Heating structure used in scanning electron microscope and use method thereof

Abstract

The invention discloses a heating structure used in a scanning electron microscope and a use method of the heating structure, and relates to the technical field of scanning electron microscope high-temperature performance tests.The heating structure comprises a laser, a shell module, a laser clamping module and an electron back scattering diffraction scanning fixing module, and the upper surface of the electron back scattering diffraction scanning fixing module is obliquely arranged; the laser clamping module is installed on the electron back scattering diffraction scanning fixing module, the shell module is installed above the laser clamping module, a heating dodging plate used for placing a sample to be tested is arranged in the shell module, and the laser clamping module is used for clamping a laser lens of a laser. Laser beams output by the laser lens are irradiated on the heating dodging plate, the two ends of the to-be-tested sample extend out of the shell module and are connected with the stretching table, and an observation hole for observing the sample is formed in the upper end of the shell module. According to the invention, the imaging definition of the scanning electron microscope can be improved, and the in-situ high-temperature mechanical property test and the EBSD high-temperature analysis experiment in the scanning electron microscope can be smoothly carried out.

Description

Technical Field

[0001] The invention relates to the technical field of high temperature performance testing of a scanning electron microscope, and in particular to a heating structure used in a scanning electron microscope and a use method thereof. Background Art

[0002] In order to simulate the conditions of high-temperature alloys in the service environment, a heater is usually used to heat the sample surface when the performance of high-temperature alloys is characterized by a scanning electron microscope. The traditional heating method is usually electric current heating. Its working principle is to apply voltage to both ends of the tungsten wire. Under the excitation of the voltage, current will pass through the tungsten wire and generate Joule heat. The heat is then conducted to the ceramic on the tungsten wire, and finally the heat is conducted to the sample close to the ceramic to increase the sample temperature.

[0003] In recent years, the in-situ observation technology of mechanical experiments using scanning electron microscopes combined with stretching tables has gradually developed. The study of the initiation and expansion of microcracks in high-temperature alloys under extremely harsh conditions has great scientific significance for the application of materials in engineering. The in-situ high-temperature mechanical properties test and the electron backscatter diffraction (EBSD) high-temperature analysis experiment conducted in a scanning electron microscope combine the material performance test with its microstructure evolution in real time and dynamically. While performing performance tests, the evolution of the material's microstructure can be observed in real time, and the deformation and damage process of the material under extreme conditions can be dynamically studied.

[0004] However, due to the high heat transfer resistance of the current heating method, the temperature indicators of the in-situ high-temperature mechanical property test based on the scanning electron microscope and the EBSD high-temperature analysis experiment are currently concentrated below 800°C. Although there are a few devices that can heat the sample to above 900°C, the life of these heaters and the imaging quality of the scanning electron microscope will be seriously affected. The main reason is that after the current passes through the heating wire, the temperature of the heating wire is too high, which will release a large number of hot electrons, causing serious impact on the imaging of the scanning electron microscope. In addition, if the existing electric heater works in a high-temperature environment for a long time, its heating element is very easy to fail. For example, the resistance wire in the heater will fail due to a short circuit, affecting the in-situ high-temperature experiment. Summary of the invention

[0005] The purpose of the present invention is to provide a heating structure for use in a scanning electron microscope and a method for using the same, so as to solve the problems existing in the above-mentioned prior art, improve the imaging clarity of the scanning electron microscope, and ensure the smooth progress of in-situ high-temperature mechanical properties testing and EBSD high-temperature analysis experiments in the scanning electron microscope.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a heating structure for use in a scanning electron microscope, comprising a laser, a housing module, a laser clamping module and an electron backscatter diffraction scanning and fixing module, wherein the upper surface of the electron backscatter diffraction scanning and fixing module is arranged obliquely, the laser clamping module is mounted on the electron backscatter diffraction scanning and fixing module, and the housing module is mounted above the laser clamping module, a heating light-homogenizing plate for placing a sample to be tested is arranged in the housing module, the laser clamping module is used to clamp a laser lens of the laser, and irradiate the laser beam output by the laser lens onto the heating light-homogenizing plate, two ends of the sample to be tested extend out of the housing module and are connected to a stretching table, and an observation hole for observing the sample is arranged at the upper end of the housing module.

