Test Method for Wear Performance of Particle Reinforced Metal Matrix Composites

Abstract

The present invention relates to a method for testing the wear performance of a particulate-reinforced metal matrix composite, comprising: determining a test area on the surface of a test sample made of the particulate-reinforced metal matrix composite, wherein hard phase particles are exposed in the test area; scanning the test area with a cantilever probe in an atomic force microscope, and obtaining a friction force image and a surface height image of the test area by using the atomic force microscope; and obtaining the wear performance of the test sample according to the friction force image and the surface height image of the test area. The test method in the present invention can better reflect the wear performance of the particulate-reinforced metal matrix composite.

Description

Technical Field

[0001] The present invention relates to the technical field of material property detection, and particularly to a method for testing the wear performance of particle-reinforced metal matrix composites. Background Art

[0002] Particle Reinforced Metal Matrix Composites (PRMMCs) combine the advantages of high hardness and high chemical inertness of ceramic particles and high toughness of metal bonding phases, and are widely used in fields such as the automotive industry, aerospace industry, electronics industry, and surface engineering.

[0003] In terms of the wear resistance evaluation of PRMMCs materials, existing technologies mostly adopt friction and wear experiments for analysis, and compare the friction and wear experiment results of different samples under different experimental conditions. During specific experiments, the samples can be pre-ground first, and then the pre-ground samples can be subjected to rapid wear tests using friction parts according to the same wear parameters. After the wear is completed, the topography information of the worn surface is obtained through an optical profiler, and the wear volume is calculated through special software to evaluate the wear resistance of PRMMCs materials.

[0004] However, due to the complex structure of PRMMCs materials themselves, wear tests like the above cannot well characterize the wear resistance of PRMMCs materials. Summary of the Invention

[0005] Based on this, in view of the technical problem that the existing wear resistance evaluation method for particle-reinforced metal matrix composites cannot accurately characterize the wear resistance of the material itself, it is necessary to provide a wear performance test method that can better reflect the wear performance of particle-reinforced metal matrix composites.

[0006] An embodiment of the present application provides a method for testing the wear performance of particle-reinforced metal matrix composites. In one embodiment, it includes:

[0007] Determine a test area on the surface of a test sample made of particle-reinforced metal matrix composites, wherein hard phase particles are exposed in the test area;

[0008] Scan the test area using the cantilever probe in an atomic force microscope, and obtain the friction force image and surface height image of the test area using the atomic force microscope;

[0009] Obtain the wear performance of the test sample according to the friction force image and surface height image of the test area.

[0010] In one embodiment, the step of forming a test area on the surface of the test sample specifically includes:

[0011] Cut at least one exposed hard-phase particle on the surface of the sample to be tested, and form a groove on the side of the cutting position on the surface of the sample to be tested, so that the cut surface of the cut hard-phase particle is exposed to the outside of the sample to be tested through the first side wall of the groove, and a test area including the cut hard-phase particle is formed on the surface of the sample to be tested.

[0012] In one embodiment, the step of cutting at least one exposed hard-phase particle on the surface of the sample to be tested specifically includes:

[0013] Cut along the center of at least one exposed hard-phase particle.

[0014] In one embodiment, in the step of cutting at least one exposed hard-phase particle on the surface of the sample to be tested:

[0015] The cutting is performed along the normal direction of the surface of the sample to be tested; and / or

[0016] The depth of the cutting extends below the bottom of the cut hard-phase particle.

[0017] In one embodiment, the first side wall of the groove is continuous with the edge of the test area.

[0018] In one embodiment, after the step of scanning the test area with the cantilever probe in the atomic force microscope and obtaining the friction force image and the surface height image of the test area by using the atomic force microscope, the following steps are further included:

[0019] Obtain an optical image of the first side wall of the groove;

[0020] The step of obtaining the wear performance of the sample to be tested according to the friction force image and the surface height image of the test area specifically includes:

[0021] Obtain the wear performance of the sample to be tested according to the optical image of the first side wall of the groove, and the friction force image and the surface height image of the test area.

[0022] In one embodiment, the step of obtaining the optical image of the first side wall of the groove specifically includes:

[0023] Place the sample to be tested obliquely on the workbench of the electron microscope so that the scanning electron beam of the electron microscope forms an angle with the first side wall of the groove;

[0024] Obtain the optical image of the first side wall of the groove by using the electron microscope.

[0025] In one embodiment, the step of cutting at least one exposed hard-phase particle on the surface of the sample to be tested specifically includes:

[0026] Select spherical hard phase particles among the hard phase particles exposed on the surface of the sample to be measured, and cut at least one spherical hard phase particle.

[0027] In one embodiment, before the step of forming a test area on the surface of the sample to be measured, it further includes:

[0028] Pretreat the surface of the sample to be measured of the particle-reinforced metal matrix composite material, so that some hard phase particles in the sample to be measured are exposed on the surface of the sample to be measured.

[0029] In one embodiment, the step of pretreating the surface of the sample to be measured of the particle-reinforced metal matrix composite material so that some hard phase particles in the sample to be measured are exposed on the surface of the sample to be measured specifically includes:

[0030] Repeatedly grind and polish the surface of the sample to be measured, and use an atomic force microscope to obtain the surface height image of the sample to be measured until some hard phase particles in the sample to be measured are exposed from the matrix phase of the sample to be measured.

[0031] In one embodiment, after the step of pretreating the surface of the sample to be measured of the particle-reinforced metal matrix composite material, it further includes:

[0032] Make a feature mark on the surface of the pretreated sample to be measured.

