Long-life brazed diamond abrasive block and preparation process

Abstract

The application discloses a long-life brazing diamond abrasive block and a preparation process thereof. The long-life brazing diamond abrasive block is composed of a plurality of multilayer units and fillers between the units, the multilayer unit is prepared by vacuum brazing of a sintered pure iron composite sheet, diamond particles arranged on the surface of the sintered pure iron composite sheet and alloy solder, the sintered pure iron composite sheet is prepared by hot-press sintering of iron powder and framework phase particles, the highest hot-press sintering temperature is 1100-1250 DEG C, and the framework phase particles are abrasives with a heat-resistant temperature of 1250 DEG C or above. The long-life brazing diamond abrasive block obtained by the special structural design and process not only realizes multilayer use of the brazing diamond tool surface diamond, guarantees stable working efficiency during long-life realization, and overcomes the problems of ineffective abrasion of the traditional multilayer tool matrix and easy blockage of the multilayer diamond surface.

Description

Technical Field

[0001] This invention belongs to the field of brazed diamond tool manufacturing, specifically relating to a long-life brazed diamond grinding block and its preparation process. Background Technology

[0002] Brazed diamond tools are now widely used in the stone industry, particularly in cutting marble and concrete, and drilling ceramics. Due to their high sharpness, large chip space, and excellent heat dissipation, brazed diamond tools can effectively replace electroplated diamond tools and some sintered diamond tools. However, because brazed diamond tools are single-layer tools, once the surface diamond wears down or fails, the tool can no longer be used for processing. Sintered diamond tools, on the other hand, offer the advantages of multi-layer diamond processing, and are currently the mainstream choice for granite, ceramics, and some concrete materials.

[0003] Currently, there are two main approaches to improving the lifespan of diamond tools by multiplying brazed diamond. One approach involves creating layers on the substrate surface (e.g., CN201712070U thin-film brazed multi-layered diamond saw blades; CN201151217Y brazed and sintered multi-layered diamond tools with optimized abrasive arrangement), creating a gradient in the diamond distribution on the substrate surface to achieve multi-layered diamond usage. The other approach borrows from the principles of sintered diamond processing (e.g., CN101862834B one-piece molded multi-layered brazed diamond drill bits), mixing brazing filler metal and other additives with diamond using a specific process to achieve multi-layered diamond. Based on current usage, neither of these approaches has completely solved the problem of manufacturing multi-layered brazed diamond tools. When altering the surface structure of the matrix to achieve multi-layered wear of diamond particles, the lower-layer diamonds often fail to expose, preventing effective wear of the matrix and hindering the multi-layer effect. Alternatively, the lower-layer diamonds may be affected by the wear of higher-layer diamonds, preventing effective removal of grinding debris and impacting grinding efficiency. When using multi-layer brazing, a process similar to sintering, the brazed diamonds have higher weld strength than those in sintering, making it difficult for the diamonds to detach and expose subsequent diamonds. To achieve exposure, a pore-forming agent is often added to the solder alloy; however, the resulting pores are easily clogged by grinding debris, causing the tool to lose its multi-layered effect. Summary of the Invention

[0004] To address the issue of wear resistance in traditional multi-layer tool substrates, this invention provides a long-life brazed diamond grinding block that achieves stable multi-layer diamond grinding through structural design. The purpose of this invention is to enable multi-layer diamond grinding on the surface of brazed diamond tools, thereby achieving a long service life. Furthermore, the structure and process designed in this invention also ensure relatively stable working efficiency while achieving a long service life, overcoming the problems of ineffective wear resistance in traditional multi-layer tool substrates and easy clogging of multi-layer diamond surfaces.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A long-life brazed diamond grinding block is composed of several multi-layer units and fillers between the units. The multi-layer units are prepared by vacuum brazing of sintered pure iron composite sheets and diamond particles arranged on their surfaces with alloy solder.

