A method of testing the diamond holding power of an iron-based matrix

Abstract

The present application relates to the technical field of diamond tool, and particularly relates to a method for testing the holding force of iron-based matrix and diamond. First, composite powder is prepared through a mixing device, and 10g of the composite powder is weighed. 5g of the composite powder is added into a graphite mold, and a pressure of 10-20MPa is applied. A hole is punched in the middle position of the graphite mold cold-pressed blank, and a diamond is embedded in the punched position by using tweezers. The remaining 5g of the composite powder is added into the graphite mold. The graphite mold is placed in a sintering device for sintering, the sintering temperature is 760-840 DEG C, the holding time is 5-10min, and the sintering pressure is 30-40MPa. The sample is polished for a three-point bending test, the area S1 of the cross section is measured under a 3D microscope, and the area S2 of the diamond fracture surface is measured. The holding force is calculated through a holding force calculation formula. The test method used in the present application can accurately calculate the tensile force value borne by a single diamond. The embedding idea adopted in the present application can reflect the real situation of the diamond in the matrix.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of diamond tools, in particular to a method for testing the holding force of iron-based matrix and diamond. BACKGROUND

[0002] At present, diamond tools are widely used in mining, marble and granite cutting. There is no suitable method to judge the problem of diamond falling off in the production process. The holding force is used to represent the size of the interaction force between the diamond and the matrix. The holding force affects the service life of the diamond tool. Therefore, the present application provides a simple and accurate method for testing the holding force, which provides a new idea for studying the problem of diamond falling off.

[0003] Application No. CN201920084065.7 designs a device for measuring the holding force of diamond tool matrix on diamond in situ. The composite material of the fixed matrix and diamond is grabbed by the jaw and pulled upward to measure the holding force. In the literature, the diamond is regarded as a sphere, and the embedding force of the metal matrix and the diamond is calculated by using the formula of elasticity. The defect is that the diamond is actually a hexahedron or octahedron, and the contact area with the matrix cannot be equivalent to the sphere. SUMMARY

[0004] Other features and advantages of the present application will be set forth in the following specification, and in part will become apparent from the specification, or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and obtained by the structure specifically pointed out in the specification and other accompanying drawings.

[0005] The purpose of the present application is to overcome the above-mentioned shortcomings, and provide a method for testing the holding force of iron-based matrix and diamond.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: a method for testing the holding force of iron-based matrix and diamond, comprising the following steps

[0007] (1) First, mix Fe, Al, Cu and Sn into uniform composite powder by mixing equipment, wherein the content of Fe is 55wt%-70wt%, the content of Al is 4wt%-9wt%, the content of Cu is 15wt%-25wt%, and the content of Sn is 1wt%-1.5wt%.

[0008] (2) Weigh 10g of the above-mentioned composite powder prepared by the formula.

[0009] (3) Add 5g of the composite powder to the graphite mold, and apply a pressure of 10-20MPa.

[0010] (4) Punch a hole in the middle of the graphite mold cold-pressed blank, with a depth of 0.2-0.4 mm, a number of 4-12 particles, and a diamond particle size of 50 / 60 mesh, which is uniformly distributed in the middle of the composite powder.

[0011] (5) Embed the diamond into the punched position with tweezers.

[0012] (6) Add the remaining 5 g of composite powder to the graphite mold.

[0013] (7) Place the graphite mold in a sintering device for sintering, with a sintering temperature of 760-840 DEG C, a holding time of 5-10 min, and a sintering pressure of 30-40 MPa.

[0014] (8) Grind the sample for a three-point bending test, press down along the middle line position where the diamond is added, and record the elastic modulus E1 of the diamond particles, the elastic modulus E2 of the matrix, and the bending strength E1 of the diamond particles in the process.

[0015] (9) Measure the area S1 of the section and the area S2 of the diamond fracture surface under a 3D microscope. wherein the interference shrinkage deformation rate of the matrix to the diamond is epsilon, which is caused by the difference in cooling shrinkage coefficients of the diamond and the matrix. S1: the area of the matrix embedding the diamond (mm 2 ), S2: the area of the diamond particles (mm 2 ), E1: the elastic modulus of the diamond particles (GPa), and E2: the elastic modulus of the matrix (GPa).

