Nondestructive evaluation method for interface bonding strength of coated grain

Abstract

The invention belongs to the technical field of nondestructive testing, and particularly relates to a nondestructive evaluation method for the interface bonding strength of a coated grain, and the coated grain is a solid propellant at least provided with a coating layer and a lining layer; the method comprises the following steps: heating a coated grain to be detected in a water bath; the heated coated grain to be detected is subjected to negative pressure loading, and a speckle interference image of the surface of the coated grain to be detected is obtained through a high-vibration-resistance electronic speckle interference system; extracting an out-of-plane displacement field in the speckle interference image; evaluating the interface bonding strength of the coated grain based on the extracted out-of-plane displacement field; wherein the coated grain to be detected has a weak viscosity defect. Compared with the prior art, the method provided by the invention solves the problem that the existing nondestructive testing method is difficult to distinguish and screen the interface bonding strength of the coated grain with weak bonding defects. According to the scheme, lossless and high-resolution detection of the coated grains with the weakly-sticky defects is realized, and the method can be used for relative comparison and quality evaluation of the interface bonding strength between the coated grains with the weakly-sticky defects.

Description

Technical Field

[0001] This invention belongs to the field of nondestructive testing technology, specifically relating to a nondestructive evaluation method for the interfacial bonding strength of coated propellant columns. Background Technology

[0002] Coated propellant grains are adhesive composite structures in which a rubber sheath and solid propellant are bonded together. During curing, long-term storage, transportation, and flight, they are subjected to various loads and are also affected by storage conditions such as temperature and humidity, leading to changes in their physical and chemical properties. Under the combined influence of these factors, defects such as debonding and cracking are easily caused.

[0003] The interfacial bonding quality of coated propellant grains is a core determinant of their operational reliability. In practical applications, the interfacial bonding strength may fall below design requirements due to various factors, forming a so-called "weak bonding" defect. This "weak bonding" defect is a manifestation of insufficient interfacial bonding strength; it exists before obvious debonding defects form, but is usually difficult to detect. Currently, non-destructive testing and evaluation methods for this "weak bonding" defect are severely lacking, which has become a major challenge in the field of solid propellant interfacial quality control. Current non-destructive testing methods for interfacial bonding defects in coated propellant grains include X-ray, CT, ultrasound, and infrared thermography. However, these techniques have certain limitations, such as: X-ray and CT are not sensitive to area-type defects, the detection rate is closely related to the angle between the X-ray beam and the debonding defect, and there are also radioactivity issues, so they are generally not used; although ultrasonic testing technology has been applied to the field of interfacial bonding, ultrasonic waves suffer from signal attenuation and scattering problems when propagating in the medium, and are difficult to detect, prone to missed defects, and easily affected by environmental interference; infrared thermography can only detect larger defects; etc.

[0004] Generally, coated propellant grains with weak adhesion defects exhibit more speckle interference fringes and larger out-of-plane displacement compared to conventional coated propellant grains (without weak adhesion defects) under the same experimental testing conditions. Specifically, the out-of-plane displacement of coated propellant grains with weak adhesion defects is approximately 1.5 times that of conventional coated propellant grains. According to a method for identifying interface defects in the coating layer of solid propellant grains disclosed in Chinese Patent CN202210626459.7 (Publication No. CN115046823A), negative pressure loading can effectively identify defect categories. However, for coated propellant grains with weak adhesion defects, the negative pressure loading proposed in this prior art can only distinguish coated propellant grains with relatively large differences in adhesive strength, while it is ineffective and difficult to further distinguish coated propellant grains with similar adhesive strengths. In addition, water bath heating instead of negative pressure loading also has the limitation of only being able to distinguish coated drug columns with large differences in relative bonding strength. Furthermore, water bath heating is prone to thermal noise interference due to optical path jitter caused by thermal disturbance, resulting in inconsistent image background and irregular stripe fluctuations. It is impossible to accurately determine the relative magnitude of the interface bonding strength, and the stripe quality is even worse in practical applications.