[0033] In one embodiment, use the cantilever probe in the atomic force microscope to scan the test area, and use the atomic force microscope to obtain the friction force image and the surface height image of the test area;

[0034] The step of obtaining the optical image of the first side groove wall specifically includes:

[0035] A. Place the sample to be measured at the first preset position in the atomic force microscope by using the feature mark, use the cantilever probe in the atomic force microscope to scan the test area, and use the atomic force microscope to obtain the friction force image and the surface height image of the test surface;

[0036] B. Place the sample to be measured at the second preset position in the electron microscope by using the feature mark, and use the electron microscope to obtain the optical image of the first side groove wall.

[0037] In one embodiment, repeat step A and step B until the cantilever probe in the atomic force microscope breaks.

[0038] In one embodiment, before the step of obtaining the optical image of the first side groove wall, it includes:

[0039] Clean the groove.

[0040] In one embodiment, the step of using a cantilever probe in an atomic force microscope to scan a test area specifically includes:

[0041] Divide the test area into a number of parallel scanning areas, and use the cantilever probe in the atomic force microscope to scan the scanning areas row by row.

[0042] In one embodiment, before the step of using the cantilever probe in the atomic force microscope to scan the test area, it further includes: heating the sample to be tested to 600°C to 800°C.

[0043] The beneficial effects of the above wear performance test method for the particle-reinforced metal matrix composite:

[0044] Use the cantilever probe in the atomic force microscope to conduct a wear test on the test area in the sample to be tested, and use the atomic force microscope to obtain the friction force image and surface height image of the test area, which is to test the wear resistance of the surface of the sample to be tested microscopically. Compared with the macroscopic friction and wear experiments in the prior art, in this solution, the tip of the cantilever probe in the atomic force microscope is used to simulate a single rough peak in the actual counter pair, and a microscopic friction and wear test is carried out with the microscopic test area of the PRMMCs, which can better analyze the microscopic failure mechanism of the PRMMCs, better reflect the wear performance of the particle-reinforced metal matrix composite, and thus better guide the material design. Description of the Drawings

[0045] Figure 1 It is a schematic flow chart of the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0046] Figure 2 It is a schematic structural diagram of the atomic force microscope scanning the sample to be tested in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0047] Figure 3 It is a schematic structural diagram of obtaining an optical image of the first groove wall by using an electron microscope in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0048] Figure 4 It is a schematic structural diagram of making a characteristic mark on the surface of the sample to be tested in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0049] Figure 5a It is a schematic structural diagram of forming a groove on the surface of the sample to be tested in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0050] Figure 5bAn image of the surface of the test area obtained by using an electron microscope in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0051] Figure 5c A friction force image of the test area of the sample to be measured obtained by using an atomic force microscope in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0052] Figure 5d A surface height image of the test area of the sample to be measured obtained by using an atomic force microscope in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0053] Figure 5e An optical image of the test area of the sample to be measured and the first side groove wall obtained by using an electron microscope in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0054] Figure 5f An image of the cantilever probe obtained by using an electron microscope in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application;

[0055] Figure 6 A schematic structural diagram of a heating device for heating the sample to be measured in the wear performance test method for the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0056] Explanation of the reference numerals in the drawings:

[0057] 100. Sample to be measured; 10. Matrix phase; 11. Test area; 20. Hard phase particles; 21. Exposed hard phase particles; 30. Groove; 31. First side groove wall; 51. Support platform; 52. Electron beam incident on the electron microscope; 53. Nanoindentation; 54. Cantilever probe; 60. Heating device; 61. Silicon wafer; 62. Thermal conductive adhesive; 63. Tantalum sheet; 64. Sapphire sheet; 65. Molybdenum wire. Detailed implementation manners

[0058] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0059] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0060] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0061] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0063] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0064] The particulate-reinforced metal matrix composite of the embodiment of the present application will be described below with reference to the accompanying drawings.

[0065] It should be noted that the sample to be tested in the present application can be a structure entirely made of particulate-reinforced metal matrix composite. In this case, any surface of the sample to be tested can be used as the test surface.

[0066] The test sample can also be a structure formed by making a particulate-reinforced metal matrix composite layer on other types of materials. In this case, the surface of the particulate-reinforced metal matrix composite layer in the sample to be tested can be used as the test surface.

[0067] Figure 1 It is a schematic flow chart of the wear performance test method for the particulate-reinforced metal matrix composite provided by the embodiment of the present application. Refer to Figure 1 , the present embodiment provides a wear performance test method for particulate-reinforced metal matrix composite, including the following steps:

[0068] S10. Determine a test area on the surface of the sample to be tested made of particulate-reinforced metal matrix composite, wherein the hard phase particles are exposed in the test area;

[0069] S20. Scan the test area with the cantilever probe in the atomic force microscope, and obtain the friction force image and surface height image of the test area by using the atomic force microscope;

[0070] S30. Obtain the wear performance of the sample to be tested according to the friction force image and surface height image of the test area.

[0071] In the above solution, the wear test is carried out on the test area in the sample to be tested with the cantilever probe in the atomic force microscope, and the friction force image and surface height image of the test area are obtained by using the atomic force microscope. This is to test the wear resistance of the surface of the sample to be tested microscopically. Compared with the macroscopic friction and wear experiments in the prior art, in this solution, the tip of the cantilever probe in the atomic force microscope is used to simulate a single rough peak in the actual counterbody, and the microscopic friction and wear test is carried out on the microscopic test area of PRMMCs, which can better analyze the microscopic failure mechanism of PRMMCs, better reflect the wear performance of particulate-reinforced metal matrix composite, and thus better guide the material design.

[0072] In the embodiment of the present application, the steps of step S10 specifically include:

[0073] Cut at least one exposed hard phase particle on the surface of the sample to be tested, and form a groove on the side of the cutting position on the surface of the sample to be tested, so that the cut surface of the cut hard phase particle is exposed to the outside of the sample to be tested through the first side wall of the groove, and a test area including the cut hard phase particle is formed on the surface of the sample to be tested.

