Device and method for testing indentation and scratch of material under composite energy field

Abstract

The invention relates to the technical field of material mechanical property testing, and discloses a material indentation and scratch testing device and method under a composite energy field, and the device comprises a supporting experiment table, a vertical micro-motion platform, a horizontal micro-motion platform, a high-definition optical microscope, a force sensor, a displacement sensor and an additional energy field generation system. According to the method, a controllable additional energy field is synchronously applied while a mechanical indentation or scratch load is applied to a hard and brittle material sample, and load displacement data is collected in real time. In the data processing stage, the real hardness is calculated by adopting a corrected proportion sample resistance model, the elastic modulus is calculated based on the Oliver-Pharr theory, and the fracture toughness of the material is analyzed and calculated according to the size of the indentation tip crack. The problem that in-situ mechanical property characterization cannot be carried out in a composite energy field in a traditional test is solved, the hardness calculation precision is improved, the fracture toughness measurement function is expanded, and the experimental device and method are provided for research of a hard and brittle material composite machining mechanism.

Description

Technical Field

[0001] This invention relates to the field of material mechanical property testing technology, specifically to a device and method for testing material indentation and scratches under a composite energy field. Background Technology

[0002] High-performance ceramics and their composites, due to their high strength, high hardness, and wear resistance, have wide applications in aerospace, advanced manufacturing, and other fields. However, the high hardness of these materials also makes them typical difficult-to-machine materials, and the lack of efficient and precise machining technologies restricts their application. Composite machining technology, which introduces one or more additional energy fields such as lasers, electrical discharges, or plasmas during machining, is an important development direction for improving the processing efficiency and quality of these materials.

[0003] In composite machining processes, the coupling effect of multiple energy fields makes the material removal mechanism more complex than in traditional machining. A deep understanding of the material deformation behavior and mechanical properties under the influence of composite energy fields is crucial for revealing the machining mechanism and optimizing process parameters. Indentation and scratch testing are conventional methods for characterizing the hardness, elastic modulus, and fracture toughness of materials, and are widely used to study the surface deformation mechanisms of materials in traditional grinding and polishing processes.

[0004] However, existing microindentation and scratch testing devices and methods are primarily designed for testing under single mechanical load conditions. These existing technologies typically lack the ability to simultaneously and controllably apply an additional energy field (such as a thermal or electromagnetic field) to the same micro-region of the hard and brittle material specimen during the mechanical loading process of indentation or scratching. Therefore, they cannot reproduce the true physical environment of composite processing and struggle to obtain in-situ mechanical property parameters and deformation behavior data of materials under the influence of composite energy fields. This presents a technical obstacle to in-depth research into the mechanism of composite processing. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a device and method for testing material indentation and scratches under a composite energy field, which solves the problem that existing technologies cannot perform in-situ testing of the mechanical properties and deformation behavior of materials under simulated composite energy field conditions.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution.

[0007] The first aspect of the present invention provides a material indentation and scratch testing device under a composite energy field, comprising: Support experimental platform; A vertical micro-motion platform is fixed to the supporting experimental table by a vertical clamp, and a Vickers diamond indenter is installed on it; A clamp is mounted on the vertical clamp and is used to clamp a high-definition optical microscope; A horizontal micro-motion platform is set on the supporting experimental platform, located below the Vickers diamond indenter, and is used to realize horizontal movement; A force sensor is mounted on the horizontal micro-motion platform; An insulated and heat-insulated worktable is positioned above the force sensor to support hard and brittle material samples. A displacement sensor is used to measure the vertical displacement of the vertical micro-motion platform; Additional energy field generating device; and an end effector assembly, which is fixed to the horizontal micro-motion platform by a support clamp, the end effector assembly comprising: At least one end effector, selected from a copper wire electrode, a laser head, or a plasma head; Furthermore, when the end effector is the copper wire electrode, the end effector assembly also includes an electrode servo feeding mechanism, which is mounted on the fixture and is used to feed the copper wire electrode in real time during the discharge process to compensate for its loss.

