A finite element-based porous material pore structure thermal imaging detection device and method

Abstract

The application discloses a kind of porous material pore structure thermal imaging detection device and method based on finite element, it relates to a kind of porous material pore structure thermal imaging detection device and method.The present application is to solve the problems of the existing pore structure detection method, destructive, easy to damage material;Nondestructive testing precision is limited.The device includes microscope, porous material fixer, air pipe and adjustable temperature air source;Porous material fixer is set on the object table of microscope, and porous material fixer is connected with adjustable temperature air source by air pipe.The application belongs to the field of material precision detection technology.

Description

TECHNICAL FIELD

[0001] The application relates to a porous material pore structure thermal imaging detection device and method, and belongs to the technical field of material precision detection. BACKGROUND

[0002] With the rapid development of precision machining, ultra-precision machining, chemical industry, aerospace and other fields, porous materials, as a kind of special material with many pores, are widely used. The porous material combines the pore structure in the material with the characteristics of the material itself to realize the required physical and chemical properties such as force, heat, electricity and magnetism, and has the advantages of sound insulation, heat insulation and good permeability. However, with the specialization and refinement of the application of porous materials, the performance indicators of porous materials are becoming more and more stringent.

[0003] The pore structure of the porous material is the main factor affecting the performance of the porous material. Common detection methods include liquid delivery method, immersion medium method and destructive sampling detection method, but the above methods are easy to damage the material. At the same time, in the non-destructive detection method, the traditional infrared thermal imaging is easy to be affected by the temperature and deformation of the ceramic itself due to the direct use of high-temperature gas ventilation for detection, which reduces the detection precision. Therefore, a high-precision non-destructive detection method is needed. SUMMARY

[0004] The application is to solve the problems of the existing pore structure detection method, which is destructive and easy to damage the material, and the limited precision of non-destructive detection. Therefore, a porous material pore structure thermal imaging detection device and method based on finite elements are proposed.

[0005] The technical solution adopted by the application to solve the above problems is that the porous material pore structure thermal imaging detection device based on finite elements comprises a microscope, a porous material fixer, an air pipe and an adjustable temperature gas source.

[0006] The porous material fixer is arranged on the object table of the microscope, and the porous material fixer is connected with the adjustable temperature gas source through the air pipe.

[0007] Further, the porous material fixer comprises an outer shell.

[0008] The top surface of the outer shell is provided with a mounting hole, the porous material is arranged in the mounting hole, the lower surface of the porous material and the inner wall and the inner bottom surface of the outer shell form a closed cavity, the outer side wall of the outer shell is provided with an air hole, the air hole is communicated with the cavity, and the air hole is connected with the adjustable temperature gas source through the air pipe.

[0009] Further, the porous material fixer further comprises an air pipe quick connector.

[0010] The trachea quick connector is installed in the air hole of the outer side wall of the shell, one end of the trachea is connected with the trachea quick connector, and the other end of the trachea is connected with the adjustable temperature gas source.

[0011] Further, the microscope is an infrared imaging microscope.

[0012] The specific steps of the porous material pore structure thermal imaging detection method based on finite elements include:

[0013] Step 1, place the measured porous material in the porous material holder, seal with an O-ring to ensure the air tightness of the device;

[0014] Step 2, introduce high-temperature gas higher than room temperature T℃ and keep for a certain time to ensure that the temperature gradient distribution of the porous material solid part can be observed by the microscope, and save the temperature gradient distribution Heat-image under high-temperature conditions;

[0015] Step 3, after the porous material restores to room temperature, introduce low-temperature gas lower than room temperature T℃ and keep for a certain time to ensure that the temperature gradient distribution of the porous material solid part can be observed by the microscope, and save the temperature gradient distribution Cold-image under low-temperature conditions;

[0016] Step 4, repeat steps 1 to 3 for multiple measurements.

[0017] Further, the pore distribution calculation method is as follows:

[0018] Step 201, calculate the temperature gradient distribution Heat-image under high-temperature conditions according to the two-dimensional heat diffusion principle, and solve the pore structure distribution under high-temperature conditions, and the pore size is defined as D heat .

[0019] Step 202, calculate the temperature gradient distribution Cold-image under low-temperature conditions according to the two-dimensional heat diffusion principle, and solve the pore structure distribution under low-temperature conditions, and the pore size is defined as D cold .

[0020] Further, based on the two-dimensional heat diffusion principle, the temperature diffusion in the material is analyzed by the finite element analysis method for the pores containing different temperature gases, the temperature gradient template generated by the pores of different sizes through the set temperature gas is obtained, and the pore structure measurement result better than the resolution of the microscope is obtained by inversion.

