A high-precision TEM pre-specimen blanking device and its usage method

Abstract

The present invention discloses a high-precision TEM pre-specimen blanking device and a usage method, belonging to the field of TEM pre-specimen blanking. It includes a blanking base, a material ejecting component arranged inside the blanking base, a blanking platform placed at the top of the blanking base, a transparent pressing sheet placed at the top of the blanking platform, and a multi-mode blanking mechanism arranged above the transparent pressing sheet. The multi-mode blanking mechanism includes a driving component, a transmission component connected to the bottom output end of the driving component, and a mode switching component connected to the output end of the transmission component. The mode switching component includes a TEM in-situ tensile blanking component and a TEM microscopic characterization blanking component. By adopting the above high-precision TEM pre-specimen blanking device and usage method, it has the advantages of high blanking precision and efficiency, preventing specimen warping, flexible use, and low manufacturing cost, and can be widely used in fields such as performance characterization of welded joints of deep-sea equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of TEM pre-sample blanking, and particularly to a high-precision TEM pre-sample blanking device and a usage method thereof. Background Art

[0002] During the assembly process of deep-sea equipment, welding is an indispensable key process. The mechanical properties of welded joints are directly related to the safety and reliability of these equipment when serving in extreme environments. Due to the unique challenges of the deep-sea environment, thick plates are usually used for deep-sea equipment and are connected through a multi-layer and multi-pass welding process. However, this complex welding process is accompanied by the influence of thermal cycles, forming different microstructural characteristics at the positions of different welding passes, resulting in significant differences in the mechanical properties of each part. Specifically, the performance indicators such as strength and toughness are inconsistent, directly affecting the overall load-bearing capacity of the welded joint.

[0003] In order to comprehensively understand the performance characteristics of deep-sea equipment welded joints and their microstructural evolution laws, it is necessary to accurately characterize the microstructures and the tissue changes during in-situ mechanical experiments at the high resolution of a transmission electron microscope (TEM). This research helps to reveal the microstructural differences and deformation mechanisms in different regions, providing a scientific basis for optimizing the welding process.

[0004] Specifically, a welded joint consists of three parts: the base metal, the heat-affected zone, and the weld. During the welding process, the distance of the base material from the center of the weld determines the different peak temperatures and high-temperature retention times, thereby forming the near heat-affected zone, the middle heat-affected zone, and the far heat-affected zone. The width range of the entire heat-affected zone is usually between 2 mm and 3 mm. In the thickness direction, due to the action of multiple thermal cycles, microstructural regions with different scales are formed inside the welded joint.

[0005] The current blanking dies used for preparing TEM characterization pre-samples have the following defects:

[0006] 1. It is mainly applicable to homogeneous materials and is limited by the accuracy requirements of the sampling position, with poor adaptability. 2. Existing devices are difficult to effectively process TEM characterization pre-samples and TEM in-situ tensile pre-samples with heterogeneous microstructures. 3. The thickness of the blanked samples usually does not exceed 60 microns, and obvious warping phenomena are likely to occur during the blanking process. After blanking, the remaining material will move with the upper punch, making it difficult to achieve effective blanking. 4. When taking the samples, the surface of the samples is easily scratched or deformed, seriously affecting the surface quality and characterization results of subsequent TEM samples. Summary of the Invention

[0007] The purpose of the present invention is to provide a high-precision TEM pre-sample blanking device and a usage method thereof to solve the above technical problems.

[0008] To achieve the above object, the present invention provides a high-precision TEM pre-sample blanking device, which includes a blanking base, a blanking component disposed inside the blanking base, a blanking platform placed at the top of the blanking base, a transparent pressing sheet placed at the top of the blanking platform, and a multi-mode blanking mechanism disposed above the transparent pressing sheet. The multi-mode blanking mechanism includes a driving component, a transmission component connected to the bottom output end of the driving component, and a mode switching component connected to the output end of the transmission component. The mode switching component includes a TEM in-situ tensile blanking component and a TEM microscopic characterization blanking component.

[0009] Preferably, the bottom end of the blanking base is fixed to the top end of the base by fastening screws, and a connecting arm is also fixed to the top end of the base. The connecting arm is respectively assembled and connected to the driving component and the transmission component;

[0010] The driving component includes a cantilever block fixed to the top end of the connecting arm by fastening screws at one end, a rotating pressing plate vertically rotating at the other end of the cantilever block, and a pressing rod threadedly connected to the outer circumferential side of the rotating pressing plate. The rotating pressing plate is elliptical-like.

