阅读说明：本技术 一种3d打印制件孔型缺陷的可检测性能的检测方法 (Detection method for detection performance of hole type defects of 3D printing workpiece ) 是由 钟波 杨扬 虞永杰 罗少蚺 王小兵 傅范平 于 2021-06-25 设计创作，主要内容包括：本发明提出了一种3D打印制件孔型缺陷的可检测性能的检测方法；通过圆柱基体和孔型缺陷圆柱体对各种不同能量和型号的工业CT检测设备的验证,并可重复制作,确保高质量水平,从而确定工业CT检测方法与检测设备是否可靠,还可通过不同厚度下所发现的孔型缺陷对比,验证CT检测设备在此厚度下的极限孔型缺陷的检出能力,为3D打印制件直接提供可量化的缺陷检出,为3D打印制造工艺水平的提升提供依据。(The invention provides a detection method for the detection performance of hole type defects of 3D printing parts; the industrial CT detection equipment with different energies and models is verified through the cylindrical base body and the hole-pattern defect cylinder, and can be repeatedly manufactured, so that the high quality level is ensured, whether the industrial CT detection method and the detection equipment are reliable or not is determined, the detection capability of the limit hole-pattern defect of the CT detection equipment under the thickness can be verified through comparison of the hole-pattern defects found under different thicknesses, quantifiable defect detection is directly provided for 3D printing parts, and a basis is provided for improving the level of the 3D printing manufacturing process.)

1. A detection method for the detectable performance of hole type defects of 3D printing parts is used for detecting the detectable performance of industrial CT detection equipment, and is characterized by comprising the following steps:

step 1: manufacturing a hole type defect cylinder (2); the hole-type defect cylinder (2) is a cylinder with the overall dimension of phi 10mm multiplied by 10mm, and the dimensional accuracy is minus 0.05mm to 0.00 mm; setting artificial hole defects of different specifications on the hole defect cylinder (2);

step 2: manufacturing a cylindrical base body (1) for placing a hole type defect cylinder (2); the cylindrical base body (1) is provided with five models, and the overall dimensions are respectively as follows: phi 20mm multiplied by 80mm, phi 30mm multiplied by 80mm, phi 40mm multiplied by 80mm, phi 50mm multiplied by 80mm, phi 60mm multiplied by 80mm, specification size precision is +/-0.1 mm, and surface roughness Ra (mum) is 1.6; processing the center of the upper end face of each cylindrical base body (1) to generate a concave flat bottom hole with the diameter of 10mm multiplied by 10mm, wherein the size precision is 0.00mm to +0.05mm, and the concave flat bottom hole is mainly used for placing a hole type defect cylinder (2);

and step 3: detecting the hole type defect of the manual hole type by using industrial CT detection equipment to detect the hole type defect cylinder (2) or the combination of the hole type defect cylinder (2) and the cylindrical substrate (1);

and 4, step 4: and analyzing the detectable performance degree of the industrial CT detection equipment according to the detection result.

2. The method for detecting the detectable performance of the hole type defect of the 3D printing workpiece according to claim 1, wherein the setting of the artificial hole type defect in the step 1 is specifically as follows: prefabricating 5 artificial hole defects at the position with the radius of 2.5mm on the upper end surface of the hole defect cylinder (2) at intervals of 72 degrees; the artificial hole type defects are round holes with diameters of 500 micrometers, 400 micrometers, 300 micrometers, 200 micrometers and 100 micrometers respectively, the diameter size precision is +/-0.01 mm, the hole diameter depth is 2mm, and the specification depth precision is +/-0.1 mm.

3. The method for detecting the detectable performance of the hole type defect of the 3D printing part as claimed in claim 1, wherein in the step 3, the specific operation of combining the hole type defect cylinder (2) and the cylinder base body (1) is as follows: lubricating the concave-flat bottom hole of the cylindrical base body (1) by using grease, and then placing the hole-type defect cylinder (2) in the concave-flat bottom hole.

4. The method for detecting the hole type defect detection performance of the 3D printing part as claimed in claim 1, wherein the cylindrical base (1) and the hole type defect cylinder (2) are both manufactured by a 3D printing mode of a powder feeding mode; in the manufacturing process: firstly, manufacturing a 3D printing blank material with a size slightly larger than the actual specification, determining that no defect exists in the blank material after nondestructive testing, and then processing the blank material to the required size and roughness by adopting a machining mode; finally, defects existing in the raw materials are checked, and the defects which are not checked are used as the final manufactured finished product.