[0021] The beneficial effects of the present application are: the present application uses different temperature gases to pass through the porous material, so that the porous material generates different temperature gradients due to the thermal diffusion effect, and then determines the pore structure of the porous ceramic cross section through an infrared microscope; due to the influence of the thermal expansion effect, the material structure will expand during the process of passing through high-temperature gas, resulting in a decrease in the pore structure, and the test result of the pore structure of the porous material is smaller; during the process of passing through low-temperature gas, the material structure will shrink, resulting in an increase in the pore structure, and the test result of the pore structure of the porous material is larger; the pore structure size at high temperature and the pore structure size at low temperature are obtained through testing, and the accurate pore structure of the porous material is obtained through the means of finite element analysis of the thermal diffusion effect; the method can effectively remove the influence of gas temperature on the pore structure during the measurement process. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the porous material pore structure thermal imaging detection device based on finite elements described in the present application;

[0023] Figure 2 is a structural schematic diagram of the porous material fixer;

[0024] Figure 1 and Figure 2 In the formula, 1 is a microscope, 2 is a porous material fixer, 201 is an outer shell, 202 is a porous material, 203 is a gas pipe quick connector, 204 is a cavity, 3 is a gas pipe, and 4 is a temperature-adjustable gas source. DETAILED DESCRIPTION

[0025] Detailed implementation one: as shown in the formula, a porous material pore structure thermal imaging detection device based on finite elements comprises a microscope 1, a porous material fixer 2, a gas pipe 3, and a temperature-adjustable gas source 4; Figure 1 The porous material fixer 2 is arranged on the object table of the microscope 1, and the porous material fixer 2 is connected with the temperature-adjustable gas source 4 through the gas pipe 3.

[0026] Detailed implementation two: as shown in the formula, on the basis of the detailed implementation one, the porous material fixer 2 comprises an outer shell 201;

[0027] Figure 2 The top surface of the outer shell 201 is provided with a mounting hole, the porous material 202 is arranged in the mounting hole, the lower surface of the porous material 202 and the inner wall and inner bottom surface of the outer shell 201 form a closed cavity 204, the outer side wall of the outer shell 201 is provided with a gas hole, the gas hole is in communication with the cavity 204, and the gas hole is connected with the temperature-adjustable gas source 4 through the gas pipe 3.

[0028] Detailed implementation three: as shown in the formula, on the basis of the detailed implementation two, the outer shell 201 is provided with a plurality of gas holes, and the gas holes are in communication with the cavity 204.

[0029] Detailed implementation four: as shown in the formula, on the basis of the detailed implementation three, the outer shell 201 is provided with a plurality of gas holes, and the gas holes are in communication with the cavity 204.​Figure 2 As shown in the second embodiment, the porous material holder 2 further comprises a tracheal quick connector 203;

[0030] The tracheal quick connector 203 is installed in the air hole of the outer wall of the shell 201, one end of the trachea 3 is connected with the tracheal quick connector 203, and the other end of the trachea 3 is connected with the adjustable temperature gas source 4.

[0031] The fourth embodiment is as shown in the first embodiment. Figure 1 As shown in the first embodiment, the microscope 1 is an infrared imaging microscope.

[0032] The fifth embodiment is as shown in the first embodiment. Figure 1 And Figure 2 A porous material pore structure thermal imaging detection method based on finite elements, the specific steps comprising:

[0033] Step 1, place the measured porous material 202 in the porous material holder 2, seal with O-ring, and ensure the air tightness of the device;

[0034] Step 2, introduce high-temperature gas higher than room temperature T℃, and keep for a certain time to ensure that the temperature gradient distribution of the solid part of the porous material 202 can be observed by the microscope 1, and save the temperature gradient distribution Heat-image under high-temperature condition;

[0035] Step 3, after waiting for the porous material 202 to recover to room temperature, introduce low-temperature gas lower than room temperature T℃, and keep for a certain time to ensure that the temperature gradient distribution of the solid part of the porous material 202 can be observed by the microscope 1, and save the temperature gradient distribution Cold-image under low-temperature condition;

[0036] Step 4, repeat steps 1 to 3 for multiple measurements.

[0037] Among them, the room temperature in the high-temperature gas higher than the room temperature T℃ is 25℃, the high-temperature gas is the gas with a temperature of 65℃, and the low-temperature gas is the gas with a temperature of-5℃.