[0016] The existing technology has a large operation difficulty, the diamond particles are small, and most of the diamonds have edges and corners, so the design of the clamping jaw is difficult and difficult to achieve. The holding force of the metal matrix and the diamond is currently calculated by some scholars considering the diamond as a sphere, and there is an error between the actual situation and the theoretical calculation. The present application first places the matrix on the graphite mold and punches a hole after pressing, then embeds the diamond into the matrix, and then calculates the corresponding holding force after the sample is subjected to a bending test and the data are recorded. The method is simple and the data are accurate.

[0017] In some embodiments, the mixing device is a three-dimensional mixer, a planetary ball mill, or a horizontal high-energy ball mill.

[0018] In some embodiments, the size of the graphite mold is 25 mm*8 mm*6 mm.

[0019] In some embodiments, the sintering method of the graphite mold in the sintering device is any one of vacuum hot pressing, hot isostatic pressing, and plasma sintering.

[0020] In some embodiments, the bending resistance test uses a holding force detection device, and the detection mode of the holding force detection device is any one of a support roller type bending, a V-shaped die type bending, a vice type bending, and a plate type bending.

[0021] In some embodiments, the diamond is arranged in the metal matrix in a direction.

[0022] In some embodiments, the method for testing the holding force of the iron-based matrix and the diamond is used to accurately determine the holding force between the metal matrix and the diamond.

[0023] By adopting the technical scheme, the application has the following beneficial effects:

[0024] 1. The test method used in the application can accurately calculate the tensile force value of a single diamond, and visually describe the holding force between the metal matrix and the diamond.

[0025] 2. The application has high technical feasibility and is easy to operate compared with other technologies.

[0026] 3. The application can reflect the real situation of the diamond in the matrix by using the embedding idea.

[0027] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure.

[0028] It is obvious that the above purposes and other purposes of the application will become more apparent after the description of the preferred embodiments of the application with various drawings and diagrams.

[0029] In order to make the above and other purposes, features and advantages of the application more obvious and easy to understand, one or more preferred embodiments are described in detail below, and the drawings are shown, and the detailed description is as follows. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings are used to provide a further understanding of the application, and constitute a part of the specification, and are used to explain the application together with the embodiments of the application, and do not constitute a limitation on the application.

[0031] In the drawings, the same components are marked with the same reference numerals, and the drawings are schematic and are not necessarily drawn according to the actual proportions.

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description can only be one or several embodiments of the application, and those skilled in the art can obtain other drawings according to such drawings without creative labor.

[0033] Figure 1 FIG. 1 is a structural schematic diagram of the area S1 of the section and the area S2 of the diamond fracture surface in the embodiment 1 of the present application;

[0034] Figure 2 FIG. 2 is a structural schematic diagram of the area S1 of the section and the area S2 of the diamond fracture surface in the embodiment 2 of the present application;

[0035] Figure 3 FIG. 3 is a structural schematic diagram of the area S1 of the section and the area S2 of the diamond fracture surface in the embodiment 3 of the present application. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not used to limit the present application.

[0037] In addition, in the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0038] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. However, it is noted that direct connection means that the connection between the two main bodies does not form a connection relationship through a transition structure, but only connects through a connection structure to form a whole. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0039] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can 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. In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0040] According to some embodiments of the present application, the present application provides a method for testing the holding force of an iron-based matrix with a diamond, comprising the following steps

[0041] (1) First, mix Fe, Al, Cu, Sn into a uniform composite powder by a mixing device, wherein the Fe content is 55wt%-70wt%, the Al content is 4wt%-9wt%, the Cu content is 15wt%-25wt%, and the Sn content is 1wt%-1.5wt%. wt% is the unit of weight (mass) percentage, indicating the weight ratio and the proportion of a substance in the mixture.

[0042] (2) Take 10g of the composite powder prepared according to the above formula.

[0043] (3) Add 5g of the composite powder to a graphite mold and apply a pressure of 10-20MPa.

[0044] (4) Punch a hole in the middle position of the graphite mold cold-pressed blank, with a depth of 0.2-0.4mm, a number of 4-12 particles, and a diamond particle size of 50 / 60 mesh, uniformly distributed in the middle position of the composite powder.

[0045] (5) Embed the diamond into the punched position with tweezers.

[0046] (6) Add the remaining 5g of the composite powder to the graphite mold.

