Material indentation mechanical property testing device and method based on optical microscopy

Abstract

The invention discloses a material indentation mechanical property testing device and method based on optical microscopy, and relates to the technical field of material micromechanical property testing. The material indentation mechanical property testing device based on optical microscopy comprises an optical microscope, a transparent pressure head, a sample table, a force sensor, an observation baffle, a displacement sensor, a load loading assembly and a controller. An optical microscope, a displacement sensor and a force sensor are respectively used for acquiring an indentation image, indentation depth and indentation load in a contact state of a transparent indenter and a material in real time, and on the basis, the mechanical property of a material microcell in the indentation process of a material sample can be represented in real time; and a new technical means is provided for the technical field of material micromechanical property testing.

Description

Technical Field

[0001] The present application relates to the technical field of material microscopic mechanical property testing, and in particular to a material indentation mechanical property testing device and method based on optical microscopy. Background Art

[0002] Indentation testing technology is a common material testing method based on the elastic contact model. It characterizes the performance and quality of the material by applying a certain load and observing the deformation of the material under the load. As a non-destructive testing method, indentation testing technology does not affect the integrity of the material during testing and can test rare materials. At the same time, indentation testing technology has the characteristics of strong flexibility, wide application range and low cost. These application characteristics make indentation testing technology more feasible and valuable in application than other testing methods. It is an indispensable testing method in the fields of materials science, engineering manufacturing, etc. Therefore, the development of material testing technology can provide technical support for micro-material performance evaluation, quality control, new material research and development, intelligent manufacturing and other fields.

[0003] Normally, the indentation test applies a certain amount of static or dynamic force on the surface of the material, causing the material to deform and form an indentation. The indentation depth is used to indirectly measure the contact area and characterize the mechanical properties of the material. The more commonly used test method is the Oliver-Pharr method. As the most classic test method, the Oliver-Pharr method has been widely used in the field of materials and is an international standard test method. However, the Oliver-Pharr method can only calculate the material parameters at the maximum load, and it cannot continuously obtain the material micro-area mechanical parameters during a single indentation process. Summary of the invention

[0004] The purpose of the present application is to provide a material indentation mechanical properties testing device and method based on optical microscopy, which can characterize the elastic-plastic mechanical behavior of the material micro-region during the indentation process of the material sample in real time.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a material indentation mechanical property testing device based on optical microscopy, comprising:

[0007] Material indentation mechanical properties testing sub-device and controller;

[0008] The material indentation mechanical property testing sub-device comprises an optical microscope, a transparent indenter, a sample table, a force sensor, an observation baffle, a displacement sensor and a load loading assembly which are arranged in sequence in the same direction;

[0009] The transparent indenter is fixed directly below the optical microscope by a fixture;

[0010] The sample table is used to hold the material sample, and when the sample table holds the material sample, the material sample is located directly below the transparent pressure head;

[0011] The force sensor is located between the sample platform and the observation baffle;

[0012] The displacement sensor and the load loading assembly are both located below the observation baffle;

[0013] The load loading assembly is used to apply a loading force to the sample table, and the loading force is a force that causes the material sample to move in the direction of the transparent indenter;

[0014] The optical microscope is used to collect in real time the indentation image of the material sample each time it is pressed during the indentation test;

[0015] The force sensor is used to collect the pressing depth of each pressing in real time, wherein the pressing depth is the displacement of the observation baffle;

[0016] The displacement sensor is used to collect the pressing load of each pressing in real time;

[0017] The optical microscope, the force sensor, the displacement sensor and the load loading assembly are all connected to the controller;

[0018] The controller is used to control the load applying component and calculate the material mechanical property parameters according to the corresponding indentation image, the indentation depth and the indentation load.

[0019] In a second aspect, the present application provides a material indentation mechanical property testing method based on optical microscopy, comprising: the material indentation mechanical property testing method based on optical microscopy is implemented by the material indentation mechanical property testing device based on optical microscopy, and the material indentation mechanical property testing method based on optical microscopy comprises:

[0020] Control the load loading assembly to apply loading force to the specimen table;

[0021] Obtain the indentation image, indentation depth and indentation load of each indentation of the material sample during the indentation test;

[0022] The material mechanical property parameters are calculated according to the corresponding indentation image, the indentation depth and the indentation load.

