In-situ tension-compression fatigue detection method for micro-scale material

Abstract

The invention belongs to the technical field of micro-scale material tension and compression fatigue detection, and particularly relates to a micro-scale material in-situ tension and compression fatigue detection method, which comprises the following steps: step 1 to step 6, selecting a blank, and preparing a substrate through milling and rounding; taking enough tiny samples, and curing the tiny samples on a substrate by using an adhesive to form a test block; fixing a strain element on the outer surface of the test block for monitoring a strain signal of the test block; opening a clamp of the in-situ loading table, and clamping the substrate from two ends; starting the in-situ loading table to realize a stretching, compression or fatigue test on the micro sample; acquiring strain data of the test block, and calculating the loading strength borne by the test block through a Hooke's law formula. According to the invention, a micro sample, a strain element and a substrate are compounded, a clamp device of an in-situ loading table does not need to be transformed or replaced, and the stretching, compression or fatigue test of the micro sample is realized only through a stretching device of the in-situ loading table.

Description

Technical Field

[0001] The present invention belongs to the technical field of tensile and compressive fatigue detection of micro-scale materials, and in particular relates to an in-situ tensile and compressive fatigue detection method for micro-scale materials. Background Art

[0002] Testing the physical properties of materials is the main way to study material performance. Testing items include stretching, bending, compression, high temperature or thermal cycling, etc. Among them, in-situ loading technology and in-situ loading devices can obtain real-time images of the surface structure of materials when the materials are subjected to external forces (such as stretching, compression, fatigue), temperature changes or chemical corrosion.

[0003] In the detection of physical properties of micro-scale materials, the in-situ loading technology of materials does not need to destroy practical samples. For example, a Chinese invention with publication number CN115655936A was retrieved, which invented a micro-sized in-situ material fatigue test method. It uses a reciprocating linear motion mechanism of a linear motor + an anti-rotating plate to solve the problem that when the transmission method is used to test material samples, only monotonous tensile tests can be performed but not compression tests; and the self-aligning ball head assembly solves the problem of additional bending moments generated during complex tests such as compression / unloading and reloading / fatigue tests of material samples. For the tensile and compressive fatigue detection of micro-scale materials, there are still the following problems that need to be improved:

[0004] 1. At present, the in-situ loading device needs to replace the corresponding fixture when performing loading modes of different natures, which increases the complexity of operation.

[0005] 2. For in-situ loading devices, for loading modes of different natures, in order to obtain better experimental results, it is often necessary to process the specimen into a special shape, which brings difficulties to in-situ experiments on small-sized components that are difficult to process into complex shapes and difficult to prepare. Summary of the invention

[0006] The purpose of the present invention is to provide an in-situ tensile and compressive fatigue detection method for micro-scale materials, which is in the form of a composite of a micro-specimen, a strain element and a substrate. There is no need to modify or replace the clamp device of the in-situ loading platform. The tensile, compression or fatigue test of the micro-specimen can be achieved only through the tensile device of the in-situ loading platform.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A method for in-situ tensile and compressive fatigue detection of micro-scale materials, comprising the following steps:

[0009] Step 1: Select the blank and make the base by milling and chamfering;

[0010] Step 2: Take a sufficient amount of micro-samples, and use adhesive to solidify the micro-samples onto the substrate to form test blocks of a certain size for later use;

[0011] Step 3: Fix the strain element on the outer surface of the test block by adhesive to monitor the strain signal of the test block and avoid the in-situ loading platform;

[0012] Step 4: Open the clamp of the in-situ loading platform, clamp the base from both ends, keep a safe distance between the clamp and the test block, and complete the loading of the micro-sample;

[0013] Step 5: Start the in-situ loading platform and select the in-situ loading mode according to the experimental needs to realize the tensile, compression or fatigue test of the micro specimen;

[0014] Step 6: During the loading process, the strain data of the test block is obtained, and the loading intensity borne by the test block is calculated using the Hooke's law formula.