[0074] It can be understood that the sample to be tested of the particle-reinforced metal matrix composite material may include a matrix phase and hard phase particles distributed in the matrix phase. Before step S10, the step of forming a test area on the surface of the sample to be tested further includes:

[0075] Pretreat the surface of the sample to be tested of the particle-reinforced metal matrix composite material so that some hard phase particles in the sample to be tested are exposed to the surface of the sample to be tested. That is, in order to expose the hard phase particles from the matrix phase, generally, the surface of the sample to be tested needs to be pretreated.

[0076] Specifically, the step of pretreating the surface of the sample to be tested includes grinding and polishing the surface of the sample to be tested.

[0077] It can be understood that in order to determine when the grinding and polishing processes end, it can be judged by observing with an atomic force microscope. That is, repeatedly perform grinding and polishing processes, and use the atomic force microscope to obtain the surface height image of the sample to be tested until some hard phase particles in the sample to be tested are exposed from the matrix phase of the sample to be tested.

[0078] Of course, in order to be able to test the sample to be tested with an atomic force microscope, before pretreatment, a sample to be tested with a suitable size needs to be cut from a larger particle-reinforced metal matrix composite material raw material.

[0079] Specifically, wire cut the raw material of the particle-reinforced metal matrix composite material into a sample with a diameter <15 mm and a height <7 mm as the sample to be tested.

[0080] After forming a suitable sample to be tested, it is necessary to cut the hard phase particles so that their interiors are exposed outside the sample to be tested for easy observation.

[0081] Figure 2 It is a schematic structural diagram of the atomic force microscope scanning the sample to be tested in the particle-reinforced metal matrix composite material wear performance testing method provided by the embodiment of the present application.

[0082] Refer to Figure 2, after the surface of the sample to be tested 100 is pretreated as described above, on the surface of the sample to be tested 100, the hard phase particles 20 are exposed from the matrix phase 10.

[0083] As described above, at least one exposed hard phase particle 21 is cut. Figure 2 Taking the example of cutting three exposed hard phase particles 21 simultaneously for illustration. The cutting in this embodiment can be carried out by using a focused ion beam. After cutting the three exposed hard phase particles 21, grooves 30 will be formed on the side of the cutting position on the surface of the sample to be tested 100. The grooves 30 can include multiple side groove walls. Define the groove walls passing through these three exposed hard phase particles 21 as the first side groove walls 31. In this way, the cutting surfaces of the cut hard phase particles 21 are exposed to the outside of the sample to be tested 100 via the first side groove walls 31. As long as the breakage condition of the first side groove walls 31 is observed during the test, the internal breakage condition of the sample to be tested 100 can be obtained.

[0084] In order to better observe the internal cracking condition of the hard phase particles 21 during the test, it can be considered to cut along the center of at least one exposed hard phase particle 21. Further, the cutting can be carried out along the normal direction of the surface of the sample to be tested 100.

[0085] It can be understood that, in order to observe phenomena such as the wear condition of each phase in the test area 11, whether the hard phase particles 20 are cracked, the generation of cracks, and whether the interface between the hard phase particles 20 and the matrix phase 10 is damaged, etc., it can be considered to extend the cutting depth below the bottom of the cut hard phase particles 21.

[0086] In addition, due to the complexity of the microstructure of the particle-reinforced metal matrix composite, it is necessary to preliminarily screen the size, shape of the particles on the surface of the sample to be tested, and the distribution of the surrounding particles, roughly select the first test area (not shown) that meets the test requirements, and then cut the hard phase particles included in the first test area. For example, the first test area to be tested can be preliminarily selected before cutting. For the hard phase particles on the surface of the sample to be tested, the smaller the hard phase particles, the easier it is to observe the phenomenon of the overall removal of the hard phase particles in the atomic force microscope. However, the size of the hard phase particles should not be too small, which is not conducive to subsequent electron microscope observation. Exemplarily, spherical hard phase particles can be selected from the hard phase particles exposed on the surface of the sample to be tested, and at least one spherical hard phase particle is cut. That is, the area including at least one spherical hard phase particle is selected as the first test area. When cutting, the spherical hard phase particles in the first test area are cut, that is, the hard phase particles passed by the first side groove walls of the grooves can be spherical hard phase particles.

[0087] As a preferred method, hard-phase particles that meet the following conditions can be selected, namely, the diameter is 3 - 6 μm, the shape is close to equiaxial (spherical), and there are fewer hard-phase particles distributed around. That is, in the selected first test area, hard-phase particles that meet the above conditions are required to be included.

[0088] After the groove is cut, the area in the first test area except the grooved part can form the final test area 11, as Figure 2 shown, for atomic force microscope scanning. Refer to Figure 2 shown, as a possible implementation manner, when the cut hard-phase particle 21 is exactly at the edge of the first test area, after the cutting is completed, the edge of the formed test area 11 is exactly continuous with the first side groove wall 31. In this way, when the wear scanning of the test area 100 is carried out, the rupture situation inside the test sample 100 can be obtained from the first side groove wall 31.

[0089] It should be noted that in addition to selecting the first test area on the surface of the test sample and forming the test area through grooving as described above, a region can also be directly selected on the surface of the test sample as the test area.

[0090] For example, directly select the first test area on the surface of the test sample as the test area for subsequent experiments.

[0091] After the test area 11 is selected, first use the cantilever probe in the atomic force microscope to scan the test area 11 on the surface of the test sample 100.