[0005] Therefore, it is necessary to study a non-destructive testing method to evaluate the bonding quality of coated propellant columns to solve the technical problems mentioned above, so as to achieve comparative evaluation and screening of the relative bonding strength between coated propellant columns with weak adhesion defects. Summary of the Invention

[0006] The purpose of this invention is to provide a non-destructive evaluation method for the interfacial bond strength of coated propellant columns, addressing at least one of the aforementioned problems. This method overcomes the limitations of existing non-destructive testing methods in further distinguishing and screening the interfacial bond strength of coated propellant columns with weak bonding defects. This solution enables non-destructive, high-resolution testing of coated propellant columns with weak bonding defects, and can be used for relative comparison of the interfacial bond strength between coated propellant columns with weak bonding defects, thereby achieving quality evaluation.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A non-destructive evaluation method for the interfacial bonding strength of a coated propellant grain, wherein the coated propellant grain is a solid propellant having at least a coating layer and a liner layer;

[0009] The non-destructive evaluation method includes the following steps:

[0010] S1: Heat the coated drug column to be tested in a water bath;

[0011] S2: Apply negative pressure to the heated coated propellant column to be tested, and obtain the speckle interference image on the surface of the coated propellant column to be tested through a high vibration-resistant electronic speckle interferometry system;

[0012] S3: Extract the out-of-plane displacement field from the speckle interferometer image;

[0013] Evaluation of interfacial adhesion strength of coated propellant columns based on extracted out-of-plane displacement field;

[0014] The coated drug column to be tested has a weak viscosity defect.

[0015] Preferably, in step S1, the water temperature for water bath heating does not exceed 80°C.

[0016] Preferably, in step S1, during the water bath heating process, the coated drug column to be tested is heated in a water-isolated manner to avoid interference from the water in the water bath.

[0017] Preferably, in step S1, during the water bath heating process, the water level in the water bath is higher than that of the coated drug column, so that the coated drug column is immersed in the water bath, and the coated drug column to be tested is heated evenly and the overall temperature rises.

[0018] Preferably, in step S2, the relative negative pressure value of the negative pressure loading does not exceed 30 kPa.

[0019] Preferably, the negative pressure loading is implemented via a vacuum chamber; and / or,

[0020] The relative negative pressure value of the negative pressure loading is 5, 10, or 15 kPa.

[0021] For coated propellant columns with significantly different bond strengths, a lower relative negative pressure value can detect obvious differences. However, for coated propellant columns with similar bond strengths, a higher relative negative pressure value is needed to amplify the differences and obtain a more significant comparison. However, there are limitations to the applied relative negative pressure value. If an excessively high relative negative pressure value is applied, the testing process will cause structural damage to the coated propellant column, thus not constituting non-destructive testing.

[0022] Preferably, the interfacial adhesion strength of the coated propellant column is evaluated as follows:

[0023] The non-destructive testing methods of steps S1-S3 were performed sequentially on different coated propellant columns to be tested, and the out-of-plane displacement fields corresponding to different coated propellant columns to be tested were extracted. By comparing the differences between the out-of-plane displacement fields corresponding to different coated propellant columns to be tested, the relative interfacial bonding strength between each coated propellant column to be tested was evaluated.

[0024] Preferably, a single-factor (temperature, relative negative pressure value) change test is performed on the coated drug column to be tested, and the test results of different coated drug columns to be tested are compared under the same factor at the same level, so as to evaluate the relative interfacial adhesion strength between the coated drug columns to be tested from multiple perspectives.

[0025] Preferably, the difference includes one or more of the number, density, and order of speckle fringes in the out-of-plane displacement field.

[0026] Preferably, the diameter of the coated drug column to be tested is 80 mm and the height is 200 mm; and / or,

[0027] The coating layer is a rubber-like material; and / or,

[0028] The thickness of the coating layer is 2 mm; and / or,

[0029] The thickness of the liner is 0.5 mm.