[0008] Preferably, the vertical micro-motion platform on which the Vickers diamond indenter is mounted and the fixture on which the high-definition optical microscope is mounted are both placed on the same vertical fixture, so that the Vickers diamond indenter and the high-definition optical microscope have a fixed spatial relative position, so that the test point and the observation point can be accurately switched by moving the horizontal micro-motion platform before and after the test without re-clamping the sample.

[0009] Preferably, when the energy field is applied using the copper wire electrode, the hard and brittle material sample is fixed on the insulating and heat-resistant workbench by a metal clamp, and a preset discharge gap is maintained between the copper wire electrode and the hard and brittle material sample; during the discharge process, the metal clamp also serves as an electrode connecting the pulse discharge circuit.

[0010] Preferably, the force sensor is positioned between the horizontal micro-motion platform and the insulated worktable to directly measure the normal force applied to the hard and brittle material sample. This structure separates the force measurement system from the vertical motion system, improving measurement stability.

[0011] A second aspect of the present invention provides a method for testing material deformation and mechanical properties under a composite energy field using the apparatus described in any of the preceding claims, the method comprising the following steps: a) The hard and brittle material sample is clamped on the horizontal micro-motion platform; b) Activate the additional energy field generation system to apply an additional energy field to the test area of ​​the sample; c) Drive the vertical micro-motion platform and / or the horizontal micro-motion platform to perform indentation or scratch testing on the sample; d) During the test, load and displacement data are recorded in real time using the force sensor and displacement sensor; e) After the test, the geometric dimensions of the residual morphology are observed and measured using the high-definition optical microscope; f) Based on the recorded data and measured dimensions, calculate the mechanical property parameters of the material, including the actual hardness of the material. Elastic modulus and fracture toughness At least one of them must be calculated.

[0012] In one specific embodiment, the calculated material's true hardness The steps include: First, under the same composite energy field conditions, indentation experiments were conducted using at least five different maximum loading loads to obtain multiple sets of maximum loads. Average length of the corresponding residual indentation diagonal Data; Then, the multiple groups Substituting the data into the resistance model of the modified proportional hard and brittle material sample 5, a nonlinear fitting was performed. The model expression is as follows: ; in, For maximum load, The length of the diagonal of the residual indentation. , and These are the coefficients obtained from the fitting; Finally, the coefficients of the quadratic term obtained from the fitting are... The value of is used as the true hardness of the material to eliminate the influence of indentation size effect. The true hardness of the material surface under the action of a composite energy field: .

[0013] In one specific embodiment, the elastic modulus of the calculated material The steps include: First, starting from the initial portion of the unloading segment of the recorded load-displacement curve, we differentiate... Calculate the contact stiffness ; Secondly, based on the contact stiffness Maximum load and maximum indentation depth The actual contact area between the indenter and the material is calculated. , The actual contact area between the indenter and the material: ; The actual contact depth between the indenter and the material: ; Then, the contact stiffness and actual contact area Substitution The equivalent elastic modulus of the indentation system was calculated. ; Finally, based on the equivalent elastic modulus And the known elastic modulus of the indenter material Compared to Poisson Poisson's ratio of hard and brittle material samples Through relational formulas The elastic modulus of the hard and brittle material sample was calculated. In the formula and The Poisson's ratio of the Vickers diamond indenter 12 is 0.07 and the elastic modulus is 1141 GPa.

[0014] In one specific embodiment, the fracture toughness of the calculated material The steps include: First, determine the crack type: based on the length from the indentation center to the crack tip measured under different loading loads. Or the length from the indentation apex to the crack tip ,analyze and or The relationship is used to determine whether the crack is a radial median crack system or a Palmqvist crack system; Secondly, classification calculation: if determined to be a radial-median crack system, when When, then through the formula Calculation; if determined to be a Palmqvist crack system, when When, then through the formula Calculation, where or For elastic modulus, Hardness, This is the length of the indentation diagonal.

[0015] Preferably, when performing a scratch test, the method further includes calculating the plastic strain rate of the material. The calculation formula is as follows: ,in The scratch rate is the speed at which the horizontal micro-motion platform moves. This represents the width of the residual scratch.