5. The method for detecting the detectable performance of the hole type defect of the 3D printing part as claimed in any one of claims 1 to 4, wherein the cylindrical base body (1) and the hole type defect cylinder (2) are made of high-temperature alloy powder.

6. The method for detecting the hole type defect detectability of the 3D printing product according to claim 5, wherein the cylindrical base body (1) and the hole type defect cylinder (2) are made of aluminum powder.

7. The method for detecting the hole type defect detectability of the 3D printing product according to claim 5, wherein the cylindrical base body (1) and the hole type defect cylindrical body (2) are made of titanium powder.

Technical Field

The invention belongs to the technical field of nondestructive testing, and particularly relates to a detection method for the detection performance of hole type defects of 3D printing workpieces.

Background

3D printing is a rapid prototyping technology, which is a technology for constructing an object by using a bondable material such as powdered metal or plastic and the like in a layer-by-layer printing mode on the basis of a digital model file. The hole type defect is an internal defect which is easy to generate in 3D printing and manufacturing, and is easy to seriously influence the mechanical property of a 3D printing part, so that the engineering application of an actual product is restricted. In the laser melting process of the alloy powder, the laser beam melts the alloy powder into a liquid phase, the action time of the laser and the powder is extremely short (generally in the range of 0.5-25 ms), and the solidification process of the liquid phase is also fast. If the compactness of the alloy powder is not enough, gaps exist among particles, and gas also exists, in the process of rapidly solidifying the alloy, part of the gas exists in the melt because the gas cannot be discharged completely in time, and the gas is separated out again during solidification to form holes.

Aiming at the detection of hole type defects in a 3D printing part, a ray detection technology and an industrial CT (computed tomography) detection technology can be selected.

The 3D printing part with simple structure and small part configuration thickness can generally directly adopt the ray detection technology. The technology utilizes the fact that rays can penetrate through an object which cannot be penetrated by visible light, and complex physical and chemical actions can be generated with substances while the rays penetrate through the object, so that atoms can be ionized, some substances can emit fluorescence, and some substances can generate photochemical reactions. If the internal area of the workpiece has defects, the attenuation of the object to the ray is changed, and the intensity of the transmitted ray is changed, so that the ray intensity after penetration is received by a film or a digital area array detector, and a ray film or a digital ray image is obtained after subsequent processing. The defect identification capability of the ray detection is related to the thickness of the ray penetrating through the detected object, the identification capability of the ray detection to the fine defect is poorer after the thickness detection is more, and in order to verify the hole type defect identification capability of the detected object, the detection sensitivity corresponding to the hole type image quality meter verification is generally adopted in the detection process. The technology is applied to the industry for hundreds of years, and the technology and the quality control system are very mature. However, this technique has a great influence on the shape and shape of the object to be detected, and the more complicated the object to be detected, the more blind areas are detected.

The industrial CT detection technology is developed on the basis of ray detection technology, and the basic principle is that when collimated ray energy beams pass through a detected object, according to different attenuation coefficients of volume elements in all projection directions and different ray energies received by a detector, a CT detection image of the section of the detected object can be obtained according to a certain image reconstruction algorithm. The technology can make up the defects of a ray detection technology, no matter how many complex detected objects are, the industrial CT can carry out 100% detection, the ray energy of the industrial CT is up to 16MeV, and the detection of objects with large thickness can be met. According to the basic principle of ray detection, the identification capability of the industrial CT detection technology to the tiny defects is reduced along with the increase of the detection thickness, and meanwhile, the difference in tiny defect identification is caused due to the difference of ray energy, the difference of detectors and the difference of software reconstruction algorithms. Aiming at 3D printing parts which are multi-cavity, large in thickness and pure in a dot matrix structure, an industrial CT detection technology is a preferred detection method.

At present, 3D printing parts are rapidly increased every year, and the demand for industrial CT detection is increasingly vigorous. However, the detection service provider of the industrial CT cannot systematically prove that the limit identification capability of the industrial CT apparatus for the hole type defects can be identified only by judging the defects based on experience under the condition that various materials have different penetration thicknesses, and cannot provide reliable quality guarantee for 3D printed products, and is not beneficial to the development and promotion of 3D printing manufacturing technology, and is not beneficial to the part manufacturing designer to compile related part acceptance technical documents.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a detection method for the detection performance of the hole type defects of a 3D printing part; the industrial CT detection equipment with different energies and models is verified through the cylindrical base body and the hole-pattern defect cylinder, and can be repeatedly manufactured, so that the high quality level is ensured, whether the industrial CT detection method and the detection equipment are reliable or not is determined, the detection capability of the limit hole-pattern defect of the CT detection equipment under the thickness can be verified through comparison of the hole-pattern defects found under different thicknesses, quantifiable defect detection is directly provided for 3D printing parts, and a basis is provided for improving the level of the 3D printing manufacturing process.