[0015] As an optional solution, the blank is made of stainless steel or aluminum alloy, formed by milling, with a material distribution area in the middle and clamping ends for clamping on the in-situ loading platform at both ends.

[0016] As an optional solution, after the substrate is formed, it needs to be placed in a mixed solution of acetone and alcohol for ultrasonic cleaning for about 15 minutes to remove pollutants on the surface of the substrate, and then placed under a baking lamp for at least 3 minutes for drying to keep it dry.

[0017] As an optional solution, the adhesive is any one of KD-855HL metal adhesive or DP8407NS metal bonding acrylic adhesive.

[0018] As an optional solution, the micro-sample solidification in step 2 is specifically as follows:

[0019] Use an alloy mold with square holes to cover the base, take enough micro-samples to cover the square holes, and use adhesive to solidify the micro-samples in the middle of the fabric area, avoiding the clamping end;

[0020] Alloy molds with square holes avoid adhesives to prevent sticking;

[0021] Press the test block with a metal block for 3 minutes. After the test block is stable, remove the metal block and the alloy mold in turn.

[0022] As an optional solution, the strain element is either a first strain gauge or a grating.

[0023] As an optional solution, the bonding area of ​​the strain element is smaller than half of its bottom area, leaving enough gap for deformation with the test block.

[0024] As an optional solution, in step 4, the central axis of the substrate is kept coincident with the central axis of the clamp to prevent the clamp from being pulled sideways when the clamp moves.

[0025] As an optional solution, the in-situ loading mode is specifically as follows:

[0026] Move the two clamps closer to each other to squeeze the substrate toward the middle and perform a compression test;

[0027] Moving the two clamps away from each other to pull the substrate outwards to perform a tensile test;

[0028] The two fixtures were moved to reciprocate along the central axis and maintained at a low frequency of 0.05 Hz to reciprocate the tension and compression of the substrate for fatigue loading experiments.

[0029] As an optional solution, the strain data of the test block is any one of the first strain gauge deformation variable or the grating deformation variable.

[0030] The technical effects achieved by the present invention are:

[0031] The present invention combines the in-situ loading mode of the in-situ loading platform with a micro-sample, a strain element and a substrate in a composite form. There is no need to modify or replace the clamp device of the in-situ loading platform. The tensile, compression or fatigue test of the micro-sample is achieved only through the tensile device of the in-situ loading platform, thereby simplifying the instrument operation process.

[0032] The present invention does not require the test sample to be processed into a special shape, nor does it require a large-sized test sample to meet the loading conditions, and can be used for in-situ experiments on micro-sized components that are difficult to process and prepare.

[0033] The present invention directly measures the deformation of a tiny sample by an electrical measurement method or an optical measurement method, thereby achieving accurate characterization of the deformation of the tiny sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of a method for in-situ tensile and compressive fatigue detection of micro-scale materials in Embodiment 1 of the present invention;

[0035] Figure 2 is a schematic diagram of a substrate in Embodiment 1 of the present invention;

[0036] Figure 3 This is a flow chart of a method for in-situ tensile and compressive fatigue detection of micro-scale materials in Embodiment 3 of the present invention;

[0037] Figure 4 It is a schematic diagram of the substrate in the third embodiment of the present invention.

[0038] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0039] 1. Base; 2. Micro sample; 3. Grating; 4. First strain gauge; 5. Clamping end; 6. Fabric area; 7. Second strain gauge. DETAILED DESCRIPTION

[0040] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0041] Embodiment 1:

[0042] like Figure 1-Figure 2 As shown, a method for in-situ tensile and compressive fatigue detection of micro-scale materials includes the following steps:

[0043] Step 1: Make base 1:

[0044] Select a stainless steel blank (such as a stainless steel plate or a stainless steel ingot) and place it on a CNC machining center for milling. The edge of the blank is rounded by a ball cutter. The base size is determined according to the fixture size, maximum load, and travel distance of the in-situ loading platform configured with a scanning electron microscope.