[0092] Atomic Force Microscope (AFM) is an analytical instrument that can be used to study the surface structure of solid materials. It studies the surface structure and properties of substances by detecting the extremely weak interatomic interaction force between the surface of the test sample and the cantilever probe. One end of the cantilever probe is fixed, and the tiny probe at the other end approaches the test area of the test sample. At this time, the two will interact, and the interaction force will cause the cantilever probe to deform or its motion state to change. When scanning the test area of the test sample, these changes are detected by the sensor, and the force distribution information can be obtained, so as to obtain the surface topography structure information and surface roughness information with nanometer-level resolution. For example, obtain the friction force image and surface height image of the test area.

[0093] Continue to refer to Figure 2, during the scanning process, the test area 11 can be divided into several mutually parallel scanning areas, and the cantilever probe 54 in the atomic force microscope is used to scan the test area 11 row by row. That is, the scanning direction of the cantilever probe 54 is perpendicular to the cantilever probe 54, and a raster scanning method is used. It should be noted that after the entire area of the test area 11 has been scanned, it can be considered that one scan of the cantilever probe 54 has been performed on the test area 11.

[0094] During the scanning process of the cantilever probe 54, the atomic force microscope can automatically obtain the friction force image and the surface height image of the test area 11.

[0095] In the embodiments of the present application, in order to observe phenomena such as the wear conditions of each phase in the test area, whether the hard phase particles are cracked, the generation of cracks therein, and whether the interface between the hard phase particles and the matrix is damaged, after a certain number of scans of the test area, that is, after a certain number of scanning images are completed in the microscopic friction and wear test using the atomic force microscope, the sample to be tested can be taken out from the workbench of the atomic force microscope and placed on the workbench of the electron microscope to observe the changes in the surface and cross-section of the wear area.

[0096] That is, the step of obtaining the optical image of the first side wall 31 of the groove can be performed.

[0097] The step of obtaining the wear performance of the sample to be tested according to the friction force image and the surface height image of the test area may specifically include:

[0098] Obtain the wear performance of the sample to be tested by using the optical image of the first side wall 31 of the groove, as well as the friction force image and the surface height image obtained by the atomic force microscope.

[0099] In the above solution, since a groove is opened on the surface of the sample to be tested, the internal structure of the hard phase particles is exposed through the first side wall of the groove, and the optical image of the first side wall is obtained. In this way, during the wear test, phenomena such as whether the inside of the hard phase particles is cracked, the generation of cracks, and whether the interface between the hard phase particles and the matrix phase is damaged can be obtained through the optical image of the first side wall. The characteristics of the hard phase particles can be analyzed from an additional dimension, especially the change of the interface between the hard phase particles and the matrix phase with friction and wear, so that the evaluation of the test sample and the test results are more comprehensive, and the wear performance of the particle-reinforced metal matrix composite can be better reflected.

[0100] Figure 3 It is a schematic structural diagram of obtaining the optical image of the first groove wall by using an electron microscope in the particle-reinforced metal matrix composite wear performance test method provided by the embodiments of the present application.

[0101] Refer to Figure 1 and Figure 3, in specific implementation, the steps of obtaining the optical image of the first side groove wall may specifically include:

[0102] Place the sample 100 to be measured obliquely on the workbench of the electron microscope, so that the electron beam 52 incident on the electron microscope forms an angle with the first side groove wall 31, and use the electron microscope to obtain the optical image of the first side groove wall 31.

[0103] Among them, since the first side groove wall 31 is substantially perpendicular to the surface of the test area 11, in order to enable the scanning electron beam 52 of the electron microscope to irradiate the first side groove wall 31, the sample 100 to be measured can be placed obliquely.

[0104] Exemplarily, the sample 100 to be measured can be pasted onto the support table 51 with a 45° inclined plane using conductive double-sided tape, and attention should be paid to ensuring that the normal direction F of the first side groove wall 31 faces obliquely upward, so that the electron beam 52 incident in the electron microscope can be incident on the position of the first side groove wall 31 and the detector can receive the signal for imaging.

[0105] It should be noted that because sometimes the accumulation of abrasive debris will block the observation of the test area and the first side groove wall by the electron microscope, before the step of obtaining the optical image of the first side groove wall, a step of cleaning the groove can also be included. That is, the sample to be measured can be placed in deionized water for ultrasonic cleaning.

[0106] It can be understood that the process of obtaining the optical image can be carried out on the workbench of the atomic force microscope, or the sample to be measured can be taken out from the workbench of the atomic force microscope and placed on the workbench of the electron microscope as described above, so as to photograph the sample to be measured.

[0107] It should be noted that in the case where it is necessary to repeatedly use the atomic force microscope to scan the test area and use the electron microscope to obtain the optical image of the first side groove wall, it is necessary to repeatedly change the position of the sample to be measured between the atomic force microscope and the electron microscope. It is possible that during different scanning tests, the sample to be measured will be located at different positions on the workbench of the atomic force microscope, and it is impossible to repeatedly scan and test the same test area. To avoid this situation, feature marks can be made on the surface of the sample to be measured after pretreatment, and the test area on the sample to be measured can be accurately positioned with the workbench of the atomic force microscope and the workbench of the electron microscope with the feature marks as a reference.

[0108] Specifically, the sample to be measured can be placed at the first preset position in the atomic force microscope using the feature marks, the test area can be scanned using the cantilever probe in the atomic force microscope, and the friction image and surface height image of the test surface can be obtained using the atomic force microscope;

[0109] Place the sample to be tested at the second preset position in the electron microscope using the feature marker, and obtain an optical image of the first side groove wall using the electron microscope.

[0110] In addition, due to the limitation of the maximum scanning size of the atomic force microscope, the selected area of the aforementioned first test area is generally at the micron level. In order to locate the first test area more quickly, it is also necessary to make feature marks on the surface of the sample to be tested.