[0011] Preferably, the transmission component includes a fixed block assembled on the connecting arm and a punching rod vertically slidably connected to the fixed block. A limiting cylinder is fixed to the fixed block at a position corresponding to the punching rod. The limiting cylinder is vertically slidably connected to the bottom end of the punching rod. The top end of the punching rod is threadedly connected to the bottom end of a pressing block. The top end of the pressing block is pressed against the bottom end of the rotating pressing plate, and a first compression spring is disposed on the punching rod between the pressing block and the limiting cylinder;

[0012] In the natural state, the bottom end of the punching rod is flush with the bottom end of the fixed block.

[0013] Preferably, the mode switching component includes a rotating block disposed at the bottom end of the fixed block through a limiting rotation assembly. Two mounting holes are axially symmetrically opened inside the rotating block, and a TEM in-situ tensile blanking component and a TEM microscopic characterization blanking component are respectively disposed in the two mounting holes;

[0014] The TEM in-situ tensile blanking component includes a TEM in-situ tensile sample punch disposed in one of the mounting holes through a second compression spring;

[0015] The TEM microscopic characterization blanking component includes a TEM circular sample punch disposed in the other mounting hole through a third compression spring.

[0016] Preferably, the limiting rotation assembly includes a screw rod fixed to the top end of the rotating block. The screw rod passes through a rotating hole opened in the center of the fixed block and is threadedly connected to a limiting post arranged at the top end of the fixed block. Two stop rods are fixed to the bottom end of the limiting post and respectively correspond to the positions of the TEM in-situ tensile test punch and the TEM circular sample punch. The stop rods extend into a limiting hole concentrically opened with the rotating hole, and two limiting baffles are symmetrically fixed between the inner wall of the limiting hole and the outer wall of the rotating hole. The stop rods rotate within the interval enclosed by the two limiting baffles.

[0017] Preferably, the ejecting assembly includes a TEM circular sample ejecting rod and a TEM in-situ tensile sample ejecting rod. The bottom end of the TEM circular sample ejecting rod is vertically slidably arranged inside the blanking base through a fourth compression spring. A convex ring is integrally formed in the middle of the TEM circular sample ejecting rod, and the TEM circular sample ejecting rod at the top end of the convex ring is vertically slidably connected to the inside of the TEM in-situ tensile sample ejecting rod.

[0018] Preferably, the transparent pressing sheet is a glass plate. The four corners of the glass plate are respectively lapped with the bosses at the four corners of the top end of the blanking platform. The bottom end of the blanking platform is threadedly connected to the top end of the blanking base. A sample to be processed is clamped between the glass plate and the top end of the blanking platform, and a processing hole is left in the glass plate corresponding to the processing position of the sample to be processed;

[0019] In the natural state, the top ends of the TEM circular sample ejecting rod and the TEM in-situ tensile sample ejecting rod are flush with the top end of the blanking platform, and both the TEM circular sample ejecting rod and the EM in-situ tensile sample ejecting rod are aligned with the processing hole.

[0020] Preferably, a cross positioning line is opened at the top end of the blanking platform, and the intersection point of the cross positioning line coincides with the processing center of the sample to be processed.

[0021] A using method of a high-precision TEM pre-sample blanking device includes the following steps:

[0022] S1. Remove the transparent pressing sheet, place the sample to be processed on the blanking platform, and make the processing center of the sample to be processed coincide with the intersection point of the cross positioning line on the blanking platform;

[0023] S2. Reinstall the transparent pressing sheet, and make the processing hole of the transparent pressing sheet aligned with the processing position of the sample to be processed;

[0024] S3. Rotate the pressing rod downward. The pressing rod drives the rotating pressing plate to rotate downward to press the pressing block. The pressing block drives the punching rod to move downward, and the first compression spring stores energy. Then, it presses the TEM in-situ tensile specimen punch or the TEM circular specimen punch downward. After the TEM in-situ tensile specimen punch or the TEM circular specimen punch passes through the processing hole, it cooperates with the TEM in-situ tensile specimen ejector rod or the TEM circular specimen ejector rod to realize blanking of the specimen to be processed. At this time, the second compression spring or the third compression spring and the fourth compression spring store energy;

[0025] S4. After blanking is completed, release the pressing rod. Under the restoring force of the first compression spring, the punching rod resets. At the same time, under the restoring force of the second compression spring or the third compression spring, the TEM in-situ tensile specimen punch or the TEM circular specimen punch resets;

[0026] S5. Remove the transparent pressing plate. The TEM circular specimen ejector rod and the TEM in-situ tensile specimen ejector rod reset under the restoring force of the fourth compression spring to complete material ejection.

