A microwave thermal imaging detection method and a detection device thereof

Abstract

The application discloses a kind of microwave thermal imaging detection method and its detection device, belong to non-metal material defect detection technical field, it includes heating box, the bottom of heating box is provided with rotating table, rotating table is provided with gripper, the top of heating box is provided with microwave heating device, spray pipeline, infrared camera and CCD camera, microwave heating device is connected with signal generator, infrared camera and CCD camera are electrically connected with image processing module.This scheme uses fluorescent penetrant to penetrate non-metal workpiece to be measured, uses the high sensitivity response of penetrant to microwave pulse to generate heat signal, uses heat signal to carry out microwave thermal sensing imaging, can fully detect the internal condition of defect;At the same time, fluorescent penetrant is used for fluorescent imaging, the visualization of defect position can be realized, so as to detect the distribution of defect surface;Two kinds of imaging are fused and analyzed, realize the comprehensive detection of surface shape and internal structure for non-metal workpiece defect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-metal material defect detection, in particular to a microwave thermal imaging detection method and a detection device thereof. BACKGROUND

[0002] Non-metal materials include composite materials, ceramic materials, plastics and polymers, insulating materials, and glass and glass fibers, etc., which are widely used in aerospace, electronic devices, construction and other fields, have various excellent properties, and are constantly expanding their use in modern industry, and are an important part of modern industry. Industrial product defect detection is an indispensable part of modern manufacturing, which can ensure product quality and reliability, ensure safety in use, reduce production cost and improve production efficiency. Therefore, defect detection of non-metal materials is particularly important.

[0003] Penetrant testing is a method that uses capillary effect and the principle of fluorescent penetrant color development to visually locate the defect position and surface shape. When detecting surface crack defects of workpieces, it can distinguish various defect categories, has high detection sensitivity, low working cost, and is suitable for defect detection of non-metal material workpieces. However, penetrant testing can only determine the presence or absence of surface defects of workpieces, but cannot detect the shape of internal defects.

[0004] Microwave thermal imaging detection method is a technology that uses the characteristics of microwaves to generate temperature distribution images of objects by collecting and analyzing microwave radiation information on the surface and inside of the object. In the field of defect detection, non-metal materials have good microwave penetration and suitable dielectric properties, and the temperature distribution image of the object obtained by microwave thermal imaging can effectively detect the surface position and internal structure of the defect. Microwave thermal imaging detection method has the advantages of non-destructive, penetration of obstacles, strong anti-interference ability, etc., which can obtain the temperature information inside the object, not just the surface temperature, so it has wide application prospects in various fields.

[0005] However, when applying microwave thermal imaging detection to non-metal materials, the electromagnetic properties of the defect air gap and the material body are similar, resulting in a small defect air gap with little temperature change in response to microwaves, low detection sensitivity, and the inability of microwave thermal imaging detection to visually display on the surface of the workpiece. SUMMARY

[0006] In view of the above shortcomings of the prior art, the present application provides a microwave thermal imaging detection method and a detection device thereof, which can greatly improve the sensitivity and accuracy of microwave thermal imaging detection in non-metal material defect detection. Moreover, the present application combines two detection methods to achieve comprehensive detection of the surface shape and internal structure of non-metal workpiece defects.

[0007] To achieve the above object, the technical scheme adopted by the present application is:

[0008] In a first aspect, a microwave thermal imaging detection device is provided, which comprises a heating box, a rotating table is arranged at the bottom of the heating box, a clamping jaw for limiting a workpiece to be detected is arranged on the rotating table, a microwave heating device, a spraying pipeline, an infrared camera and a CCD camera are arranged at the top of the heating box, the microwave heating device is connected with a signal generator, and the infrared camera and the CCD camera are both electrically connected with an image processing module.

[0009] Further, the infrared camera and the CCD camera are symmetrically arranged at two sides of the top of the heating box, and the infrared camera and the CCD camera are both inclined to point to the workpiece to be detected.

[0010] Further, the spraying pipeline is annular, and a plurality of spraying units pointing to the workpiece to be detected are arranged on the circumference of the spraying pipeline.

[0011] Further, a side opening door is arranged on one side of the heating box, and a plurality of drying heat pipes are arranged on the inner side wall of the heating box.

[0012] Further, the bottom surface of the heating box is a slope surface, and a fluorescent penetrant recovery opening is arranged on the side wall of the heating box close to the low end of the slope surface.