[0045] The base size can be selected as 60*10*2mm, the middle of the base is a material area 6 for placing the sample, and the two ends are clamping ends 5 for clamping the in-situ loading platform;

[0046] After the substrate 1 is formed, it needs to be placed in a mixed solution of acetone and alcohol for ultrasonic cleaning for about 15 minutes to remove pollutants on the surface of the substrate, and then placed under a baking lamp for at least 3 minutes for drying to keep it dry;

[0047] Step 2: Load the sample:

[0048] An alloy mold with a square hole is used to cover the base 1, and a sufficient amount of micro-sample 2 is taken to cover the square hole. The micro-sample 2 is solidified to the middle of the fabric area 6 by an adhesive, avoiding the clamping end 5. Since the micro-sample 2 is a cube, a test block can be formed at the square hole, which is convenient for the subsequent calculation of the strength σ;

[0049] In this embodiment, the length of the test block solidified into the micro-sample 2 is less than 29 mm, the width is less than 10 mm, and the thickness is less than 2 mm, so that it will not protrude from the top of the substrate 1, and it is not necessary to process the test sample into a special shape, nor is it necessary to have a large size of the test sample to meet the loading conditions. It can be used for in-situ experiments on micro-sized components that are difficult to process and difficult to prepare;

[0050] Among them, the adhesive can be selected from KD-855HL metal adhesive or DP8407NS metal bonding acrylic adhesive. The metal adhesive has the characteristics of low whitening, high transparency, and does not affect the appearance of the material. The metal bonding acrylic adhesive is a gray structural adhesive. Both can firmly adhere to the micro-sample 2 to prevent the micro-sample 2 from being separated from the substrate 1 due to shearing.

[0051] Note that the alloy mold with square holes should not contact the adhesive to prevent adhesion. Use a 4kg metal block to press the test block for 3 minutes. After the test block is stable, remove the metal block and alloy mold in turn.

[0052] Step 3: Install the strain gauge:

[0053] In order to accurately measure the deformation of the test block, the present embodiment adopts an electrical measurement method to collect data after deformation, mainly by using an adhesive to alternately fix the first strain gauge 4 and the second strain gauge 7 on the upper surface of the test block as a strain element for monitoring the strain signal of the test block, and the cables of the first strain gauge 4 and the second strain gauge 7 are kept away from the clamping end 5 to prevent damage;

[0054] See also Figure 1 , the first strain gauge 4 is arranged along the X-axis direction, and the second strain gauge 7 is arranged along the Y-axis direction, for collecting data in different directions to form the Poisson's ratio of the measuring test block, and the bonding area of ​​the two is less than half of the bottom area of ​​the two, leaving enough gap for deformation with the test block;

[0055] Step 4: Start the machine and clamp:

[0056] Open the clamp of the in-situ loading platform, clamp the substrate 1 from the two clamping ends 5, and leave a sufficient safety distance between the clamp and the test block. At this time, the central axis of the substrate 1 should be kept coincident with the central axis of the clamp as much as possible to prevent partial pulling when the clamp is moved;

[0057] Step 5: Apply load:

[0058] Start the servo motor and select the in-situ loading mode according to the experimental needs. You can perform tensile, compression or fatigue loading to achieve tensile, compression or fatigue experiments on tiny specimens, as follows:

[0059] The two clamps are moved closer to each other to squeeze the substrate 1 toward the middle to perform a compression test;

[0060] Moving the two clamps away from each other to pull the substrate 1 outward to perform a tensile test;

[0061] Move the two fixtures to reciprocate along the central axis, maintaining a low frequency of 0.05 Hz, for reciprocating tension and compression of the substrate 1 to perform a fatigue loading test;

[0062] This embodiment realizes the tensile, compression or fatigue test of the micro-sample only through the tensile device of the in-situ loading platform, which simplifies the instrument operation process. Since the adhesive firmly connects the test block and the substrate 1, the substrate 1 will drive the test block to deform synchronously, which is convenient;

[0063] Step 6: Calculate the results:

[0064] During the loading process, the loading strength σ borne by the test block is calculated as follows:

[0065] σ=Eε

[0066] Wherein, E is the elastic modulus of the test block, which can be measured by a nanoindenter, and ε is the strain data of the test block measured by the first strain gauge 4 .