[0016] Preferably, the method further includes calculating the critical depth at which the hard and brittle material undergoes a brittle-plastic transition. The steps are as follows: obtain the experimental value of the critical depth through a scratch test, and then determine the elastic modulus measured under that energy field. ,hardness and fracture toughness Through formula The equivalent geometric parameters under the action of this composite energy field were obtained by fitting. For traditional indentation testing Under the influence of the energy field It can be obtained by fitting experimental and theoretical values ​​of the critical depth.

[0017] This invention provides a device and method for testing indentation and scratch marks on materials under a composite energy field. It has the following beneficial effects: 1. This invention solves the technical challenge of traditional micro-indentation or scratching devices being unable to perform in-situ mechanical property testing under combined energy fields such as lasers and electrical discharges by integrating a mechanical loading system and an additional energy field generation system. This not only expands the functionality of the device and testing method but also provides an intuitive and reliable testing device and method for cutting-edge research on material removal mechanisms in the efficient composite processing of hard and brittle materials.

[0018] 2. The testing method of this invention introduces a modified proportional sample resistance model (PSR model) to calculate hardness. This model eliminates the error caused by the inherent "indentation size effect" in traditional Vickers hardness calculations, obtaining the true hardness of the material and significantly improving the accuracy of hardness testing. Furthermore, this method proposes specific steps for calculating the fracture toughness of the material based on the crack size analysis at the indentation tip, solving the problem that traditional indentation testing cannot directly measure this key parameter.

[0019] 3. This invention utilizes a servo-driven feeding mechanism to compensate for electrode loss in real time, ensuring the stability of energy input. Furthermore, the modular fixation of the vertical micro-motion platform using independent fixtures enhances the structural stability and maintainability of the device. These structural optimizations collectively ensure the reliability of the entire testing process and the repeatability of the results under high-precision testing requirements. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] The components include: 1. Supporting experimental platform; 2. Horizontal micro-motion platform; 3. Force sensor; 4. Insulated and heat-insulating worktable; 5. Hard and brittle material sample; 6. Metal clamp; 7. High-definition optical microscope; 8. Clamp; 9. Vertical fixing clamp; 10. Displacement sensor; 11. Vertical micro-motion platform; 12. Vickers diamond indenter; 13. Electrode servo feeding mechanism; 14. Copper wire electrode; 15. Laser head; 16. Plasma head; 17. Supporting clamp; 18. Additional energy field generating device. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] See attached document Figure 1 , Figure 1 This is a schematic diagram of the overall structure of a material indentation and scratch testing device under a composite energy field according to an embodiment of the present invention. All functional components of the device are mounted on a supporting experimental platform 1, which provides a stable mounting base and working platform for the entire device.

[0024] The apparatus includes a horizontal micro-motion platform 2, which is mounted on a supporting experimental table 1 to support and fix the hard and brittle material sample 5 to be tested; and a vertical micro-motion platform 11, which is fixed to the column structure of the supporting experimental table 1 by a vertical fixing clamp 9, located above the horizontal micro-motion platform 2. A Vickers diamond indenter 12 is clamped at the lower end of the vertical micro-motion platform 11 for applying mechanical load to the hard and brittle material sample 5.

[0025] The apparatus also includes components for data acquisition and morphological observation. A force sensor 3 is mounted in series on the horizontal micro-motion platform 2 to measure the normal load. A displacement sensor 10 is fixed to the vertical fixing fixture 9 and associated with the vertical micro-motion platform 11 to measure the vertical displacement of the Vickers diamond indenter 12. A high-definition optical microscope 7 is positioned beside the Vickers diamond indenter 12 and aligned with the test area via an optical path for morphological observation and geometric dimension measurement before and after testing.

[0026] The device also includes components for applying an additional energy field. Depending on the required type of energy field, the internal pulse discharge generator and its corresponding copper wire electrode 14, laser generator and its corresponding laser head 15, or air plasma generator and its corresponding plasma head 16 can be selected and configured via a switch on the lower left side of the panel of the additional energy field generator 18; and the parameters of the energy field source can be set via the keyboard on the lower right side of the panel of the additional energy field generator 18. In addition, for pulse discharge applications, an electrode servo feeding mechanism 13 for compensating for the loss of the copper wire electrode 14 and a metal clamp 6 for fixing the hard and brittle material sample 5 are also included. The metal clamp 6 also serves as an electrode connecting the pulse discharge circuit.

