Metal binders, diamond cutting tools, their preparation methods and applications

Abstract

This invention discloses a metal binder, a diamond cutting tool, its preparation method, and its application, belonging to the field of diamond tool technology. The metal binder comprises metal powder and rare earth oxides. The metal powder comprises the following components by mass percentage: cobalt 51%-84%, tin 4%-8%, silver 2%-6%, copper 8%-20%, and ferric hydroxide 2%-15%. This invention optimizes the matrix layer composition, selects a cobalt-based binder with good matrix performance, and appropriately adds copper, ferric hydroxide, and other auxiliary materials to adjust its hardness, making it match the hardness of semiconductor crystal materials. This avoids problems such as clogging, dulling, and slippage during the rounding process of semiconductor crystals. Simultaneously, it improves the holding force of the matrix layer on the diamond, significantly extending the service life and processing efficiency of the diamond cutting tool.

Description

Technical Field

[0001] This invention relates to the field of diamond tool technology, specifically to a metal bond, a diamond cutting tool, its preparation method, and its application. Background Technology

[0002] Currently, domestic semiconductor manufacturers still use traditional processing methods to process semiconductor ingot blanks into round ingots, which involves directly grinding the outer circle of the blank with a diamond grinding wheel. Due to the irregular shape of the ingot blank and the large machining allowance, this method suffers from extremely low processing efficiency, severe wheel wear, and long processing cycles. Therefore, the industry has begun to seek more efficient processing methods, such as directly hollowing out the semiconductor ingot blank into a circular shape, using a diamond hollowing tool as the grinding wheel.

[0003] Currently, the most widely used diamond cutting tools on the market are brazed cutting tools. These tools use a single layer of diamond particles fixed to the surface of the substrate through a brazing process. Their working principle is to rely on the exposed diamond particles on the surface brazed layer to cut semiconductor crystal materials.

[0004] However, when actually machining high-hardness semiconductor crystal materials such as silicon carbide, brazed cutter tools have the following significant drawbacks: extremely short service life; limited bonding strength between the brazed layer and the substrate, and diamond particles are prone to detach from the brazed layer when machining high-hardness and high-brittle materials, leading to rapid tool failure.

[0005] The main reasons for the above-mentioned shortcomings include: silicon carbide single crystal material has extremely high hardness (Mohs hardness 9.5, only about 0.5 lower than diamond), making it difficult to process and causing very severe wear on diamond tools; brazed cutter tools have a single-layer diamond structure and lack an abrasive layer to supplement subsequent cutting capabilities, so their service life is extremely short, and the brazing flux is easy to peel off from the substrate, making them prone to failure and scrap.

[0006] In addition, the industry has also tried using copper-based bonded diamond cutting tools (i.e., forming a metal bond matrix through powder metallurgy sintering with embedded diamond particles). However, when processing high-hardness crystals such as silicon carbide, traditional copper-based bonded matrices are prone to clogging, dulling, and slippage due to the mismatch between the matrix hardness and the workpiece, requiring frequent adjustments and failing to meet the demands for efficient and long-life processing. Summary of the Invention

[0007] The purpose of this invention is to provide a metal binder, a diamond cutting tool, its preparation method and application, in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A metal binder comprising metal powder and rare earth oxides; said metal powder comprising the following components by mass percentage: cobalt 51%-84%, tin 4%-8%, silver 2%-6%, copper 8%-20%, and ferric hydroxide 2%-15%.

[0009] Furthermore, the metal powder comprises the following components by mass percentage: cobalt 58%-78%, tin 5%-7%, silver 3%-5%, copper 10%-18%, and ferric hydroxide 4%-12%.

[0010] Furthermore, the cobalt is ultrafine cobalt powder with an average particle size of 15-20 μm; the copper is ultrafine copper powder with an average particle size of 15-20 μm; the tin is tin powder with a particle size of 300-500 mesh; the silver is silver powder with a particle size of 300-500 mesh; and the hydroxyl iron is hydroxyl iron powder with an average particle size of 3-5 μm.

[0011] Furthermore, the mass of the rare earth oxide is 2%-5% of the mass of the metal powder.

[0012] Furthermore, the rare earth oxide is cerium oxide.