The specific implementation content of the invention is as follows:

the invention provides a detection method of the detectable performance of hole type defects of 3D printing parts, which is used for detecting the detectable performance of industrial CT detection equipment and specifically comprises the following steps:

step 1: manufacturing a hole-type defect cylinder; the hole pattern defect cylinder has the overall dimension of phi 10mm multiplied by 10mm and the dimensional accuracy of minus 0.05mm to 0.00 mm; setting artificial hole defects of different specifications on the hole defect cylinder;

step 2: manufacturing a cylindrical base body for placing the hole-type defect cylinder; the cylindrical base body is provided with five models, and the overall dimensions are respectively as follows: phi 20mm multiplied by 80mm, phi 30mm multiplied by 80mm, phi 40mm multiplied by 80mm, phi 50mm multiplied by 80mm, phi 60mm multiplied by 80mm, specification size precision is +/-0.1 mm, and surface roughness Ra (mum) is 1.6; processing the center of the upper end face of each cylindrical base body to generate a concave flat bottom hole with the diameter of 10mm multiplied by 10mm, the size precision of 0.00mm to +0.05mm, and the concave flat bottom hole is mainly used for placing a hole type defect cylinder;

and step 3: detecting the hole type defect cylinder by using industrial CT detection equipment or detecting the manual hole type defect by using the combination of the hole type defect cylinder and the cylindrical substrate;

and 4, step 4: and analyzing the detectable performance degree of the industrial CT detection equipment according to the detection result.

In order to better implement the present invention, further, the setting of the artificial hole type defect in step 1 specifically includes: prefabricating 5 artificial hole defects at the position with the radius of 2.5mm on the upper end surface of the hole defect cylinder at intervals of 72 degrees; the artificial hole type defects are round holes with diameters of 500 micrometers, 400 micrometers, 300 micrometers, 200 micrometers and 100 micrometers respectively, the diameter size precision is +/-0.01 mm, the hole diameter depth is 2mm, and the specification depth precision is +/-0.1 mm.

In order to better implement the present invention, further, in step 3, the specific operation of combining the hole-type defect cylinder with the cylindrical substrate is as follows: and lubricating the concave-flat bottom hole of the cylindrical base body with grease, and then placing the hole-type defect cylinder in the concave-flat bottom hole.

In order to better realize the invention, the cylindrical substrate (1) and the hole-type defect cylinder (2) are manufactured by adopting a 3D printing mode of a powder feeding mode; in the manufacturing process: firstly, manufacturing a 3D printing blank material with a size slightly larger than the actual specification, determining that no defect exists in the blank material after nondestructive testing, and then processing the blank material to the required size and roughness by adopting a machining mode; finally, defects existing in the raw materials are checked, and the defects which are not checked are used as the final manufactured finished product.

In order to better realize the invention, the cylindrical substrate (1) and the hole-type defect cylinder (2) are further made of high-temperature alloy powder.

In order to better realize the invention, the cylindrical base body (1) and the hole-type defect cylinder (2) are made of aluminum powder.

In order to better realize the invention, the cylindrical substrate (1) and the hole-type defect cylinder (2) are further made of titanium powder.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the invention verifies various industrial CT detection equipment with different energy and types through the cylindrical substrate (1) and the hole type defect cylinder (2), can be repeatedly manufactured, and ensures high quality level, thereby determining whether the industrial CT detection method and the detection equipment are reliable, verifying the detection capability of the limit hole type defect of the CT detection equipment under the thickness through the comparison of the hole type defects found under different thicknesses, directly providing quantifiable defect detection for 3D printing products, and providing basis for the improvement of the level of the 3D printing manufacturing process.

Drawings

FIG. 1 is a schematic structural diagram of a cylindrical substrate and hole-type defective cylinder assembly according to the present invention;

FIG. 2 is I₁A 450kV industrial CT detection schematic diagram is combined by a cylindrical substrate and a hole-type defect cylinder of a gear;

FIG. 3 is I₁Gear cylinder base and hole-type defect cylinder combination 9MeV industrial CTA detection schematic diagram;

FIG. 4 is I₄A 450kV industrial CT detection schematic diagram is combined by a cylindrical substrate and a hole-type defect cylinder of a gear;

FIG. 5 is I₄The cylindrical substrate and the hole-type defect cylinder of the gear are combined into a 9MeV industrial CT detection schematic diagram.

