In-situ mechanical property testing system and method

Abstract

The invention provides an in-situ mechanical property testing system and method. The in-situ mechanical property testing system comprises a base, a force sensor and a first piezoelectric displacement module, a pressure head is arranged on a sensing part of the force sensor, a second piezoelectric displacement module is mounted on the first piezoelectric displacement module, a third piezoelectric displacement module is mounted on the second piezoelectric displacement module, and the third piezoelectric displacement module is mounted on the base. A first base is mounted on the third piezoelectric displacement module; the third piezoelectric displacement module is used for driving the first base to move in the X direction, the second piezoelectric displacement module is used for driving the third piezoelectric displacement module to move in the Z direction, and the first piezoelectric displacement module is used for driving the second piezoelectric displacement module to move in the Y direction; a sample table is mounted at the end part of the first base. Precise movement of the sample relative to the pressure head is realized by adopting the piezoelectric displacement module with nano resolution, and the advantages of small mechanical gap, low displacement error, high displacement resolution and the like are realized.

Description

Technical Field

[0001] This invention relates to the field of material mechanical property testing technology, and in particular to an in-situ mechanical property testing system and method. Background Technology

[0002] As materials science continues to delve deeper into the microscale, the study of the mechanical behavior of materials at the micro- and nano-scale has become a key pathway to revealing the intrinsic properties of materials. Traditional macroscopic mechanical testing methods have significant limitations due to scale effects. When the characteristic dimensions of materials are reduced to the micro- and nano-scale, their strength, plasticity, and deformation mechanisms often show significant differences from macroscopic mechanical testing results. Simultaneously, the real-time surface morphology and crystal structure of micro- and nano-scale samples during loading are also of great significance in materials science research.

[0003] Existing in-situ mechanical property testing devices employ transmission mechanisms such as lead screws and nuts, rolling / sliding guides, and worm gear mechanisms as the means of converting power into motion. These transmission mechanisms often suffer from problems such as mechanical backlash, friction, and multi-stage motion, and their motion accuracy, positioning accuracy, and other aspects are no longer sufficient to meet the requirements of further in-depth materials science research at the micro-nano scale.

[0004] Due to the advantages of piezoelectric ceramic elements, such as rapid response, large output force, high displacement resolution, high electromechanical conversion efficiency and compact structure, they have been used to develop a considerable number of micro-precision drive mechanisms and have broad application prospects in various fields.

[0005] Currently, in the field of nanomechanical characterization, most in-situ mechanical devices at the nanoscale employ a design scheme of high-precision MEMS sensors combined with precision piezoelectric actuators to obtain the mechanical property curves of nanoscale samples. However, current high-precision MEMS chips suffer from problems such as complex manufacturing processes, difficult packaging, small measurement range, high failure rate, and reliance on imports. This results in high production and maintenance costs for such devices, and a limited application scope, primarily applicable only to samples at the nanoscale. They cannot be effectively used for samples ranging from a few micrometers to tens of micrometers. Summary of the Invention

[0006] The purpose of this invention is to provide an in-situ mechanical property testing system and method, which uses a high-precision piezoelectric actuator to achieve high-precision in-situ mechanical property testing of microscale samples.

[0007] The technical solution of the present invention is: an in-situ mechanical performance testing system, comprising a base, a force sensor installed at one end of the base in the X direction, and a first piezoelectric displacement module installed at the other end of the base in the X direction. The force sensor is provided with a pressure head on its sensing part. A second piezoelectric displacement module is installed on the first piezoelectric displacement module through a first connecting plate. A third piezoelectric displacement module is installed on the second piezoelectric displacement module through a second connecting plate. A first base is installed on the third piezoelectric displacement module. The third piezoelectric displacement module is used to drive the first base to move along the X direction, the second piezoelectric displacement module is used to drive the third piezoelectric displacement module and the first base thereon to move along the Z direction, and the first piezoelectric displacement module is used to drive the second piezoelectric displacement module and the third piezoelectric displacement module thereon and the first base thereon to move along the Y direction. A sample stage is detachably mounted on the end of the first base, and the sample stage is correspondingly arranged with the pressure head.