[0008] In one embodiment, the shell module includes a shell cover, a temperature measuring insulating seat, the heating homogenizing plate, a heating pad and a shielding shell assembly, the shielding shell assembly is installed in the middle groove of the electron backscatter diffraction scanning fixing module, and the shell cover can be removably installed on the upper end opening of the shielding shell assembly, the upper end of the shielding shell assembly is provided with a mounting groove, the heating pad is fixed in the mounting groove, the temperature measuring insulating seat is installed at the upper end of the heating pad, and the temperature measuring insulating seat is used to fix the temperature measuring element, the upper end of the heating pad is provided with a fixing groove, the temperature measuring insulating seat is provided with a fixing hole, the lower end of the heating homogenizing plate passes through the fixing hole and is fixed in the fixing groove, the side wall of the shielding shell assembly is provided with through holes for the two ends of the sample to be tested to extend out, the shell cover, the temperature measuring insulating seat, the heating pad and the shielding shell assembly are all provided with through holes corresponding in position and used for the laser beam output by the laser lens to pass through.

[0009] In one embodiment, the shielding shell assembly includes an outer shielding shell and an inner shielding shell, the inner shielding shell is installed in the outer shielding shell, and the interior of the inner shielding shell is provided with a frosted layer, and the outer shielding shell and the inner shielding shell are both provided with through holes that correspond in position and are used for the laser beam output by the laser lens to pass through.

[0010] In one embodiment, two holes for fixing the temperature measuring element are provided on the temperature measuring insulating seat, and the temperature measuring end of the temperature measuring element can extend close to the sample to be measured. The temperature measuring insulating seat is made of zirconia ceramic material, and the temperature measuring element is a thermocouple.

[0011] In one embodiment, the laser clamping module includes a water-cooled top cover, a lens cooling platform and a water-cooled head. The lens cooling platform is installed on the electron backscatter diffraction scanning fixing module, and the lens cooling platform is located below the shell module. The water-cooled top cover can be buckled with the lens cooling platform and used to clamp the laser lens. A water cooling channel is provided in the lens cooling platform, and the two ends of the water cooling channel are respectively connected to a water cooling head, and the water cooling head is installed on the outer wall of the lens cooling platform.

[0012] In one embodiment, the two water-cooling heads are installed on the first side wall of the lens cooling platform, and an external light baffle is also installed on the electron backscatter diffraction scanning fixing module. The external light baffle is arranged close to the first side wall, and the external light baffle is provided with a hole for the water-cooling head to pass through.

[0013] In one embodiment, the electron backscatter diffraction scanning fixing module includes a fixed bottom plate, an oblique fixing and a base, the oblique fixing is installed on the upper end surface of the base, and the cross-section of the oblique fixing is a right triangle, the fixed bottom plate is installed on the upper surface of the oblique fixing, and the oblique fixing makes the fixed bottom plate inclined, the laser clamping module is installed in the middle of the upper end of the base, the two oblique fixings are respectively located on both sides of the laser clamping module, and the fixed bottom plate is located on the periphery of the laser clamping module.

[0014] In one embodiment, the included angle between the fixed bottom plate and the upper surface of the base is 45°, and the included angle between the heating light-diffusing plate and the upper surface of the fixed bottom plate is 25°.

[0015] In one embodiment, the heating light-diffusing plate is made of high-purity graphite material.

