A combined device for micro-punching shear test and Brinell hardness measurement of metal materials

Abstract

A metal material micro-punching shear test and Brinell hardness combined measurement device, comprising a testing machine, a tooling die is installed on the base of the testing machine, and the tooling die clamps the sample; a load sensor is installed at the output end of the testing machine, and the load sensor is connected to the punch through a detachable connector, and the punch is directly opposite to the punching hole on the tooling die; a position measuring device is installed on the tooling die and the punch or on the base of the testing machine and the output end of the testing machine; the tooling die includes a lower boss, the lower boss is matched with the inner hole of the die positioning sleeve, the die is placed in the die positioning sleeve and is positioned by the die positioning sleeve; the inner hole of the outer sleeve is matched with the outer circumference of the die positioning sleeve; the upper boss is matched with the inner hole of the outer sleeve and is detachably fixed to the outer sleeve and the lower boss through screws. A metal material micro-punching shear test and Brinell hardness combined measurement device provided by the present invention can improve the accuracy of the test and complete the Brinell hardness test at the same time.

Description

Technical Field

[0001] The invention relates to a testing device, in particular to a metal material micro-punching shearing test and Brinell hardness combined measuring device. Background Art

[0002] At present, the mechanical properties of metal material strength are mainly characterized by two indicators: yield strength and tensile strength. The test of these two indicators is usually completed by a unidirectional static load tensile test. The test requires the preparation of standard tensile specimens. Common specimens are plate type and round rod type. The total length is about 200mm. The specimen size is large. The test result is the average mechanical property of the specimen during the tensile process, so it cannot test the local mechanical properties of the material and the specimens with uneven mechanical properties of the material (such as the mechanical properties of the weld area) and the local mechanical properties of smaller specimens.

[0003] At present, the main methods for measuring local mechanical properties include micro-shear test, micro-tensile test and small punch test, but each test method has certain limitations.

[0004] Micro shear test method This method uses a point-by-point shearing method to test the mechanical performance index of each test point on a smaller piece of material (1.5mm*1.5mm*50mm square cross-section long strip sample). The test accuracy of this method is heavily dependent on the processing accuracy of the sample and the test equipment. The test error is large, and it cannot test the tensile properties of the material.

[0005] Micro-tensile test method The micro-tensile test method is to cut a small piece of sample from the test material (usually the sample thickness is less than 1mm), and then obtain the mechanical properties of the material through the tensile test method to determine the relationship between stress and strain. However, the sample form and test equipment of this test method are not unified. The preparation of the sample has a great influence on the test results, and it is not ideal in practical application.

[0006] Small punch test method This method uses a steel ball or punch with a smaller diameter to apply a downward load to the center of the micro-thin sample. The deformation of the sample gradually increases with the increase of the load until it breaks. The loading load and displacement data of the sample from deformation to failure are recorded to generate a load-displacement curve. However, the load and displacement data obtained by this test method are essentially a comprehensive mechanical property, which includes the results of multiple mechanical properties such as tension and shear, and the evaluation of a single mechanical property index is not accurate. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a combined measuring device for micro-punching and shearing test and Brinell hardness of metal materials. The present invention adopts a very small gap and boss pressing method to clamp the sample through the tooling mold to ensure that the sample is completely fixed during the test, and no rigid displacement and elastic slip will occur, thereby avoiding the generation of tensile force and bending force components to the greatest extent, making the shear force purer and single, and making the test results more accurate, so as to analyze the load-displacement data of the local position of the test material under the punching and shearing action, and obtain the strength and plasticity indicators of the material; and the function of Brinell hardness test can be realized at the same time.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A metal material micro punching shear test and Brinell hardness combined measurement device, comprising a testing machine, a tooling die is installed on the base of the testing machine, and the tooling die clamps the sample; a load sensor is installed at the output end of the testing machine, and the load sensor is connected to the punch through a detachable connecting piece, and the punch is directly opposite to the punching hole on the tooling die; a position measuring device is installed on the tooling die and the punch or on the base of the testing machine and the output end of the testing machine;

[0010] The tooling mold includes a lower boss, which cooperates with the inner hole of the die positioning sleeve, and the die is placed in the die positioning sleeve and positioned by the die positioning sleeve; the inner hole of the outer sleeve cooperates with the outer circumference of the die positioning sleeve; the upper boss cooperates with the inner hole of the outer sleeve and is detachably fixed to the outer sleeve and the lower boss through screws.