[0047] (7) Place the graphite mold in a sintering device for sintering, with a sintering temperature of 760℃-840℃, a holding time of 5-10min, and a sintering pressure of 30-40MPa.

[0048] (8) Grind the sample for a three-point bending test, and press down along the middle line position where the diamond is added. In this process, record the elastic modulus E1 of the diamond particles and the elastic modulus E2 of the matrix.

[0049] (9) The area S1 of the section and the area S2 of the diamond fracture surface are measured under a 3D microscope, and the holding force F is calculated

[0050]

[0051] The existing technology has the problems of high operation difficulty, small diamond particles, and most of the diamonds have edges, so that the design of the claw is difficult to achieve. The scholars currently calculate the holding force of the metal matrix and the diamond by regarding the diamond as a sphere, and there is an error between the actual situation and the theoretical calculation. The present application first punches a hole in the graphite mold and inserts the matrix, then embeds the diamond into the matrix, and after high-temperature sintering, the sample is subjected to a bending test and the data are recorded to calculate the corresponding holding force. The method is simple and the data are accurate.

[0052] According to some embodiments of the present application, the mixing device is a three-dimensional mixer, a planetary ball mill, or a horizontal high-energy ball mill.

[0053] According to some embodiments of the present application, the size of the graphite mold is 25mm*8mm*6mm.

[0054] According to some embodiments of the present application, the sintering method of the graphite mold in the sintering device is any one of vacuum hot pressing, hot isostatic pressing, and plasma sintering.

[0055] According to some embodiments of the present application, the bending test uses a holding force detection device for testing, and the detection method of the holding force detection device is any one of a roller-type bending, a V-shaped mold bending, a vice-type bending, and a plate-type bending.

[0056] According to some embodiments of the present application, the diamond is arranged in the metal matrix.

[0057] According to some embodiments of the present application, the method for testing the holding force of the iron-based matrix and the diamond is used to accurately obtain the holding force between the metal matrix and the diamond.

[0058] Example 1

[0059] Reference Figure 1 , Figure 1 The present application is a schematic diagram of the area S1 of the section and the area S2 of the diamond fracture surface in Example 1.

[0060] The present application provides a method for testing the holding force of the iron-based matrix and the diamond, which comprises the following steps

[0061] (1) First, mix Fe, Al, Cu, Sn into a uniform composite powder by a three-dimensional mixer, wherein the content of Fe is 70wt%, the content of Al is 4wt%, the content of Cu is 25wt%, and the content of Sn is 1wt%.

[0062] (2) Take 10g of the composite powder prepared according to the above formula.

[0063] (3) Add 5g of the composite powder to a graphite mold, and apply a pressure of 10MPa.

[0064] (4) Punch holes in the middle position of the 25mm*8mm*6mm graphite mold cold-pressed blank, with a depth of 0.2mm, a number of 8, a diamond particle size of 50 / 60 mesh, and uniformly distributed in the middle position of the composite powder.

[0065] (5) Embed the diamond in the punched position with tweezers, and arrange the diamond in the metal matrix in a directional manner.

[0066] (6) Add the remaining 5g of the composite powder to the graphite mold.

[0067] (7) Place the graphite mold in a sintering device for sintering, with a sintering temperature of 840℃, a holding time of 5min, and a sintering pressure of 30MPa.

[0068] (8) Polish the sample for three-point bending test, press down along the middle line position where the diamond is added, and record the elastic modulus E1 of the diamond particles and the elastic modulus E2 of the matrix in the process.

[0069] (9) Measure the area S1 of the cross section and the area S2 of the diamond fracture surface under a 3D microscope, and calculate the holding force

[0070]

[0071] The sintering mode of the graphite mold in the sintering device is vacuum hot pressing. The holding force detection device is used for the bending test, and the detection mode of the holding force detection device is the roller type bending.

[0072] Example 2

[0073] Reference Figure 2 , Figure 2 is a structural schematic view of the area S1 of the cross section and the area S2 of the diamond fracture surface in Example 2 of the present application.

[0074] The present embodiment provides a method for testing the holding force of an iron-based matrix and diamond, comprising the following steps

[0075] (1) First, mix Fe, Al, Cu, Sn into a uniform composite powder by a planetary ball mill, wherein the Fe content is 65wt%, the Al content is 9wt%, the Cu content is 24.5wt%, and the Sn content is 1.5wt%.