[0016] The present invention also provides a method for using a heating structure in a scanning electron microscope based on any one of the above technical solutions, comprising the following steps:

[0017] S1. Assemble the heating structure for the scanning electron microscope, place the sample to be tested on the stretching table and fix the two ends of the sample to be tested, then adjust the heating structure and the stretching table for the scanning electron microscope, and make the sample to be tested fit closely with the upper surface of the heating homogenizing plate, place the matched heating structure and the stretching table for the scanning electron microscope on the scanning electron microscope operating table, and prepare for high temperature mechanical properties testing;

[0018] S2. Place the laser lens on the lens cooling table and adjust the position of the lens cooling table to ensure that the laser beam output by the laser lens can accurately pass through each through hole and irradiate the heated light homogenizing plate. Then start the laser and measure the temperature with a thermocouple. After the verification is completed, turn off the laser and turn on the water cooling head to allow cooling water to enter the lens cooling table through the water cooling head. Then close the door of the scanning electron microscope and evacuate the cabin.

[0019] S3. When the vacuum degree in the chamber drops below 0.02Pa, the in-situ high-temperature mechanical property test and EBSD high-temperature analysis experiment are started. During the experiment, the heating structure in the scanning electron microscope is first raised to a predetermined height by operating the scanning electron microscope operating table, and then the scanning electron microscope probe is used to scan the sample to be tested to observe the initial morphology of the sample to be tested. Subsequently, the EBSD probe is extended to ensure that the initial grain size of the sample to be tested can be accurately measured and observed;

[0020] S4. After completing the initial morphology observation of the sample to be tested, the output power of the laser is changed by adjusting the electric knob of the laser, so that the temperature of the heating diffuser plate rises rapidly, and the heat of the heating diffuser plate is transferred to the sample to be tested, thereby increasing the temperature of the sample to be tested, and the temperature measured by the thermocouple is monitored at the same time. When the temperature reaches the preset value, the electronic cavity of the scanning electron microscope is turned on, the sample to be tested is observed, and the experiment is started;

[0021] S5. After the temperature measured by the thermocouple stabilizes, open the electronic cavity of the scanning electron microscope, and operate the scanning electron microscope to perform in-situ high-temperature mechanical properties testing and EBSD high-temperature analysis experiments to observe the microstructure of the sample to be tested. After the microanalysis is completed, close the electronic cavity of the scanning electron microscope, retract the EBSD probe, and restore the scanning electron microscope operating table to its original position. Then, turn off the laser and the water-cooling head, and wait for the temperature measured by the thermocouple to drop below 100°C. When the temperature reaches the predetermined value, open the hatch of the scanning electron microscope, take out the heating structure used in the scanning electron microscope, and the experiment is over.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The heating structure for use in a scanning electron microscope and the use method thereof provided by the present invention are characterized in that the upper surface of an electron backscatter diffraction scanning fixing module is arranged obliquely, the laser clamping module is installed on the electron backscatter diffraction scanning fixing module, and the housing module is installed above the laser clamping module, a heating light homogenizing plate for placing a sample to be tested is arranged in the housing module, the laser clamping module is used to clamp a laser lens of a laser, and irradiate a laser beam output by the laser lens on the heating light homogenizing plate, and the laser beam is used to act on the heating light homogenizing plate and cause a thermal effect, thereby realizing a rapid increase in the temperature of the sample to be tested, and by using a laser beam for heating, no power is required during the heating process, and thus no additional electromagnetic field is introduced, and interference with the imaging system can be avoided even in a biased state, and at the same time, the laser heating Heat has good directionality and high energy concentration, and can quickly and evenly transfer heat to the surface of the sample to be tested, achieving rapid temperature rise and stable control, further improving imaging stability and clarity, and thus significantly improving the imaging effect under biased conditions, providing higher quality image data for microscopic analysis under high temperature conditions. Both ends of the sample to be tested extend out of the shell module and are connected to the stretching table, thereby achieving stretching of the sample to be tested. By combining the heating structure in the scanning electron microscope with the stretching table, in-situ observation of the sample to be tested under service conditions and in-situ high-temperature performance testing can be achieved, thereby achieving real-time observation of the evolution of the microstructure of the sample to be tested under the action of tensile stress. An observation hole for observing the sample is provided at the upper end of the shell module, which is convenient for observing the sample to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the structure of the heating structure used in the scanning electron microscope in Example 1;