[0013] Another object of the present invention is to provide a diamond cutting tool comprising the above-mentioned metal binder.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned diamond boring tool, comprising the following steps: After mixing metal powder and rare earth oxides, diamond particles are added and mixed evenly to obtain a mixture. The mixture is placed in a mold and hot-pressed and sintered under a protective atmosphere to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0015] Furthermore, the concentration of diamond particles in the matrix layer is 150%-250%.

[0016] Furthermore, the sintering process of the hot pressing forming sintering is specifically as follows: the first stage is to raise the temperature from 25-35℃ to 450-550℃ within 80-100 minutes; the second stage is to hold the temperature at 450-550℃ for 50-70 minutes; the third stage is to raise the temperature from 450-550℃ to 750-850℃ within 100-150 minutes; the fourth stage is to hold the temperature at 750-850℃ for 150-200 minutes; the fifth stage is to lower the temperature from 750-850℃ to 450-550℃ within 100-150 minutes; and the sixth stage is to allow the temperature to naturally cool from 450-550℃ to 25-35℃.

[0017] Another object of the present invention is to provide an application of the above-mentioned diamond cutting tool in the processing of semiconductor crystal materials.

[0018] This invention provides a metal binder that can be used to prepare diamond cutting tools. By optimizing the matrix layer composition and selecting a cobalt-based binder with good matrix performance, and by appropriately adding copper, ferric hydroxide, and other auxiliary materials to adjust its hardness, it matches the hardness of the semiconductor crystal material. This avoids problems such as clogging, dulling, and slippage during the rounding process of semiconductor crystals. At the same time, it improves the holding force of the matrix layer on the diamond, significantly extending the service life and processing efficiency of the diamond cutting tool. It solves the problems of short processing life, frequent replacement, and low efficiency that are common in traditional brazed diamond cutting tools used in the rounding process of semiconductor crystals. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram of a diamond cutting tool provided in an embodiment of the present invention.

[0020] Figure 2 The image shows the ground surface of the diamond cutting tool provided in Example 2 after processing silicon carbide crystals.

[0021] Figure 3 Image of the ground surface of the diamond cutter provided for Comparative Example 2 after machining silicon carbide crystal. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Traditional metal binders (such as copper-based binders) have poor self-sharpening properties, and diamond cutters are prone to dulling and slipping during processing, requiring repeated dressing. Therefore, the Rockwell hardness of the metal binder diamond cutter matrix cannot be too high and must match the hardness of the semiconductor crystal material being processed. Thus, adjusting the hardness of the metal binder matrix without causing clogging on the grinding wheel surface during use becomes the primary issue.

[0024] To address the aforementioned problems, in one embodiment of the present invention, a metal binder is provided, comprising metal powder and rare earth oxides; wherein the metal powder comprises the following components by mass percentage: cobalt 51%-84%, tin 4%-8%, silver 2%-6%, copper 8%-20%, and ferric hydroxide 2%-15%.

[0025] Preferably, the metal powder comprises the following components by mass percentage: 58%-78% cobalt, 5%-7% tin, 3%-5% silver, 10%-18% copper, and 4%-12% ferrohydroxyl. The cobalt is ultrafine cobalt powder with an average particle size of 15-20 μm; the copper is ultrafine copper powder with an average particle size of 15-20 μm; the tin is tin powder with a particle size of 300-500 mesh; the silver is silver powder with a particle size of 300-500 mesh; and the ferrohydroxyl is ferrohydroxyl powder with an average particle size of 3-5 μm.

[0026] Furthermore, the mass of rare earth oxides is 2%-5% of the mass of the metal powder. Cerium oxide is preferred as the rare earth oxide. The main functions of cerium oxide are as follows: providing lubricity and optimizing grinding performance; reducing the oxide film on the surface of various elemental metal powders during sintering; and dispersing and strengthening the matrix strength.

[0027] In another embodiment of the present invention, a diamond cutting tool comprising the aforementioned metal binder is also provided; wherein the diamond cutting tool comprises a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles.

[0028] Specifically, the preparation method of the above-mentioned diamond boring tool includes the following steps: S1. Mix the metal powder and rare earth oxides, then add diamond particles and mix evenly to obtain a mixture. S2. The mixture is placed in a mold and hot-pressed and sintered under a protective atmosphere (such as nitrogen or argon) to form a matrix layer. After cooling, a diamond blanking tool is obtained. This diamond blanking tool can be used to process semiconductor crystal materials, and is especially suitable for rounding semiconductor ingots.