[0011] A material leakage hole is arranged on the base of the testing machine, and a positioning sleeve is arranged coaxially above the material leakage hole, and the positioning sleeve positions the lower boss.

[0012] The outer sleeve is provided with a spring installation hole, and the spring is placed in the spring installation hole and partially extends out.

[0013] The detachable connecting piece comprises a connecting sleeve, which connects the boss of the punch with the spherical ejector rod, and the upper end of the spherical ejector rod is connected with the load sensor.

[0014] The punch is a micro-punching punch or a Brinell hardness indenter.

[0015] The present invention provides a metal material micro-punching shear test and Brinell hardness combined measurement device, which has the following technical effects:

[0016] 1) Integrate the hardness test and the punching and shear test to keep the test conditions consistent, making the test results comparable and reducing errors caused by inconsistent equipment.

[0017] 2) The tooling mold is fixed by nesting positioning, with accurate positioning. The punch and die can be quickly disassembled while ensuring rigidity, so that the punch and die can be replaced as needed to improve efficiency.

[0018] 3) As the original device has tensile and bending force components, this device adopts a very small gap and boss pressing method to clamp the sample through the tooling mold to ensure that the sample is completely fixed during the test, without rigid displacement and elastic slippage, and to avoid the generation of tensile and bending force components to the greatest extent, making the shear force purer and single, and making the test results more accurate.

[0019] 4) Since the accuracy of traditional LVDT displacement sensors will decrease due to friction, this device can use LVDT displacement sensors as initial displacement measurement and laser displacement sensors as fine displacement measurement, so that the measurement accuracy can reach within 2 microns. Since the laser displacement sensor is non-contact measurement during testing, there is no friction and the accuracy is guaranteed.

[0020] 5) Compared with the unidirectional static load tensile test, the present invention will use the test of local shear mechanical properties to evaluate the mechanical properties of smaller specimens, which can better solve the problem that traditional tensile specimens are not suitable for evaluating the mechanical properties of small specimen materials; Compared with the micro-shear test method, the present invention uses high-carbon alloy steel or cemented carbide as the material of the working part of the specimen device, adopts high-precision processing technology to ensure the processing accuracy and the stability of the device during the specimen process, and adopts high-precision pressure sensors and displacement sensors to ensure the accuracy of the test results, solving the problem of large test errors; For the existing small punch test method, the present invention adopts a very small gap and boss pressing method to clamp the specimen through the tooling mold, ensuring that the specimen is completely fixed during the test, and no rigid displacement and elastic slippage will occur, thereby avoiding the generation of tensile force and bending force components to the greatest extent, making the shear force more pure and single, and making the test results more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0022] Figure 1 It is a schematic diagram of the present invention.

[0023] Figure 2 for Figure 1 A partial schematic diagram of .

[0024] Figure 3 It is a top view of the tooling mold in the present invention.

[0025] Figure 4 for Figure 3 Top view of point A in the middle.

[0026] Figure 5 It is a top view of the tooling mold in the present invention.

[0027] Figure 6 for Figure 5 Top view of point B in the middle.

[0028] In the figure: testing machine 1, tooling die 2, test specimen 3, load sensor 4, detachable connector 5, punch 6, leakage hole 7, positioning sleeve 8, lower boss 2.1, outer sleeve 2.2, spring 2.3, upper boss 2.4, screw 2.5, die 2.6, die positioning sleeve 2.7, connecting sleeve 5.1, spherical ejector pin 5.2. DETAILED DESCRIPTION

[0029] like Figures 1-2 As shown, a metal material micro-punching shear test and Brinell hardness combined measurement device includes a testing machine 1, on which a tooling die 2 is installed, and the tooling die 2 is used to clamp a sample 3. The moving crossbeam of the testing machine 1 is connected to a punch 6 through a detachable connecting member 5, and the punch 6 is directly opposite to the punching hole on the tooling die 2. When the moving crossbeam of the testing machine 1 moves downward, the punch 6 also moves downward and completes the test.

[0030] In order to accurately obtain the data required for the test, a load sensor 4 is set between the moving crossbeam and the detachable connecting member 5, and the load sensor 4 is used to obtain load data. A position measuring device 9 is installed on the moving crossbeam of the testing machine 1 and on the workbench at the lower end of the testing machine 1, and the position measuring device 9 is used to obtain displacement data. Alternatively, the position measuring device 9 can also be installed between the tooling die 2 and the punch 6 for measurement, so that the data is more accurate.