[0026] Figure 2 It is a structural explosion diagram of the heating structure used in the scanning electron microscope in the first embodiment;

[0027] In the figure: 1-shell cover, 2-temperature measuring insulation seat, 3-heating homogenizing plate, 4-sample to be tested, 5-heating pad, 6-outer shielding shell, 7-fixed bottom plate, 8-inner shielding shell, 9-water-cooling cover, 10-laser lens, 11-fixed mounting plate, 12-lens cooling platform, 13-water cooling head, 14-outer light blocking plate, 15-oblique fixing, 16-base. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide a heating structure for use in a scanning electron microscope and a method for using the same, so as to solve the problems existing in the prior art, improve the imaging clarity of the scanning electron microscope, and ensure the smooth progress of in-situ high-temperature mechanical property testing and EBSD high-temperature analysis experiments in the scanning electron microscope.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Embodiment 1

[0032] like Figure 1-Figure 2 As shown, this embodiment provides a heating structure for use in a scanning electron microscope, including a laser, a housing module, a laser clamping module and an electron backscatter diffraction scanning fixing module. The upper surface of the electron backscatter diffraction scanning fixing module is inclined, the laser clamping module is installed on the electron backscatter diffraction scanning fixing module, and the housing module is installed above the laser clamping module. A heating light homogenizing plate 3 for placing a sample 4 to be tested is provided in the housing module. The laser clamping module is used to clamp a laser lens 10 of the laser, and irradiate the laser beam output by the laser lens 10 on the heating light homogenizing plate 3. The laser beam is used to act on the heating light homogenizing plate 3 and cause a thermal effect, thereby realizing a rapid increase in the temperature of the sample 4 to be tested. In addition, by using a laser beam for heating, no power is required during the heating process, and thus no additional electromagnetic field is introduced, and the sample 4 to be tested can be heated even in a biased state. Avoid interference with the imaging system. At the same time, laser heating has good directionality and high energy concentration, and can quickly and evenly transfer heat to the surface of the sample 4 to be tested, achieving rapid temperature rise and stable control, further improving imaging stability and clarity, and thus significantly improving the imaging effect under the biased state, providing higher quality image data for microscopic analysis under high temperature conditions. Both ends of the sample 4 to be tested extend out of the shell module and are connected to the stretching table, thereby achieving stretching of the sample 4 to be tested. By combining the heating structure in the scanning electron microscope with the stretching table, in-situ observation of the sample 4 to be tested under service conditions and in-situ high-temperature performance testing can be achieved, thereby observing the evolution of the microstructure of the sample 4 to be tested under the action of tensile stress in real time. An observation hole for observing the sample is provided at the upper end of the shell module, which is convenient for observing the sample 4 to be tested.

[0033] Specifically, the shell module includes a shell cover 1, a temperature measuring insulating seat 2, a heating homogenizing plate 3, a heating pad 5 and a shielding shell assembly. The shielding shell assembly is installed in the middle groove of the electron backscatter diffraction scanning fixed module, and the shell cover 1 can be detachably installed on the upper end opening of the shielding shell assembly. The upper end of the shielding shell assembly is provided with a mounting groove, and the heating pad 5 is fixed in the mounting groove. The heating pad 5 can effectively prevent excess laser from entering the electronic cavity of the scanning electron microscope to prevent damage to various probes in the scanning electron microscope. The temperature measuring insulating seat 2 is installed on the upper end of the heating pad 5, and the temperature measuring insulating seat 2 is installed on the upper end of the heating pad 5. The edge seat 2 is used to fix the temperature measuring element, the upper end of the heating pad 5 is provided with a fixing groove, the temperature measuring insulating seat 2 is provided with a fixing hole, the lower end of the heating homogenizing plate 3 passes through the fixing hole and is fixed in the fixing groove, and at the same time, the position setting of the heating pad 5 can make the heating homogenizing plate 3 more stable. The heating homogenizing plate 3 is used to receive the laser beam, and the side wall of the shielding shell assembly is provided with through holes for the two ends of the sample 4 to be measured to extend out, and the shell cover 1, the temperature measuring insulating seat 2, the heating pad 5 and the shielding shell assembly are all provided with through holes with corresponding positions and used for the laser beam output by the laser lens 10 to pass through.