[0111] Figure 4 It is a schematic structural diagram of making feature marks on the surface of the sample to be tested in the wear performance test method of the particle-reinforced metal matrix composite material provided by the embodiment of the present application.

[0112] Specifically, referring to Figure 4 , a series of nano-indentations 53 can be made on the surface of the pretreated sample 100 to be tested using a Vickers microhardness tester. During the production process, it is necessary to control the load size to obtain an indentation array visible to the naked eye and under the electron microscope, and use this array image as the positioning of the first test area and the test area. For example, the nano-indentations 53 shown as black squares in the figure are used as feature marks. Figure 4 It is an optical microscope image of the surface of the sample to be tested of the SiC ceramic particle-reinforced Al metal matrix composite material after grinding and polishing. It can be seen that many micron-sized darker gray SiC particles are embedded in the grayish-white Al matrix.

[0113] It can be understood that the number of times of performing the steps of scanning the test area using the atomic force microscope and obtaining the optical image of the first side groove wall using the electron microscope can be selected according to actual needs. However, in the atomic force microscope, after scanning a certain number of times, the cantilever probe may break. In the case of the cantilever probe breaking, it is not advisable to continue the above tests.

[0114] Therefore, exemplarily, the step of obtaining the optical image of the first side groove wall specifically includes:

[0115] A. Place the sample to be tested at the first preset position in the atomic force microscope using the feature marker, scan the test area using the cantilever probe in the atomic force microscope, and obtain the friction force image and surface height image of the test surface using the atomic force microscope;

[0116] B. Place the sample to be tested at the second preset position in the electron microscope using the feature marker, and obtain an optical image of the first side groove wall using the electron microscope.

[0117] Repeat step A and step B until the cantilever probe in the atomic force microscope breaks.

[0118] It should be noted that for step A and step B here, step A can be executed first and then step B, or step B can be executed first and then step A.

[0119] An electron microscope can be used to obtain an image of the cantilever probe to determine whether the cantilever probe has cracked.

[0120] In addition, the actual application working conditions of the particle-reinforced metal matrix composite are complex and often involve high-temperature fields. For example, when used as a wear-resistant coating for the brush seal of an aero-engine, the actual use temperature can reach 600 - 800 °C. In order to better simulate the real working conditions of the material, it is necessary to set the test temperature of the sample to be tested in the wear performance test method of this particle-reinforced metal matrix composite.

[0121] Exemplarily, before the step S20 of scanning the test area using the cantilever probe in the atomic force microscope, it further includes: heating the sample to be tested to 600 °C - 800 °C.

[0122] When specifically implemented, referring to Figure 6 , a heating device 60 can be set on the workbench of the atomic force microscope. The heating device can include: a silicon wafer 61, a thermal conductive adhesive 62, a tantalum sheet 63, a sapphire sheet 64, and a molybdenum wire 65.

[0123] The number of sapphire sheets 64 is two, and the sapphire sheet 64 can be configured in a ring shape. A silicon wafer 61 is clamped between the two sapphire sheets 65. The sample to be tested 100 can be bonded to the silicon wafer 61 through the thermal conductive adhesive 62. Both ends of the silicon wafer 61 are connected to the two molybdenum wires 65 through a tantalum sheet 63 respectively. Specifically, one end of each tantalum sheet 63 contacts the bottom of one end of the silicon wafer 61, and the other end is wound around the molybdenum wire 65. The molybdenum wire 65 is connected to the DC power supply built into the atomic force microscope to form a circuit.

[0124] When the heating device 60 works, the power supply passes direct current through both ends of the silicon wafer 61 through the molybdenum wire 65 and the tantalum sheet 63, generating Joule heat inside the silicon wafer 61. This heat is transferred to the sample to be tested 100 through the thermal conductive adhesive 62, thereby realizing the heating of the sample to be tested 100.

[0125] Among them, the silicon wafer can be a single-sided polished silicon wafer produced by Jingxin Electronic Technology Co., Ltd. The thickness of the silicon wafer is 400 μm, the resistivity is 0.01 - 0.05 Ω·cm, P-type doping, and the silicon wafer is cut into a long strip with a length of 8.5 mm and a width of 1.5 mm using a diamond knife.

[0126] Since the silicon wafer 61 and the tantalum wafer 63 are sandwiched between two annular sapphire wafers 64, the sapphire wafers 64 can play a heat insulation role. On the one hand, it can ensure the temperature stability of the silicon wafer 61 and the sample to be measured 100 during the heating process. On the other hand, it can reduce the heat conduction of heat to other components of the device and avoid damaging other components at high temperatures. Here, in order to minimize the heat capacity of the system, the sample to be measured 100 needs to be cut into small pieces with a length and width of about 1.5 mm and a thickness of about 1 mm, and it is glued to the upper part of the middle section of the silicon wafer 61 with a thermal conductive adhesive 62.

[0127] Among them, the thermal conductive adhesive 62 used is a high-temperature thermal conductive adhesive with the model Yk8906 produced by Yikun Company. The material is inorganic silicon aluminate, and the heat-resistant temperature reaches 1210 °C.

[0128] Here, by passing a current of 1-2 A through the silicon wafer 61, the sample to be measured 100 can be heated to 800 °C. Of course, this application is not limited to this. The specific current magnitude in the circuit depends on the resistance of the heating system. Here, the actual temperature on the surface of the sample to be measured 100 during the heating process can be measured by an infrared thermometer.

[0129] The following gives a specific example to illustrate the wear performance test method of the particle-reinforced metal matrix composite material in the embodiment of this application.