[0030] Preferably, the non-destructive evaluation method is implemented through a non-destructive evaluation system, which includes a constant temperature water bath, a vacuum chamber, and a high vibration-resistant electronic speckle interferometry system.

[0031] A support is provided inside the vacuum chamber, and the coated drug column to be tested is placed on the support;

[0032] The field of view of the high vibration-resistant electronic speckle interferometry system completely covers the test-coated propellant column;

[0033] The interfacial bonding strength of the coated propellant column is evaluated non-destructively by acquiring the out-of-plane displacement field on the surface of the column to be tested.

[0034] The working principle of this invention is as follows:

[0035] The combination of negative pressure loading and water bath heating reduces thermal noise primarily because the vacuum environment eliminates the presence of air particles. During traditional water bath heating, the heated air above the sample (the coated propellant column under test) generates intense convection, causing jitter in the laser path of the highly vibration-resistant electronic speckle interferometry system and creating thermal noise from interfering fringes. However, after evacuation, the influence of air is eliminated, thus completely eliminating convection and thermal disturbance, creating an extremely stable optical measurement environment. Simultaneously, the water bath provides uniform thermal excitation, which, combined with uniform negative pressure loading, works synergistically to excite clear defect signals even under low-load conditions, resulting in high-quality, low-noise speckle interferometry images.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. Compared with negative pressure loading or thermal loading (water bath heating) applied alone, the combination of negative pressure and thermal loading adopted in this scheme shows more significant differences in the out-of-plane displacement field of coated propellant columns with different interfacial bonding strengths. It can effectively distinguish coated propellant columns with different interfacial bonding strengths, including "weak bonding" defects with similar bonding strengths, and provides a reliable non-destructive testing method for "weak bonding" defects, which is expected to solve related testing problems.

[0038] 2. This scheme adopts water bath heating followed by negative pressure loading, which can provide both heat loading and negative pressure loading simultaneously when the coated drug column to be tested is being tested. Furthermore, the test is carried out in a vacuum environment, avoiding the problem of optical path distortion and affecting the test results caused by heat loading.

[0039] 3. This scheme significantly improves the quality of speckle interferometry images, making the fringes in the images clearer and more regular, and greatly reducing thermal noise interference, thus making the detection results more accurate and reliable.

[0040] 4. This method achieves high-precision detection while requiring a small loading amount, which not only reduces potential damage to the coated drug column to be tested, but also reduces experimental costs and operational difficulty, and improves the safety and economy of detection.

[0041] 5. The non-destructive evaluation method proposed in this scheme can effectively distinguish the interfacial bonding strength of different coated propellant columns with the same weak adhesion defect. Furthermore, based on the evaluation results, the service life of the corresponding coated propellant column can be preliminarily predicted and the effectiveness of the corresponding coated propellant column can be preliminarily judged. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a drug cartridge coated with different bonding strengths according to a preferred embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of a highly vibration-resistant electronic speckle interferometer system according to a preferred embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of a constant temperature water bath according to a preferred embodiment of the present invention.

[0045] Figure 4 This is a schematic diagram of experimental results under the same relative negative pressure value but different temperatures according to a preferred embodiment of the present invention.

[0046] Figure 5 This is a schematic diagram of experimental results under the same temperature and different relative negative pressure values ​​according to a preferred embodiment of the present invention.

[0047] Figure 6 This is a comparison diagram of the magnitude of out-of-plane displacement based on experimental results according to a preferred embodiment of the present invention.

[0048] Figure 7 This is a schematic diagram of the experimental results tested under different air pressures in Comparative Example 1.

[0049] Figure 8 This is a schematic diagram of the experimental results tested at different temperatures in Comparative Example 2. Detailed Implementation

[0050] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. These specific embodiments are intended to illustrate the present invention in detail, but should not be construed as limiting the present invention. Various modifications and variations can be made without departing from the spirit and scope of the present invention, and all of these should be included within the protection scope of the present invention.

