阅读说明：本技术 变厚度碳化硅纤维复合材料x射线检测方法 (Variable-thickness silicon carbide fiber composite material X-ray detection method ) 是由 刘菲菲 刘松平 章清乐 于 2021-09-18 设计创作，主要内容包括：本发明公开一种变厚度碳化硅纤维复合材料X射线检测方法,包括：提供检测试块、确定最佳透照参数,并计算在所述最佳透照参数下的X射线的有效透照厚度范围,以及选择位于此厚度范围内的待检测变厚度碳化硅纤维复合材料,并采用所述最佳透照参数的X射线参数对其进行检测。不仅减少了X射线透照试验次数和对零部件的透照次数,提高了效率,减少了能耗；而且也考虑了SiC纤维复合材料零部件厚度变化可能对X射线检测效果的影响,避免了微细缺陷漏检的风险,进而更有利于提高X射线检测的可靠性,更加适合变厚度SiC纤维复合材料零部件X射线检测。(The invention discloses a variable thickness silicon carbide fiber composite material X-ray detection method, which comprises the following steps: providing a detection test block, determining the optimal transillumination parameter, calculating the effective transillumination thickness range of the X-ray under the optimal transillumination parameter, selecting the silicon carbide fiber composite material with the thickness to be detected within the thickness range, and detecting the silicon carbide fiber composite material by adopting the X-ray parameter of the optimal transillumination parameter. The X-ray transillumination test frequency and the transillumination frequency to parts are reduced, the efficiency is improved, and the energy consumption is reduced; and moreover, the influence of thickness change of the SiC fiber composite material parts on the X-ray detection effect is considered, the risk of missing detection of fine defects is avoided, the reliability of X-ray detection is further improved, and the X-ray detection method is more suitable for X-ray detection of the variable-thickness SiC fiber composite material parts.)

1. A variable thickness silicon carbide fiber composite material X-ray detection method is characterized by comprising the following steps:

obtaining the thickness range of the variable-thickness silicon carbide fiber composite material to be detected;

providing a plurality of detection test blocks according to the thickness range of the variable-thickness silicon carbide fiber composite material to be detected, wherein the plurality of detection test blocks have preset defects inside, and the thickness range of the plurality of detection test blocks covers the thickness range of the variable-thickness silicon carbide fiber composite material to be detected;

respectively detecting the plurality of detection test blocks by using X-rays with different transillumination parameters, and respectively obtaining X-ray gray distribution maps of the plurality of detection test blocks under the different transillumination parameters;

determining an optimal transillumination parameter according to gray values of a defective area and a non-defective area in an X-ray gray distribution diagram of the plurality of detection test blocks under different transillumination parameters, and calculating an effective transillumination thickness range of the X-ray under the optimal transillumination parameter;

and selecting the silicon carbide fiber composite material with the variable thickness to be detected within the thickness range according to the effective transillumination thickness range, and detecting the silicon carbide fiber composite material with the optimal transillumination parameters by adopting the X-ray.

2. The method for X-ray inspection of a silicon carbide fiber composite material with a variable thickness according to claim 1, wherein determining the optimal transillumination parameters according to the gray values of the defect regions and the non-defect regions in the X-ray gray distribution map of the plurality of inspection blocks under different transillumination parameters comprises:

and respectively calculating absolute values of the difference between the gray values of the defective area and the non-defective area in the X-ray gray distribution map of the plurality of detection test blocks under different transillumination parameters, and selecting a group of corresponding transillumination parameters with the maximum absolute values of the difference between the gray values of the defective area and the non-defective area as the optimal transillumination parameters.

3. The method for X-ray inspection of a variable thickness silicon carbide fiber composite as claimed in claim 2, wherein: and averaging the gray values of the defect area and the non-defect area.

4. The method for X-ray inspection of a variable thickness silicon carbide fiber composite as claimed in claim 2, wherein: calculating the gray value of the X-ray gray distribution diagram of each of the plurality of detection test blocks corresponding to the optimal transillumination parameter, and constructing a thickness gray function according to the thickness of each of the plurality of detection test blocks and the gray value of the X-ray gray distribution diagram corresponding to the thickness gray function, wherein the thickness gray function is h_i＝G(G_i)；

Calculating the effective transillumination thickness range of the X-ray under the optimal transillumination parameter according to the thickness gray function;

wherein h is_iFor the thickness of the test piece, G_iIs a thickness of h_iThe gray value of the X-ray gray distribution diagram of the test block is detected.

5. The method for X-ray inspection of a variable thickness silicon carbide fiber composite as claimed in claim 4, wherein: calculating an effective transillumination thickness range of the X-ray under the optimal transillumination parameter according to the thickness gray function comprises:

the minimum effective transillumination thickness is h_min＝G(G_Rmax×k₁％)；

The maximum effective transillumination thickness is h_max＝G(G_Rmin×k₂％)；

Wherein G is_Rmax、G_RminMaximum and minimum gray value, k, respectively, for the X-ray imaging₁、k₂Are all constants.