[0130] Step 1: Wire-cut the raw materials of the particle-reinforced metal matrix composite material to process them into samples to be measured, where the diameter of the sample to be measured < 15 mm and the height < 7 mm, so as to be able to put them into an atomic force microscope for subsequent tests.

[0131] Step 2: Grind and polish the surface of the cut sample to be measured.

[0132] Specifically, silicon carbide sandpapers with mesh numbers of 180, 320, 600, 1000, 1200, 2000, and 4000 are successively used to grind the surface of the sample to be tested with water added on a metallographic polishing machine. When uniform scratches in a single direction are formed, the mesh number of the sandpaper can be changed, and it is ensured that the grinding direction is perpendicular to the direction of the previous scratch. After grinding, a polishing cloth is pasted on the polishing disc and wetted with water. A diamond spray polishing agent is sprayed on the surface of the polishing cloth for 3 - 5 s to evenly distribute diamond particles on the surface of the polishing cloth. The rotation speed is adjusted to 200 r / min, and the surface of the sample to be tested is polished. Diamond polishing agents with particle sizes of 3 μm and 1 μm are respectively used to rough-polish and fine-polish the surface of the sample to be tested, with each time being 10 minutes. During the polishing process, the water flow is controlled to drip, and attention is paid to replenishing the diamond polishing agent. After polishing, the surface of the sample to be tested is ultrasonically cleaned multiple times with deionized water, and finally the surface of the sample to be tested is dried with nitrogen. Since the particle-reinforced metal matrix composite is different from the ordinary homogeneous material, a flat and flawless mirror surface cannot be obtained on the polished sample surface. Instead, due to the difference in wear resistance of each phase in the composite material, a structure with certain undulations will be formed on the surface after polishing, that is, the hard-phase particles protrude a certain height from the matrix.

[0133] Utilizing this characteristic, we can easily distinguish whether the hard-phase particles in the particle-reinforced metal matrix composite protrude from the matrix phase through the surface height map obtained by scanning in an atomic force microscope, thereby helping us determine to what extent the aforementioned pretreatment such as grinding and polishing should end.

[0134] Step 3: Make a series of nano-indentations on the surface of the polished sample to be tested as characteristic marks. For example, the nano-indentations can be made in the central area of the surface of the sample to be tested. Use a Vickers microhardness tester to make a series of nano-indentations on the surface of the polished sample to be tested, control the load size, obtain an indentation array visible both to the naked eye and under an electron microscope, and use the array image as a characteristic mark to locate the first test area.

[0135] Step 4: Screen a suitable first test area in a scanning electron microscope.

[0136] Specifically, when implementing, hard-phase particles with a diameter of 3 - 6 μm, a shape close to equiaxed, and less distribution of surrounding hard-phase particles can be selected on the surface of the sample to be tested, and the relative positions of the selected first test area and the characteristic mark area in Step 3 are recorded.

[0137] Step 5: Use a focused ion beam to create a groove.

[0138] Since the electron microscope can only obtain the size and shape information of the hard-phase particles on the polished surface and cannot determine the size and shape of the part of the hard-phase particles embedded in the matrix, this brings uncertain factors to the analysis of the micro friction and wear experiments of the composite material system. In order to analyze the characteristics of the particles from an additional dimension and observe the changes in the subsurface of friction and wear, especially the interface between the hard-phase particles and the matrix during friction and wear (such as crack initiation and propagation), it is necessary to cut a groove in the first test area of the sample to be tested before the friction and wear test, and the first side wall of the groove should pass through the inside of at least one exposed hard-phase particle. The first test area after cutting forms the test area. Here, the cutting area should not be too small, and it is necessary to completely expose the part of the hard-phase particles embedded in the matrix without blocking the observation of the electron microscope on the first side wall. However, the cutting area should not be too large either, because the cutting time increases in multiples with the area size, which will increase the unnecessary cost of the test. The position of the first side wall is preferably at the middle of the hard-phase particle, so as to reflect the overall information of the hard-phase particle as much as possible.

[0139] Step 6: Conduct atomic force microscope micro friction and wear tests.

[0140] In this step, the atomic force microscope AFM uses CypherS from Oxford Instruments, and its maximum scanning range is 30μm×30μm. The friction and wear test uses the lateral force mode built into the software, and the scanning method is raster scanning. Refer to Figure 2 , that is, within the test area 11, the cantilever probe starts from the upper left corner of the test area 11 and moves parallel from left to right (fast scan direction) to complete one row of scanning. 256 pixel point data are sampled in one scan. Immediately afterwards, the cantilever probe moves from right to left and returns to the upper left corner of the test area 11 to complete one row of scanning. That is, one row of scanning includes two scans back and forth. Then the cantilever probe moves down a certain distance (for the second row of scanning) to complete the second row of scanning, and so on until 256 rows of scanning are completed. In this way, two 256×256 pixel point images can be obtained back and forth, called the Trace and Retrace images. The above process is to complete one scan.

[0141] Overall, the cantilever probe conducts multiple scans from top to bottom and then from bottom to top within the test area 11 in a reciprocating manner to complete the micro friction and wear experiment. The motion feedback of the cantilever probe adopts the constant force mode, that is, the deflection degree of the cantilever probe in the normal direction is controlled to be unchanged, and the height of the cantilever probe's movement is adjusted through the feedback loop, so as to ensure that the normal force applied by the cantilever probe to the surface of the sample to be tested remains unchanged. By recording the height change of the cantilever probe's movement, the height change of different positions on the surface of the test area with the increase of the scan times can be obtained. Since the cantilever probe is also affected by the force that hinders its movement on the surface of the sample to be tested during the scanning and sliding process of each row, by measuring the lateral deflection signal of the cantilever probe, the magnitude of the lateral force received by the probe can be obtained. The magnitude of the frictional force can be obtained by subtracting the lateral force signals obtained from two scans in the same row and then dividing by 2.