[0031] like Figures 3 to 6 As shown, the tooling die 2 includes a lower boss 2.1, the lower end of which is fixedly connected to the base of the testing machine 1, the lower boss 2.1 has a hole in the center and a cylindrical protrusion on the upper part, and the cylindrical protrusion of the lower boss 2.1 cooperates with the inner hole of the die positioning sleeve 2.7. The die 2.6 is installed into the inner hole of the die positioning sleeve 2.7 and the outer wall is positioned by the die positioning sleeve 2.7, and the bottom end of the die 2.6 is supported by the lower boss 2.1. A micro-punching hole is provided in the center of the die 2.6. The inner hole of the outer sleeve 2.2 cooperates with the outer wall of the die positioning sleeve 2.7.

[0032] The upper boss 2.4 is positioned with the inner hole of the outer sleeve 2.2, and four screws 2.5 pass through the four through holes on the upper boss 2.4, and then pass through the threaded holes on the outer sleeve 2.2 and the boss 2.1 to press the sample 3 between the upper boss 2.4 and the die 2.6. In addition, a spring mounting hole is drilled at a suitable position of the outer sleeve 2.2, and the spring 2.3 is placed in the spring mounting hole and partially extended. When the four screws 2.5 are unscrewed, the upper boss 2.4 is lifted upward along the axial direction under the action of the springs 2.3 on both sides, and the sample 3 can move forward and backward.

[0033] Here, the lower boss 2.1, the outer sleeve 2.2, the die 2.6, the die positioning sleeve 2.7 and other parts are installed in a small clearance fit. The entire tooling mold 2 is basically installed in a nested positioning manner, which is more accurate in positioning and more compact in structure than the pin or block positioning mode used in traditional molds.

[0034] like Figure 2 As shown, a countersunk material leakage hole 7 is drilled in the center of the base of the test machine 1, a positioning sleeve 8 is arranged in the material leakage hole 7, and the tooling mold 2 is correspondingly provided with a countersunk hole similar to the material leakage hole 7, the lower end of the tooling mold 2 is positioned by the positioning sleeve 8, and the edge of the tooling mold 2 is fixed to the base of the test machine 1 by bolts, thereby ensuring the uniformity of the installation position.

[0035] like Figure 2 As shown, the detachable connector 5 includes a connecting sleeve 5.1, which connects the boss of the punch 6 to the spherical top rod 5.2, and the upper end of the spherical top rod 5.2 is connected to the load sensor 4. By setting the punch 6 to be detachable from the spherical top rod 5.2, it is convenient to replace the punch 6.

[0036] Furthermore, the punch 6 is a micro-punching punch or a Brinell hardness indenter. Thus, two loading modes can be implemented on the same device, which has the advantage of testing two mechanical properties on the same device, avoiding errors caused by differences between different devices, thereby avoiding the situation where the test results cannot be compared.

[0037] Furthermore, the punch 6 will be made into a circle with a diameter of Φ5mm, or a square with a side length of 4-5mm, a rectangle with a side length of less than 20mm, or other forms of polygons (with a total side length not exceeding 20mm).

[0038] Furthermore, in order to ensure the punching and shearing performance, the chamfers of the punch 6 and the die 2.6 are initially required to be no greater than 0.1 mm; and the single-side gap between the punch 6 and the die 2.6 is required to be no greater than 0.1 mm.

[0039] In the above device, the punching and shearing specimen is in sheet form, with a maximum width of no more than 100mm (generally about 50mm), a maximum thickness of no more than 1.2mm (generally 0.5mm-1.0mm), and no restriction in the length direction; the Brinell hardness specimen is not less than 3mm in thickness, with the same width as the punching and shearing specimen and a length direction of no more than 100mm.

[0040] In the above device, the load requirements are: the load is not less than 500Kgf; the recommended precision range is 500Kgf, and the maximum range is 750Kgf; the loading method requires that it can be loaded by displacement and by required force, and the holding time can be adjusted.