[0051] Example 1

[0052] A non-destructive evaluation method for the interfacial bonding strength of a coated propellant grain, wherein the coated propellant grain is a solid propellant having at least a coating layer and a liner layer;

[0053] The non-destructive evaluation method includes the following steps:

[0054] S1: Heat the coated drug column to be tested in a water bath;

[0055] S2: Apply negative pressure to the heated coated propellant column to be tested, and obtain the speckle interference image on the surface of the coated propellant column to be tested through a high vibration-resistant electronic speckle interferometry system;

[0056] S3: Extract the out-of-plane displacement field from the speckle interferometer image;

[0057] Evaluation of interfacial adhesion strength of coated propellant columns based on extracted out-of-plane displacement field;

[0058] The coated drug column to be tested has a weak viscosity defect.

[0059] in,

[0060] The coated propellant grain has a multi-layered bonded structure, with a coating layer made of a rubber-like material, followed by a liner layer, and the interior containing solid propellant. More specifically, the coated propellant grain is prepared with a diameter of 80 mm and a height of 200 mm; the coating layer is 2 mm thick, and the liner layer is 0.5 mm thick.

[0061] In step S1, the water temperature for water bath heating does not exceed 80℃; during the water bath heating process, the coated drug column to be tested is heated in a water-insulated manner to avoid interference from the water in the water bath; during the water bath heating process, the water level in the water bath is higher than the coated drug column so that the coated drug column is immersed in the water bath, so that the coated drug column to be tested is heated evenly and the overall temperature rises.

[0062] In step S2, negative pressure loading is implemented through a vacuum cavity. The relative negative pressure value of the negative pressure loading does not exceed 30 kPa, specifically 5, 10, or 15 kPa. The high vibration-resistant electronic speckle interferometry system can adopt the high vibration-resistant electronic speckle interferometry real-time phase measurement system given in Example 1 of the published patent CN111578856A.

[0063] The specific evaluation of the interfacial adhesion strength of the coated propellant column is as follows:

[0064] The non-destructive testing methods of steps S1-S3 were performed sequentially on different coated propellant columns to be tested, and the out-of-plane displacement fields corresponding to different coated propellant columns under the same testing conditions were extracted. By comparing the differences between the out-of-plane displacement fields corresponding to different coated propellant columns to be tested, the relative interfacial bonding strength between each coated propellant column to be tested was evaluated.

[0065] The differences between out-of-surface displacement fields include one or more of the number, density, and order of speckle fringes in the out-of-surface displacement field.

[0066] Example 2

[0067] Please see Figures 1 to 6 ,in Figure 1 This is a schematic diagram of a propellant column with different bonding strengths. Figure 2 This is a schematic diagram of a highly vibration-resistant electronic speckle interferometer system. Figure 3 This is a schematic diagram of a constant temperature water bath device. Figure 4 and Figure 5 This is a schematic diagram showing the experimental results for different test condition groups. Figure 6 This is a comparison chart of the magnitudes of out-of-plane displacement.

[0068] This embodiment provides a non-destructive testing method for evaluating the interfacial adhesion strength of coated propellant columns and an apparatus for implementing the corresponding method. The non-destructive testing method includes the following steps:

[0069] Prepare coated propellant grain products with different bonding strengths. The coated propellant grain consists of a coating layer, a liner, and an internal solid propellant.

[0070] Using a constant temperature water bath, coated drug cartridges with different interfacial bonding strengths are sealed in plastic bags and placed in the water bath for indirect heating to the target temperature (set according to the experimental objectives). To prevent damage to the coated drug cartridges, the water temperature during the experiment generally does not exceed 80℃.