[0023] Optionally, calculating material mechanical property parameters according to the corresponding indentation image, the indentation depth and the indentation load specifically includes:

[0024] Performing grayscale processing on the indentation image to obtain a grayscale indentation image;

[0025] Determining an indentation profile according to a pixel grayscale value and a grayscale threshold in the grayscale indentation image;

[0026] Performing edge extension on the indentation profile to obtain an expanded indentation area;

[0027] removing edge burrs of the expanded indentation area and performing smoothing processing to obtain a processed indentation image;

[0028] determining a contact area according to the processed indentation image;

[0029] Determine whether there is a false detection in the contact area, and obtain a first determination result;

[0030] If the first judgment result is yes, then filling the holes and cracks in the processed indentation image to obtain a filled indentation image;

[0031] Taking the filled processed indentation image as a new processed indentation image, and returning to the step of “determining the contact area according to the processed indentation image”;

[0032] If the first judgment result is no, calculating the contact depth according to the contact area;

[0033] Calculating the elastic deformation depth according to the contact depth and the corresponding indentation depth;

[0034] The material mechanical property parameters are calculated according to the indentation depth, the indentation load, the contact area, the contact depth and the elastic deformation depth.

[0035] Optionally, the material mechanical property parameters include stiffness, hardness and reduced modulus of the material; the specific calculation process of the stiffness includes:

[0036] The stiffness is calculated according to the pressing load and the elastic deformation depth corresponding to each pressing.

[0037] Optionally, the specific calculation process of the hardness includes:

[0038] The hardness at different indentation depths is calculated according to the indentation load and the contact area corresponding to each indentation, wherein the contact area and the indentation depth have a one-to-one correspondence.

[0039] Optionally, the specific calculation process of the reduced modulus includes:

[0040] The reduced modulus is calculated according to the pressing load, the elastic deformation depth and the contact area corresponding to each pressing.

[0041] Optionally, after executing the step of “calculating material mechanical property parameters according to the corresponding indentation image, the indentation depth and the indentation load”, the material indentation mechanical property testing method based on optical microscopy further includes:

[0042] According to the corresponding contact depth, the pressing depth and the elastic deformation depth, judging whether the material sample has a bulging phenomenon, and obtaining a second judgment result;

[0043] When the second judgment result is yes, the plastic uplift parameter of the material sample under the uplift phenomenon is calculated according to the contact depth, the indentation depth, the elastic deformation depth and the indentation load.

[0044] Optionally, the stiffness is calculated as follows:

[0045] S=P / h s ;

[0046] Where S represents stiffness; P represents the indentation load; h s Indicates the elastic deformation depth.

[0047] Optionally, the calculation formula of the hardness is:

[0048] H=P / A c ;

[0049] Where H represents hardness; P represents indentation load; A c Represents the contact area.

[0050] Optionally, the calculation formula of the reduced modulus is:

[0051]

[0052] Among them, E r represents the reduced modulus; S represents the stiffness; β represents the constant; A c Represents the contact area.

[0053] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0054] The present application provides a material indentation mechanical property testing device and method based on optical microscopy. The material indentation mechanical property testing device includes an optical microscope, a transparent indenter, a sample table, a force sensor, an observation baffle, a displacement sensor, a load loading assembly and a controller. During the indentation test of the material sample using the transparent indenter, the indentation image, the indentation depth and the indentation load under the contact state between the transparent indenter and the material are respectively collected in real time by the optical microscope, the displacement sensor and the force sensor. Based on this, the mechanical properties of the material micro-area of ​​the material sample during the indentation process can be characterized in real time, providing a new technical means for the technical field of material microscopic mechanical property testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 A schematic diagram of the structure of a material indentation mechanical properties testing device based on optical microscopy provided in an embodiment of the present application;

[0057] Figure 2 A schematic diagram of the process of the material indentation mechanical property testing method based on optical microscopy provided in an embodiment of the present application;

[0058] Figure 3 Schematic diagram of the relationship between the indentation load and the contact depth during the indentation process in the embodiment of the present application;