[0029] The concentration of diamond particles in the matrix layer is 150%-250%. It should be noted that the concentration of diamond particles adopts the international concentration standard for diamond products.

[0030] Furthermore, the sintering process of hot pressing forming sintering is as follows: the first stage is to raise the temperature from 25-35℃ to 450-550℃ within 80-100 minutes; the second stage is to hold the temperature at 450-550℃ for 50-70 minutes; the third stage is to raise the temperature from 450-550℃ to 750-850℃ within 100-150 minutes; the fourth stage is to hold the temperature at 750-850℃ for 150-200 minutes; the fifth stage is to lower the temperature from 750-850℃ to 450-550℃ within 100-150 minutes; and the sixth stage is to allow the temperature to cool naturally from 450-550℃ to 25-35℃.

[0031] In this embodiment of the invention, the diamond cutting tool based on a metal binder is a monolithically sintered abrasive with a long service life and is less prone to failure due to the peeling of the matrix layer from the substrate. Regarding the selection of the metal binder used in this embodiment, since traditional copper-based binder matrices are prone to clogging, dulling, and slippage when processing semiconductor crystal materials, this embodiment selects a cobalt-based binder with better matrix performance. Simultaneously, ultrafine copper powder, ferric hydroxide, and other auxiliary materials are appropriately added to adjust its hardness.

[0032] The following embodiments are examples of the present invention in practical applications, and are only illustrative and not limited thereto.

[0033] Example 1: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 68% ultrafine cobalt powder (average particle size of 18μm), 6% tin powder (400 mesh), 4% silver powder (400 mesh), 18% ultrafine copper powder (average particle size of 18μm), and 4% hydroxyl iron powder (average particle size of 4μm); and weigh cerium oxide according to 3.5% of the total mass of the metal powder for later use.

[0034] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 200%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 35 rpm and mix for 7 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0035] The sintering process of hot pressing forming and sintering is as follows: the first stage is to raise the temperature from 30℃ to 500℃ within 90 minutes; the second stage is to hold the temperature at 500℃ for 60 minutes; the third stage is to raise the temperature from 500℃ to 800℃ within 120 minutes; the fourth stage is to hold the temperature at 800℃ for 180 minutes; the fifth stage is to lower the temperature from 800℃ to 500℃ within 120 minutes; and the sixth stage is to allow the temperature to drop naturally from 500℃ to 25℃.

[0036] Example 2: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 68% ultrafine cobalt powder (average particle size of 18μm), 6% tin powder (400 mesh), 4% silver powder (400 mesh), 14% ultrafine copper powder (average particle size of 18μm), and 8% hydroxyl iron powder (average particle size of 4μm); and weigh cerium oxide according to 3.5% of the total mass of the metal powder for later use.

[0037] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 200%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 35 rpm and mix for 7 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0038] The sintering process of hot pressing forming and sintering is as follows: the first stage is to raise the temperature from 30℃ to 500℃ within 90 minutes; the second stage is to hold the temperature at 500℃ for 60 minutes; the third stage is to raise the temperature from 500℃ to 800℃ within 120 minutes; the fourth stage is to hold the temperature at 800℃ for 180 minutes; the fifth stage is to lower the temperature from 800℃ to 500℃ within 120 minutes; and the sixth stage is to allow the temperature to drop naturally from 500℃ to 25℃.

[0039] Example 3: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 68% ultrafine cobalt powder (average particle size of 18μm), 6% tin powder (400 mesh), 4% silver powder (400 mesh), 10% ultrafine copper powder (average particle size of 18μm), and 12% hydroxyl iron powder (average particle size of 4μm); and weigh cerium oxide according to 3.5% of the total mass of the metal powder for later use.

[0040] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 200%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 35 rpm and mix for 7 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0041] The sintering process of hot pressing forming and sintering is as follows: the first stage is to raise the temperature from 30℃ to 500℃ within 90 minutes; the second stage is to hold the temperature at 500℃ for 60 minutes; the third stage is to raise the temperature from 500℃ to 800℃ within 120 minutes; the fourth stage is to hold the temperature at 800℃ for 180 minutes; the fifth stage is to lower the temperature from 800℃ to 500℃ within 120 minutes; and the sixth stage is to allow the temperature to drop naturally from 500℃ to 25℃.