[0013] Further, the microwave heating device comprises a plurality of microwave antennas.

[0014] In a second aspect, a microwave thermal imaging detection method is provided, which comprises the following steps:

[0015] S1: uniformly spraying a fluorescent penetrant on the surface of a workpiece to be detected, and allowing the fluorescent penetrant to penetrate for a preset time until the fluorescent penetrant gradually flows into the crack defects on the surface of the workpiece to be detected under the action of capillary phenomenon;

[0016] S2: uniformly spraying water on the surface of the workpiece to be detected until the fluorescent penetrant on the surface of the workpiece to be detected is washed away;

[0017] S3: drying the surface of the workpiece to be detected until the excess water on the surface of the workpiece to be detected is removed, and the fluorescent penetrant in the crack defects of the workpiece to be detected is retained;

[0018] S4: irradiating the workpiece to be detected with a microwave pulse until the temperature of the fluorescent penetrant in the crack defects of the workpiece to be detected is obviously increased;

[0019] S5: capturing the temperature change of the workpiece to be detected by an infrared camera, and transmitting the temperature change to an image processing module for image processing, so as to obtain a topographic image and a distribution position of internal defects of the workpiece to be detected;

[0020] S6: The surface of the workpiece to be tested is uniformly sprayed with a developer, and the fluorescent penetrant in the crack defects of the workpiece to be tested is adsorbed out by the developer, and under the light, the fluorescent penetrant emits fluorescence or color on the surface of the workpiece to be tested;

[0021] S7: The surface image of the workpiece to be tested is recorded by a CCD camera, and the surface image is transmitted to an image processing module for processing, and the topographic image and distribution position of the surface crack of the workpiece to be tested are obtained;

[0022] S8: The topographic image and distribution position of the surface crack of the workpiece to be tested are combined with the topographic image and distribution position of the internal defect of the workpiece to be tested, respectively, and finally the overall detection data of the surface shape and internal structure of the defect of the workpiece to be tested are obtained.

[0023] Further, the fluorescent penetrant comprises a surfactant, oil, alcohol and ketone solvent.

[0024] The beneficial effects of the present application are:

[0025] The present scheme combines the capillary penetration effect and microwave thermal sensing detection; the fluorescent penetrant is used to complete the penetration of the non-metal material workpiece, and provides a carrier for microwave heating, and provides a basis for the subsequent color visualization step; the microwave is generated by a signal generator, and the microwave pulses act on the workpiece to be tested by the microwave heating device, and the biological tissues and polar molecules in the fluorescent penetrant will rub in the microwave field and rapidly increase the temperature, and the thermal expansion caused by the temperature rise will cause mechanical vibration, thereby generating a thermal signal, so that the microwave thermal sensing detector can detect the internal shape of the workpiece defect, and realize the overall detection of the internal condition of the defect; at the same time, the color developing agent can adsorb the fluorescent penetrant in the crack defects of the workpiece to be tested, and develop color on the surface of the workpiece to be tested, so that the distribution of the defect on the surface of the workpiece can be directly detected; and the internal defect condition and the surface crack condition of the workpiece to be tested can be combined and verified with each other, so that the overall detection of the surface shape and internal structure of the defect of the workpiece to be tested is realized, and the detection efficiency and detection precision are high. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural schematic view of the microwave thermal imaging detection device.

[0027] Figure 2 It is a front view of the microwave thermal imaging detection device.

[0028] Figure 3 It is a structural schematic view of the microwave heating device and the signal generator.

[0029] Figure 4 It is a structural schematic view of the spray pipeline.

[0030] Figure 5Structure diagram of heating box bottom.

[0031] Wherein, 1, heating box, 2, microwave heating device, 3, spraying pipeline, 4, infrared camera, 5, CCD camera, 6, signal generator, 7, rotating table, 8, clamping jaw, 9, spraying unit, 10, side opening door, 11, drying heat pipe, 12, inclined surface, 13, fluorescent penetrant recovery port, 14, microwave antenna, 15, workpiece to be tested. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application are described below to facilitate the understanding of the present application by those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, as long as various changes are within the spirit and scope of the present application defined and determined by the appended claims, all the inventions utilizing the concept of the present application are within the scope of protection.