[0076] (2) Take 10g of the composite powder prepared according to the above formula.

[0077] (3) Add 5g of the composite powder to a graphite mold, and apply a pressure of 10-20MPa.

[0078] (4) Punch holes in the middle position of the 25mm*8mm*6mm graphite mold cold-pressed blank, with a depth of 0.2mm, a number of 4, a diamond particle size of 50 / 60 mesh, and uniformly distributed in the middle position of the composite powder.

[0079] (5) Embed the diamond in the punched position with tweezers, and arrange the diamond in the metal matrix in a directional manner.

[0080] (6) Add the remaining 5g of the composite powder to the graphite mold.

[0081] (7) Place the graphite mold in a sintering device for sintering, with a sintering temperature of 800℃, a holding time of 7min, and a sintering pressure of 35MPa.

[0082] (8) Polish the sample for three-point bending test, press down along the middle line position where the diamond is added, and record the elastic modulus E1 of the diamond particles and the elastic modulus E2 of the matrix in the process.

[0083] (9) Measure the cross-sectional area S1 and the diamond fracture surface area S2 under a 3D microscope, and calculate the holding force

[0084]

[0085] The sintering mode of the graphite mold in the sintering device is hot isostatic pressing. The holding force detection device is used for the bending test, and the detection mode of the holding force detection device is V-shaped mold bending.

[0086] Example 3

[0087] Reference Figure 3 , Figure 3 is a structural schematic view of the cross-sectional area S1 and the diamond fracture surface area S2 in Example 3 of the present application.

[0088] The present embodiment provides a method for testing the holding force of an iron-based matrix and diamond, comprising the following steps

[0089] (1) First, mix Fe, Al, Cu and Sn into a uniform composite powder by a horizontal high-energy ball mill, wherein the content of Fe is 65wt%, the content of Al is 8.5wt%, the content of Cu is 25wt%, and the content of Sn is 1.5wt%.

[0090] (2) Take 10g of the composite powder prepared according to the above formula.

[0091] (3) Add 5g of the composite powder to a graphite mold and apply a pressure of 10-20MPa.

[0092] (4) Punch holes in the middle of the 25mm*8mm*6mm graphite mold cold-pressed blank, with a depth of 0.3mm, a number of 12, a diamond particle size of 50 / 60 mesh, and uniformly distributed in the middle of the composite powder.

[0093] (5) Embed the diamond in the punched position with tweezers, and arrange the diamond in the metal matrix in a directional manner.

[0094] (6) Add the remaining 5g of the composite powder to the graphite mold.

[0095] (7) Place the graphite mold in a sintering device for sintering, with a sintering temperature of 760℃, a holding time of 10min, and a sintering pressure of 40MPa.

[0096] (8) Polish the sample for three-point bending test, press along the middle line position where the diamond is added, and record the elastic modulus E1 of the diamond particles and the elastic modulus E2 of the matrix in the process.

[0097] (9) Measure the area S1 of the cross section and the area S2 of the diamond fracture surface under a 3D microscope, and calculate the holding force

[0098]

[0099] The sintering method of the graphite mold in the sintering device is plasma sintering. The holding force detection device is used for the bending test, and the detection method of the holding force detection device is the vise type bending.

[0100] Example 4

[0101] The embodiment provides a method for testing the holding force of an iron-based matrix and diamond, comprising the following steps

[0102] (1) First, mix Fe, Al, Cu and Sn into a uniform composite powder by a three-dimensional mixer, wherein the content of Fe is 70wt%, the content of Al is 7wt%, the content of Cu is 21.5wt%, and the content of Sn is 1.5wt%.

[0103] (2) Take 10g of the composite powder prepared according to the above formula.

[0104] (3) Add 5g of the composite powder into the graphite mold and apply a pressure of 10-20 MPa.

[0105] (4) Punch holes in the middle of the 25mm*8mm*6mm graphite mold cold-pressed blank, with a depth of 0.4mm, a number of 4, a diamond particle size of 50 / 60 mesh, and uniformly distributed in the middle of the composite powder.

[0106] (5) Embed the diamond into the punched position with tweezers, and arrange the diamond in the metal matrix in a directional manner.

[0107] (6) Add the remaining 5g of the composite powder into the graphite mold.