[0027] Functionally, the device integrates three main functional systems and a support and control system (not shown in the figure). The three functional systems are: an indentation / scratching system, an observation and measurement system, and an additional energy field generation system.

[0028] The indentation / scratching system, consisting of a vertical micro-motion platform 11 and a horizontal micro-motion platform 2, is used to achieve precise relative movement and mechanical loading between the Vickers diamond indenter 12 and the hard and brittle material sample 5.

[0029] The observation and measurement system consists of a high-definition optical microscope 7, a displacement sensor 10, and a force sensor 3. It is used to collect load displacement data in real time during the test process and to perform subsequent morphological observation and dimensional measurement.

[0030] The additional energy field generation system consists of an additional energy field generation device 18 (containing a pulse discharge generator, laser generator, or air plasma generator), an end effector (copper wire electrode 14, laser head 15 or plasma head 16), and related auxiliary mechanisms (metal clamp 6, electrode servo feeding mechanism 13), used to simultaneously apply a controllable additional energy field to the test micro-area of ​​the hard and brittle material sample 5 while mechanically loading.

[0031] During a complete test, the support and control system coordinates the operation of all functional systems. This system receives real-time data from the observation and measurement system and, according to a preset program, issues commands to the indentation / scratching system (a) and the additional energy field generation system, controlling the platform's movement, the loading of the indenter, and the start / stop and parameters of the energy field, thereby achieving automated material mechanical property testing under the influence of a composite energy field.

[0032] The indentation / scratching system of the device mainly consists of a vertical micro-motion platform 11, a horizontal micro-motion platform 2, and an electrode servo feeding mechanism 13 used in a specific embodiment. The vertical micro-motion platform 11 is fixed to the column structure supporting the experimental table 1 by a vertical fixing clamp 9. It itself is composed of a piezoelectric ceramic actuator or a similar precision actuator to achieve nanometer or micrometer-level displacement control of the Vickers diamond indenter 12 in the vertical direction, thereby performing loading and unloading actions. The horizontal micro-motion platform 2 is driven by a servo motor in conjunction with a ball screw or linear motor, and can perform two-dimensional motion in the horizontal plane. It is used to carry the hard and brittle material sample 5 and perform uniform feed in scratch testing or area positioning before indentation testing.

[0033] The observation and measurement system of the device includes a force sensor 3, a displacement sensor 10, and a high-definition optical microscope 7. The force sensor 3 is a strain gauge or piezoelectric sensor, physically connected in series with the output end of the horizontal micro-motion platform 2. This structure ensures that it can directly measure the true normal load applied to the hard and brittle material sample 5. The displacement sensor 10 is a capacitive or grating sensor, configured to measure the real-time vertical displacement of the vertical micro-motion platform 11, which is the indentation depth of the Vickers diamond indenter 12. The high-definition optical microscope 7 has a switchable objective lens group, its optical path aligned with the test point of the Vickers diamond indenter 12, used to observe the morphology of the surface of the hard and brittle material sample 5 before and after testing, and to accurately measure geometric parameters such as the indentation diagonal, crack length, or scratch width.

[0034] The additional energy field generation system of the device is a configurable system. In one embodiment, the system is a pulse discharge system, the energy field source of which is a pulse discharge generator inside the additional energy field generation device 18, and the end effector is a copper wire electrode 14. In this embodiment, the hard and brittle material sample 5 is fixed to an insulated and heat-resistant worktable 4 on a horizontal micro-motion platform 2 by a metal clamp 6. The insulated and heat-resistant worktable 4 is made of ceramic or similar insulating and high-temperature resistant material to achieve electrical and thermal isolation between the hard and brittle material sample 5 and the conductive horizontal micro-motion platform 2. The electrode servo feeding mechanism 13 is used to clamp and drive the copper wire electrode 14 for micro-feeding to compensate for its loss during the discharge process.