6. The method for X-ray inspection of variable thickness silicon carbide fiber composites of claim 1 wherein the number of test coupons is at least 5.

7. The method for X-ray inspection of variable thickness silicon carbide fiber composites of claim 1 wherein a plurality of said test coupons are inspected using at least 3 sets of X-rays of different transillumination parameters.

8. The method for X-ray inspection of variable thickness silicon carbide fiber composites of claim 1 wherein k1, k2 is between 0.05 and 0.2.

9. The method for X-ray inspection of a variable thickness silicon carbide fiber composite according to any one of claims 1 to 8, wherein the inspection of the variable thickness silicon carbide fiber composite to be inspected is performed by X-ray radiography or digital X-ray imaging.

Technical Field

The invention relates to the field of nondestructive testing, in particular to an X-ray detection method for a variable-thickness silicon carbide fiber composite material.

Background

In the manufacturing process of the SiC fiber reinforced composite material part, 100% nondestructive testing must be carried out on the SiC fiber reinforced composite material part in order to ensure the quality. In order to obtain an ideal X-ray transillumination effect and realize reliable nondestructive detection of the SiC fiber reinforced composite material part, proper X-ray transillumination parameters are required to be selected to obtain an X-ray gray image which effectively reflects the internal defect of a detected object, gray values in the X-ray image are generally used for representing the gray values, and the defect is judged according to the gray values. Whereas the gray value distribution of the X-ray gray image is directly related to the selection of the X-ray transillumination parameters. Under other conditions, the selection of the X-ray transillumination parameters is directly related to the thickness of the irradiated area of the SiC fiber reinforced composite part being inspected. Therefore, the gray value distribution of the X-ray gray image is related to the thickness of the irradiated area of the detected SiC fiber reinforced composite part.

Currently, the following methods are generally used for the X-ray detection of SiC fiber reinforced composites in the prior art:

1) according to the thickness of the irradiation area of the SiC fiber reinforced composite material part to be detected, X-ray transillumination parameters are determined through an X-ray transillumination test, and the main defects are as follows: multiple X-ray transillumination tests are required, the efficiency is low, the energy consumption is increased, and the detection cost is enhanced;

2) for the variable thickness SiC fiber reinforced composite material parts, the same X-ray transillumination parameters are adopted for detection, and the main defects are as follows: the influence of the thickness change of the SiC fiber reinforced composite material part on the X-ray detection effect is not considered, the risk of missing detection of fine defects exists, and the reliability of X-ray detection is further influenced.

Disclosure of Invention

The invention mainly aims to provide a variable-thickness silicon carbide fiber composite material X-ray detection method, aiming at solving the problems mentioned in the background technology.

In order to achieve the purpose, the invention provides a variable thickness silicon carbide fiber composite material X-ray detection method, which comprises the following steps: obtaining the thickness range of the variable-thickness silicon carbide fiber composite material to be detected;

providing a plurality of detection test blocks according to the thickness range of the variable-thickness silicon carbide fiber composite material to be detected, wherein the plurality of detection test blocks have preset defects inside, and the thickness range of the plurality of detection test blocks covers the thickness range of the variable-thickness silicon carbide fiber composite material to be detected;

respectively detecting the plurality of detection test blocks by using X-rays with different transillumination parameters, and respectively obtaining X-ray gray distribution maps of the plurality of detection test blocks under the different transillumination parameters;

determining an optimal transillumination parameter according to gray values of a defective area and a non-defective area in an X-ray gray distribution diagram of the plurality of detection test blocks under different transillumination parameters, and calculating an effective transillumination thickness range of the X-ray under the optimal transillumination parameter;

and selecting the silicon carbide fiber composite material with the variable thickness to be detected within the thickness range according to the effective transillumination thickness range, and detecting the silicon carbide fiber composite material with the optimal transillumination parameters by adopting the X-ray.

Optionally, the determining the optimal transillumination parameters according to the gray values of the defective area and the non-defective area in the X-ray gray distribution map of the plurality of detection test blocks under different transillumination parameters includes:

and respectively calculating absolute values of the difference between the gray values of the defective area and the non-defective area in the X-ray gray distribution map of the plurality of detection test blocks under different transillumination parameters, and selecting a group of corresponding transillumination parameters with the maximum absolute values of the difference between the gray values of the defective area and the non-defective area as the optimal transillumination parameters.

Optionally, the gray values of the defect region and the non-defect region are averaged.

