In-situ micro-nano scratch testing device and method under optical microscope
By designing a compact in-situ micro/nano scratch testing device under an optical microscope, the problems of expensive equipment and complex operation in existing technologies are solved. This enables efficient real-time observation of material deformation and damage processes under a conventional optical microscope, reducing costs and improving imaging quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JILIN UNIVERSITY
- Filing Date
- 2023-08-01
- Publication Date
- 2026-07-14
AI Technical Summary
In the existing technology, in-situ micro-nano scratch testing equipment is expensive and complicated to operate, and there is a contradiction between the imaging quality and refresh rate of optical microscopes, making it difficult to achieve efficient real-time observation of material deformation and damage processes.
A compact in-situ micro/nano scratch testing device under an optical microscope was designed, including a base, a piezoelectric precision loading unit, a large-stroke piezoelectric coarse feed unit, a biaxial force sensor unit, a stage, and a piezoelectric precision scratch unit. Real-time observation is performed using an optical microscope, simplifying the operation process.
It enables high-quality in-situ micro-nano scratch testing under a conventional optical microscope, capturing real-time images of the material-indenter contact area, studying material deformation and damage mechanisms, and reducing equipment costs and operational complexity.
Smart Images
Figure CN116973215B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of micro-nano mechanical property testing of materials, and in particular to a micro-nano scratch testing device and method for in-situ observation under an optical microscope. Background Technology
[0002] Scratch testing is a common method for studying the hardness, deformation and removal mechanisms, and damage mechanisms of materials. Based on whether the contact area between the material and the indenter can be observed in real time during the test, it can be divided into in-situ scratch testing and off-situ scratch testing. In-situ scratch testing under an optical microscope allows for real-time observation of the scratch morphology and the contact between the indenter and the specimen, providing a new technical means for studying the mechanical properties of materials.
[0003] Previously, researchers such as R. Rabe from Switzerland and MG Gee from the UK proposed in-situ scanning electron microscopy (SEM) micro / nano scratch testing instruments, and Bruker Corporation from the US launched commercial in-situ SEM micro / nano scratch testing instruments, both of which can achieve in-situ micro / nano scratch testing within SEMs. However, SEMs are expensive, and the testing process requires placing the scratch testing instrument within the vacuum chamber of the SEM, making preparation and operation cumbersome. Furthermore, the imaging quality of SEMs is related to the image refresh rate; a higher refresh rate results in poorer image quality, while a lower refresh rate, although providing a clearer image, cannot record the interaction between the indenter and the sample in real time. This significantly limits the development of in-situ micro / nano scratch testing technology.
[0004] Meanwhile, optical microscopes are relatively inexpensive, easy to use, and require no vacuum environment, greatly facilitating in-situ micro- and nano-scratch experiments. Their high image refresh rate makes it easier to obtain real-time, high-quality images and videos, creating conditions for studying the potential deformation and damage processes of materials. Therefore, the development of an in-situ micro- and nano-scratch instrument under an optical microscope is of great significance. Summary of the Invention
[0005] The purpose of this invention is to provide an in-situ micro / nano scratch testing device and method under an optical microscope, which solves the aforementioned problems existing in the prior art. This invention has low requirements for testing conditions, a compact device structure, and can meet the limitations of optical microscope stages on sample size and weight.
[0006] The above-mentioned objective of the present invention is achieved through the following technical solution:
[0007] An in-situ micro-nano scratch test device under an optical microscope includes: a base 1, a piezoelectric precision loading unit 2, a large-stroke piezoelectric coarse feed unit 3, a two-way force sensor unit 4, a stage 5, and a piezoelectric precision scratch unit 6; the piezoelectric precision loading unit 2 is composed of a flexible hinge 201 and a piezoelectric stack 202, and is fixed on the base 1 by bolts; the large-stroke piezoelectric coarse feed unit 3 is composed of a z-axis stick-slip piezoelectric driver 301 and a connecting part A 302, and is connected to the piezoelectric precision loading unit 2 by bolts; the two-way force sensor unit 4 is composed of a two-way force sensor 401, a diamond indenter 402 and a connecting part B 403, and is fixed on the large-stroke piezoelectric coarse feed unit 3 by bolts; the stage 5 is composed of a "Ji"-shaped structure part 501 with an observation window in the middle and a connecting plate 502, and is fixed on the piezoelectric precision scratch unit 6 by bolts; the diamond indenter 402 on the two-way force sensor unit 4 is located inside the "Ji"-shaped structure part 501; the piezoelectric precision scratch unit 6 is composed of an x-axis stick-slip piezoelectric driver 601 and a y-axis stick-slip piezoelectric driver 602, and is fixed on the base 1 by bolts.