[0108] (7) Place the graphite mold in the sintering equipment for sintering, with a sintering temperature of 780℃, a holding time of 8min, and a sintering pressure of 35MPa.

[0109] (8) Polish the sample for three-point bending test, press down along the middle line position where the diamond is added, and record the elastic modulus E1 of the diamond particles and the elastic modulus E2 of the matrix in the process.

[0110] (9) Measure the area S1 of the cross section and the area S2 of the diamond fracture surface under the 3D microscope, and calculate the holding force

[0111]

[0112] The sintering mode of the graphite mold in the sintering equipment is vacuum hot pressing. The holding force detection device is used for the bending test, and the detection mode of the holding force detection device is plate bending.

[0113] It should be understood that the disclosed embodiments of the present application are not limited to the specific processing steps or materials disclosed herein, but extend to equivalent alternatives of such features as understood by those skilled in the relevant art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0114] The term "embodiment" mentioned in the specification means that the specific features or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. Therefore, the phrase or "embodiment" appearing throughout the specification does not necessarily mean the same embodiment.

[0115] Moreover, the described features or characteristics can be combined in any other suitable manner in one or more embodiments. In the above description, some specific details are provided for the purpose of providing a thorough understanding of embodiments of the application. However, persons of ordinary skill in the relevant art will appreciate that the application can be practiced without one or more of the specific details, or with other methods, components, materials, etc.

Claims

1. A method of testing the hold of an iron-based matrix on diamonds, characterized in that, The method comprises the following steps (1) first, Fe, Al, Cu and Sn are mixed into a uniform composite powder by a mixing device, wherein the content of Fe is 55wt%-70wt%, the content of Al is 4wt%-9wt%, the content of Cu is 15wt%-25wt%, and the content of Sn is 1wt%-1.5wt%; (2) 10g of the composite powder is weighed; (3) 5g of the composite powder is added to a graphite mold, and a pressure of 10-20MPa is applied; (4) a hole with a depth of 0.2-0.4mm and a number of 4-12 is punched in the middle position of the graphite mold cold-pressed blank, and diamond particles with a size of 50 / 60 mesh are uniformly distributed in the middle position of the composite powder; (5) the diamond is embedded in the punched position by using tweezers; (6) the remaining 5g of the composite powder is added to the graphite mold; (7) the graphite mold is placed in a sintering device for sintering, the sintering temperature is 760-840℃, the holding time is 5-10min, and the sintering pressure is 30-40MPa; (8) the sample is polished for a three-point bending test, and the elastic modulus E1 of the diamond particles and the elastic modulus E2 of the matrix are recorded during the process of pressing along the middle line position where the diamond is added; (9) the area S1 of the section and the area S2 of the diamond fracture surface are measured under a 3D microscope, and the holding force is calculated, wherein the interference shrinkage deformation rate of the matrix to the diamond is caused by the difference in cooling shrinkage coefficients of the diamond and the matrix; S1 is the area (mm2) of the matrix embedding the diamond, S2 is the area (mm2) of the diamond particles, E1 is the elastic modulus (GPa) of the diamond particles, and E2 is the elastic modulus (GPa) of the matrix. ， The mixing device is any one of a three-dimensional mixer, a planetary ball mill, and a horizontal high-energy ball mill.

2. The method of testing the hold of an iron-based matrix on a diamond according to claim 1, characterized in that, The size of the graphite mold is 25mm*8mm*6mm.

3. The method of testing the diamond holding force of an iron-based matrix according to claim 1, wherein, The sintering mode of the graphite mold in the sintering device is any one of vacuum hot pressing, hot isostatic pressing, and plasma sintering.

4. The method of testing the diamond holding force of an iron-based matrix according to claim 1, wherein, The holding force detection device is used for testing in the bending test, and the detection mode of the holding force detection device is any one of a roller type bending, a V-shaped mold type bending, a vice type bending, and a plate type bending.

5. The method of testing the diamond holding force of an iron-based matrix according to claim 1, wherein, The diamond is directionally arranged in the metal matrix.

6. The method of testing the diamond holding force of an iron-based matrix according to claim 1, wherein, The method is used for accurately obtaining the holding force between the metal matrix and the diamond.

7. The method of testing the diamond holding force of an iron-based matrix according to claim 1, wherein, ​

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