[0034] The shielding shell assembly includes an outer shielding shell 6 and an inner shielding shell 8. The inner shielding shell 8 is installed in the outer shielding shell 6, and the interior of the inner shielding shell 8 is provided with a frosted layer, which can reduce the reflection of the laser in the inner shielding shell 8, and then cooperate with the outer shielding shell 6 and the outer light baffle 14 to effectively absorb the stray light generated by the laser beam and isolate the excess heat generated. The outer shielding shell 6 and the inner shielding shell 8 are provided with corresponding positions and through holes for the laser beam output by the laser lens 10 to pass through. The outer shielding shell 6 and the heating pad 5 cooperate to prevent the laser from overflowing and affecting the imaging effect.

[0035] Two holes for fixing the temperature measuring element are provided on the temperature measuring insulating seat 2, and the temperature measuring end of the temperature measuring element can extend close to the sample 4 to be measured. The temperature measuring insulating seat 2 is made of zirconia ceramic material, the temperature measuring element is a thermocouple, and the temperature measuring wire of the thermocouple is firmly fixed in a position close to the sample 4 to be measured after passing through the holes on the temperature measuring insulating seat 2, so that the thermocouple can monitor the surface temperature of the sample 4 to be measured in real time.

[0036] The laser clamping module includes a water-cooled upper cover 9, a lens cooling platform 12 and a water-cooled head 13. The lens cooling platform 12 is installed on the electron backscatter diffraction scanning fixing module, and the lens cooling platform 12 is located below the shell module. The water-cooled upper cover 9 can be buckled with the lens cooling platform 12 and used to clamp the laser lens 10. At the same time, the water-cooled upper cover 9 is tightly connected to the upper end of the lens cooling platform 12 to ensure that the laser lens 10 is effectively fixed, and the laser lens 10 is fixed in the direction of the semi-cylindrical groove on the lens cooling platform 12. Through this structural design, the laser beam is directly irradiated onto the heating homogenizing plate 3 through the heating hole to promote its heating. At the same time, this fixing method not only ensures the accuracy of laser emission, but also optimizes the energy transfer between the laser and the heating homogenizing plate 3, improves the heating efficiency, and can be used as a method to replace the traditional tungsten wire heat source. In addition, since the laser has Good directionality, high energy, stability and concentration can quickly induce thermal effects on objects, thereby effectively avoiding the negative impact of heating on scanning electron microscope imaging and significantly improving imaging clarity. On the other hand, the above connection method also has good sealing performance, which can effectively prevent the invasion of external impurities and ensure the clean working environment of the laser lens 10; a water cooling channel is provided in the lens cooling platform 12, and a water cooling head 13 is connected to each end of the water cooling channel. The water cooling head 13 is installed on the outer wall of the lens cooling platform 12, so that water flows into the water cooling channel in the lens cooling platform 12 through the water cooling head 13. The water flows in the water cooling channel to reduce the temperature of the lens cooling platform 12. Through heat conduction, the cooled lens cooling platform 12 absorbs the heat released by the laser lens 10, thereby effectively reducing the working temperature of the laser lens 10 and ensuring its stability and service life.

[0037] Two water cooling heads 13 are installed on the first side wall of the lens cooling platform 12. An external light blocking plate 14 is also installed on the electron backscatter diffraction scanning fixing module. The external light blocking plate 14 is arranged close to the first side wall and has a hole for the water cooling head 13 to pass through.