[0008] The two-way force sensor 401 and the piezoelectric precision scratch unit 6 are both prior arts. The two-way force sensor 401 can measure the force between the diamond indenter 402 and the specimen during the scratch process, including the axial force along the z-axis direction and the lateral force along the x-axis direction. The piezoelectric precision scratch unit 6 can realize the relative movement between the diamond indenter 402 and the test piece during the scratch process.
[0009] The method for in-situ testing under an optical microscope using the aforementioned in-situ micro-nano scratch testing device includes the following steps: 1) The sample is attached to the upper surface of the "U"-shaped structural part 501 with double-sided adhesive tape, and then the in-situ micro-nano scratch testing device is placed on the stage of the optical microscope, and then the optical microscope is turned on; 2) The position of the optical microscope lens is adjusted so that the focal point is located at the lower surface of the sample; 3) The in-situ micro-nano scratch testing device is started, and appropriate motion parameters are selected to move the diamond indenter 402 upward to contact the sample, and the contact point between the diamond indenter 402 and the sample is found through the optical microscope image to determine its position in the field of view; 4) The position of the optical microscope stage is adjusted so that the contact point between the diamond indenter 402 and the sample is at the center of the field of view, and an appropriate magnification is selected to observe the contact state between the material and the diamond indenter 402 during the scratching process; 5) The piezoelectric precision... Loading unit 2 moves the diamond indenter 402 downward away from the sample and controls piezoelectric precision scratching unit 6 to move stage 5 until the contact point mentioned in step 3) leaves the field of view, completing the observation position adjustment; 6) Control the large stroke piezoelectric coarse feed unit 3 to move the diamond indenter 402 upward until the diamond indenter 402 contacts the lower surface of the sample; 7) Control the piezoelectric precision loading unit 2 to move upward to achieve precise pressing of the diamond indenter 402 into the sample; 8) Select appropriate motion parameters to move the piezoelectric precision scratching unit 6 along the x-axis to scratch, and the biaxial force sensor 401 measures the axial force and transverse force between the diamond indenter 402 and the sample, while obtaining the contact state between the material and the diamond indenter 402 during the scratching process through the image of the optical microscope; 9) After the scratching process is completed, control the piezoelectric precision loading unit 2 to move the diamond indenter 402 downward away from the sample, completing the unloading process.
[0010] Furthermore, the sample described in steps 1)-9) is a transparent material or a coated material with a transparent material as the base.
[0011] The advantages of this invention are: it requires minimal testing conditions, only needing to be used with a common optical microscope for in-situ micro / nano scratch testing. The device is compact, with dimensions of 170mm × 80mm × 80mm, which meets the limitations of optical microscope stages in terms of sample size and weight. Using this device, high-quality real-time images and videos of the material-indenter contact area during the scratching process can be captured, providing a new technical means for studying the potential deformation and damage mechanisms of materials, and showing promising application prospects in materials science, tribology, and other fields. Attached Figure Description
[0012] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate the invention and are used to explain it, but do not constitute an undue limitation of the invention.
[0013] Figure 1 This is an isometric view of the in-situ micro / nano scratch testing device under an optical microscope according to the present invention.
[0014] Figure 2 This is a front view of the in-situ micro / nano scratch testing device under an optical microscope according to the present invention.
[0015] Figure 3 This is a schematic diagram of the piezoelectric precision loading unit structure of the present invention.
[0016] Figure 4 This is a schematic diagram of the structure of the large-stroke piezoelectric coarse feed unit of the present invention.
[0017] Figure 5 This is a schematic diagram of the bidirectional force sensor unit structure of the present invention.
[0018] Figure 6 This is a schematic diagram of the stage structure of the present invention.
[0019] Figure 7 The images provided are ordinary optical images, laser confocal scanning images, and axial and lateral forces during the in-situ scratch test of fused silica under an optical microscope, as well as the test process itself.
[0020] Figure 8 The images provided are ordinary optical images, laser confocal scanning images, and axial and lateral forces during the in-situ scratch test of polymethyl methacrylate (PMMA) under an optical microscope, as well as the test process itself.
[0021] In the diagram: 1. Base; 2. Piezoelectric precision loading unit; 3. Large stroke piezoelectric coarse feed unit; 4. Biaxial force sensor unit; 5. Stage; 6. Piezoelectric precision scratch unit; 201. Flexible hinge; 202. Piezoelectric stack; 301. Z-axis stick-slip piezoelectric actuator; 302. Connector A; 401. Biaxial force sensor; 402. Diamond indenter; 403. Connector B; 501. "U"-shaped structural part; 502. Connecting plate. Detailed Implementation
[0022] The following description, in conjunction with the accompanying drawings, further illustrates the detailed content of the present invention and its specific embodiments.