[0067] Embodiment 2:

[0068] In order to reduce the contingency of the experiment in Example 1, this example provides a control experiment of Example 1.

[0069] like Figure 1-Figure 2 As shown, a method for in-situ tensile and compressive fatigue detection of micro-scale materials includes the following steps:

[0070] Step 1: Make the base 1:

[0071] An aluminum alloy blank (such as an aluminum alloy plate or an aluminum alloy ingot) is selected and placed in a CNC machining center for milling. The edge of the blank is rounded by a ball cutter. The base size is determined according to the fixture size, maximum load, and travel distance of the in-situ loading platform configured with a scanning electron microscope.

[0072] The base size can be selected as 60*10*2mm, the middle of the base is a material area 6 for placing the sample, and the two ends are clamping ends 5 for clamping the in-situ loading platform;

[0073] After the substrate 1 is formed, it needs to be placed in a mixed solution of acetone and alcohol for ultrasonic cleaning for about 15 minutes to remove pollutants on the surface of the substrate. Since aluminum alloy is easily burnt by heat, it is placed under a baking lamp for at least 1 minute for drying to keep it dry.

[0074] Step 2: Load the sample:

[0075] An alloy mold with a square hole is used to cover the base 1, and a sufficient amount of micro-sample 2 is taken to cover the square hole. The micro-sample 2 is solidified to the middle of the fabric area 6 by an adhesive, avoiding the clamping end 5. Since the micro-sample 2 is a cube, a test block can be formed at the square hole, which is convenient for the subsequent calculation of the strength σ;

[0076] In this embodiment, the length of the test block solidified into the micro-sample 2 is less than 29 mm, the width is less than 10 mm, and the thickness is less than 2 mm, so that it will not protrude from the top of the substrate 1, and it is not necessary to process the test sample into a special shape, nor is it necessary to have a large size of the test sample to meet the loading conditions. It can be used for in-situ experiments on micro-sized components that are difficult to process and difficult to prepare;

[0077] Among them, the adhesive can be selected from either KD-855HL metal adhesive or DP8407NS metal bonding acrylic adhesive. The metal adhesive has the characteristics of low whitening, high transparency, and does not affect the appearance of the material. The metal bonding acrylic adhesive is a gray structural adhesive. Both can firmly adhere to the micro-sample 2 to prevent the micro-sample 2 from being separated from the substrate 1 due to shearing.

[0078] Note that the alloy mold with square holes should not contact the adhesive to prevent adhesion. Use a 4kg metal block to press the test block for 3 minutes. After the test block is stable, remove the metal block and alloy mold in turn.

[0079] Step 3: Install the strain gauge:

[0080] In order to accurately measure the deformation of the test block, the present embodiment adopts an electrical measurement method to collect data after deformation, mainly by using an adhesive to alternately fix the first strain gauge 4 and the second strain gauge 7 on the upper surface of the test block as a strain element for monitoring the strain signal of the test block, and the cables of the first strain gauge 4 and the second strain gauge 7 are kept away from the clamping end 5 to prevent damage;

[0081] See also Figure 1 , the first strain gauge 4 is arranged along the X-axis direction, and the second strain gauge 7 is arranged along the Y-axis direction, for collecting data in different directions for calculating the Poisson's ratio of the test block, and the bonding area of ​​the two is less than half of the bottom area of ​​the two, leaving enough gap for deformation with the test block;

[0082] Step 4: Start the machine and clamp:

[0083] Open the clamp of the in-situ loading platform, clamp the substrate 1 from the two clamping ends 5, and leave a sufficient safety distance between the clamp and the test block. At this time, the central axis of the substrate 1 should be kept coincident with the central axis of the clamp as much as possible to prevent partial pulling when the clamp is moved;

[0084] Step 5: Apply load:

[0085] Start the servo motor and select the in-situ loading mode according to the experimental needs. You can perform tensile, compression or fatigue loading to achieve tensile, compression or fatigue experiments on tiny specimens, as follows:

[0086] The two clamps are moved closer to each other to squeeze the substrate 1 toward the middle to perform a compression test;

[0087] Moving the two clamps away from each other to pull the substrate 1 outward to perform a tensile test;

[0088] Move the two fixtures to reciprocate along the central axis, maintaining a low frequency of 0.05 Hz, for reciprocating tension and compression of the substrate 1 to perform a fatigue loading test;

[0089] This embodiment realizes the tensile, compression or fatigue test of the micro-sample only through the tensile device of the in-situ loading platform, which simplifies the instrument operation process. Since the adhesive firmly connects the test block and the substrate 1, the substrate 1 will drive the test block to deform synchronously, which is convenient;

[0090] Step 6: Calculate the results:

[0091] During the loading process, the loading strength σ borne by the test block is calculated as follows:

[0092] σ=Eε

[0093] Wherein, E is the elastic modulus of the test block, which can be measured by a nanoindenter, and ε is the strain data of the test block measured by the first strain gauge 4 .

[0094] Embodiment three:

[0095] like Figure 3-Figure 4 As shown, a method for in-situ tensile and compressive fatigue detection of micro-scale materials includes the following steps:

[0096] Step 1: Make the base 1:

[0097] An aluminum alloy blank (such as an aluminum alloy plate or an aluminum alloy ingot) is selected and placed in a CNC machining center for milling. The edge of the blank is rounded by a ball cutter. The base size is determined according to the fixture size, maximum load, and travel distance of the in-situ loading platform configured with a scanning electron microscope.

[0098] The base size can be selected as 60*10*2mm, the middle of the base is a material area 6 for placing the sample, and the two ends are clamping ends 5 for clamping the in-situ loading platform;

[0099] After the substrate 1 is formed, it needs to be placed in a mixed solution of acetone and alcohol for ultrasonic cleaning for about 15 minutes to remove pollutants on the surface of the substrate, and then placed under a baking lamp for at least 3 minutes for drying to keep it dry;

[0100] Step 2: Install the strain gauge:

[0101] In order to accurately measure the deformation of the test block, this embodiment uses optical measurement to collect data after deformation, mainly using a grating 3 prepared by electron beam lithography on the upper surface of the substrate 1 as a strain element to monitor the strain signal of the test block;

[0102] See also Figure 2 , the grating 3 is centered on the substrate 1 and can overlap with the central axes of the two fixtures, while the bonding area of ​​the grating 3 is less than half of its bottom area, leaving enough gap for deformation with the test block;

[0103] Step 3: Load the sample:

[0104] An alloy mold with a square hole is used to cover the base 1, and a sufficient amount of micro-sample 2 is taken to cover the square hole. The micro-sample 2 is solidified to the middle of the fabric area 6 by an adhesive, covering the grating 3 and avoiding the clamping end 5. Since the micro-sample 2 is a cube, a test block can be formed at the square hole, which is convenient for the subsequent calculation of the strength σ.

[0105] In this embodiment, the length of the test block solidified into the micro-sample 2 is less than 29 mm, the width is less than 10 mm, and the thickness is less than 2 mm, so that it will not protrude from the top of the substrate 1, and it is not necessary to process the test sample into a special shape, nor is it necessary to have a large size of the test sample to meet the loading conditions. It can be used for in-situ experiments on micro-sized components that are difficult to process and difficult to prepare;

[0106] Among them, the adhesive can be selected from KD-855HL metal adhesive or DP8407NS metal bonding acrylic adhesive. The metal adhesive has the characteristics of low whitening, high transparency, and does not affect the appearance of the material. The metal bonding acrylic adhesive is a gray structural adhesive. Both can firmly adhere to the micro-sample 2 to prevent the micro-sample 2 from being separated from the substrate 1 due to shearing.