[0059] Figure 4 This is a schematic diagram of the actual contact area of ​​the indenter at different indentation depths under an optical microscope in an embodiment of the present application;

[0060] Figure 5 Schematic diagram of the corresponding relationship between the actual contact area and the contact depth during the indentation process in the embodiment of the present application

[0061] Figure 6 Schematic diagram of the relationship between the indentation load and the elastic deformation depth during the indentation process in the embodiment of the present application;

[0062] Figure 7 A schematic diagram of the relationship between the pressing load and the actual contact area in the embodiment of the present application;

[0063] Figure 8 It is a schematic diagram of the indentation cross section during the indentation process in the embodiment of the present application.

[0064] Reference numerals:

[0065] 1- optical microscope; 2- transparent indenter; 3- material sample; 4- force sensor; 5- displacement sensor; 6- fixture; 7- sample table; 8- observation baffle; 9- piezoelectric stack; 10- flexible hinge. DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0067] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0068] like Figure 1 As shown, an embodiment of the present application provides a material mechanical parameter indentation testing device based on high-resolution optical microscopy, comprising:

[0069] Material indentation mechanical properties testing sub-device and controller.

[0070] The material indentation mechanical property testing sub-device comprises an optical microscope (1), a transparent indenter (2), a sample table (7), a force sensor (4), an observation baffle (8), a displacement sensor (5) and a load loading assembly which are arranged in sequence in the same direction, wherein the optical microscope (1) of this embodiment is a high-resolution optical microscope, and the load loading assembly comprises a piezoelectric stack (9) and a flexible hinge (10), wherein the piezoelectric stack (9) is connected to the flexible hinge (10), and the flexible hinge (10) is connected to the observation baffle (8).

[0071] The transparent indenter (2) is fixed directly below the optical microscope (1) via a clamp (6).

[0072] The sample table (7) is used to hold a material sample (3); when the sample table (7) holds the material sample (3), the material sample (3) is located directly below the transparent indenter (2), and the polished surface of the material sample (3) faces the transparent indenter (2) and the optical microscope (1).

[0073] The force sensor (4) is located between the sample platform (7) and the observation baffle (8).

[0074] The displacement sensor (5) and the load loading assembly are both located below the observation baffle (8).

[0075] The load loading assembly is used to apply a loading force to the sample platform (7), wherein the loading force is a force causing the material sample (3) to move in a direction toward the transparent pressure head (2).

[0076] The optical microscope (1) is used to collect in real time an indentation image of the material sample (3) each time it is pressed during an indentation test.

[0077] The force sensor (4) is used to collect the pressing depth of each pressing in real time, wherein the pressing depth is the displacement of the observation baffle (8).

[0078] The displacement sensor (5) is used to collect the pressing load of each pressing in real time. The displacement sensor (5) of this embodiment is a capacitive displacement sensor.

[0079] The optical microscope (1), the force sensor (4), the displacement sensor (5) and the piezoelectric stack (9) in the load-applying assembly are all connected to the controller.

[0080] The controller is used to control the piezoelectric stack so that the piezoelectric stack (9) can drive the flexible hinge (10) to perform motion loading on the sample table (7), and calculate the material mechanical property parameters based on the obtained indentation image, the indentation depth and the indentation load.

[0081] The material indentation mechanical property testing device provided in this embodiment drives the flexible hinge (10) to move and load the sample table (7) through the piezoelectric stack (9), so that the material sample (3) is fed to the transparent indenter (2). At the same time, the indentation process is synchronously observed in real time through the transparent indenter (2) using an optical microscope (1) to obtain indentation image information (i.e., indentation image) corresponding to any indentation depth, and the displacement sensor (5) and the force sensor (4) are used to respectively obtain the indentation depth h corresponding to the i-th acquisition of the indentation image. i and the indentation load P i Based on the image information, by processing the indentation image, the contact area A under any indentation load can be obtained. ci , combined with the indenter area function to process the contact area, the contact depth h under any indentation load can be obtained ci , calculation is performed based on the indentation depth, indentation load, contact area and / or contact depth, and the material mechanical property parameters of the material sample (3) under different indentation loads can be obtained in real time.