[0033] As shown in Figures 1 to 5 The microwave thermal imaging detection device of the present application includes a heating box 1, the bottom of the heating box 1 is provided with a rotating table 7, the rotating table 7 is provided with a clamping jaw 8 for limiting the workpiece to be tested 15, after the clamping jaw 8 fixes the workpiece to be tested 15, the rotating table 7 can drive the workpiece to be tested 15 to rotate horizontally; the top of the heating box 1 is provided with a microwave heating device 2, a spraying pipeline 3, an infrared camera 4 and a CCD camera 5, the microwave heating device 2 is connected with a signal generator 6, the infrared camera 4 and the CCD camera 5 are electrically connected with an image processing module.

[0034] In specific implementation, the microwave heating device 2 includes a plurality of microwave antennas 14, generates microwave signals through the signal generator 6, and generates microwave pulses through the microwave antennas 14 after filtering and modulation; the infrared camera 4 and the CCD camera 5 are symmetrically arranged on both sides of the top of the heating box 1, and the infrared camera 4 and the CCD camera 5 are both inclined to point to the workpiece to be tested 15; the spraying pipeline 3 is annular, a plurality of spraying units 9 pointing to the workpiece to be tested 15 are arranged on the circumference of the spraying pipeline 3, so as to uniformly spray fluorescent penetrant, water and developer around the workpiece to be tested 15.

[0035] A side opening door 10 is arranged on one side of the heating box 1, a plurality of drying heat pipes 11 are arranged on the inner side wall of the heating box 1, which can realize the heating and drying of the workpiece to be tested 15; the bottom surface of the heating box 1 is an inclined surface 12, the rotating table 7 is horizontally arranged on the inclined surface 12, and the side wall of the heating box 1 near the low end of the inclined surface 12 is provided with a fluorescent penetrant recovery port 13.

[0036] The present application also provides a microwave thermal imaging detection method, which includes the following steps:

[0037] S1: connecting the spray pipeline 3 with the fluorescent penetrant supply device, uniformly spraying the surface of the workpiece 15 to be tested by the plurality of spray units 9, and standing for a preset time of penetration until the fluorescent penetrant gradually flows into the crack defects on the surface of the workpiece 15 to be tested under the action of capillary phenomenon; wherein the fluorescent penetrant includes surfactants, oils, alcohols and ketone solvents;

[0038] S2: connecting the spray pipeline 3 with the water supply device, uniformly spraying the surface of the workpiece 15 to be tested with water until the fluorescent penetrant on the surface of the workpiece 15 to be tested is washed away;

[0039] S3: driving the workpiece 15 to be tested to rotate horizontally by the rotating table 7, and drying the surface of the workpiece 15 to be tested by the plurality of drying heat pipes 11 until the excess moisture on the surface of the workpiece 15 to be tested is removed and the fluorescent penetrant in the crack defects of the workpiece 15 to be tested is retained; in specific implementation, the temperature during drying of the workpiece 15 to be tested should not be too high and the time should not be too long, otherwise the fluorescent penetrant in the defects will be dried, resulting in that the defect display cannot be formed subsequently;

[0040] S4: generating a microwave pulse with a very short duration by the signal generator 6 and the microwave heating device 2, and irradiating the workpiece 15 to be tested by the microwave pulse, wherein the workpiece 15 to be tested itself belongs to a dry and non-conductive non-metallic substance and does not respond obviously to a low-power microwave pulse, while the fluorescent penetrant in the defects belongs to a polar molecule, and the polar molecules in the penetrant, such as water molecules, will rotate or oscillate with the change of the microwave electric field, which will cause intermolecular friction and thus generate heat, resulting in that the temperature of the fluorescent penetrant in the crack defects of the workpiece 15 to be tested is obviously increased;

[0041] S5: capturing the temperature change of the workpiece 15 to be tested by the infrared camera 4, wherein the larger the aperture of the defect, the more the fluorescent penetrant retained, and the more obvious the microwave heating effect generated; the greater the temperature difference between the defect area and the non-defect area, the easier the defect is detected, and vice versa; then the temperature change is transmitted to the image processing module for image processing, so as to obtain the topographic image and distribution position of the internal defects of the workpiece 15 to be tested;

[0042] S6: connecting the spray pipeline 3 with the developer supply device, and uniformly spraying the surface of the workpiece 15 to be tested with the developer, and adsorbing the fluorescent penetrant in the crack defects of the workpiece 15 to be tested out by the developer due to the action of capillary phenomenon, and emitting fluorescence or color under light on the surface of the workpiece 15 to be tested;

[0043] S7: The surface image of the workpiece 15 to be tested is recorded by the CCD camera 5, and the surface image is transmitted to the image processing module for processing. The image processing software integrated in the image processing module can identify defects and mark the defect position and size, thereby obtaining the topographic image and distribution position of the surface cracks of the workpiece 15 to be tested;

[0044] S8: The topographic image and distribution position of the surface cracks of the workpiece 15 to be tested are combined with the topographic image and distribution position of the internal defects of the workpiece 15 to be tested, and can also be verified with each other, and finally the comprehensive detection data of the surface shape and internal structure of the defects of the workpiece 15 to be tested is obtained.