[0142] During the specific test process, the cantilever probe uses a commercially available NC-LC diamond tip probe of the Adama brand. The tip is conical, and the normal elastic coefficient is about 100 N / m. This probe is wear-resistant. The SEM morphology characterization of the diamond probe tip before and after the wear test shows that the tip radius changes little, and the cantilever of this probe is relatively hard, which can apply a greater force to the surface of the sample, making it suitable for this micro friction and wear test. The friction and wear test area selected by the atomic force microscope is near the first side groove wall in step five, and it is also necessary to ensure that the scanning direction of the cantilever probe is parallel to the first side groove wall.

[0143] Step 7: Use an electron microscope to obtain pictures of the test area and the first side groove wall after the micro friction and wear test.

[0144] It can be understood that in order to observe phenomena such as the wear situation of each phase in the test area, whether the hard phase particles are cracked, the generation of cracks, and whether the interface between the hard phase particles and the matrix is damaged, after a certain number of scans are completed in the micro friction and wear test of the atomic force microscope, the sample to be tested is taken out from the workbench of the atomic force microscope and placed in the workbench of the electron microscope to observe the changes on the surface of the test area and the first side groove wall.

[0145] Specifically, the sample to be tested can be pasted onto an aluminum support platform with a 45° inclined plane using conductive double-sided tape, and attention should be paid to ensuring that the normal direction of the first side groove wall faces obliquely upward, so that the electron beam in the electron microscope can hit the position of the first side groove wall and the detector can receive the signal for imaging.

[0146] Step 8: Repeat steps 6 and 7 to observe the evolution process of the surface of the test area and the first side groove wall after different scan times for the same test area. During this process, the feature marks in step 3 can be used to ensure the unity of the sample placement direction and the repeated positioning of the test area.

[0147] Of course, after observing the fracture of the cantilever probe using an electron microscope, the testing process can be stopped.

[0148] The following describes the friction force image of the test area, the surface height image of the test area, and the optical image of the test area and the first side groove wall measured in the above testing process.

[0149] Figure 5a Schematic diagram of the structure for forming a groove on the surface of the sample to be tested in the wear performance testing method of the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0150] Figure 5b Image of the surface of the test area obtained by using an electron microscope in the wear performance testing method of the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0151] Figure 5c Friction force image of the surface of the test area of the sample to be tested obtained by using an atomic force microscope in the wear performance testing method of the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0152] Figure 5d Surface height image of the test area of the sample to be tested obtained by using an atomic force microscope in the wear performance testing method of the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0153] Figure 5e Optical image of the test area of the sample to be tested and the first side groove wall obtained by using an electron microscope in the wear performance testing method of the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0154] Figure 5f Image of the cantilever probe obtained by using an electron microscope in the wear performance testing method of the particle-reinforced metal matrix composite provided by the embodiment of the present application.

[0155] In step five, referring to Figure 5a , it is a schematic diagram of the structure of the groove 30 cut on the surface of the sample to be tested. The cutting width of the groove 30 is 34 μm, and the depth is greater than 14 μm. This groove 30 straddles two hard phase particles. Here, the hard phase particles can be SiC particles. In this embodiment, Figure 5a the hard phase particle on the right side of the drawing is taken as an experimental object for illustration. The hard phase particle on the right side has a particle diameter of about 4 μm. After cutting it, through the observation of the first side groove wall, we can know the shape of the part of the hard phase particle on the right side buried in the matrix and the burial depth of about 1 μm.

[0156] Figure 5bis an optical image of the surface of the test area obtained by an electron microscope. The numbers in the upper left corner of each picture represent the number of times the cantilever probe has scanned. In the figure, the rupture of the hard phase particles 21 during the friction scan test after 130 and 173 scans can be seen.

[0157] Figure 5c is the friction force image of the test area of the sample to be measured obtained by an atomic force microscope. Figure 5d is the surface height image of the test area of the sample to be measured obtained by an atomic force microscope. The numbers in the upper left corner of each picture represent the number of times the cantilever probe has scanned.

[0158] From Figure 5c it can be seen that as the number of scans increases, the friction force in the area near the hard phase particles 21 gradually increases.

[0159] From Figure 5d it can be seen that as the number of scans increases, the height in the area near the hard phase particles 21 gradually decreases.

[0160] In step seven, referring to Figure 5e , Figure 5e is the optical image of the surface C of the test area and the surface F of the first side groove wall. In Figure 5e , with the black solid line as the boundary, the upward area represents the surface C of the test area, the downward area is the surface F of the first side groove wall, and the area framed by the white dotted line is the cut hard phase particles 21. The numbers in the upper left corner of each picture represent the number of times the cantilever probe has scanned.

[0161] From Figure 5e it can be known that the hard phase particles are more wear-resistant than the matrix, the hard phase particles protrude from the matrix, and the hard phase particles play a role in protecting the underlying matrix from further wear. After 100 scans, as shown by the black solid line arrow in the 100 - scan picture, the hard phase particles first break at the interface between the hard phase particles and the matrix. It can be seen that there are tiny cracks at the interface after the fragmented part of the hard phase particles falls off. Continuing to observe 100, 130, 173, up to 223 scans, the hard phase particles gradually break, the remaining part gradually becomes smaller, and once the fragmented part falls off, the protection of the underlying matrix is lost. In the 223 - scan picture, as shown by the black solid line arrow, it can be seen that compared with the 173 - scan picture, the hard phase particles have broken significantly. Finally, after 237 scans, the hard phase particles are completely worn out.