[0007] The sintered pure iron composite sheet is composed of iron powder and a framework phase, with the volume percentages of iron powder being 82-99% and the framework phase being 1-18%, and the sum of the volume percentages of the two being 100%. The sintered pure iron composite sheet is prepared by hot pressing and sintering iron powder and framework phase particles, with the highest hot pressing and sintering temperature being 1100℃-1250℃.

[0008] The purity of the iron powder reaches 98.5% or higher;

[0009] The skeletal phase particles are abrasives with a heat resistance temperature of 1250℃ or higher.

[0010] The filler is a ceramic binder or a metal binder.

[0011] Furthermore, the diamond particle arrangement density on the surface of the sintered pure iron composite sheet described in this invention is 90–6500 particles / cm². 2 .

[0012] Furthermore, the diamond particles described in this invention are synthetic diamond particles with a particle size of 20 mesh to 140 mesh.

[0013] In this invention, by limiting parameters such as the diamond particle arrangement density and diamond particle size, the quantity and concentration of diamonds in the diamond composite sheet of the main working unit are determined, thereby determining the processing efficiency and surface quality of the diamond tool during processing.

[0014] Furthermore, the ratio of the filler thickness to the multilayer unit thickness in this invention is 1:1 to 5:1, and the ratio of the filler thickness to the multilayer unit thickness determines the number of diamond composite sheets.

[0015] Furthermore, the multi-layer unit of the present invention has a sheet-like structure and forms an angle of 0 to 35 degrees with the working surface, which is perpendicular or inclined. The tilt angle of the multi-layer unit determines the grinding load.

[0016] Furthermore, the iron powder of the present invention preferably has a purity of 99% or higher, and its particle size is 600 mesh to 3000 mesh.

[0017] Furthermore, the particle size of the framework phase in this invention is 170 mesh to 2000 mesh, selected from any one or a mixture of more than one of alumina, boron nitride, and silicon carbide. The parameters of the iron powder and the framework phase determine the performance of the composite preparation and affect the effect of multilayer applications.

[0018] Furthermore, the alloy solder of the present invention is a nickel-based alloy solder, the composition of which is nickel-chromium-boron-silicon-iron, and the proportions of each element are as follows: Cr (6.0-8.0), B (2.75-3.5), Si (4.0-5.0), Fe (2.5-3.5), with the remainder being nickel; the particle size of the alloy solder is limited to 40 mesh to 200 mesh.

[0019] Furthermore, the density of the sintered pure iron composite sheet described in this invention is 5.2 g / cm³. 3 -6.3g / cm, with a thickness of 0.6mm to 1.3mm.

[0020] Furthermore, the present invention also provides a process for preparing the above-mentioned long-life brazed diamond grinding block, comprising:

[0021] (1) Preparation of multi-layer unit: First, a layer of binder is coated on the surface of the sintered pure iron composite sheet, then diamond particles are arranged on the surface of the binder, and then alloy solder is arranged in the gaps between the diamond particles. The resulting unit is placed in a vacuum brazing furnace and heated to obtain a multi-layer unit.

[0022] The vacuum brazing temperature in step (1) is 1010℃~1026℃, the heating time from 940℃ to the highest temperature is 25~40min, the holding time is 7~20min, and the vacuum degree is maintained within 0.1Pa during the heating process;

[0023] (2) Preparation of long-life brazed diamond grinding blocks: The multilayer units obtained in several steps (1) and the filler are prepared by hot pressing and sintering.

[0024] The hot pressing sintering in step (2) is a vacuum hot pressing sintering process with a maximum sintering temperature of 860℃, a holding time of no more than 3 minutes, and a holding pressure of 22-28 MPa.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) Since the sintered iron sheet composite is made of pure iron powder and skeleton phase, its hardness is low. While it has a certain degree of flexibility, it can also maintain a certain strength. However, its wear resistance is lower than that of steel. This is a beneficial feature when processing stone. When diamond is brazed on its surface, after the diamond on the surface wears down, the stone will rub against the solder alloy layer and the composite. Since it is not wear-resistant, it can be worn down relatively easily. In this way, the diamond on the lower layer can be exposed and continue to work. Moreover, the skeleton phase in the composite is wear-resistant phase such as alumina and silicon carbide. After sintering, it can maintain its shape. When it wears down, it is easy to fall off under the impact of the stone. It is easy to carry away heat. The gaps formed can also improve the heat dissipation effect. This avoids the situation in conventional multi-layer structures where the steel matrix is ​​not easy to wear and is easy to adhere to the stone surface.