Wherein: 1. cylindrical base, 2, pass defect cylinder.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and therefore should not be considered as a limitation to the scope of protection. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

the embodiment provides a detection method for hole type defects of 3D printed products, as shown in fig. 1, a test block is first generated, the test block includes a cylindrical base 1 and a hole type defect cylinder 2, the hole type defect cylinder 2 can be used alone, the cylindrical base 1 and the hole type defect cylinder 2 can also be used in combination, and the industrial CT detection equipment with different energies and models can be verified and manufactured repeatedly to ensure a high quality level, so as to determine whether the industrial CT detection method and the detection equipment are reliable, and the detection capability of the limit hole type defects of the CT detection equipment under the thickness can be verified by comparing the hole type defects found under different thicknesses, thereby directly providing quantifiable defect detection for the 3D printed products and providing a basis for improving the level of the 3D printing manufacturing process.

Furthermore, the industrial CT detectability device for the hole pattern defects of the 3D printing part is characterized in that 5 cylindrical substrates 1 which are printed by aluminum powder materials through 3D printing are specifically divided into I_1、I_2、I_3、I_4、I₅Five grades and hole type defect cylinders 2. The defect detectability of the 3D printing product adopting the aluminum powder can be verified, and the titanium powder or the high-temperature alloy powder can be further adopted for printing so as to verify the detectability condition of the industrial CT under different materials.

Further, 5 cylindrical substrates I manufactured by 3D printing_1、I_2、I_3、I_4、I₅After the blank material is determined to have no defects through nondestructive testing, the shape and the size of the blank material are processed into cylindrical matrixes with the same height and different diameters by adopting a common machining mode, and the steps are as follows: phi 20mm × 80mm, phi 30mm × 80mm, phi 40mm × 80mm, phi 50mm × 80mm, phi 60mm × 80mm, with a specification and dimension accuracy of ± 0.1mm, and a surface roughness Ra (μm) of 1.6. The defects possibly existing in the raw materials are checked through nondestructive testing so as to avoid the subsequent detectable analysis of hole type defects; the different diameters of the cylindrical base bodies mainly simulate the thickness grading of actual 3D printing parts; the height of 80mm is adopted, so that a base for CT detection does not need to be arranged independently when CT detection is carried out.

Further, each machined cylindrical base I_1、I_2、I_3、I_4、I₅A concave flat bottom hole with the diameter of 10mm multiplied by 10mm is processed at the central position, the size precision is 0.00 mm- +0.05mm, and the concave flat bottom hole is mainly used for placing the hole type defect cylinder 2.

Further, the size and the shape of the flat-bottom concave hole in the cylindrical base body 1 are basically consistent with those of the hole-pattern defect cylinder 2, and the hole wall is lubricated by grease, so that the cylindrical base body 1 and the hole-pattern defect cylinder 2 can be conveniently taken out and placed, and the clamping is avoided.

Furthermore, 21 hole type defect cylinders are provided, the external dimension of each hole type defect cylinder is phi 10mm multiplied by 10mm, and the dimensional accuracy is minus 0.05 mm-0.00 mm. The cylindrical substrate 1 has positive tolerance, and the hole-type defect cylinder 2 has negative tolerance, so that the combination and the separation are facilitated, and the identification of the minimum defect capability of the detection is not influenced.

Further, 5 artificial hole type defects are prefabricated on the hole type defect cylinder 2 at the position with the radius of 2.5mm at intervals of 72 degrees, the diameter of each defect is 500 micrometers, 400 micrometers, 300 micrometers, 200 micrometers and 100 micrometers, and the diameter size precision is +/-0.01 mm; the aperture depth is 2mm, and the specification depth precision is +/-0.1 mm. The maximum diameter of the related defects is 500 mu m, the defects can meet the normal identification of conventional detection, the defects are classified into 5 grades, the minimum defects are 100 mu m, the defects are suitable for the defect identification capability and the detection precision of CT detection, the aperture depth is 2mm, and the defects are favorable for the identification of the CT detection.

Further, the hole-pattern defect cylinder 2 is printed in a powder feeding mode in a 3D mode, a 3D printing blank material with the size slightly larger than the actual specification is manufactured, no defect is formed in the blank material after nondestructive testing, the blank material is machined to the required size and roughness in a machining mode, and possible defects in the raw material are checked to avoid subsequent hole-pattern defect detectability analysis.

Further, aiming at the thickness of an actual detection object, selecting a corresponding cylindrical base body 1, placing a hole type defect cylinder 2 in a flat-bottom hole of the cylindrical base body 1, and testing, wherein the mode of combination can be switched according to different detection thicknesses.