[0027] Preferably, in step S3, when it is necessary to change the processing mode, rotate the rotating block horizontally to drive the limit post to rotate, and then drive the blocking rod to rotate until the blocking rod rotates from the current baffle position to the next baffle position to complete mode switching.

[0028] Therefore, the present invention adopts the above-mentioned high-precision TEM pre-specimen blanking device and usage method, and has the following beneficial effects:

[0029] 1. Improve blanking accuracy and efficiency: Through the precise positioning blanking platform and the observable transparent pressing plate, precise blanking of a small specific area of the welded joint specimen is realized, and the accuracy of the blanking position is significantly improved;

[0030] At the same time, the blanking process is optimized to reduce human operation errors and improve blanking efficiency.

[0031] 2. Prevent warping of thin specimens: The designed transparent pressing sheet effectively prevents warping of thin specimens with a thickness ≤ 60 µm during blanking, ensuring the flatness and quality of the specimens;

[0032] 3. Improve the applicability of the device: Integrate punches of different shapes and flexibly switch modes, such as switching between TEM characterization pre-specimens and TEM in-situ tensile pre-specimens;

[0033] 4. Reduce manufacturing costs: The modular design reduces the time and costs of die replacement and debugging, and greatly reduces the total costs of die design, manufacturing, debugging and maintenance.

[0034] The technical solutions of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0035] Figure 1 Stereogram of a high-precision TEM pre-sample blanking device according to the present invention;

[0036] Figure 2 Vertical sectional view of a high-precision TEM pre-sample blanking device according to the present invention;

[0037] Figure 3 Schematic structural diagram of a fixing block of a high-precision TEM pre-sample blanking device according to the present invention;

[0038] Figure 4 Schematic structural diagram of a blanking material ejecting assembly of a high-precision TEM pre-sample blanking device according to the present invention.

[0039] Reference numerals

[0040] 1. Base; 2. Blanking base; 3. Transparent pressing sheet; 4. Limiting cylinder; 5. First compression spring; 6. Punch rod; 7. Lower pressing block; 8. Lower pressing rod; 9. Rotating pressing plate; 10. Cantilever block; 11. Limiting column; 12. Connecting arm; 13. Fixing block; 14. Rotating block; 15. Blanking platform; 16. TEM in-situ tensile test sample punch; 17. TEM circular sample punch; 18. TEM circular sample ejecting rod; 19. TEM in-situ tensile test sample ejecting rod; 20. Sample to be processed; 21. Processing hole; 22. Stop rod; 23. Screw; 24. Second compression spring; 25. Third compression spring; 26. Limiting hole; 27. Limiting baffle; 28. Rotating hole; 29. Convex ring; 30. Fourth compression spring; 31. Positioning cylinder. Detailed implementation manners

[0041] In order to make the objectives, technical solutions and advantages of the embodiments disclosed in the present invention clearer and more understandable, the following further elaborates on the embodiments of the present invention in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end.

[0042] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0043] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] As Figures 1 - 4 shown, a high-precision TEM pre-sample blanking device includes a blanking base 2, a blanking component disposed inside the blanking base 2, a blanking platform 15 placed at the top of the blanking base 2, a transparent pressing sheet 3 placed at the top of the blanking platform 15, and a multi-mode blanking mechanism disposed above the transparent pressing sheet 3. The multi-mode blanking mechanism includes a driving component, a transmission component connected to the bottom output end of the driving component, and a mode switching component connected to the output end of the transmission component. The mode switching component includes a TEM in-situ tensile blanking component and a TEM microscopic characterization blanking component.

[0045] Specifically, the bottom end of the blanking base 2 is fixed to the top end of the base 1 by fastening screws. A connecting arm 12 is also fixed to the top end of the base 1, and the connecting arm 12 is respectively assembled and connected to the driving component and the transmission component. The driving component includes a cantilever block 10 with one end fixed to the top end of the connecting arm 12 by fastening screws, a rotating pressing plate 9 vertically rotatable at the other end of the cantilever block 10, and a downward pressing rod 8 threadedly connected to the outer circumferential side of the rotating pressing plate 9. The rotating pressing plate 9 is approximately elliptical.