[0035] In another embodiment, the additional energy field generating system is a laser system, with its energy field source being a laser generator inside the additional energy field generating device 18, and its end effector being a laser head 15. In yet another embodiment, the system's energy field source is an air plasma generator inside the additional energy field generating device 18, and its end effector is a plasma head 16. In these embodiments, the laser head 15 or plasma head 16 is fixedly mounted, and its output energy beam is precisely aligned and focused on the tiny area where the Vickers diamond indenter 12 and the hard and brittle material sample 5 are about to come into contact. The specific implementation process of the testing method described in this invention is as follows. First, test preparation is carried out, which includes cutting the hard and brittle material sample 5 to be tested, and performing metallographic grinding and polishing on its surface until its surface roughness meets the test requirements. Then, the prepared hard and brittle material sample 5 is clamped on the insulated and heat-insulating worktable 4 above the horizontal micro-motion platform 2.

[0036] After the preparation is completed, the sample is observed through a high-definition optical microscope 7, and the horizontal micro-motion platform 2 is driven to precisely move the pre-selected test area on the hard and brittle material sample 5 directly below the Vickers diamond indenter 12.

[0037] For indentation testing, the additional energy field generation system is first activated, and the energy beam (laser, plasma, or electric arc) is aligned and applied to the test area below the Vickers diamond indenter 12. Subsequently, the support and control system drives the vertical micro-motion platform 11 to descend, causing the Vickers diamond indenter 12 to press into the surface of the hard and brittle material sample 5 at a preset loading rate. Throughout the loading, holding, and unloading process, the force sensor 3 and displacement sensor 10 synchronously and continuously collect the normal load. With indentation depth The data is collected and transmitted to the control system to generate load-displacement curves. After the test, the Vickers diamond indenter 12 is removed, and the residual indentation is observed and measured using a high-definition optical microscope 7.

[0038] For the scratch test, the initial steps are the same as for the indentation test: first, an additional energy field is applied, and then the vertical micro-motion platform 11 is driven to descend, causing the Vickers diamond indenter 12 to press into the surface of the hard and brittle material sample 5 until a preset constant normal load is reached. And maintain this state. In this state, the support and control system... Simultaneously drive the horizontal micro-motion platform 2 at a constant scratching rate. The device moves along a predetermined path to the specified scratch length. After the scratching process is complete, the vertical micro-motion platform 11 drives the Vickers diamond indenter 12 to lift, completing the scratch test. The test data is also collected in real time, and after the test, the morphology and width of the residual scratch are observed and measured using a high-definition optical microscope 7.

[0039] After completing the test and obtaining the raw data, the data is processed through the following steps, and the various mechanical property parameters of the material are calculated.

[0040] For the true hardness of materials The calculations first involved performing at least five indentation tests with different maximum loading loads under the same composite energy field conditions, and measuring the average diagonal length of the residual indentation corresponding to each test group. Thus, multiple sets of data points are obtained. Subsequently, these data points were substituted into the drag model of the modified proportional hard-brittle material sample for nonlinear fitting. The expression of the model is: ; In this expression, For maximum load, The length of the diagonal of the residual indentation. , and These are the coefficients obtained from the fitting. After fitting, the coefficients of the quadratic term are extracted. The value of is defined as the true hardness of the material after excluding the influence of indentation size effect. The true hardness of the material surface under the action of a composite energy field: .

[0041] For the elastic modulus of materials The calculation first selects the initial data of the unloading phase from the load-displacement curve recorded in the indentation test. Then, by differentiating this portion of data, ... The contact stiffness was calculated. Then, based on the calculated contact stiffness... The maximum load applied during the test and maximum indentation depth The actual contact area between the indenter and the material is calculated using a given indenter geometry function. , The actual contact area between the indenter and the material: ; The actual contact depth between the indenter and the material: .