[0082] The device provided in this embodiment can also use the indentation image, the indentation depth and the indentation load to calculate the plastic uplift parameters when the material sample (3) undergoes uplift.

[0083] Another embodiment of the present application provides a material indentation mechanical property testing method based on optical microscopy. The material indentation mechanical property testing method based on optical microscopy is Figure 1 The material indentation mechanical properties testing device based on optical microscopy is implemented, and the material indentation mechanical properties testing method based on optical microscopy includes:

[0084] Control the load loading assembly to apply loading force to the specimen table.

[0085] The indentation image, indentation depth and indentation load of the material sample are obtained each time during the indentation test.

[0086] The material mechanical property parameters are calculated according to the corresponding indentation image, the indentation depth and the indentation load.

[0087] In order to make the use of the above device and the specific implementation process of the above method more clear to those skilled in the art, the following combined Figure 2-Figure 8 To explain.

[0088] See also Figure 2 , the material indentation mechanical properties test methods include:

[0089] Step 1: Select a rectangular material sample (3), clean the surface of the sample to be pressed with alcohol and water, and grind and polish it with a polishing disk to make the surface smooth and flat to reduce measurement errors.

[0090] Step 2: fix the transparent indenter (2) under the high-resolution optical microscope (1) through a clamp (6), and fix the material sample (3) on the sample table (7).

[0091] Step 3: The material sample (3) is located below the transparent indenter (2), the sample table (7) is parallel to the horizontal plane, and the intended indentation position of the material sample (3) can be directly observed through the high-resolution optical microscope (1). The focal length of the high-resolution optical microscope (1) is adjusted so that the tip of the transparent indenter (2) can be directly observed through the high-resolution optical microscope (1).

[0092] Step 4: energize the piezoelectric stack (9), and control the piezoelectric stack (9) through a controller to drive the flexible hinge (10) to apply a load to the observation baffle (8) until the material sample (3) and the surface of the transparent indenter (2) are in contact with each other, and the loading direction is the direction in which the sample platform (7) moves toward the transparent indenter (2).

[0093] Step 5: Figure 3As shown, an indentation test is performed on the sample (3). Before the test, the capacitive displacement sensor (5) and the force sensor (4) are zeroed. A high-resolution optical microscope (1) is used to obtain an image of the contact area through the transparent indenter (2) to obtain an indentation image. The actual indentation depth obtained by the displacement sensor (5) when the i-th indentation image is obtained (i-th feed) during the indentation process is recorded as h. i (i.e., the penetration depth), the penetration load obtained by the force sensor (4) is P i , record the indentation image, indentation depth and indentation load corresponding to each feeding time period.

[0094] Step 6: Perform weighted averaging on each pixel in the indentation image obtained in step 5 to achieve the conversion from color image to grayscale image and obtain a grayscale indentation image. Select a grayscale value threshold, and determine the approximate outline of the indentation by comparing the grayscale value of the pixel in the grayscale indentation image with the threshold; perform edge extension on the indentation outline (extend from the edge outward) to fill the indentation hole and connect the incomplete area to form a complete area, and obtain the expanded indentation area; remove the edge burrs of the expanded indentation area and smooth the boundary to obtain a processed indentation image with clear edges and complete area, such as Figure 4 The actual contact area A is obtained by calibrating the processed indentation image. ci (i.e., contact area) and determines whether there is a false detection in the actual contact area. If so, the holes and cracks in the image are filled and the recognition process is repeated while retaining the overall structure of the original shape.

[0095] Step 7: Figure 5 As shown, the actual contact area A is calculated using the area function of the transparent indenter used. c Convert to contact depth h c The contact depth h at any stopping time is obtained by using the indenter area function and the actual contact area obtained in step 6. ci (Contact depth corresponding to the i-th feed), the relationship between contact depth and indentation load is as follows Figure 3 shown.