[0107] Note that the alloy mold with square holes should not contact the adhesive to prevent adhesion. Use a 4kg metal block to press the test block for 3 minutes. After the test block is stable, remove the metal block and alloy mold in turn.

[0108] At the same time, an adhesive is used to adhere the first strain gauge 4 on the upper surface of the test block, avoiding the grating 3, and the detected strain data is used for reference, not for calculation results;

[0109] Step 4: Start the machine and clamp:

[0110] Open the clamp of the in-situ loading platform, clamp the substrate 1 from the two clamping ends 5, and leave a sufficient safety distance between the clamp and the test block. At this time, the central axis of the substrate 1 should be kept coincident with the central axis of the clamp as much as possible to prevent partial pulling when the clamp is moved;

[0111] Step 5: Apply load:

[0112] Start the servo motor and select the in-situ loading mode according to the experimental needs. You can perform tensile, compression or fatigue loading to achieve tensile, compression or fatigue experiments on tiny specimens, as follows:

[0113] The two clamps are moved closer to each other to squeeze the substrate 1 toward the middle to perform a compression test;

[0114] Moving the two clamps away from each other to pull the substrate 1 outward to perform a tensile test;

[0115] Move the two fixtures to reciprocate along the central axis, maintaining a low frequency of 0.05 Hz, for reciprocating tension and compression of the substrate 1 to perform a fatigue loading test;

[0116] This embodiment realizes the tensile, compression or fatigue test of the micro-sample only through the tensile device of the in-situ loading platform, which simplifies the instrument operation process. Since the adhesive firmly connects the test block and the substrate 1, the substrate 1 will drive the test block to deform synchronously, which is convenient;

[0117] Step 6: Calculate the results:

[0118] During the loading process, the loading strength σ borne by the test block is calculated as follows:

[0119] σ=Eε

[0120] Wherein, E is the elastic modulus of the test block, which can be measured by a nanoindenter before loading, and ε is the strain data of the test block measured by grating 3, which can be calculated by geometric phase analysis.

[0121] Embodiment 4:

[0122] In order to reduce the contingency of the experiment in Example 3, this example provides a control experiment of Example 1.

[0123] like Figure 3-Figure 4 As shown, a method for in-situ tensile and compressive fatigue detection of micro-scale materials includes the following steps:

[0124] Step 1: Make the base 1:

[0125] An aluminum alloy blank (such as an aluminum alloy plate or an aluminum alloy ingot) is selected and placed in a CNC machining center for milling. The edge of the blank is rounded by a ball cutter. The base size is determined according to the fixture size, maximum load, and travel distance of the in-situ loading platform configured with a scanning electron microscope.

[0126] The base size can be selected as 60*10*2mm, the middle of the base is a material area 6 for placing the sample, and the two ends are clamping ends 5 for clamping the in-situ loading platform;

[0127] After the substrate 1 is formed, it needs to be placed in a mixed solution of acetone and alcohol for ultrasonic cleaning for about 15 minutes to remove pollutants on the surface of the substrate, and then placed under a baking lamp for at least 3 minutes for drying to keep it dry;

[0128] Step 2: Install the strain gauge:

[0129] In order to accurately measure the deformation of the test block, this embodiment uses optical measurement to collect data after deformation, mainly using a grating 3 prepared by electron beam lithography on the upper surface of the substrate 1 as a strain element to monitor the strain signal of the test block;

[0130] See also Figure 2 , the grating 3 is centered on the substrate 1 and can overlap with the central axes of the two fixtures, while the bonding area of ​​the grating 3 is less than half of its bottom area, leaving enough gap for deformation with the test block;

[0131] Step 3: Load the sample:

[0132] An alloy mold with a square hole is used to cover the base 1, and a sufficient amount of micro-sample 2 is taken to cover the square hole. The micro-sample 2 is solidified to the middle of the fabric area 6 by an adhesive, covering the grating 3 and avoiding the clamping end 5. Since the micro-sample 2 is a cube, a test block can be formed at the square hole, which is convenient for the subsequent calculation of the strength σ.