Optionally, the gray value of the X-ray gray distribution map of each of the plurality of detection test blocks corresponding to the optimal transillumination parameter is calculated, and a thickness gray function is constructed according to the thickness of each of the plurality of detection test blocks and the gray value of the X-ray gray distribution map corresponding to the thickness gray function, where the thickness gray function is h_i＝G(G_i)

Calculating the effective transillumination thickness range of the X-ray under the optimal transillumination parameter according to the thickness gray function;

wherein h is_iFor the thickness of the test piece, G_iIs a thickness of h_iThe gray value of the X-ray gray distribution diagram of the test block is detected.

Optionally, calculating an effective transillumination thickness range of the X-ray under the optimal transillumination parameter according to the thickness gray scale function comprises:

the minimum effective transillumination thickness is h_min＝G(G_Rmax×k₁％)；

The maximum effective transillumination thickness is h_max＝G(G_Rmin×k₂％)；

Wherein G is_Rmax、G_RminMaximum and minimum gray value, k, respectively, for the X-ray imaging₁、k₂Are all constants.

Optionally, the number of test blocks is at least 5.

Optionally, at least 3 sets of X-rays with different transillumination parameters are used to detect a plurality of the test blocks.

Optionally, the k1, k2 is between 0.05-0.2.

Optionally, detecting the silicon carbide fiber composite material to be detected with the variable thickness by adopting an X-ray photography method or a digital X-ray imaging method.

According to the technical scheme, the detection test blocks with multiple thicknesses covering the thickness range of the variable-thickness silicon carbide fiber composite material to be detected are used for carrying out X-ray detection, so that the optimal transillumination parameter can be determined based on the thickness range of the variable-thickness silicon carbide fiber composite material to be detected, and then the effective transillumination thickness range of the X-ray of the optimal transillumination parameter is determined according to the constructed thickness gray function, so that the variable-thickness silicon carbide fiber composite material to be detected in the range is detected, the times of X-ray transillumination tests and the times of transillumination of parts are reduced, the efficiency is improved, and the energy consumption is reduced; and the influence of thickness change of the SiC fiber composite material parts on the X-ray detection effect is considered, the risk of missing detection of fine defects is avoided, the reliability of X-ray detection is improved, and the X-ray detection method is more suitable for X-ray detection of the variable-thickness SiC fiber composite material parts.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the results shown in the drawings without creative efforts.

FIG. 1 is a process diagram of one embodiment of a method of detecting a variable thickness silicon carbide fiber composite according to the present invention;

FIG. 2 is a gray scale value graph under the optimal transillumination parameter according to an embodiment of the present invention.

Detailed Description

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 is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments, and other materials may also adopt the real-time multi-frequency ultrasonic detection of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative position relationship between the components, the motion situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed more, the directional indications are correspondingly changed more.

In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

Referring to fig. 1, the invention provides a detection method of a variable thickness silicon carbide fiber composite material, which comprises the following steps:

step S100: obtaining the thickness range of the variable-thickness silicon carbide fiber composite material to be detected;

step S200: providing a plurality of detection test blocks according to the thickness range of the variable-thickness silicon carbide fiber composite material to be detected, wherein the plurality of detection test blocks have preset defects inside, and the thickness range of the plurality of detection test blocks covers the thickness range of the variable-thickness silicon carbide fiber composite material to be detected;

step S300: respectively detecting the plurality of detection test blocks by using X-rays with different transillumination parameters, and respectively obtaining X-ray gray distribution maps of the plurality of detection test blocks under the different transillumination parameters;

step S400: determining an optimal transillumination parameter according to gray values of a defective area and a non-defective area in an X-ray gray distribution diagram of the plurality of detection test blocks under different transillumination parameters, and calculating an effective transillumination thickness range of the X-ray under the optimal transillumination parameter;

step S500: and selecting the silicon carbide fiber composite material with the variable thickness to be detected within the thickness range according to the effective transillumination thickness range, and detecting the silicon carbide fiber composite material with the optimal transillumination parameters by adopting the X-ray.

Specifically, in step S100, it is first necessary to obtain the thickness variation range of the to-be-detected variable-thickness silicon carbide fiber composite part, so that the past empirical data and design drawing can be used as input, and the maximum thickness and the minimum thickness can also be manually measured.

Then, in step S200, a plurality of test blocks are provided according to the thickness variation range of the to-be-detected variable-thickness silicon carbide fiber composite part obtained in the previous step, the thickness military part of each test block is the same and needs to be met, the thickness range of each test block covers the maximum thickness and the minimum thickness of the to-be-detected variable-thickness silicon carbide fiber composite part, and each test block has a defect area inside.

Preferably, at least 5 test blocks of different thickness are provided.

Then, in step 300, the X-rays with different transillumination parameters are used to perform transillumination detection on the test block provided in step 200, and after the transillumination detection is performed on the X-rays with each transillumination parameter, a group of X-ray transillumination gray distribution maps can be obtained.