Example 2:

in this embodiment, based on the above embodiment 1, as shown in fig. 2 and 3, the minimum pinhole defect detectable condition of a 3D printed aluminum alloy part with a thickness of 20mm is verified by a 450kV industrial CT detection device and a 9MeV industrial CT detection device respectively.

Preferably using a cylindrical base I₁Is used in combination with the hole-pattern defect cylinder 2, in particular to place the hole-pattern defect cylinder 2 on the cylindrical substrate I₁In the recess of the housing. PlacingThe detection is carried out on a platform of 450kV industrial CT detection equipment, and detection parameters are determined by the detection equipment. The detection parameters adopted in this case are: tube voltage 100kV, tube current 3.0mA, SDD =1600mm, SOD =800mm, filter 2mmAL, probe size 0.1mm, focus size: 0.4mm, voxel: 0.05mm, projection matrix 1024 x 2048, the CT examination image shown in fig. 2 was obtained. Through analysis and judgment of the image, the 5 th defective hole of the hole-type defective cylinder 2 can be identified by adopting 450kV industrial CT detection equipment under the penetrating thickness, namely the limit detection capability is better than 100 mu m, and the air hole type defects of the grade higher than the limit detection capability can be identified. The combined device is also placed on a platform of 9MeV industrial CT detection equipment for detection, and detection parameters are determined by the detection equipment. The detection parameters adopted in this case are: tube voltage 9MeV, pulse frequency 200HZ, number of pulses 30Pluse, SDD =4600mm, SOD =3780mm, probe size 0.2mm, focal spot size: 2.0mm, voxel: 0.16mm, projection matrix 400 x 800, resulting in the CT examination image shown in fig. 3. Through analysis and judgment of the image, the 3 rd defective hole of the hole-type defective cylinder 2 can be identified by adopting 9MeV industrial CT detection equipment under the penetrating thickness, namely the limit detection capability is better than 300 mu m, and only the air hole type defects larger than the grade can be identified.

Other parts of this embodiment are the same as those of embodiment 1, and thus are not described again.

Example 3:

in this embodiment, based on the above embodiment 1, as shown in fig. 4 and 5, the minimum pinhole defect detectable condition of a 3D printed aluminum alloy part with a thickness of 50mm is verified by a 450kV industrial CT detection device and a 9MeV industrial CT detection device respectively.

Preferably using a cylindrical base I₄Is used in combination with the hole-pattern defect cylinder 2, in particular to place the hole-pattern defect cylinder 2 on the cylindrical substrate I₄In the recess of the housing. And (3) placing the sample on a platform of 450kV industrial CT detection equipment for detection, wherein detection parameters are determined by the detection equipment. The detection parameters adopted in this case are: tube voltage 300kV, tube current 2.0mA, SDD =1600mm, SOD =800mm, filter 2mmFE, probe size 0.1mm, focus size: 0.4mm, voxel: 0.05mm, projection matrix 1500 x 2048, resulting in the CT examination shown in fig. 4And (5) imaging. Through analysis and judgment of the image, the 4 th defective hole of the hole-type defective cylinder 2 can be identified by adopting 450kV industrial CT detection equipment under the penetrating thickness, namely the limit detection capability is better than 200 mu m, and the air hole type defects of the grade higher than the limit detection capability can be identified. The combined device is also placed on a platform of 9MeV industrial CT detection equipment for detection, and detection parameters are determined by the detection equipment. The detection parameters adopted in this case are: tube voltage 9MeV, pulse frequency 200HZ, number of pulses 30Pluse, SDD =4600mm, SOD =3780mm, probe size 0.2mm, focal spot size: 2.0mm, voxel: 0.16mm, projection matrix 800 x 800, resulting in the CT examination image shown in fig. 3. Through analysis and judgment of the image, the 1 st defective hole of the hole-type defective cylinder 2 can be identified by adopting 9MeV industrial CT detection equipment under the penetrating thickness, namely the limit detection capability is better than 500 mu m, and only the air hole type defects larger than the grade can be identified.

Other parts of this embodiment are the same as those of embodiment 1, and thus are not described again.

It is noted that the units in fig. 1 for the values 10, 20, 30, 40, 50, 60, 80 are all mm. In addition, fig. 2, fig. 3, fig. 4, and fig. 5 are all experimental computer interface effect display diagrams, which are only used as interface effect displays and do not have any influence on the essence of the technical solution.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiments according to the technical spirit of the present invention are included in the scope of the present invention.