[0008] Preferably, the pressure head is mounted on the force sensor sensing part via a second base.

[0009] Preferably, the second connecting plate includes a vertical plate and a horizontal plate vertically connected to the lower end of the vertical plate. The side of the vertical plate away from the horizontal plate is connected to the second piezoelectric displacement module, and the third piezoelectric displacement module is disposed on the horizontal plate.

[0010] Preferably, the base includes a base plate, a first mounting seat connected to one end of the base plate in the X direction, and a second mounting seat connected to the other end of the base plate in the X direction. The force sensor is mounted on the first mounting seat, and the first piezoelectric displacement module is mounted on the second mounting seat.

[0011] Preferably, one end of the base in the X direction is provided with a first housing, the force sensor is disposed inside the first housing, and the pressure head extends to the outside of the first housing; the other end of the base in the X direction is provided with a second housing, the first piezoelectric displacement module, the second piezoelectric displacement module, and the third piezoelectric displacement module are disposed in the second housing, and the sample stage extends to the outside of the second housing.

[0012] Preferably, the force sensor is a micro-pressure sensor.

[0013] The present invention also provides an in-situ mechanical property testing method, characterized by comprising the following steps: Step 1: Place the above-mentioned in-situ mechanical property testing system in the vacuum chamber of an electron scanning microscope; Step 2: The sample is attached to the end of the sample stage, and the sample to be tested is processed using micro-nano fabrication methods to form a sample at the micro-nano scale. Step 3: Install the sample stage onto the first base; Step four: Machin the tip of the indenter to match the micro / nano-scale sample; Step 5: Activate the first piezoelectric displacement module, the second piezoelectric displacement module, and the third piezoelectric displacement module respectively, move the sample to be tested into the field of view of the electron scanning microscope, and align the indenter with the sample; Step 6: Activate the third piezoelectric displacement module to bring the sample into contact with the indenter and generate pressure. Use an electron scanning microscope to observe and record the deformation of the sample and output the mechanical curve.

[0014] Compared with related technologies, the beneficial effects of the present invention are as follows: I. This invention uses a nanometer-resolution piezoelectric displacement module to achieve precise movement of the sample relative to the indenter. Compared with traditional mechanically driven in-situ mechanical testing devices, this invention has small mechanical gaps, low displacement errors, and high displacement resolution. Second, the present invention uses a micro-force sensor to realize the force value change during the sample deformation process. Compared with MEMS sensors, the present invention has a low failure rate, low maintenance cost, good replaceability, mature technology, wide application range, and the equipment resolution can meet the accuracy requirements of in-situ mechanical testing of microscale samples. Third, this invention adopts a modular design. According to the mechanical properties of different materials and testing requirements, different indenter sizes, micro-force sensor ranges, piezoelectric displacement module strokes and displacement resolutions can be selected, thereby achieving high flexibility in in-situ mechanical property testing of different types of materials (such as soft polymers, hard ceramics, biological tissues, etc.). Fourth, this invention, combined with electron scanning microscope imaging and subsequent data processing, can realize the detection of microstructure deformation and evolution on the surface of microscale samples under high spatial resolution microscopic environment, which is of great significance to scientific research in the fields of materials and bioengineering. Fifth, this invention fills the gap in existing testing equipment for in-situ mechanical testing of samples ranging from several micrometers to tens of micrometers in size. It is a device specifically designed to address the needs of in-situ mechanical testing of microscale samples. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the in-situ mechanical performance testing system provided by the present invention; Figure 2 This is a schematic diagram after the first and second housings are installed.