[0038] The electron backscatter diffraction scanning fixed module includes a fixed base plate 7, an oblique fixing 15 and a base 16. The oblique fixing 15 is installed on the upper end surface of the base 16, and the cross section of the oblique fixing 15 is a right triangle. The lower end of the fixed base plate 7 is provided with a limiting groove corresponding to the position of each oblique fixing 15, so that the fixed base plate 7 can be installed on the upper surface of the oblique fixing 15, and the oblique fixing 15 makes the fixed base plate 7 tilted. The laser clamping module is installed in the middle of the upper end of the base 16. The two oblique fixings 15 are respectively located on both sides of the laser clamping module, and the fixed base plate 7 is located at the periphery of the laser clamping module. The base 16 can be fixed on the scanning electron microscope operating table, so that the heating structure used in the scanning electron microscope can be adjusted accordingly with the movement of the scanning electron microscope operating table. This design enables the probe of the scanning electron microscope to stably lock the sample 4 to be tested, thereby effectively analyzing the surface phenomenon of the sample 4 to be tested, and improving the observation accuracy and convenience. A fixed mounting plate 11 is also installed on the inner side of the fixed base plate 7, and the fixed mounting plate 11 is used to connect the outer shielding shell 6.

[0039] The angle between the fixed bottom plate 7 and the upper surface of the base 16 is 45°, and the angle between the heating light-diffusing plate 3 and the upper surface of the fixed bottom plate 7 is 25°. This combined structure allows the sample 4 to be tested to present an angle of 70° with the horizontal plane, so that it can effectively cooperate with the EBSD probe to facilitate in-depth analysis of the grains of the sample 4 to be tested.

[0040] The heating light-diffusing plate 3 is made of high-purity graphite material.

[0041] Embodiment 2

[0042] This embodiment provides a method for using the heating structure in a scanning electron microscope based on the first embodiment, comprising the following steps:

[0043] S1. Assemble the heating structure used in the scanning electron microscope, place the sample 4 to be tested on the stretching table and fix the two ends of the sample 4 to be tested, then adjust the heating structure used in the scanning electron microscope and the stretching table position, and make the sample 4 to be tested fit closely with the upper surface of the heating homogenizing plate 3. The precise matching of the heating structure used in the scanning electron microscope and the stretching table can ensure that the surface of the sample 4 to be tested is heated evenly, and through this matching method, the heat transfer efficiency can be significantly improved, thereby achieving rapid heating. The matched heating structure and stretching table used in the scanning electron microscope are placed on the scanning electron microscope operating table, ready for high-temperature mechanical properties testing;

[0044] S2. Place the laser lens 10 on the lens cooling platform 12, and adjust the position of the lens cooling platform 12 to ensure that the laser beam output by the laser lens 10 can accurately pass through each through hole and irradiate the heating homogenizing plate 3, then start the laser and make the laser work at low power, and measure the temperature by thermocouple to confirm the normal working state of the heating structure in the scanning electron microscope. After the verification is completed, turn off the laser and turn on the water cooling head 13, so that the cooling water enters the lens cooling platform 12 through the water cooling head 13, and then close the door of the scanning electron microscope, and evacuate the cabin;

[0045] S3. When the vacuum degree in the chamber drops below 0.02Pa, the in-situ high-temperature mechanical property test and EBSD high-temperature analysis experiment are started. During the experiment, the heating structure in the scanning electron microscope is first raised to a predetermined height by operating the scanning electron microscope operating table, and then the scanning electron microscope probe is used to scan the sample 4 to observe the initial morphology of the sample 4 to be tested. Subsequently, the EBSD probe is extended to ensure that the initial grain size of the sample 4 to be tested can be accurately measured and observed;

[0046] S4. After the initial morphology observation of the sample 4 is completed, the output power of the laser is changed by adjusting the electric knob of the laser, so that the temperature of the heating light-diffusing plate 3 rises rapidly, and the heat of the heating light-diffusing plate 3 is transferred to the sample 4 to increase the temperature of the sample 4. At the same time, the temperature measured by the thermocouple is monitored. When the temperature reaches the preset value, the electronic cavity of the scanning electron microscope is turned on to observe the sample 4 and start the experiment;