[0071] After heating, the product is removed from its packaging and placed in a negative pressure chamber. A high-vibration-resistance electronic speckle interferometry system is used to apply negative pressure to the water-bath-heated coated propellant cartridge sample. The relative negative pressure value is sequentially controlled to the target pressure value, such as 5 kPa, 10 kPa, and 15 kPa, with fixed time intervals set at each relative negative pressure value. Stable speckle interferometry images of the coated propellant cartridge product at different vacuum levels and temperatures are acquired, forming an image set. By comparing the image sets of speckle interferometry images of different coated propellant cartridges under different negative pressures and temperatures, the subtle differences in the surface displacement field between images under the same conditions are extracted, thereby effectively distinguishing the interfacial adhesion strength of each coated propellant cartridge product.

[0072] Among them, the high vibration-resistant electronic speckle interferometry system can adopt the high vibration-resistant electronic speckle interferometry real-time phase measurement system disclosed in Chinese Patent 202010415402.3 (Announcement No. CN111578856B).

[0073] More specifically, the prepared coated propellant grains have a diameter of 80 mm and a height of 200 mm. The coating layer of the coated propellant grain is a rubber-like material with a thickness of 2 mm, followed by a liner layer with a thickness of 0.5 mm, and the interior contains solid propellant. During water bath heating, coated propellant grains with different interfacial bonding strengths need to be sealed in plastic bags and placed in the water bath, ensuring the grains are completely submerged. The water bath lid is then closed, and the grains are heated to the target temperature using a water bath. During negative pressure loading, the heated coated propellant grains are removed from the plastic wrap and placed on supports inside the negative pressure / vacuum chamber. The position of the supports is adjusted to ensure the coated propellant grains are centered in the field of view of the high vibration-resistant electronic speckle interferometry system for better acquisition of speckle interferometry images. The adjusted relative negative pressure value generally does not exceed 30 kPa, but is not limited to the three experimental scenarios described above. During negative pressure loading, after closing and locking the chamber door, evacuation is completed using a vacuum pump. It is important to ensure that the time from heating and removal of each coated propellant grain to evacuation is consistent. After the airflow inside the chamber stabilizes, the speckle interferogram of the product under test is recorded as a reference image. Then, the vacuum level inside the negative pressure chamber is adjusted by controlling the precision air inlet valve. Once the relative vacuum level reaches the target value required by the experiment, the image is refreshed. A fixed time interval is set to acquire stable speckle interferograms of the coated drug column product at different vacuum levels and temperatures.

[0074] More specifically, the measured out-of-plane displacement of the coated propellant column with weak viscosity defects is approximately 1.5 times that of the standard coated propellant column (coated propellant column without weak viscosity defects).

[0075] This approach combines negative pressure loading and water bath heating to provide a more effective and accurate non-destructive evaluation method for the interfacial bonding strength of coated propellant columns.

[0076] Figure 4 and Figure 5 The method described above is shown. Figure 1The test results of the two coated propellant columns (hereinafter referred to as Specimen 1 and Specimen 2) are shown in Test Condition Group 1: 40, 50, 60, 70℃, relative negative pressure 5kPa, and Test Condition Group 2: 50℃, relative negative pressure 5kPa, 10kPa, 15kPa. It can be seen that when the negative pressure loading and water bath heating of this scheme are combined, the speckle patterns show significant differences with changes in the degree of negative pressure loading and thermal loading (water bath heating). Specifically, under low loading pressure and water bath temperature, for coated propellant columns with weak viscosity defects, the number of speckle patterns in Specimen 2 is significantly greater than that in Specimen 1, and the pattern density is also higher; however, with the increase of thermal loading or negative pressure loading, the speckle pattern order of Specimen 2 is still greater than that of Specimen 1. According to... Figure 6 The comparison diagram of out-of-plane displacement also shows that the out-of-plane displacement of specimen 2 is greater than that of specimen 1. These results indicate that the combination of negative pressure loading and thermal loading can significantly improve the contrast between coated drug columns with different bonding strengths.

[0077] Comparative Example 1

[0078] Please see Figure 7 , Figure 7 The speckle interference patterns of coated propellant grains with different bonding strengths (all with weak adhesion defects) under different gas pressures after being treated only by negative pressure loading.