[0016] In the attached diagram: 1. Base; 101. Base plate; 102. First mounting base; 103. Second mounting base; 2. First piezoelectric displacement module; 3. First connecting plate; 4. Second piezoelectric displacement module; 5. Second connecting plate; 6. Third piezoelectric displacement module; 7. First base; 8. Screw; 9. Sample stage; 10. Indenter; 11. Second base; 12. Force sensor; 13. First outer shell; 14. Second outer shell. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0018] like Figure 1 , Figure 2 As shown, the in-situ mechanical performance testing system provided in this embodiment includes a base 1, a force sensor 12 installed at one end of the base 1 in the X direction, and a first piezoelectric displacement module 2 installed at the other end of the base 1 in the X direction. A pressure head 10 is provided on the sensing part of the force sensor 12. A second piezoelectric displacement module 4 is installed on the first piezoelectric displacement module 2 via a first connecting plate 3. A third piezoelectric displacement module 6 is installed on the second piezoelectric displacement module 4 via a second connecting plate 5. A first base 7 is installed on the third piezoelectric displacement module 6.

[0019] The third piezoelectric displacement module 6 is used to drive the first base 7 to move along the X direction, the second piezoelectric displacement module 4 is used to drive the third piezoelectric displacement module 6 and the first base 7 thereon to move along the Z direction, and the first piezoelectric displacement module 2 is used to drive the second piezoelectric displacement module 4 and the third piezoelectric displacement module 6 and the first base 7 thereon to move along the Y direction.

[0020] A sample stage 9 is detachably mounted on the end of the first base 7, and the sample stage 9 is correspondingly arranged with the pressure head 10. The pressure head 10 is mounted on the sensing part of the force sensor 12 via the second base 11.

[0021] The second connecting plate 5 includes a vertical plate 51 and a horizontal plate 52 vertically connected to the lower end of the vertical plate 51. The side of the vertical plate 51 away from the horizontal plate 52 is connected to the second piezoelectric displacement module 4, and the third piezoelectric displacement module 6 is disposed on the horizontal plate 52.

[0022] The base 1 includes a base plate 101, a first mounting base 102 connected to one end of the base plate 101 in the X direction, and a second mounting base 103 connected to the other end of the base plate 101 in the X direction. The force sensor 12 is mounted on the first mounting base 102, and the first piezoelectric displacement module 2 is mounted on the second mounting base 103. The force sensor 12 is a micro-pressure sensor.

[0023] The base 1 has a first outer shell 13 at one end in the X direction, the force sensor 12 is disposed inside the first outer shell 13, and the pressure head 10 extends to the outside of the first outer shell 13; the base 1 has a second outer shell 14 at the other end in the X direction. The first piezoelectric displacement module 2, the second piezoelectric displacement module 4, and the third piezoelectric displacement module 6 are disposed in the second outer shell 14, and the sample stage 9 extends to the outside of the second outer shell 14.

[0024] The present invention also provides an in-situ mechanical property testing method, comprising the following steps: Step 1: Place the in-situ mechanical property testing system described above into the vacuum chamber of an electron scanning microscope; Step 2: Use high-rigidity adhesive to attach the sample to the end of the sample stage 9, and use micro-nano fabrication methods to process the sample to be tested, so that the sample is formed into a micro-nano scale sample. Step three, then install the sample stage 9 onto the first base 7 using screws 8. It should be noted that during Wiener machining, the position of the sample stage 9 should be consistent with the direction in which it is fixed to the first base 7. Step four: According to the test requirements, process the tip of the indenter 10 to match the micro / nano-scale sample. For example, a cylindrical compression head for micropillar compression, or a through-groove mounting tensile head for micron-scale I-shaped tensile sample testing, etc. Step 5: Activate the first piezoelectric displacement module 2, the second piezoelectric displacement module 4, and the third piezoelectric displacement module 6 respectively, move the sample to be tested into the field of view of the electron scanning microscope, and adjust each displacement module in real time according to the microscope imaging results so that the pressure head 10 is aligned with the sample. Step 6: Activate the third piezoelectric displacement module 6 to make the sample contact the pressure head 10 to generate pressure or tension. Use an electron scanning microscope to observe and record the deformation of the sample and output the mechanical curve.