[0047] S5. After the temperature measured by the thermocouple stabilizes, open the electronic cavity of the scanning electron microscope, and operate the scanning electron microscope to perform in-situ high-temperature mechanical properties testing and EBSD high-temperature analysis experiments to observe the microstructure of the sample 4 to be tested. After the microanalysis is completed, close the electronic cavity of the scanning electron microscope, retract the EBSD probe, and restore the scanning electron microscope operating table to its original position. Subsequently, turn off the laser and the water-cooled head 13, and wait for the temperature measured by the thermocouple to drop below 100°C. When the temperature reaches the predetermined value, open the hatch of the scanning electron microscope, take out the heating structure used in the scanning electron microscope, and the experiment ends.

[0048] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A heating structure for use in a scanning electron microscope, characterized in that: It includes a laser, a shell module, a laser clamping module and an electron backscatter diffraction scanning and fixing module. The upper surface of the electron backscatter diffraction scanning and fixing module is inclined. The laser clamping module is installed on the electron backscatter diffraction scanning and fixing module, and the shell module is installed above the laser clamping module. A heating and light-diffusing plate for placing a sample to be tested is provided in the shell module. The laser clamping module is used to clamp the laser lens of the laser and irradiate the laser beam output by the laser lens on the heating and light-diffusing plate. Both ends of the sample to be tested extend out of the shell module and are connected to a stretching table. An observation hole for observing the sample is provided at the upper end of the shell module.

2. The heating structure for use in a scanning electron microscope according to claim 1, characterized in that: The shell module includes a shell cover, a temperature measuring insulating seat, a heating homogenizing plate, a heating pad and a shielding shell assembly. The shielding shell assembly is installed in the middle groove of the electron backscatter diffraction scanning fixing module, and the shell cover can be detachably installed on the upper end opening of the shielding shell assembly. The upper end of the shielding shell assembly is provided with a mounting groove, the heating pad is fixed in the mounting groove, the temperature measuring insulating seat is installed at the upper end of the heating pad, and the temperature measuring insulating seat is used to fix the temperature measuring element, the upper end of the heating pad is provided with a fixing groove, the temperature measuring insulating seat is provided with a fixing hole, the lower end of the heating homogenizing plate passes through the fixing hole and is fixed in the fixing groove, the side wall of the shielding shell assembly is provided with through holes for the two ends of the sample to be measured to extend out, and the shell cover, the temperature measuring insulating seat, the heating pad and the shielding shell assembly are all provided with through holes corresponding in position and used for the laser beam output by the laser lens to pass through.

3. The heating structure for use in a scanning electron microscope according to claim 2, characterized in that: The shielding shell assembly includes an outer shielding shell and an inner shielding shell. The inner shielding shell is installed in the outer shielding shell, and a frosted layer is provided inside the inner shielding shell. The outer shielding shell and the inner shielding shell are both provided with through holes that correspond in position and are used for the laser beam output by the laser lens to pass through.

4. The heating structure for use in a scanning electron microscope according to claim 2, characterized in that: The temperature measuring insulating seat is provided with two holes for fixing the temperature measuring element, and the temperature measuring end of the temperature measuring element can extend close to the sample to be measured. The temperature measuring insulating seat is made of zirconia ceramic material, and the temperature measuring element is a thermocouple.

5. The heating structure for use in a scanning electron microscope according to claim 1, characterized in that: The laser clamping module includes a water-cooled upper cover, a lens cooling platform and a water-cooled head. The lens cooling platform is installed on the electron backscatter diffraction scanning fixing module, and the lens cooling platform is located below the shell module. The water-cooled upper cover can be buckled with the lens cooling platform and used to clamp the laser lens. A water-cooling channel is provided in the lens cooling platform. The two ends of the water-cooling channel are respectively connected to a water-cooling head, and the water-cooling head is installed on the outer wall of the lens cooling platform.