[0046] The transmission component includes a fixed block 13 assembled on the connecting arm 12 and a punching rod 6 vertically slidably connected to the fixed block 13. A limiting cylinder 4 is fixed to the fixed block 13 at a position corresponding to the punching rod 6, and the limiting cylinder 4 is vertically slidably connected to the bottom end of the punching rod 6. The top end of the punching rod 6 is threadedly connected to the bottom end of a pressing block 7, the top end of the pressing block 7 is pressed against the bottom end of the rotating pressing plate 9, and a first compression spring 5 is disposed on the punching rod 6 between the pressing block 7 and the limiting cylinder 4. In the natural state, the bottom end of the punching rod 6 is flush with the bottom end of the fixed block 13.

[0047] The mode switching component includes a rotating block 14 disposed at the bottom end of the fixed block 13 through a limiting rotation assembly. Two mounting holes are axially symmetrically opened inside the rotating block 14, and a TEM in-situ tensile blanking component and a TEM microscopic characterization blanking component are respectively disposed in the two mounting holes. The TEM in-situ tensile blanking component includes a TEM in-situ tensile sample punching head 16 disposed in one of the mounting holes through a second compression spring 24. The TEM microscopic characterization blanking component includes a TEM circular sample punching head 17 disposed in the other mounting hole through a third compression spring 25.

[0048] The limiting rotation assembly includes a screw rod 23 fixed to the top end of the rotating block 14. The screw rod 23 passes through a rotating hole 28 opened at the center of the fixed block 13 and is threadedly connected to a limiting column 11 provided at the top end of the fixed block 13. At the bottom end of the limiting column 11 and respectively corresponding to the positions of the TEM in-situ tensile specimen punch 16 and the TEM circular specimen punch 17, two stop rods 22 are fixed. The stop rods 22 extend into a limiting hole 26 concentrically opened with the rotating hole 28. Between the inner wall of the limiting hole 26 and the outer wall of the rotating hole 28, two limiting baffles 27 are axially symmetrically fixed. The stop rods 22 rotate within the interval surrounded by the two limiting baffles 27.

[0049] The blanking component includes a TEM circular specimen ejector rod 18 and a TEM in-situ tensile specimen ejector rod 19. The bottom end of the TEM circular specimen ejector rod 18 is vertically slidably arranged inside the blanking base 2 through a fourth compression spring 30. A convex ring 29 is integrally formed in the middle of the TEM circular specimen ejector rod 18. The TEM circular specimen ejector rod 18 above the convex ring 29 is vertically slidably connected to the inside of the TEM in-situ tensile specimen ejector rod 19. A positioning cylinder 31 is sleeved on the TEM circular specimen ejector rod 18 below the convex ring 29. A fourth compression spring 30 is sleeved on the TEM circular specimen ejector rod 18 between the positioning cylinder 31 and the convex ring 29. The positioning cylinder 31 is arranged inside the blanking base 2 through a positioning set screw.

[0050] The transparent pressing sheet 3 is a glass plate. The four corners of the glass plate are respectively lapped with the bosses at the four corners of the top end of the blanking platform 15. The bottom end of the blanking platform 15 is threadedly connected to the top end of the blanking base 2. A specimen to be processed 20 is clamped between the glass plate and the top end of the blanking platform 15. And a processing hole 21 is left at the processing position of the glass plate corresponding to the specimen to be processed 20.

[0051] In the natural state, the top ends of the TEM circular specimen ejector rod 18 and the TEM in-situ tensile specimen ejector rod 19 are flush with the top end of the blanking platform 15, and both the TEM circular specimen ejector rod and the TEM in-situ tensile specimen ejector rod are aligned with the processing hole.

[0052] A cross positioning line is opened at the top end of the blanking platform 15, and the intersection point of the cross positioning line coincides with the processing center of the specimen to be processed 20.

[0053] A usage method of a high-precision TEM pre-specimen blanking device includes the following steps:

[0054] S1. Remove the transparent pressing sheet 3, place the specimen to be processed 20 on the blanking platform 15, and make the processing center of the specimen to be processed 20 coincide with the intersection point of the cross positioning line on the blanking platform 15. In the original state, the punch rod 6 is aligned with the TEM in-situ tensile specimen punch 16 or the TEM circular specimen punch 17.