[0042] In obtaining contact stiffness and actual contact area Then, the equivalent elastic modulus of the indentation system is calculated using the following formula. : ; Finally, based on the equivalent elastic modulus And the known elastic modulus of the indenter material Compared to Poisson Poisson's ratio of hard and brittle material samples The elastic modulus of the hard and brittle material sample 5 was calculated using the following formula. : ; in, and The Poisson's ratio for the Vickers diamond indenter is 0.07 and the elastic modulus is 1141 GPa.

[0043] For the fracture toughness of materials The first step in the calculation is to determine the type of crack induced by indentation. This will be done under different loading loads. The length measured from the center of the indentation to the tip of the crack. Or the length from the indentation apex to the crack tip ,analyze and or The relationship is described. Based on the specific form of this functional relationship, the crack system is determined to be either a radial-median crack system or a Palmqvist crack system. If it is determined to be a radial-median crack system, when... When, the formula is used. Perform calculations. If the system is determined to be a Palmqvist crack system, when... At that time, among them For the Meyer index, the formula is used. Perform the calculation. The formula contains... or Given the obtained elastic modulus, For the actual hardness that has been obtained, This is the length of the indentation diagonal.

[0044] During scratch testing, the plastic strain rate of the material can be further calculated. The calculation formula is as follows: ,in The scratch rate is the speed at which the horizontal micro-motion platform 2 moves. The width of the residual scratch is measured using a high-resolution optical microscope 7. Furthermore, the method of this invention can also be used to determine the critical depth at which a hard-brittle material undergoes a brittle-ductile transition. The critical depth at which this transition occurs was observed and recorded through scratch experiments, and combined with the elastic modulus calculated under this combined energy field condition. ,hardness and fracture toughness Substitute into the formula The equivalent geometric parameters under the action of the composite energy field were finally determined through fitting. For traditional indentation testing Under the influence of the energy field It can be obtained by fitting experimental and theoretical values ​​of the critical depth.

Claims

1. A material indentation and scratch testing device under a composite energy field, characterized in that, include: Supporting experimental platform (1); A vertical micro-motion platform (11) is fixed on the supporting experimental table (1) by a vertical clamp (9), and a Vickers diamond indenter (12) is installed on it. The clamp (8) is mounted on the vertical clamp (9) and is used to clamp the high-definition optical microscope (7). A horizontal micro-motion platform (2) is set on the supporting experimental platform (1), located below the Vickers diamond indenter (12), and is used to realize horizontal movement; Force sensor (3) is mounted on the horizontal micro-motion platform (2); An insulated and heat-insulating workbench (4) is set above the force sensor (3) and is used to support hard and brittle material samples (5). A displacement sensor (10) is used to measure the vertical displacement of the vertical micro-motion platform (11); Additional energy field generating device (18); and an end effector assembly, which is fixed to the horizontal micro-motion platform (2) by a support clamp (17), the end effector assembly comprising: At least one end effector is selected from a copper wire electrode (14), a laser head (15), or a plasma head (16). Furthermore, when the end effector is the copper wire electrode (14), the end effector assembly also includes an electrode servo feeding mechanism (13), which is mounted on the fixture (8) and is used to feed the copper wire electrode (14) in real time during the discharge process to compensate for its loss.

2. The material indentation and scratch testing device under a composite energy field according to claim 1, characterized in that, The vertical micro-motion platform (11) on which the Vickers diamond indenter (12) is mounted and the fixture (8) on which the high-definition optical microscope (7) is mounted are both placed on the same vertical fixture (9), so that the Vickers diamond indenter (12) and the high-definition optical microscope (7) have a fixed spatial relative position, so that the test point and the observation point can be accurately switched by moving the horizontal micro-motion platform (2) before and after the test without re-clamping the sample.

3. The material indentation and scratch testing device under a composite energy field according to claim 1, characterized in that, When the energy field is applied using the copper wire electrode (14), the hard and brittle material sample (5) is fixed on the insulating and heat-insulating workbench (4) by the metal clamp (6), and a preset discharge gap is maintained between the copper wire electrode (14) and the hard and brittle material sample (5); during the discharge process, the metal clamp (6) also serves as an electrode to connect the pulse discharge circuit.