[0027] (2) The processing object is stone and chips. Due to their high hardness, they will rub and impact the sintered iron sheet composite of the multi-layer unit and the nickel-based alloy layer on the surface of the composite. Since the composite and the nickel-based alloy layer have relatively low hardness, they will be worn away by the chips. Moreover, the filler between the multi-layer units has very low strength and is easily worn away. In this way, the diamond of the next layer can be exposed to continue working.

[0028] On the other hand, since the multi-layer units are perpendicular to or at a certain angle to the processing surface, after multiple multi-layer units are combined into a whole, the diamond distribution on the surface is uniform. After continuous wear after grinding, the grinding efficiency is stable and the life is long. Attached Figure Description

[0029] Figure 1 This refers to the multi-layer unit structure in the long-life brazed diamond grinding block described in this invention.

[0030] Figure 2 This is the long-life brazed diamond grinding block structure described in this invention.

[0031] The following are labeled in the figure: 1. Sintered pure iron composite sheet, 2. Alloy solder, 3. Diamond particles, 4. Filler. Detailed Implementation

[0032] The following detailed embodiments further illustrate the above-described content of the present invention, but are not limited to these embodiments. Various substitutions or modifications made based on ordinary technical knowledge and conventional methods in the art, encompassing the above-described technical concepts, should be included within the scope of the present invention.

[0033] A long-life brazed diamond grinding block is composed of several multi-layer units and fillers between the units. The multi-layer units are prepared by vacuum brazing of sintered pure iron composite sheets and diamond particles arranged on their surfaces with alloy solder.

[0034] The sintered pure iron composite sheet is composed of iron powder and a framework phase, with the volume percentages of iron powder being 82-99% and the framework phase being 1-18%, and the sum of the volume percentages of the two being 100%. The sintered pure iron composite sheet is prepared by hot pressing and sintering iron powder and framework phase particles, with the highest hot pressing and sintering temperature being 1100℃-1250℃.

[0035] The purity of the iron powder reaches 98.5% or higher;

[0036] The skeletal phase particles are abrasives with a heat resistance temperature of 1250℃ or higher.

[0037] The filler is a ceramic binder or a metal binder.

[0038] The diamond particles are arranged at a density of 90–6500 particles / cm² on the surface of the sintered pure iron composite sheet. 2 .

[0039] The ratio of the filler thickness to the thickness of the multilayer unit is 1:1 to 5:1.

[0040] The multi-layer unit has a sheet-like structure and forms an angle of 0 to 35 degrees with the working surface, either perpendicular or inclined.

[0041] The purity of the iron powder is preferably above 99%, and its particle size is 600 mesh to 3000 mesh.

[0042] The skeletal phase particles have a particle size of 170 mesh to 2000 mesh and are selected from any one or a mixture of more than one of alumina, boron nitride, and silicon carbide.

[0043] The diamond particles are synthetic diamond particles with a particle size of 20 mesh to 140 mesh.

[0044] The alloy solder is a nickel-based alloy solder, and its composition is nickel-chromium-boron-silicon-iron, with the following proportions of each element: Cr (6.0-8.0), B (2.75-3.5), Si (4.0-5.0), Fe (2.5-3.5), and the remainder being nickel; the particle size of the alloy solder is limited to 40 mesh to 200 mesh.

[0045] The density of the sintered pure iron composite sheet is 5.2 g / cm³. 3 -6.3g / cm 3 The thickness is 0.6mm to 1.3mm.

[0046] The preparation process of the long-life brazed diamond grinding block of the present invention includes:

[0047] (1) Preparation of multi-layer unit: First, a layer of binder is coated on the surface of the sintered pure iron composite sheet, then diamond particles are arranged on the surface of the binder, and then alloy solder is arranged in the gaps between the diamond particles. The resulting unit is placed in a vacuum brazing furnace and heated to obtain a multi-layer unit.