[0096] Step 8: Figure 6 As shown, it is known that each indentation depth satisfies the relationship at different stages: c =hh s , using the indentation depth h obtained in step 5 i The contact depth h obtained in step 7 ci , can synchronously obtain h in any time period si , which corresponds to the relationship between load and elastic deformation depth, according to the formula S = P / h s or S n =P n / h sn, based on the obtained elastic deformation depth and load relationship, the indentation stiffness (i.e., rigidity) can be characterized in real time.

[0097] Step 9: Figure 7 As shown, the actual contact area A obtained in step 7 is ci The contact depth h obtained in step 8 ci One-to-one correspondence, combined formula H = P / A c or H n =P n / A cn , can simultaneously characterize the indentation hardness (i.e. material hardness) at any indentation depth. In addition, based on the contact stiffness S obtained in step eight and the actual contact area A obtained in step six c , the material reduced modulus can be continuously characterized by the following formula or β is a constant related to the geometry of the indenter: for the Bohr indenter, β=1.034; for the Vickers indenter, β=1.012.

[0098] It has been found through research that the existing Oliver-Pharr method cannot accurately characterize the actual mechanical properties of the material when the bulge phenomenon occurs. In order to solve this technical problem, the material indentation mechanical property testing method provided in this embodiment also includes:

[0099] Step 10: Use h obtained in step 5 and h obtained in step 7 c and h obtained in step 8 s , determine whether the material sample (3) has bulged. When hh c ≠h s When the material sample (3) produces a bulge phenomenon. When the bulge phenomenon occurs, according to h s +h c -h=f(σ / E) characterizes the plastic uplift parameter at each indentation depth, where σ is the yield strength of the material and E is the elastic modulus of the material.

[0100] The material indentation mechanical property testing device and method provided in this embodiment solves the problems that the existing micro-nano indentation quasi-static testing method cannot continuously obtain the mechanical parameters of the material micro-area in a single indentation process, the elastic deformation depth that the existing micro-nano indentation testing method cannot directly obtain, and the test errors caused by the material bulge phenomenon. This embodiment can characterize the multiple mechanical properties of the material under any load in the loading process in real time by synchronously recording the actual contact area between the transparent indenter and the material sample and the indentation depth of the transparent indenter in the indentation process based on the displacement sensor and the high-resolution optical microscope, and can continuously obtain the elastic-plastic mechanical parameters of the material micro-area under each load in a single indentation process, and quantitatively characterize the bulge phenomenon, which will enable the indentation testing technology to have the ability to directly characterize the elastic-plastic mechanical behavior of the material micro-area, further expand the accuracy and application scope of the indentation testing technology, and provide a new technical means for the field of material micro-mechanical property testing technology. Compared with the existing testing technology, this embodiment has the advantages of rich test information and more accurate test results, and is also highly versatile for testing materials.

[0101] This embodiment uses a transparent indenter to perform an indentation test on the sample, uses an optical microscope to observe the contact state of the transparent indenter and the material in real time, and simultaneously obtains the actual indentation depth and the actual contact area, which can characterize the elastic-plastic mechanical behavior of the material micro-area during the indentation process in real time. Compared with the existing testing technology, this embodiment can obtain the material stiffness under any load during the loading process through the contact area synchronously obtained by the indentation test. This embodiment has the advantages of simple operation steps and strong versatility, and has broad application prospects in the field of material micromechanical property testing technology.

[0102] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A material indentation mechanical properties testing device based on optical microscopy, characterized in that: The material indentation mechanical properties testing device based on optical microscopy comprises: Material indentation mechanical properties testing sub-device and controller; The material indentation mechanical property testing sub-device comprises an optical microscope, a transparent indenter, a sample table, a force sensor, an observation baffle, a displacement sensor and a load loading assembly which are arranged in sequence in the same direction; The transparent indenter is fixed directly below the optical microscope by a fixture; The sample table is used to hold the material sample, and when the sample table holds the material sample, the material sample is located directly below the transparent pressure head; The force sensor is located between the sample platform and the observation baffle; The displacement sensor and the load loading assembly are both located below the observation baffle; The load loading assembly is used to apply a loading force to the sample table; the loading force is a force that causes the material sample to move in the direction of the transparent indenter; The optical microscope is used to collect in real time the indentation image of the material sample each time it is pressed during the indentation test; The force sensor is used to collect the pressing depth of each pressing in real time, wherein the pressing depth is the displacement of the observation baffle; The displacement sensor is used to collect the pressing load of each pressing in real time; The optical microscope, the force sensor, the displacement sensor and the load loading assembly are all connected to the controller; The controller is used to control the load applying component and calculate the material mechanical property parameters according to the corresponding indentation image, the indentation depth and the indentation load.