[0038] The sixth embodiment is as shown in the first embodiment. Figure 1 And Figure 2 The pore distribution calculation method is as follows:

[0039] Step 201, according to the two-dimensional heat diffusion principle, the temperature gradient distribution Heat-image under high-temperature condition is calculated, and the pore structure distribution under high-temperature condition is solved, and the pore size is defined as D heat .

[0040] Step 202, according to the two-dimensional heat diffusion principle, the temperature gradient distribution under low temperature condition Cold-image is calculated, and the pore structure distribution under low temperature condition is solved, and the pore size is defined as D cold .

[0041] wherein,

[0042] u(x,y,t) is the temperature distribution at position (x,y) and time t; α is the thermal diffusivity, which represents the heat transfer capacity per unit time per unit temperature difference of the material; is the partial derivative of time t, which represents the rate of change of temperature with time; and are the spatial second-order partial derivatives in the x and y directions, respectively, which represent the rate of change of temperature distribution in these directions.

[0043] Specific implementation seven: as shown in Figure 1 and Figure 2 , based on the two-dimensional heat diffusion principle, the temperature diffusion in the material containing different temperature gas pores is analyzed by finite element analysis method, the temperature gradient template generated by the pores of different sizes through the set temperature gas is obtained, and the pore structure measurement result better than the resolution of microscope 1 is obtained by inversion.

[0044] The above is only the preferred embodiment of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, and the equivalent embodiments with equivalent changes can be made. Any simple modification, equivalent replacement and improvement of the above embodiments, which does not depart from the technical solution of the present application, is within the scope of protection of the present application.

Claims

1. A finite element based thermal imaging detection method for porous material pore structure, characterized in that, The detection device used in the detection method comprises a microscope (1), a porous material holder (2), an air pipe (3) and a temperature-adjustable air source (4); the porous material holder (2) is arranged on an objective table of the microscope (1), and the porous material holder (2) is connected with the temperature-adjustable air source (4) through the air pipe (3); The specific steps of the porous material pore structure thermal imaging detection method based on finite elements comprise: Step 1, the measured porous material (202) is placed in the porous material holder (2), and an O-ring is used for sealing to ensure the air tightness of the device; Step 2, high-temperature gas higher than room temperature T℃ is introduced, and a certain time is kept to ensure that the temperature gradient distribution of the solid part of the porous material (202) can be observed through the microscope (1), and the temperature gradient distribution Heat-image under the high-temperature condition is saved; Step 3, after the porous material (202) returns to room temperature, low-temperature gas lower than room temperature T℃ is introduced, and a certain time is kept to ensure that the temperature gradient distribution of the solid part of the porous material (202) can be observed through the microscope (1), and the temperature gradient distribution Cold-image under the low-temperature condition is saved; Step 4, steps 1 to 3 are repeated for multiple measurements; The pore structure calculation method is as follows: Step 201, according to the two-dimensional heat diffusion principle, the temperature gradient distribution Heat-image under high temperature conditions is calculated, and the pore structure distribution under high temperature conditions is solved, and the pore size is defined as ; Step 202, according to the two-dimensional heat diffusion principle, the temperature gradient distribution Cold-image under low temperature conditions is calculated, and the pore structure distribution under low temperature conditions is solved, and the pore size is defined as ; Based on the two-dimensional heat diffusion principle, the temperature diffusion of the pores containing different temperature gases in the material is analyzed by the finite element analysis method, the temperature gradient template generated by the pores of different sizes through the set temperature gas is obtained, and the pore structure measurement result better than the resolution of the microscope (1) is obtained by inversion.

2. The finite element based thermal imaging detection method of porous material pore structure according to claim 1, characterized in that, The porous material holder (2) comprises an outer shell (201); The top surface of the outer shell (201) is provided with a mounting hole, the porous material (202) is arranged in the mounting hole, the lower surface of the porous material (202) and the inner wall and inner bottom surface of the outer shell (201) form a closed cavity (204), the outer side wall of the outer shell (201) is provided with an air hole, the air hole is in communication with the cavity (204), and the air hole is connected with the temperature-adjustable air source (4) through the air pipe (3).

3. The finite element based method for thermal imaging detection of pore structure of porous materials according to claim 2, wherein, The porous material holder (2) further comprises an air pipe quick connection plug (203); The air pipe quick connection plug (203) is installed in the air hole in the outer side wall of the outer shell (201), one end of the air pipe (3) is connected with the air pipe quick connection plug (203), and the other end of the air pipe (3) is connected with the temperature-adjustable air source (4).

4. The finite element based thermal imaging detection method of porous material pore structure according to claim 1, characterized in that, The microscope (1) is an infrared imaging microscope.

Images