[0079] The high vibration-resistant electronic speckle interferometry real-time phase measurement system disclosed in Chinese Patent 202010415402.3 (Publication No. CN111578856B) is adopted, and the phase measurement is performed using ESPI (electronic speckle interferometry) technology. Figure 1 The deformation behavior of coated propellant columns with different bonding strengths under negative pressure load was observed.

[0080] The specific implementation steps are as follows:

[0081] Coated propellant grain samples with different interfacial bonding strengths were placed on supports inside the negative pressure chamber. The position of the base was adjusted to ensure the sample was centered in the field of view of the speckle system. After closing and locking the chamber door, the chamber was first evacuated using a vacuum pump. Once the airflow inside the chamber stabilized, the speckle interferogram of the test sample was recorded as a reference image. Then, the vacuum level inside the negative pressure chamber was adjusted by controlling the precision air inlet valve. Once the relative vacuum level reached the target value required for the experiment, a stable speckle image was acquired, which is the out-of-plane field image of the coated propellant grain sample under that relative vacuum level. The experimental operation was repeated, and the speckle interferograms of the coated propellant grain samples under different relative vacuum levels (5, 10, 15 kPa) were recorded respectively.

[0082] Figure 7The experimental results are shown. In the initial negative pressure loading stage (relative pressure 5 kPa), interference fringes appeared in the speckle patterns of different coated propellant columns. However, at this time, the density of the fringes was similar, and the contrast difference was not obvious, making it impossible to effectively distinguish differences in bonding strength. As the negative pressure load gradually increased (the amount of negative pressure pumped increased), the fringe order in the image increased, and the fringes became denser, but there was still no significant difference in the bonding strength of coated propellant columns with different bonding strengths, making it unsuitable as an evaluation criterion. It is evident that applying negative pressure loading only to coated propellant columns with weak bonding defects before performing ESPI testing is insufficient for comparing the relative interfacial bonding strength between coated propellant columns with similar weak bonding defects.

[0083] Comparative Example 2

[0084] Please see Figure 8 , Figure 8 For coated propellant columns with different adhesive strengths ( Figure 1 The coated propellant columns shown all have weak viscosity defects. The speckle interference patterns are obtained at different temperatures after water bath heating treatment.

[0085] The specific implementation steps are as follows:

[0086] Coated propellant columns with different bonding strengths were sealed in plastic bags and placed in a water bath for indirect heating, ensuring the columns were completely submerged. After heating to the target temperature, the columns with different interfacial bonding strengths were removed together, the plastic bags were removed, and the columns were placed on a vibration isolation table, ensuring the column to be tested was centered in the field of view. The speckle interferogram of the current state of the coated propellant column was quickly recorded and defined as the reference image. Then, at fixed time intervals, the sample was allowed to slowly dissipate heat, and speckle images of the deformed samples with different interfacial bonding strengths were recorded.

[0087] Figure 8 The experimental results are shown. After water bath heating, the speckle fringe order of propellant columns with different bonding strengths showed significant differences. At low temperatures, the fringe density of the tested propellant columns was similar, with only a slight difference in the order. As the water bath temperature increased, the fringe order of both coated propellant columns increased, with specimen 2 showing a more significant change in fringe order and denser fringes. The contrast between specimens 1 and 2 was significant, indicating that using ESPI technology to evaluate the bonding strength of the propellant column coating layer after water bath heating is feasible to a certain extent. However, similarly... Figure 8 It is evident that water bath heating has significant limitations. At low temperatures, it is difficult to effectively distinguish the striation characteristics of propellant columns with different bonding strengths, and thermal noise interference causes large striation fluctuations and poor quality. Although the contrast is slightly clearer at high temperatures, it first relies on temperature increases and cannot quickly and clearly complete the evaluation at low temperatures. Secondly, the presence of thermal noise can easily affect the interpretation of the results, especially for specimens with small differences in interfacial bonding strength. Furthermore, Figure 8 The image shows a measurement under relatively ideal laboratory conditions. However, the stripe quality obtained in practical applications is much worse, making it difficult to apply in practice.