6. The heating structure for use in a scanning electron microscope according to claim 5, characterized in that: The two water-cooling heads are installed on the first side wall of the lens cooling platform. An external light baffle is also installed on the electron backscatter diffraction scanning fixing module. The external light baffle is arranged close to the first side wall and is provided with a hole for the water-cooling head to pass through.

7. The heating structure for use in a scanning electron microscope according to claim 1, characterized in that: The electron backscatter diffraction scanning fixed module includes a fixed base plate, an oblique fixer and a base, the oblique fixer is installed on the upper end surface of the base, and the cross-section of the oblique fixer is a right triangle, the fixed base plate is installed on the upper surface of the oblique fixer, and the oblique fixer makes the fixed base plate tilted, the laser clamping module is installed in the middle of the upper end of the base, the two oblique fixers are respectively located on both sides of the laser clamping module, and the fixed base plate is located on the periphery of the laser clamping module.

8. The heating structure for use in a scanning electron microscope according to claim 7, characterized in that: The included angle between the fixed bottom plate and the upper surface of the base is 45°, and the included angle between the heating light-diffusing plate and the upper surface of the fixed bottom plate is 25°.

9. The heating structure for use in a scanning electron microscope according to claim 1, characterized in that: The heating light-homogenizing plate is made of high-purity graphite material.

10. A method for using a heating structure in a scanning electron microscope based on any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Assemble the heating structure for the scanning electron microscope, place the sample to be tested on the stretching table and fix the two ends of the sample to be tested, then adjust the heating structure and the stretching table for the scanning electron microscope, and make the sample to be tested fit closely with the upper surface of the heating homogenizing plate, place the matched heating structure and the stretching table for the scanning electron microscope on the scanning electron microscope operating table, and prepare for high temperature mechanical properties testing; S2. Place the laser lens on the lens cooling table and adjust the position of the lens cooling table to ensure that the laser beam output by the laser lens can accurately pass through each through hole and irradiate the heated light homogenizing plate. Then start the laser and measure the temperature with a thermocouple. After the verification is completed, turn off the laser and turn on the water cooling head to allow cooling water to enter the lens cooling table through the water cooling head. Then close the door of the scanning electron microscope and evacuate the cabin. S3. When the vacuum degree in the chamber drops below 0.02Pa, the in-situ high-temperature mechanical property test and EBSD high-temperature analysis experiment are started. During the experiment, the heating structure in the scanning electron microscope is first raised to a predetermined height by operating the scanning electron microscope operating table, and then the scanning electron microscope probe is used to scan the sample to be tested to observe the initial morphology of the sample to be tested. Subsequently, the EBSD probe is extended to ensure that the initial grain size of the sample to be tested can be accurately measured and observed; S4. After completing the initial morphology observation of the sample to be tested, the output power of the laser is changed by adjusting the electric knob of the laser, so that the temperature of the heating diffuser plate rises rapidly, and the heat of the heating diffuser plate is transferred to the sample to be tested, thereby increasing the temperature of the sample to be tested, and the temperature measured by the thermocouple is monitored at the same time. When the temperature reaches the preset value, the electronic cavity of the scanning electron microscope is turned on, the sample to be tested is observed, and the experiment is started; S5. After the temperature measured by the thermocouple stabilizes, open the electronic cavity of the scanning electron microscope, and operate the scanning electron microscope to perform in-situ high-temperature mechanical properties testing and EBSD high-temperature analysis experiments to observe the microstructure of the sample to be tested. After the microanalysis is completed, close the electronic cavity of the scanning electron microscope, retract the EBSD probe, and restore the scanning electron microscope operating table to its original position. Then, turn off the laser and the water-cooling head, and wait for the temperature measured by the thermocouple to drop below 100°C. When the temperature reaches the predetermined value, open the hatch of the scanning electron microscope, take out the heating structure used in the scanning electron microscope, and the experiment is over.

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