4. The material indentation and scratch testing device under a composite energy field according to claim 1, characterized in that, The force sensor (3) is positioned between the horizontal micro-motion platform (2) and the insulated and heat-insulating worktable (4) to directly measure the normal force applied to the hard and brittle material sample (5). This structure separates the force measurement system from the vertical motion system, thereby improving measurement stability.

5. A test method for the apparatus as described in any one of claims 1 to 4, characterized in that, Includes the following steps: a) The hard and brittle material sample (5) is clamped on the horizontal micro-motion platform (2); b) Activate the additional energy field generating device (18) to apply an additional energy field to the test area of ​​the hard and brittle material sample (5); c) Drive the vertical micro-motion platform (11) and / or the horizontal micro-motion platform (2) to perform indentation or scratch testing on the hard and brittle material sample (5); d) During the test, load and displacement data are recorded in real time using the force sensor (3) and displacement sensor (10); e) After the test, the geometric dimensions of the residual morphology are observed and measured using the high-definition optical microscope (7); f) Calculate the material's mechanical properties based on the recorded data and measured dimensions, including the calculation of the material's true hardness. Elastic modulus and fracture toughness At least one of them must be calculated.

6. The method according to claim 5, characterized in that, The calculated true hardness of the material The steps include: S1. Under the same composite energy field conditions, indentation experiments were conducted using at least five different maximum loading loads to obtain multiple sets of maximum loads. Average length of the corresponding residual indentation diagonal Data; S2, the multiple groups Substitute the data into the following modified proportional hard and brittle material sample resistance model for nonlinear fitting: ； in, For maximum load, The length of the diagonal of the residual indentation. , and These are the coefficients obtained from the fitting; S3. Obtain the coefficients of the quadratic term from the fitted sample. The value of is used as the true hardness of the material to eliminate the influence of indentation size effect. The true hardness of the material surface under the action of a composite energy field: .

7. The method according to claim 5, characterized in that, The elastic modulus of the calculated material The steps include: From the initial portion of the unloading segment of the recorded load-displacement curve, by differentiation... Calculate the contact stiffness ; According to the contact stiffness Maximum load and maximum indentation depth The actual contact area between the indenter and the material is calculated. , The actual contact area between the indenter and the material: ; The actual contact depth between the indenter and the material: ; The contact stiffness and actual contact area Substituting into the following formula, the equivalent elastic modulus of the indentation system can be calculated. : ； Based on the equivalent elastic modulus And the known elastic modulus of the indenter material Compared to Poisson Poisson's ratio of 5 hard and brittle material samples The elastic modulus of the hard and brittle material sample (5) was calculated using the following formula. : In the formula and The Poisson's ratio for the Vickers diamond indenter is 0.07 and the elastic modulus is 1141 GPa.

8. The method according to claim 5, characterized in that, The fracture toughness of the calculated material The steps include: Determining crack type: based on different loading loads The length measured from the center of the indentation to the tip of the crack. Or the length from the indentation apex to the crack tip ,analyze and or The relationship is used to determine whether the crack is a radial median crack system or a Palmqvist crack system; Categorical calculation: If When the system is determined to be a radial-mid-crack system, it is then determined using the formula... calculate; like At that time, it was determined to be a Palmqvist crack system, in which For the Meyer index, it is calculated using the formula... Calculation, where or For elastic modulus, Hardness This is the length of the indentation diagonal.

9. The method according to claim 5, characterized in that, When performing a scratch test, the method also includes calculating the plastic strain rate of the material. The calculation formula is as follows: ； in The scratch rate is the speed at which the horizontal micro-motion platform (2) moves. This represents the width of the residual scratch.

10. The method according to claim 8, characterized in that, The method also includes calculating the critical depth at which a hard and brittle material undergoes a brittle-plastic transition. The steps are as follows: obtain the experimental value of the critical depth through a scratch test, and then determine the elastic modulus measured under that energy field. ,hardness and fracture toughness Through formula The equivalent geometric parameters under the action of this composite energy field were obtained by fitting. For traditional indentation testing Under the influence of the energy field It can be obtained by fitting experimental and theoretical values ​​of the critical depth.

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