[0055] S2. Reinstall the transparent pressing sheet 3, and align the processing hole 21 of the transparent pressing sheet 3 with the processing position of the sample to be processed 20;

[0056] S3. Rotate the lower pressing rod 8 downward. The lower pressing rod 8 drives the rotating pressing plate 9 to rotate downward to press the lower pressing block 7. The lower pressing block 7 drives the punching rod 6 to move downward, and the first compression spring 5 stores energy. Then, it presses the TEM in-situ tensile sample punch 16 or the TEM circular sample punch 17 downward. The TEM in-situ tensile sample punch 16 or the TEM circular sample punch 17 passes through the processing hole 21 and cooperates with the TEM in-situ tensile sample ejector rod 19 or the TEM circular sample ejector rod 18 (in this embodiment, when the TEM in-situ tensile sample punch 16 is selected, the TEM in-situ tensile sample punch 16 serves as the punch and cooperates with the TEM in-situ tensile sample ejector rod 19 serving as the die to achieve blanking. Similarly, the TEM circular sample punch 17 and the TEM circular sample ejector rod 18 can also cooperate to achieve blanking), to achieve blanking of the sample to be processed 20. At this time, the second compression spring 24 or the third compression spring 25 and the fourth compression spring 30 store energy;

[0057] In step S3, when it is necessary to change the processing mode, horizontally rotate the rotating block 14 to drive the limit post 11 to rotate, and then drive the blocking rod 22 to rotate until the blocking rod 22 rotates from the current baffle position to another baffle position (in this embodiment, a horizontal rotation of 180° is sufficient to reach the position), to complete the mode switching. For example, when it is necessary to punch the TEM in-situ tensile pre-sample, rotate the rotating block 14 so that the TEM in-situ tensile sample punch 16 is aligned with the punching rod 6; when it is necessary for the TEM microscopic characterization sample, rotate the rotating block 14 so that the TEM circular sample punch 17 is aligned with the punching rod 6.

[0058] S4. After blanking, release the lower pressing rod 8. Under the restoring force of the first compression spring 5, the punching rod 6 resets. At the same time, under the restoring force of the second compression spring 24 or the third compression spring 25, the TEM in-situ tensile sample punch 16 or the TEM circular sample punch 17 resets;

[0059] S5. Remove the transparent pressing plate. The TEM circular sample ejector rod 18 and the TEM in-situ tensile sample ejector rod 19 reset under the restoring force of the fourth compression spring 30 to complete the ejecting of the material.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-precision TEM pre-sample punching device, characterized in that: It includes a punching base, a material ejecting assembly arranged inside the punching base, a punching platform arranged at the top of the punching base, a transparent pressing sheet arranged at the top of the punching platform, and a multi-mode punching mechanism arranged above the transparent pressing sheet, wherein the multi-mode punching mechanism includes a driving component, a transmission component connected to the bottom output end of the driving component, and a mode switching component connected to the output end of the transmission component, wherein the mode switching component includes a TEM in-situ stretching punching component and a TEM microscopic characterization punching component; The bottom end of the punching base is fixed to the top end of the base through a fastening screw, and a connecting arm is also fixed to the top end of the base, and the connecting arm is respectively assembled and connected with the driving component and the transmission component; The transmission component includes a fixed block assembled on the connecting arm and a punch rod vertically slidably connected to the fixed block, a limiting cylinder is fixed on the fixed block and corresponds to the position of the punch rod, the limiting cylinder is vertically slidably connected to the bottom end of the punch rod, the top end of the punch rod is threadedly connected to the bottom end of the lower pressing block, the top end of the lower pressing block is crimped to the bottom end of the rotating pressing plate, and a first compression spring is arranged on the punch rod between the lower pressing block and the limiting cylinder; In the natural state, the bottom end of the punch is flush with the bottom end of the fixed block; The mode switching component includes a rotating block arranged at the bottom end of the fixed block via a limited rotating assembly, and two mounting holes are axially symmetrically provided inside the rotating block, and a TEM in-situ stretching and blanking assembly and a TEM microscopic characterization and blanking assembly are respectively arranged in the two mounting holes; The TEM in-situ stretching and blanking assembly comprises a TEM in-situ stretching sample punch arranged in one of the mounting holes via a second compression spring; The TEM microscopic characterization punching assembly comprises a TEM circular sample punch which is arranged in another mounting hole via a third compression spring.