[0133] In this embodiment, the length of the test block solidified into the micro-sample 2 is less than 29 mm, the width is less than 10 mm, and the thickness is less than 2 mm, so that it will not protrude from the top of the substrate 1, and it is not necessary to process the test sample into a special shape, nor is it necessary to have a large size of the test sample to meet the loading conditions. It can be used for in-situ experiments on micro-sized components that are difficult to process and difficult to prepare;

[0134] Among them, the adhesive can be selected from KD-855HL metal adhesive or DP8407NS metal bonding acrylic adhesive. The metal adhesive has the characteristics of low whitening, high transparency, and does not affect the appearance of the material. The metal bonding acrylic adhesive is a gray structural adhesive. Both can firmly adhere to the micro-sample 2 to prevent the micro-sample 2 from being separated from the substrate 1 due to shearing.

[0135] Note that the alloy mold with square holes should not contact the adhesive to prevent adhesion. Use a 4kg metal block to press the test block for 3 minutes. After the test block is stable, remove the metal block and alloy mold in turn.

[0136] At the same time, an adhesive is used to adhere the first strain gauge 4 on the upper surface of the test block, avoiding the grating 3, and the detected strain data is used for reference, not for calculation results;

[0137] Step 4: Start the machine and clamp:

[0138] Open the clamp of the in-situ loading platform, clamp the substrate 1 from the two clamping ends 5, and leave a sufficient safety distance between the clamp and the test block. At this time, the central axis of the substrate 1 should be kept coincident with the central axis of the clamp as much as possible to prevent partial pulling when the clamp is moved;

[0139] Step 5: Apply load:

[0140] Start the servo motor and select the in-situ loading mode according to the experimental needs. You can perform tensile, compression or fatigue loading to achieve tensile, compression or fatigue experiments on tiny specimens, as follows:

[0141] The two clamps are moved closer to each other to squeeze the substrate 1 toward the middle to perform a compression test;

[0142] Moving the two clamps away from each other to pull the substrate 1 outward to perform a tensile test;

[0143] Move the two fixtures to reciprocate along the central axis, maintaining a low frequency of 0.05 Hz, for reciprocating tension and compression of the substrate 1 to perform a fatigue loading test;

[0144] This embodiment realizes the tensile, compression or fatigue test of the micro-sample only through the tensile device of the in-situ loading platform, which simplifies the instrument operation process. Since the adhesive firmly connects the test block and the substrate 1, the substrate 1 will drive the test block to deform synchronously, which is convenient;

[0145] Step 6: Calculate the results:

[0146] During the loading process, the loading strength σ borne by the test block is calculated as follows:

[0147] σ=Eε

[0148] Wherein, E is the elastic modulus of the test block, which can be measured by a nanoindenter, and ε is the strain data of the test block measured by grating 3;

[0149] Embodiment five:

[0150] The present invention also provides a micro-scale material in-situ tension and compression fatigue detection system, the system comprising:

[0151] A memory, for storing computer programs, which may also be a flash memory;

[0152] The computer program is an application program, a functional module, etc. for implementing the in-situ tensile and compressive fatigue detection method of micro-scale materials in Embodiments 1 to 4;

[0153] The processor is used to execute the computer program stored in the memory to implement the various steps performed by the device in the in-situ tensile and compressive fatigue detection method for micro-scale materials in Examples 1 to 4. For details, please refer to the relevant description in the previous method embodiments.

[0154] As an optional embodiment, the memory may be independent or integrated with the processor;

[0155] When the memory is a device independent of the processor, the system may further include:

[0156] A bus that connects memory and processor.