[0023] See Figures 1 to 6, an in-situ micro-nano scratch test device under an optical microscope in the present invention comprises: a base 1, a piezoelectric precision loading unit 2, a large-stroke piezoelectric coarse feeding unit 3, a two-way force sensor unit 4, a stage 5, and a piezoelectric precision scratching unit 6; the piezoelectric precision loading unit 2 is composed of a flexure hinge 201 and a piezoelectric stack 202, and is fixed on the base 1 by bolts; the large-stroke piezoelectric coarse feeding unit 3 is composed of a z-axis stick-slip piezoelectric actuator 301 and a connecting member A 302, and is connected to the piezoelectric precision loading unit 2 by bolts; the two-way force sensor unit 4 is composed of a two-way force sensor 401, a diamond indenter 402 and a connecting member B 403, and is fixed on the large-stroke piezoelectric coarse feeding unit 3 by bolts; the stage 5 is composed of a "ji"-shaped structural part 501 with an observation window in the middle and a connecting plate 502, and is fixed on the piezoelectric precision scratching unit 6 by bolts; the diamond indenter 402 on the two-way force sensor unit 4 is located inside the "ji"-shaped structural part 501; the piezoelectric precision scratching unit 6 is composed of an x-axis stick-slip piezoelectric actuator 601 and a y-axis stick-slip piezoelectric actuator 602, and is fixed on the base 1 by bolts.
[0024] The method for in-situ testing under an optical microscope using the aforementioned in-situ micro-nano scratch testing device includes the following steps: 1) The sample is attached to the upper surface of the "U"-shaped structural part 501 with double-sided adhesive tape, and then the in-situ micro-nano scratch testing device is placed on the stage of the optical microscope, and then the optical microscope is turned on; 2) The position of the optical microscope lens is adjusted so that the focal point is located at the lower surface of the sample; 3) The in-situ micro-nano scratch testing device is started, and appropriate motion parameters are selected to move the diamond indenter 402 upward to contact the sample, and the contact point between the diamond indenter 402 and the sample is found through the optical microscope image to determine its position in the field of view; 4) The position of the optical microscope stage is adjusted so that the contact point between the diamond indenter 402 and the sample is at the center of the field of view, and an appropriate magnification is selected to observe the contact state between the material and the diamond indenter 402 during the scratching process; 5) The piezoelectric precision... Loading unit 2 moves the diamond indenter 402 downward away from the sample and controls piezoelectric precision scratching unit 6 to move stage 5 until the contact point mentioned in step 3) leaves the field of view, completing the observation position adjustment; 6) Control the large stroke piezoelectric coarse feed unit 3 to move the diamond indenter 402 upward until the diamond indenter 402 contacts the lower surface of the sample; 7) Control the piezoelectric precision loading unit 2 to move upward to achieve precise pressing of the diamond indenter 402 into the sample; 8) Select appropriate motion parameters to move the piezoelectric precision scratching unit 6 along the x-axis to scratch, and the biaxial force sensor 401 measures the axial force and transverse force between the diamond indenter 402 and the sample, while obtaining the contact state between the material and the diamond indenter 402 during the scratching process through the image of the optical microscope; 9) After the scratching process is completed, control the piezoelectric precision loading unit 2 to move the diamond indenter 402 downward away from the sample, completing the unloading process.
[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made to the present invention should be included within the scope of protection of the present invention.
[0026] Example
[0027] This invention proposes an in-situ micro / nano scratch testing device and method under an optical microscope to perform in-situ scratch testing on fused silica and PMMA. The following examples further illustrate the implementation process and beneficial effects of this invention.
[0028] First, assemble the in-situ micro-nano scratch test device under an optical microscope. Then, paste the polished fused quartz sample onto the upper surface of the "Ji"-shaped structure part (501) with double-sided tape. Set the scratch load to 300 mN, the scratch speed to 410 µm / min, and the total magnification of the microscope to 864 times, and conduct the in-situ scratch test. The ordinary optical images, laser confocal scanning images during the scratch test, and the axial force and lateral force measured by the two-way force sensor during the test are as Figure 7 shown.
[0029] As can be seen from Figure 7 , during the scratch test, the material shows brittleness. The residual scratch edge behind the diamond indenter is uneven, and loose debris and块状 debris are generated on both sides. The brittle fracture of the material also leads to fluctuations in the lateral force.