[0045] In summary, in the present scheme, the non-metal workpiece 15 to be tested is penetrated by the fluorescent penetrating liquid, the high sensitivity response of the penetrating liquid to the microwave pulse generates a thermal signal, and the microwave thermal sensing imaging is performed by using the thermal signal, which can comprehensively detect the internal conditions of the defects; at the same time, the fluorescent imaging is performed by using the fluorescent penetrating liquid, which can realize the visualization of the defect position, thereby detecting the distribution of the surface of the defects; the penetration detection image and the microwave thermal detection image are fused and studied, which can realize the comprehensive detection of the surface shape and internal structure of the defects of the non-conductive material workpiece, thereby greatly improving the sensitivity and accuracy of the microwave thermal imaging detection method in the detection of non-metal material defects.

Claims

1. A method of microwave thermographic detection, characterized in that, The method comprises the following steps: S1: uniformly spraying a fluorescent penetrant on the surface of the workpiece to be tested, and allowing the fluorescent penetrant to penetrate into the crack defects on the surface of the workpiece to be tested under capillary action for a preset time; S2: uniformly spraying water on the surface of the workpiece to be tested until the fluorescent penetrant on the surface of the workpiece to be tested is washed away; S3: drying the surface of the workpiece to be tested until the excess water on the surface of the workpiece to be tested is removed, and the fluorescent penetrant in the crack defects of the workpiece to be tested is retained; S4: irradiating the workpiece to be tested with microwave pulses until the temperature of the fluorescent penetrant in the crack defects of the workpiece to be tested is significantly increased; S5: capturing the temperature change of the workpiece to be tested by an infrared camera, and transmitting the temperature change to an image processing module for image processing, so as to obtain the topographic image and distribution position of the internal defects of the workpiece to be tested; S6: uniformly spraying a developer on the surface of the workpiece to be tested, adsorbing the fluorescent penetrant in the crack defects of the workpiece to be tested by the developer, and under the light, the fluorescent penetrant emits fluorescence or color on the surface of the workpiece to be tested; S7: recording the surface image of the workpiece to be tested by a CCD camera, and transmitting the surface image to an image processing module for processing, and obtaining the topographic image and distribution position of the surface cracks of the workpiece to be tested; S8: combining the topographic image and distribution position of the surface cracks of the workpiece to be tested with the topographic image and distribution position of the internal defects of the workpiece to be tested, and finally obtaining the comprehensive detection data of the surface shape and internal structure of the defects of the workpiece to be tested; The fluorescent penetrant comprises a surfactant, oil, alcohol and ketone solvent.

2. A microwave thermographic detection device based on the microwave thermographic detection method of claim 1, characterized by The heating box is provided with a rotating table at the bottom, the rotating table is provided with a clamping jaw for limiting the workpiece to be tested, the top of the heating box is provided with a microwave heating device, a spraying pipeline, an infrared camera and a CCD camera, the microwave heating device is connected with a signal generator, and the infrared camera and the CCD camera are electrically connected with an image processing module.

3. The microwave thermography inspection apparatus of claim 2, wherein, The infrared camera and the CCD camera are symmetrically arranged on the two sides of the top of the heating box, and the infrared camera and the CCD camera are both inclined and directed to the workpiece to be tested.

4. The microwave thermography inspection apparatus of claim 2, wherein, The spraying pipeline is annular, and a plurality of spraying units directed to the workpiece to be tested are arranged on the circumference of the spraying pipeline.

5. The microwave thermographic detection apparatus of claim 2, wherein, One side of the heating box is provided with a side opening door, and a plurality of drying heat pipes are arranged on the inner side wall of the heating box.

6. The microwave thermography inspection apparatus of claim 2, wherein, The bottom surface of the heating box is a slope, and a fluorescent penetrant recovery port is formed in the side wall of the heating box close to the low end of the slope.

7. The microwave thermographic detection device of claim 2, wherein, The microwave heating device comprises a plurality of microwave antennas.

Images