[0025] This invention overcomes the shortcomings of traditional drive devices, such as ordinary motors, lead screws, nuts, and worm gears, which are large-scale macroscopic components that are difficult to meet precision requirements and have cumulative errors. It offers advantages such as small error, high precision, and convenient control. Simultaneously, it avoids the use of MEMS sensors, employing micro-force sensors whose current range and precision are sufficient to meet the mechanical property testing needs of microscale samples. This reduces equipment manufacturing and maintenance costs while ensuring the reliability of test results and providing a wider testing range. Using this invention, in-situ tensile / compression tests can be performed on micro / nano-sized samples, and in-situ observations can be conducted on crack initiation, propagation, and fracture during the fracture process of the tested parts. This provides a more precise and scientifically effective testing device for further research on the mechanical properties of materials and the mechanisms of crack initiation and fracture.

[0026] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An in-situ mechanical performance testing system, comprising a base (1), characterized in that, It also includes a force sensor (12) installed at one end of the base (1) in the X direction and a first piezoelectric displacement module (2) installed at the other end of the base (1) in the X direction. The force sensor (12) is provided with a pressure head (10) on its sensing part. A second piezoelectric displacement module (4) is installed on the first piezoelectric displacement module (2) through a first connecting plate (3). A third piezoelectric displacement module (6) is installed on the second piezoelectric displacement module (4) through a second connecting plate (5). A first base (7) is installed on the third piezoelectric displacement module (6). The third piezoelectric displacement module (6) is used to drive the first base (7) to move along the X direction, the second piezoelectric displacement module (4) is used to drive the third piezoelectric displacement module (6) and the first base (7) thereon to move along the Z direction, and the first piezoelectric displacement module (2) is used to drive the second piezoelectric displacement module (4) and the third piezoelectric displacement module (6) thereon and the first base (7) thereon to move along the Y direction; The first base (7) is detachably mounted with a sample stage (9) at its end, and the sample stage (9) is correspondingly arranged with the pressure head (10).

2. The in-situ mechanical property testing system according to claim 1, characterized in that, The pressure head (10) is mounted on the sensing part of the force sensor (12) via the second base (11).

3. The in-situ mechanical property testing system according to claim 1, characterized in that, The second connecting plate (5) includes a vertical plate (51) and a horizontal plate (52) vertically connected to the lower end of the vertical plate (51). The side of the vertical plate (51) away from the horizontal plate (52) is connected to the second piezoelectric displacement module (4), and the third piezoelectric displacement module (6) is disposed on the horizontal plate (52).

4. The in-situ mechanical property testing system according to claim 1, characterized in that, The base (1) includes a base plate (101), a first mounting seat (102) connected to one end of the base plate (101) in the X direction, and a second mounting seat (103) connected to the other end of the base plate (101) in the X direction. The force sensor (12) is mounted on the first mounting seat (102), and the first piezoelectric displacement module (2) is mounted on the second mounting seat (103).

5. The in-situ mechanical property testing system according to claim 1, characterized in that, The base (1) has a first housing (13) at one end in the X direction, the force sensor (12) is located inside the first housing (13), and the pressure head (10) extends to the outside of the first housing (13); the base (1) has a second housing (14) at the other end in the X direction, the first piezoelectric displacement module (2), the second piezoelectric displacement module (4), and the third piezoelectric displacement module (6) are located in the second housing (14), and the sample stage (9) extends to the outside of the second housing (14).

6. The in-situ mechanical property testing system according to claim 1, characterized in that, The force sensor (12) is a micro pressure sensor.

7. An in-situ mechanical property testing method, characterized in that, Includes the following steps: Step 1: Place the in-situ mechanical property testing system as described in any one of claims 1-6 into the vacuum chamber of an electron scanning microscope; Step 2: The sample is attached to the end of the sample stage (9), and the sample to be tested is processed using micro-nano processing method to form a micro-nano scale sample. Step 3: Install the sample stage (9) onto the first base (7); Step 4: Machin the tip of the indenter (10) to match the micro-nano scale sample; Step 5: Activate the first piezoelectric displacement module (2), the second piezoelectric displacement module (4), and the third piezoelectric displacement module (6) respectively, move the sample to be tested into the field of view of the electron scanning microscope, and align the indenter (10) with the sample; Step 6: Activate the third piezoelectric displacement module (6) to make the sample contact the pressure head (10) to generate pressure. Use an electron scanning microscope to observe and record the deformation of the sample and output the mechanical curve.

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