[0088] As can be seen from the experimental results of Examples 2 and Comparative Examples 1 and 2, for different coated propellant columns with the same weak adhesion defect, especially those with similar adhesion strength, the proposed scheme of negative pressure loading + thermal loading can exhibit more significant differences in speckle fringes (including number, density, and order) in the out-of-plane displacement field. This improves the contrast of the test results and allows for a more accurate evaluation and comparison of the adhesion strength between different coated propellant columns with weak adhesion defects. In contrast, the schemes using only negative pressure loading or only thermal loading show only minor differences in speckle fringes in the out-of-plane displacement field. Although these differences can be forcibly distinguished to some extent, the extremely small differences and the inability to completely avoid minor changes in external test environment factors easily lead to erroneous conclusions for coated propellant columns with similar adhesion strength and weak adhesion defects. Therefore, the non-destructive evaluation method based on negative pressure loading + thermal loading proposed in this scheme has significant performance advantages compared to single negative pressure loading or thermal loading (water bath heating) methods.

[0089] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A non-destructive evaluation method for the interfacial bonding strength of a coated propellant grain, wherein the coated propellant grain is a solid propellant having at least a coating layer and a liner layer; Its features are, The non-destructive evaluation method includes the following steps: S1: Heat the coated drug column to be tested in a water bath; S2: Apply negative pressure to the heated coated propellant column to be tested, and obtain the speckle interference image on the surface of the coated propellant column to be tested through a high vibration-resistant electronic speckle interferometry system; S3: Extract the out-of-plane displacement field from the speckle interferometer image; Evaluation of interfacial adhesion strength of coated propellant columns based on extracted out-of-plane displacement field; The coated drug column to be tested has a weak viscosity defect.

2. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, In step S1, the water temperature for water bath heating does not exceed 80°C.

3. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, In step S1, during the water bath heating process, the coated drug column to be tested is heated in a water-insulated manner.

4. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, In step S1, during the water bath heating process, the water level in the water bath is higher than that of the coated drug column, so that the coated drug column is immersed in the water bath.

5. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, In step S2, the relative negative pressure value of the negative pressure loading does not exceed 30 kPa.

6. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 5, characterized in that, The negative pressure loading is implemented through a vacuum chamber; and / or, The relative negative pressure value of the negative pressure loading is 5, 10, or 15 kPa.

7. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, The interfacial adhesion strength of the coated propellant column is evaluated as follows: The non-destructive testing methods of steps S1-S3 were performed sequentially on different coated propellant columns to be tested, and the out-of-plane displacement fields corresponding to different coated propellant columns to be tested were extracted. By comparing the differences between the out-of-plane displacement fields corresponding to different coated propellant columns to be tested, the relative interfacial bonding strength between each coated propellant column to be tested was evaluated.

8. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 7, characterized in that, The differences include one or more of the number, density, and order of speckle fringes in the out-of-plane displacement field.

9. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, The diameter of the coated drug column to be tested is 80 mm and the height is 200 mm; and / or, The coating layer is a rubber-like material; and / or, The thickness of the coating layer is 2 mm; and / or, The thickness of the liner is 0.5 mm.

10. The non-destructive evaluation method for the interfacial adhesion strength of coated propellant columns according to claim 1, characterized in that, The non-destructive evaluation method is implemented through a non-destructive evaluation system, which includes a constant temperature water bath, a vacuum chamber, and a high vibration-resistant electronic speckle interferometry system. A support is provided inside the vacuum chamber, and the coated drug column to be tested is placed on the support; The field of view of the high vibration-resistant electronic speckle interferometry system completely covers the test-coated propellant column; The interfacial bonding strength of the coated propellant column is evaluated non-destructively by acquiring the out-of-plane displacement field on the surface of the column to be tested.

Images