2. A high-precision TEM pre-sample punching device according to claim 1, characterized in that: The driving component includes a cantilever block with one end fixed to the top of the connecting arm by a fastening screw, a rotating pressure plate vertically rotating at the other end of the cantilever block, and a lower pressure rod threadedly connected to the outer circumference of the rotating pressure plate. The rotating pressure plate is elliptical.

3. A high-precision TEM pre-sample punching device according to claim 2, characterized in that: The limit rotation assembly includes a screw fixed to the top of the rotating block. The screw passes through a rotating hole opened in the center of the fixed block and is threadedly connected to a limit column arranged at the top of the fixed block. Two baffles are fixed to the bottom of the limit column corresponding to the positions of the TEM in-situ tensile specimen punch and the TEM circular specimen punch respectively. The baffles extend into a limit hole opened concentrically with the rotating hole. Two limit baffles are axially symmetrically fixed between the inner wall of the limit hole and the outer wall of the rotating hole. The baffles rotate in a range surrounded by the two limit baffles.

4. A high-precision TEM pre-sample punching device according to claim 3, characterized in that: The ejection assembly comprises a TEM circular sample ejection rod and a TEM in-situ tensile sample ejection rod. The bottom end of the TEM circular sample ejection rod is vertically slidably arranged inside the blanking base via a fourth compression spring. A convex ring is integrally formed in the middle of the TEM circular sample ejection rod. The TEM circular sample ejection rod at the top end of the convex ring is vertically slidably connected to the inside of the TEM in-situ tensile sample ejection rod.

5. A high-precision TEM pre-sample punching device according to claim 4, characterized in that: The transparent pressing sheet is a glass plate, the four corners of the glass plate are respectively overlapped with the bosses at the four corners of the top of the punching platform, the bottom of the punching platform is threadedly connected with the top of the punching base, a sample to be processed is clamped between the glass plate and the top of the punching platform, and a processing hole is left on the glass plate corresponding to the processing position of the sample to be processed; In the natural state, the top of the ejector rod of the TEM circular specimen and the top of the ejector rod of the TEM in-situ tensile specimen are flush with the top of the blanking platform, and the ejector rod of the TEM circular specimen and the ejector rod of the EM in-situ tensile specimen are aligned with the processed hole.

6. A high-precision TEM pre-sample punching device according to claim 5, characterized in that: A cross positioning line is provided on the top of the punching platform, and the intersection of the cross positioning line coincides with the machining center of the sample to be processed.

7. A method for using a high-precision TEM pre-sample punching device according to claim 6, characterized in that: The following steps are involved: S1. Remove the transparent pressing sheet and place the sample to be processed on the blanking platform, and make the processing center of the sample to be processed coincide with the intersection of the cross positioning lines on the blanking platform; S2. Reinstall the transparent pressing sheet and align the processing hole of the transparent pressing sheet with the processing position of the sample to be processed; S3, the lower pressing rod is rotated downward, the lower pressing rod drives the rotating pressing plate to rotate and press the lower pressing block downward, the lower pressing block drives the punch rod to move downward, the first compression spring stores energy, and then presses the TEM in-situ tensile sample punch or the TEM circular sample punch downward, the TEM in-situ tensile sample punch or the TEM circular sample punch passes through the processing hole and cooperates with the TEM in-situ tensile sample ejector rod or the TEM circular sample ejector rod to achieve blanking of the sample to be processed, at this time, the second compression spring or the third compression spring and the fourth compression spring store energy; S4. After the punching is completed, the lower pressure rod is released, and the punch is reset under the restoring force of the first compression spring. At the same time, the TEM in-situ tensile specimen punch or the TEM circular specimen punch is reset under the restoring force of the second compression spring or the third compression spring; S5. Remove the transparent pressing plate, and the TEM circular specimen ejector rod and the TEM in-situ tensile specimen ejector rod are reset under the restoring force of the fourth compression spring to complete the ejection.

8. The method for using the high-precision TEM pre-sample punching device according to claim 7, characterized in that: In step S3, when the processing mode needs to be changed, the rotating block is rotated horizontally to drive the limit column to rotate, and then drive the baffle rod to rotate until the baffle rod rotates from the current baffle position to the next baffle position, completing the mode switching.

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