[0041] In the above device, the test accuracy is: the test machine accuracy is 0.5 level, and an external displacement sensor (preferably a laser displacement sensor, considering economic conditions, a mechanical displacement sensor can be used initially) and a load sensor are required. According to the needs of the test, an extensometer can be installed (mainly considering the needs of tensile tests). Preferably, the load sensor 4 uses a spoke load sensor PSD-SJTH-500kg; a JHBM-7-300 load sensor can also be used. The position measuring device 9 uses a laser sensor LOD2-30W04 with a resolution of 2 microns and a repeatability of 6 microns; an LVDT displacement sensor YDC-20D can also be used.

[0042] Working process and principle:

[0043] 1) First, prepare the sample: the thickness of sample 3 should be uniform, the thickness error should be controlled within ±0.05mm, the surface should be smooth, and the surface roughness should not be greater than Ra1.6μm. The maximum thickness of the micro-punching sample 3 should not exceed 1.2mm, and the minimum thickness of the Brinell hardness sample should not be less than 3.0mm.

[0044] 2) Test operation process: mark the position of the sample 3 to be tested, then place the sample 3 on the position where the sample is placed on the tooling die 2, then align the punch 6 with the position to be tested, and then start the test machine. When performing a micro-punching and shearing test, just use the punch 6 as a micro-punching and shearing punch and load it in the micro-punching and shearing mode. When performing a Brinell hardness test, replace the punch 6 with a Brinell hardness indenter and load it in the Brinell hardness loading mode.

[0045] The measured position data and load data can be collected and processed by the data acquisition card to process the micro punching and shearing test data. The tensile performance data of the material can be calculated by the shear performance data according to the theory of material mechanics, achieving the purpose of using a small sample to test the tensile mechanical properties of the material. The test results of the Brinell hardness are measured and processed by the Brinell hardness calculation formula.

Claims

1. A combined measuring device for micro-punching shear test and Brinell hardness test of metal materials, characterized in that: The test machine (1) comprises a tooling die (2) installed on the base of the test machine (1), and the tooling die (2) clamps the sample (3); a load sensor (4) is installed on the output end of the test machine (1), and the load sensor (4) is connected to a punch (6) through a detachable connecting piece (5), and the punch (6) is directly opposite to the punching hole on the tooling die (2); a position measuring device (9) is installed on the tooling die (2) and the punch (6) or on the base of the test machine (1) and the output end of the test machine (1); The tooling die (2) comprises a lower boss (2.1), the lower boss (2.1) matches with the inner hole of the die positioning sleeve (2.7), the die (2.6) is placed in the die positioning sleeve (2.7) and positioned by the die positioning sleeve (2.7); the inner hole of the outer sleeve (2.2) matches with the outer circumference of the die positioning sleeve (2.7); the upper boss (2.4) matches with the inner hole of the outer sleeve (2.2) and is detachably fixed to the outer sleeve (2.2) and the lower boss (2.1) by screws (2.5); The lower boss (2.1) has a hole in the center and a cylindrical protrusion on the upper part. The cylindrical protrusion of the lower boss (2.1) matches with the inner hole of the die positioning sleeve (2.7), and the bottom end of the die (2.6) is supported by the lower boss (2.1); A micro-punching hole is provided at the center of the concave die (2.6), a spring mounting hole is drilled at a suitable position of the outer sleeve (2.2), and the spring (2.3) is placed in the spring mounting hole and partially extends out; when the four screws (2.5) are screwed out, the upper boss (2.4) is lifted upward along the axial direction under the action of the springs (2.3) on both sides.

2. A metal material micro-punching shear test and Brinell hardness combined measurement device according to claim 1, characterized in that: A material leakage hole (7) is provided on the base of the testing machine (1), and a positioning sleeve (8) is coaxially provided above the material leakage hole (7), and the positioning sleeve (8) positions the lower boss (2.1).

3. A metal material micro-punching shear test and Brinell hardness combined measurement device according to claim 1, characterized in that: The outer sleeve (2.2) is provided with a spring installation hole, and the spring (2.3) is placed in the spring installation hole and partially protrudes out.

4. A metal material micro-punching shear test and Brinell hardness combined measurement device according to claim 1, characterized in that: The detachable connecting member (5) comprises a connecting sleeve (5.1), the connecting sleeve (5.1) connects the boss of the punch (6) with the spherical top rod (5.2), and the upper end of the spherical top rod (5.2) is connected to the load sensor (4).

5. The metal material micro-punching shear test and Brinell hardness combined measurement device according to claim 1, characterized in that: The punch (6) is a micro-punching punch or a Brinell hardness indenter.

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