intensities from the position 3 to the position 4 and from the position 8 to the right periphery of the sample, and further, the regions with strong diffraction intensities on the YZ cross sections from the position 3 to the position 4 and from the position 8There is also a significant visible difference in diffraction intensity for the domains, i.e., some subgrain boundaries.

In addition, WK alpha of sample YZ cross section of different X coordinates is scanned and nondestructively detected₁Diffraction intensity and distribution thereof, and measured WK alpha of sample YZ cross section of different X coordinates₁The diffraction intensity and the distribution thereof are superposed to obtain the WK alpha₁And judging the defects of grain boundaries and subgrain boundaries according to the obtained short-wavelength characteristic X-ray diffraction intensity and the three-dimensional distribution thereof or the difference and the degree of the three-dimensional distribution of the diffraction coefficient, judging whether the defects of the grain boundaries and the subgrain boundaries exist in the measured single crystal sample or not, and judging the existing positions, thereby obtaining the three-dimensional distribution of the defects of the grain boundaries and the subgrain boundaries in the whole measured sample.

Example 3

The embodiment focuses on a method for nondestructively detecting crystal orientation difference and grain boundary defects in a hollow single crystal, in particular to a method for nondestructively detecting crystal orientation difference and grain boundary defects of an internal gamma' phase (420) crystal plane of a cross section of a nickel-based high-temperature alloy hollow single crystal.

The method and the device adopted by the embodiment refer to the embodiment 2, and the main difference of the method and the device from the embodiment 2 is that:

the sample to be detected is a nickel-based superalloy hollow single crystal sample;

a diffraction intensity correction method is added;

the parameters are selected differently: in this embodiment, a gold target X-ray tube is used as the radiation source, the focal spot size is 5.5mm × 5.5mm, and AuK α is selected for diffraction₁A wavelength of 0.0180nm and a corresponding photon energy of 68.794kev, a diffraction angle of the gamma' - (420) plane 2 theta₄₂₀12.95 °; the two-dimensional array detector is a GaAs array detector with 0.1mm multiplied by 0.1mm pixels, each pixel has single photon measurement and the energy resolution is better than 5%, each pixel can set two energy thresholds, the two energy thresholds of each pixel are respectively set to be 65kev and 73kev and used for detecting and recording AuK alpha₁The intensity of diffraction; the tube voltage is set to 270kv, the tube current is set to 10mA, and the measurement time of step scan is set to 15 s.

In this example, a hollow single crystal of a nickel-based superalloyThe direction of the gamma' - (200) plane of the sample was substantially parallel to the lengthwise direction of the sample, which was 50mm long, 20mm wide and 12mm thick as shown in FIG. 1, and AuK alpha in the test₁The path length of the actual material penetrating the sample is not more than 5.5 mm; when K is 0 ° and θ is 0 °, the sample is mounted on the sample stage such that its longitudinal direction is parallel to the X axis, its width direction is parallel to the Y axis, and its thickness direction is parallel to the Z axis.

In this example, the added diffraction intensity correction: and adopting qualified samples which are made of the same material and have the same process and the same structure size as standard samples, carrying out nondestructive testing on the short-wavelength characteristic X-ray intensity and the distribution thereof diffracted by each part of the cross section at the same position of the standard samples, carrying out diffraction intensity correction, calculating the diffraction coefficient of each part of the tested samples, and obtaining the diffraction coefficient and the distribution diagram thereof of each part of the tested cross section of the tested samples.

Scanning one section of the sample for nondestructive detection, correcting diffraction intensity, and measuring the WKalpha of the whole YZ cross section of the sample₁The diffraction coefficients and the distribution thereof are schematically shown in fig. 7, in which the gray regions are the grains of abnormal orientation, i.e., the hetero-crystals or the recrystallization defects different from the rest of the single crystal body in the cross section, and the boundaries thereof are the grain boundary defects in the single crystal body.