2. A material indentation mechanical property testing method based on optical microscopy, characterized in that: The material indentation mechanical property testing method based on optical microscopy is implemented by the material indentation mechanical property testing device based on optical microscopy according to claim 1, and the material indentation mechanical property testing method based on optical microscopy comprises: Control the load loading assembly to apply loading force to the specimen table; Obtain the indentation image, indentation depth and indentation load of each indentation of the material sample during the indentation test; The material mechanical property parameters are calculated according to the corresponding indentation image, the indentation depth and the indentation load.

3. The material indentation mechanical property testing method based on optical microscopy according to claim 2, characterized in that: Calculating material mechanical property parameters according to the corresponding indentation image, the indentation depth and the indentation load specifically includes: Performing grayscale processing on the indentation image to obtain a grayscale indentation image; Determining an indentation profile according to a pixel grayscale value and a grayscale threshold in the grayscale indentation image; Performing edge extension on the indentation profile to obtain an expanded indentation area; removing edge burrs of the expanded indentation area and performing smoothing processing to obtain a processed indentation image; determining a contact area according to the processed indentation image; Determine whether there is a false detection in the contact area, and obtain a first determination result; If the first judgment result is yes, then filling the holes and cracks in the processed indentation image to obtain a filled indentation image; The filled indentation image is used as a new processed indentation image, and the process returns to the step of "determining the contact area according to the processed indentation image"; If the first judgment result is no, calculating the contact depth according to the contact area; Calculating the elastic deformation depth according to the contact depth and the corresponding indentation depth; The material mechanical property parameters are calculated according to the indentation depth, the indentation load, the contact area, the contact depth and the elastic deformation depth.

4. The material indentation mechanical property testing method based on optical microscopy according to claim 3 is characterized in that: The material mechanical property parameters include the material's stiffness, hardness and reduced modulus; the specific calculation process of the stiffness includes: The stiffness is calculated according to the pressing load and the elastic deformation depth corresponding to each pressing.

5. The material indentation mechanical property testing method based on optical microscopy according to claim 4, characterized in that: The specific calculation process of the hardness includes: The hardness at different indentation depths is calculated according to the indentation load and the contact area corresponding to each indentation, wherein the contact area and the indentation depth have a one-to-one correspondence.

6. The material indentation mechanical property testing method based on optical microscopy according to claim 4, characterized in that: The specific calculation process of the reduced modulus includes: The reduced modulus is calculated according to the pressing load, the elastic deformation depth and the contact area corresponding to each pressing.

7. The material indentation mechanical property testing method according to claim 3, characterized in that: After executing the step of "calculating material mechanical property parameters according to the corresponding indentation image, the indentation depth and the indentation load", the material indentation mechanical property testing method based on optical microscopy further includes: According to the corresponding contact depth, the pressing depth and the elastic deformation depth, judging whether the material sample has a bulging phenomenon, and obtaining a second judgment result; When the second judgment result is yes, the plastic uplift parameter of the material sample under the uplift phenomenon is calculated according to the contact depth, the indentation depth, the elastic deformation depth and the indentation load.

8. The material indentation mechanical property testing method based on optical microscopy according to claim 4, characterized in that: The calculation formula of the stiffness is: S=P / h s ; Where S represents stiffness; P represents indentation load; h s Indicates the elastic deformation depth.

9. The material indentation mechanical property testing method based on optical microscopy according to claim 4, characterized in that: The calculation formula of the hardness is: H=P / A c ; Where H represents hardness; P represents indentation load; A c Represents the contact area.

10. The material indentation mechanical property testing method based on optical microscopy according to claim 4, characterized in that: The calculation formula of the reduced modulus is: Among them, E r represents the reduced modulus; S represents the stiffness; β represents the constant; A c Represents the contact area.

Images