[0048] The vacuum brazing temperature in step (1) is 1010℃~1026℃, the heating time from 940℃ to the highest temperature is 25~40min, the holding time is 7~20min, and the vacuum degree is maintained within 0.1Pa during the heating process;

[0049] (2) Preparation of long-life brazed diamond grinding blocks: The multilayer units obtained in several steps (1) and the filler are prepared by hot pressing and sintering.

[0050] The hot pressing sintering in step (2) is a vacuum hot pressing sintering process with a maximum sintering temperature of 860℃, a holding time of no more than 3 minutes, and a holding pressure of 22-28 MPa.

[0051] Example 1

[0052] A long-life brazed diamond grinding block is composed of several multi-layer units and fillers between the units. The multi-layer units are prepared by vacuum brazing of sintered pure iron composite sheets and diamond particles arranged on their surfaces with alloy solder.

[0053] The sintered pure iron composite sheet is composed of iron powder and a framework phase, with the volume percentages being 82% iron powder and 18% framework phase, respectively. The sintered pure iron composite sheet is prepared by hot pressing and sintering iron powder and framework phase particles, with the highest hot pressing and sintering temperature being 1100℃.

[0054] The purity of the iron powder reaches 98.5% or higher;

[0055] The skeletal phase particles are alumina with a heat resistance temperature of over 1250℃ and a particle size of 170 mesh to 2000 mesh.

[0056] The filler is a ceramic binder;

[0057] The diamond particles are arranged at a density of 500 particles / cm² on the surface of the sintered pure iron composite sheet. 2 ;

[0058] The ratio of the filler thickness to the thickness of the multilayer unit is 1:1;

[0059] The multi-layer unit has a sheet-like structure and is perpendicular to the working surface;

[0060] The purity of the iron powder is preferably above 99%, and its particle size is 600 mesh to 3000 mesh;

[0061] The diamond particles are synthetic diamond particles with a particle size of 20 mesh to 140 mesh.

[0062] The alloy solder is a nickel-based alloy solder, and its composition is nickel-chromium-boron-silicon-iron, with the following proportions of each element: Cr (6.0-8.0), B (2.75-3.5), Si (4.0-5.0), Fe (2.5-3.5), and the remainder being nickel; the particle size of the alloy solder is limited to 40 mesh to 200 mesh.

[0063] The density of the sintered pure iron composite sheet is 5.2 g / cm³. 3 The thickness is 0.6mm.

[0064] Example 2

[0065] A long-life brazed diamond grinding block is composed of several multi-layer units and fillers between the units. The multi-layer units are prepared by vacuum brazing of sintered pure iron composite sheets and diamond particles arranged on their surfaces with alloy solder.

[0066] The sintered pure iron composite sheet is composed of iron powder and a framework phase, with the volume percentages of iron powder being 99% and the framework phase being 1%, and the sum of the volume percentages of the two being 100%. The sintered pure iron composite sheet is prepared by hot pressing and sintering iron powder and framework phase particles, with the highest hot pressing and sintering temperature being 1250℃.

[0067] The purity of the iron powder reaches 98.5% or higher;

[0068] The skeletal phase particles are boron nitride with a heat resistance temperature of over 1250℃ and a particle size of 170 mesh to 2000 mesh.

[0069] The filler is a metal binder;

[0070] The diamond particles are arranged at a density of 5500 particles / cm² on the surface of the sintered pure iron composite sheet. 2 ;

[0071] The ratio of the filler thickness to the thickness of the multilayer unit is 5:1.

[0072] The multi-layer unit has a sheet-like structure and is inclined at a 35-degree angle to the working surface;

[0073] The purity of the iron powder is preferably above 99%, and its particle size is 600 mesh to 3000 mesh;

[0074] The diamond particles are synthetic diamond particles with a particle size of 20 mesh to 140 mesh.