[0030] Remove the fused quartz sample, and paste the polished PMMA sample onto the upper surface of the "Ji"-shaped structure part (501) with tape. Set the scratch load to increase linearly from 0 to 100 mN, the scratch speed to 460 µm / min, and the total magnification of the microscope to 864 times, and conduct the in-situ scratch test. The ordinary optical images, laser confocal scanning images during the scratch test, and the axial force and lateral force measured by the two-way force sensor during the test are as Figure 8 shown.
[0031] As can be seen from Figure 8 , during the scratch test, the material shows ductility. The residual scratch behind the diamond indenter is relatively regular, no debris is generated, and the changes in the axial force and lateral force are relatively stable.
[0032] This in-situ scratch test shows that during the scratch test, real-time images of the interaction between the diamond indenter and the material surface can be observed, providing materials for studying the potential deformation and damage mechanisms of the material.
[0033] The above are only preferred examples of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made to the present invention shall be included within the protection scope of the present invention.
Claims
1. An in-situ micro / nano scratch testing device under an optical microscope, characterized in that: It includes a base (1), a piezoelectric precision loading unit (2), a large-stroke piezoelectric coarse feeding unit (3), a two-way force sensor unit (4), a stage (5), and a piezoelectric precision scratching unit (6); the piezoelectric precision loading unit (2) consists of a flexure hinge (201) and a piezoelectric stack (202), and is fixed on the base (1) by bolts; the large-stroke piezoelectric coarse feeding unit (3) is composed of a z-axis stick-slip piezoelectric actuator (301) and a connecting part A (302), and is connected to the piezoelectric precision loading unit (2) by bolts; the two-way force sensor unit (4) consists of a two-way force sensor (401), a diamond indenter (402), and a connecting part B (403), and is fixed on the large-stroke piezoelectric coarse feeding unit (3) by bolts; the stage (5) is composed of a "Ji"-shaped structural part (501) with an observation window in the middle and a connecting plate (502), and is fixed on the piezoelectric precision scratching unit (6) by bolts; the diamond indenter (402) on the two-way force sensor unit (4) is located inside the "Ji"-shaped structural part (501); the piezoelectric precision scratching unit (6) consists of an x-axis stick-slip piezoelectric actuator (601) and a y-axis stick-slip piezoelectric actuator (602), and is fixed on the base (1) by bolts.
2. A method for conducting in-situ micro / nano scratch testing under an optical microscope using the in-situ micro / nano scratch testing device under an optical microscope as described in claim 1, characterized in that... It includes the following steps: 1) Paste the specimen on the upper surface of the "Ji"-shaped structural part (501) through double-sided tape, then place the in-situ micro-nano scratching test device on the stage of the optical microscope, and then turn on the optical microscope; 2) Adjust the position of the optical microscope lens so that the focus is located at the lower surface of the specimen; 3) Start the in-situ micro-nano scratching test device described in claim 1, select appropriate motion parameters to make the diamond indenter (402) move upward to contact the specimen, and find the contact point between the diamond indenter (402) and the specimen through the optical microscope image, and determine its position in the field of view; 4) Adjust the position of the optical microscope stage so that the contact point between the diamond indenter (402) and the specimen is at the center of the field of view, and select an appropriate magnification to observe the contact state between the material and the diamond indenter (402) during the scratching process; 5) Control the piezoelectric precision loading unit (2) to make the diamond indenter (402) move downward to leave the specimen, and control the piezoelectric precision scratching unit (6) to move the stage (5) until the contact point described in step 3) leaves the field of view, and complete the adjustment of the observation position; 6) Control the large-stroke piezoelectric coarse feeding unit (3) to make the diamond indenter (402) move upward until the diamond indenter (402) contacts the lower surface of the specimen; 7) Control the piezoelectric precision loading unit (2) to move upward to achieve the precision indentation of the diamond indenter (402) into the specimen; 8) Select appropriate motion parameters to make the piezoelectric precision scratching unit (6) move along the x-axis direction for scratching. The two-way force sensor (401) measures the axial force and transverse force between the diamond indenter (402) and the specimen, and at the same time obtains the contact state between the material and the diamond indenter (402) during the scratching process through the image of the optical microscope. 9) After the scribing process is completed, control the piezoelectric precision loading unit (2) to move the diamond indenter (402) downward away from the sample to complete the unloading process.
3. The method for in-situ micro / nano scratch testing under an optical microscope according to claim 2, characterized in that: The sample described in steps 1)-9) is a transparent material or a coated material with a transparent material as the base.