Preferably, at least three X-rays with different transillumination parameters are selected for detection, so that at least three groups of X-ray transillumination gray-scale distribution maps can be obtained, and each group of X-ray transillumination gray-scale distribution map at least comprises the X-ray transillumination gray-scale distribution maps corresponding to five detection test blocks with different thicknesses.

In step S400, an optimal transillumination parameter is determined according to the plurality of sets of X-ray transillumination gray-scale distribution maps acquired in step S300.

Taking the example of providing five detection test blocks in step S200 and selecting three different transillumination parameters in step S300, then in step S300, three groups of X-ray gray distribution maps with different parameters may be obtained, each group having X-ray gray distribution maps corresponding to five detection test blocks with different thicknesses, first, the gray values corresponding to the defective area and the non-defective area in each group of X-ray gray distribution maps are calculated, where the average gray value of the defective area may be taken as the gray value of the defective area, the average gray value of the non-defective area may also be taken as the gray value of the non-defective area, then, the absolute values of the difference between the gray values of the defective area and the gray value of the non-defective area in all five groups are calculated, and then, the transillumination parameter with the largest absolute value corresponding to one group is the optimal transillumination parameter.

After the optimal transillumination parameter is determined, calculating the effective transillumination thickness range of the X-ray of the optimal transillumination parameter, firstly selecting a group of X-ray gray distribution maps corresponding to the optimal transillumination parameter, including the X-ray gray distribution maps of the detection test blocks with different thicknesses of species, wherein the thickness of the detection test block is h_iCan be obtained in advance, and the corresponding gray value G is respectively calculated according to the X-ray gray distribution diagram corresponding to each thickness_i，Thus, five thicknesses h can be obtained_iAnd corresponding five gray values G_iAnd constructing a thickness gray function h according to the five groups of data_i＝G(G_i)；

Then according to h_min＝G(G_Rmax×k₁%) and h_max＝G(G_Rmin×k₂%) of the X-ray and the X-ray are respectively calculated according to the maximum effective transillumination thickness h of the X-ray under the transillumination parameters_maxAnd a minimum effective transillumination thickness h_minWherein G is_Rmax、G_RminRespectively X-rays forMaximum and minimum gray value of the image, k₁、k₂Are all constants, k₁、k₂It is determined by experimental and actual X-ray imaging detection effects and is preferably selected between 0.05 and 0.20.

The maximum effective transillumination thickness h of the X-ray under the optimal transillumination parameters is obtained_maxAnd a minimum effective transillumination thickness h_minThen, step S500 is performed, and the part within the effective transillumination thickness range is detected by using the optimal transillumination parameter.

Preferably, the inspection of the part within this thickness range is performed using radiography or radiography (DR).

According to the technical scheme, the detection test blocks with multiple thicknesses covering the thickness range of the variable-thickness silicon carbide fiber composite material to be detected are used for carrying out X-ray detection, so that the optimal transillumination parameter can be determined based on the thickness range of the variable-thickness silicon carbide fiber composite material to be detected, and then the effective transillumination thickness range of the X-ray of the optimal transillumination parameter is determined according to the constructed thickness gray function, so that the variable-thickness silicon carbide fiber composite material to be detected in the range is detected, the times of X-ray transillumination tests and the times of transillumination of parts are reduced, the efficiency is improved, and the energy consumption is reduced; on the other hand, the influence of thickness change of the SiC fiber composite material parts on the X-ray detection effect is considered, the risk of missing detection of fine defects is avoided, the reliability of X-ray detection is improved, and the X-ray detection method is more suitable for X-ray detection of the variable-thickness SiC fiber composite material parts.

In the following, further explanation is made according to specific embodiments.

Selecting an FDR-160X ray detection system, selecting 5 detection test blocks with different thicknesses according to the thickness range of a part to be detected, wherein the 5 detection test blocks have detectable defects and the minimum thickness d of the 5 detection test blocks_min1mm, maximum thickness d_max5 mm; x-rays of three different sets of transillumination parameters are selected, and G_Rmax＝255，G_Rmin＝0，k₁＝0.05，k₂＝0.05；

After the optimal transillumination parameter is determined, correspondingly calculating X-ray gray level distribution maps corresponding to 5 thicknesses under the transillumination parameter, and respectively calculating corresponding gray level values G_i，Thus, five thicknesses h can be obtained_iAnd corresponding five gray values G_iAnd a graph of gray scale values may be plotted as shown in fig. 2.

After drawing the grey value curve graph, respectively calculating the maximum effective transillumination thickness h of the X-ray under the transillumination parameters_maxAnd a minimum effective transillumination thickness h_minAs shown in fig. 2, then one can choose to be at h_maxTo h_minThe thickness zone of (2) is detected.

The above description is only for the preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures made by using the contents of the specification and the drawings of the present invention or directly/indirectly applied to other related technical fields are included in the scope of the present invention.