[0157] Among them, the readable storage medium can be a computer storage medium or a communication medium. Communication media include any medium that facilitates the transfer of computer programs from one place to another. Computer storage media can be any available medium that can be accessed by general-purpose or special-purpose computers. For example, a readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application-specific integrated circuit (Application Specific Integrated Circuits, abbreviated as: ASIC). In addition, the ASIC can be located in a user device. Of course, the processor and the readable storage medium can also exist in a communication device as discrete components. The readable storage medium can be a ROM (read-only memory), a RAM (random access memory), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0158] The present invention also provides a readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, it is used to implement the steps provided in the in-situ tensile and compressive fatigue detection method of micro-scale materials in Examples 1 to 4.

[0159] The present invention also provides a program product, which includes an execution instruction, which is stored in a readable storage medium. At least one processor of a device can read the execution instruction from the readable storage medium, and at least one processor executes the execution instruction so that the device implements the method provided in Embodiments 1 to 4.

[0160] In the embodiments of the above-mentioned devices, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0161] The above is only an optional implementation of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A method for in-situ tensile and compressive fatigue detection of micro-scale materials, characterized in that: The following steps are involved: Step 1: Select the blank and make the base by milling and chamfering; Step 2: Take a sufficient amount of micro-samples, and use adhesive to solidify the micro-samples onto the substrate to form test blocks of a certain size for later use; Step 3: Fix the strain element on the outer surface of the test block by adhesive to monitor the strain signal of the test block and avoid the in-situ loading platform; Step 4: Open the clamp of the in-situ loading platform, clamp the base from both ends, keep a safe distance between the clamp and the test block, and complete the loading of the micro-sample; Step 5: Start the in-situ loading platform and select the in-situ loading mode according to the experimental needs to realize the tensile, compression or fatigue test of the micro specimen; Step 6: During the loading process, the strain data of the test block is obtained, and the loading intensity borne by the test block is calculated using the Hooke's law formula.

2. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 1, characterized in that: The blank is made of stainless steel or aluminum alloy, is formed by milling, has a material distribution area in the middle, and has clamping ends at both ends for clamping the in-situ loading platform.

3. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 1 is characterized in that: After the substrate is formed, it needs to be placed in a mixed solution of acetone and alcohol for ultrasonic cleaning for about 15 minutes to remove pollutants on the surface of the substrate, and then placed under a baking lamp for at least 3 minutes for drying to keep it dry.

4. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 1, characterized in that: The adhesive is any one of KD-855HL metal adhesive or DP8407NS metal bonding acrylic adhesive.

5. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 2, characterized in that: The micro-sample solidification in step 2 is specifically as follows: Use an alloy mold with square holes to cover the base, take enough micro-samples to cover the square holes, and use adhesive to solidify the micro-samples in the middle of the fabric area, avoiding the clamping end; Alloy molds with square holes avoid adhesives to prevent sticking; Press the test block with a metal block for 3 minutes. After the test block is stable, remove the metal block and the alloy mold in turn.

6. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 1, characterized in that: The strain element is either a first strain gauge or a grating.

7. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 6, characterized in that: The bonding area of ​​the strain element is smaller than half of its bottom area, leaving enough gap for deformation with the test block.

8. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 6, characterized in that: In the step 4, the central axis of the substrate is kept coincident with the central axis of the fixture to prevent eccentric pulling when the fixture moves.

9. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 1, characterized in that: The in-situ loading mode is specifically as follows: Move the two clamps closer to each other to squeeze the substrate toward the middle and perform a compression test; Moving the two clamps away from each other to pull the substrate outwards to perform a tensile test; The two fixtures were moved to reciprocate along the central axis and maintained at a low frequency of 0.05 Hz to reciprocate the tension and compression of the substrate for fatigue loading experiments.

10. The in-situ tensile and compressive fatigue detection method for micro-scale materials according to claim 1, characterized in that: The strain data of the test block is any one of the first strain gauge deformation variable and the grating deformation variable.

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