[0162] In step eight, reference can be made to Figure 5f , which shows the original state of the cantilever probe 54 and the images after a series of scan numbers. From Figure 5fIt can be seen that after the scanning times of the atomic force microscope reached 237 times, the tip of the cantilever probe 54 was significantly fractured.

[0163] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0164] The above-described embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for testing the wear performance of a particle-reinforced metal matrix composite material, characterized in that, it includes: Determining a test area on the surface of a test sample made of a particle-reinforced metal matrix composite material, wherein the hard phase particles are exposed in the test area; Scanning the test area with a cantilever probe in an atomic force microscope, and obtaining a friction force image and a surface height image of the test area by using the atomic force microscope; Obtaining the wear performance of the test sample according to the friction force image and the surface height image of the test area; The step of forming a test area on the surface of the test sample of the particle-reinforced metal matrix composite material specifically includes: Cutting at least one exposed hard phase particle on the surface of the test sample, and forming a groove on the side of the cutting position on the surface of the test sample, so that the cutting surface of the cut hard phase particle is exposed to the outside of the test sample through the first side wall of the groove, and a test area including the cut hard phase particle is formed on the surface of the test sample.

2. The method for testing the wear performance of a particle-reinforced metal matrix composite material according to claim 1, characterized in that, The step of cutting at least one exposed hard phase particle on the surface of the test sample specifically includes: Cutting along the center of at least one exposed hard phase particle.

3. The method for testing the wear performance of a particle-reinforced metal matrix composite material according to claim 1, characterized in that, In the step of cutting at least one exposed hard phase particle on the surface of the test sample: The cutting is performed along the normal direction of the surface of the test sample; and / or The depth of the cutting extends below the bottom of the cut hard phase particle.

4. The method for testing the wear performance of a particle-reinforced metal matrix composite material according to claim 1, characterized in that, The first side wall of the groove is continuous with the edge of the test area.

5. The method for testing the wear performance of a particle-reinforced metal matrix composite material according to claim 1, characterized in that, After the step of scanning the test area with a cantilever probe in an atomic force microscope and obtaining a friction force image and a surface height image of the test area by using the atomic force microscope, the method further includes: Obtaining an optical image of the first side wall of the groove; The step of obtaining the wear performance of the test sample according to the friction force image and the surface height image of the test area specifically includes: Obtaining the wear performance of the test sample according to the optical image of the first side wall of the groove, and the friction force image and the surface height image of the test area.

6. The method for testing the wear performance of a particle-reinforced metal matrix composite material according to claim 5, characterized in that, The step of obtaining an optical image of the first side wall of the groove specifically includes: Placing the test sample obliquely on the workbench of an electron microscope, so that the scanning electron beam of the electron microscope forms an angle with the first side wall of the groove; Obtaining an optical image of the first side wall of the groove by using the electron microscope.

7. The wear performance testing method of the particulate-reinforced metal matrix composite according to any one of claims 1 to 6, characterized in that, the step of cutting at least one exposed hard phase particle on the surface of the sample to be tested specifically includes: selecting spherical hard phase particles from the hard phase particles exposed on the surface of the sample to be tested, and cutting at least one spherical hard phase particle.

8. The wear performance testing method of the particulate-reinforced metal matrix composite according to claim 5 or 6, characterized in that, before the step of forming a test area on the surface of the sample to be tested, it further includes: pretreating the surface of the sample to be tested of the particulate-reinforced metal matrix composite to expose some hard phase particles in the sample to be tested on the surface of the sample to be tested.

9. The wear performance testing method of the particulate-reinforced metal matrix composite according to claim 8, characterized in that, the step of pretreating the surface of the sample to be tested of the particulate-reinforced metal matrix composite to expose some hard phase particles in the sample to be tested on the surface of the sample to be tested specifically includes: repeatedly grinding and polishing the surface of the sample to be tested, and using an atomic force microscope to obtain the surface height image of the sample to be tested until some hard phase particles in the sample to be tested are exposed from the matrix phase of the sample to be tested.

10. The wear performance testing method of the particulate-reinforced metal matrix composite according to claim 8, characterized in that, after the step of pretreating the surface of the sample to be tested of the particulate-reinforced metal matrix composite, it further includes: making a characteristic mark on the surface of the pretreated sample to be tested.

11. The wear performance testing method of the particulate-reinforced metal matrix composite according to claim 10, characterized in that, scanning the test area with a cantilever probe in the atomic force microscope, and using the atomic force microscope to obtain the friction force image and surface height image of the test area; the step of obtaining the optical image of the first side wall specifically includes: A. Placing the sample to be tested at a first preset position in the atomic force microscope by using the characteristic mark, scanning the test area with a cantilever probe in the atomic force microscope, and using the atomic force microscope to obtain the friction force image and surface height image of the test surface; B. Placing the sample to be tested at a second preset position in the electron microscope by using the characteristic mark, and using the electron microscope to obtain the optical image of the first side wall.

12. The wear performance testing method of the particulate-reinforced metal matrix composite according to claim 11, characterized in that, repeating the step A and the step B until the cantilever probe in the atomic force microscope breaks.

13. The wear performance testing method of the particulate-reinforced metal matrix composite according to claim 5 or 6, characterized in that, before the step of obtaining the optical image of the first side wall, it includes: cleaning the groove.

14. The wear performance testing method of the particulate-reinforced metal matrix composite material according to any one of claims 1 to 6, characterized in that, the step of scanning the test area by using a cantilever probe in an atomic force microscope specifically includes: dividing the test area into a plurality of mutually parallel scanning areas, and scanning the scanning areas row by row by using a cantilever probe in an atomic force microscope; and / or before the step of scanning the test area by using a cantilever probe in an atomic force microscope, further includes: heating the sample to be tested to 600°C to 800°C.

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