[0075] The alloy solder is a nickel-based alloy solder, and its composition is nickel-chromium-boron-silicon-iron, with the following proportions of each element: Cr (6.0-8.0), B (2.75-3.5), Si (4.0-5.0), Fe (2.5-3.5), and the remainder being nickel; the particle size of the alloy solder is limited to 40 mesh to 200 mesh.

[0076] The sintered pure iron composite sheet has a density of 6.3 g / cm³ and a thickness of 1.3 mm.

[0077] The long-life brazed diamond grinding block prepared by the present invention achieves multi-layer stable grinding of diamond through structural design, while ensuring basically stable working efficiency while achieving long life, and its surface is not easily clogged during use.

Claims

1. A long-life brazed diamond grinding block, characterized in that, This long-life brazed diamond grinding block is composed of several multi-layer units and fillers between the units. The multi-layer units are prepared by vacuum brazing of sintered pure iron composite sheets and diamond particles arranged on their surfaces with alloy solder. The diamond particles are arranged at a density of 90~6500 particles / cm² on the surface of the sintered pure iron composite sheet. 2 ; The sintered pure iron composite sheet is composed of iron powder and a skeleton phase, with the volume percentages of iron powder being 82-99% and the skeleton phase being 1-18%, and the sum of the volume percentages of the two being 100%. The sintered pure iron composite sheet is prepared by hot pressing and sintering iron powder and skeleton phase particles, with the highest hot pressing and sintering temperature being 1100℃-1250℃. The purity of the iron powder reaches 98.5% or higher; The skeletal phase particles are abrasives with a heat resistance temperature of 1250℃ or higher. The filler is a ceramic binder or a metal binder; The multi-layer unit has a sheet-like structure and forms an angle of 0 to 35 degrees with the working surface, either perpendicular or inclined. The iron powder has a purity of over 99% and a particle size of 600 mesh to 3000 mesh. The skeletal phase particles have a particle size of 170 mesh to 2000 mesh and are selected from any one or a mixture of more than one of alumina, boron nitride, and silicon carbide.

2. The long-life brazed diamond grinding block according to claim 1, characterized in that, The diamond particles are synthetic diamond particles with a particle size of 20 mesh to 140 mesh.

3. The long-life brazed diamond grinding block according to claim 1, characterized in that, The ratio of the filler thickness to the thickness of the multilayer unit is 1:1 to 5:

1.

4. The long-life brazed diamond grinding block according to claim 1, characterized in that, The alloy solder is a nickel-based alloy solder, and its composition is nickel-chromium-boron-silicon-iron, with the following proportions of each element: Cr (6.0-8.0), B (2.75-3.5), Si (4.0-5.0), Fe (2.5-3.5), and the remainder being nickel; the particle size of the alloy solder is limited to 40 mesh to 200 mesh.

5. The long-life brazed diamond grinding block according to claim 1, characterized in that, The density of the sintered pure iron composite sheet is 5.2 g / cm³. 3 -6.3g / cm, with a thickness of 0.6mm~1.3mm.

6. A process for preparing a long-life brazed diamond grinding block according to any one of claims 1 to 5, characterized in that, include: (1) Preparation of multi-layer unit: First, a layer of binder is coated on the surface of the sintered pure iron composite sheet, then diamond particles are arranged on the surface of the binder, and then alloy solder is arranged in the gaps between the diamond particles. The resulting unit is placed in a vacuum brazing furnace and heated to obtain a multi-layer unit. (2) Preparation of long-life brazed diamond grinding blocks: The multilayer units obtained in several steps (1) and the filler are prepared by hot pressing and sintering.

7. The preparation process according to claim 6, characterized in that, The vacuum brazing temperature in step (1) is 1010℃~1026℃, the heating time from 940℃ to the highest temperature is 25~40min, the holding time is 7~20min, and the vacuum degree is maintained within 0.1Pa during the heating process; The hot pressing sintering described in step (2) is a vacuum hot pressing sintering process with a maximum sintering temperature of 860℃, a holding time of no more than 3 minutes, and a holding pressure of 22~28Mpa.

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