[0042] Example 4: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 51% ultrafine cobalt powder (average particle size of 15μm), 8% tin powder (300 mesh), 6% silver powder (300 mesh), 20% ultrafine copper powder (average particle size of 15μm), and 15% hydroxyl iron powder (average particle size of 3μm); and weigh cerium oxide according to 2% of the total mass of the metal powder for later use.

[0043] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 150%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 20 rpm and mix for 6 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0044] The sintering process of hot pressing forming and sintering is as follows: the first stage is to raise the temperature from 25℃ to 450℃ within 80 minutes; the second stage is to hold the temperature at 450℃ for 50 minutes; the third stage is to raise the temperature from 450℃ to 750℃ within 100 minutes; the fourth stage is to hold the temperature at 750℃ for 150 minutes; the fifth stage is to lower the temperature from 750℃ to 450℃ within 100 minutes; and the sixth stage is to allow the temperature to drop naturally from 450℃ to 25℃.

[0045] Example 5: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 84% ultrafine cobalt powder (average particle size of 20μm), 4% tin powder (500 mesh), 2% silver powder (500 mesh), 8% ultrafine copper powder (average particle size of 20μm), and 2% hydroxyl iron powder (average particle size of 5μm); and weigh cerium oxide according to 5% of the total mass of the metal powder for later use.

[0046] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 250%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 50 rpm and mix for 8 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0047] The sintering process of hot pressing forming and sintering is as follows: the first stage is to raise the temperature from 35℃ to 550℃ within 100 minutes; the second stage is to hold the temperature at 550℃ for 70 minutes; the third stage is to raise the temperature from 550℃ to 850℃ within 150 minutes; the fourth stage is to hold the temperature at 850℃ for 200 minutes; the fifth stage is to lower the temperature from 850℃ to 550℃ within 150 minutes; and the sixth stage is to allow the temperature to drop naturally from 550℃ to 35℃.

[0048] Example 6: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 58% ultrafine cobalt powder (average particle size of 15μm), 7% tin powder (300 mesh), 5% silver powder (500 mesh), 18% ultrafine copper powder (average particle size of 20μm), and 12% hydroxyl iron powder (average particle size of 4μm); and weigh cerium oxide according to 4% of the total mass of the metal powder for later use.

[0049] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 200%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 30 rpm and mix for 7 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0050] The sintering process of hot pressing forming and sintering is as follows: the first stage is to raise the temperature from 30℃ to 500℃ within 90 minutes; the second stage is to hold the temperature at 500℃ for 60 minutes; the third stage is to raise the temperature from 500℃ to 800℃ within 120 minutes; the fourth stage is to hold the temperature at 800℃ for 170 minutes; the fifth stage is to lower the temperature from 800℃ to 500℃ within 120 minutes; and the sixth stage is to allow the temperature to drop naturally from 500℃ to 30℃.

[0051] Example 7: This example provides a diamond extraction tool, including a matrix and a matrix layer disposed on the matrix, the matrix layer being composed of a metal binder and diamond particles. Specifically, the preparation method of this diamond extraction tool includes the following steps: S1. Weigh each raw material according to the following mass percentage content in the metal powder: 78% ultrafine cobalt powder (average particle size of 20μm), 5% tin powder (300 mesh), 3% silver powder (300 mesh), 10% ultrafine copper powder (average particle size of 15μm), and 4% hydroxyl iron powder (average particle size of 4μm); and weigh cerium oxide according to 3% of the total mass of the metal powder for later use.

[0052] S2. Mix the weighed ultrafine cobalt powder, ultrafine copper powder, tin powder, silver powder, hydroxyl iron powder and cerium oxide, then add MBD10 type diamond particles with a concentration of 200%, and put them together in a three-dimensional mixer (the volume of the material does not exceed 1 / 3 of the volume of the mixing barrel). Set the speed of the mixer to 40 rpm and mix for 7 hours to obtain the mixture. S2. Place the above mixture in a mold and perform hot pressing and sintering under nitrogen protection to form a matrix layer. After cooling, a diamond cutting tool is obtained.

[0053] The sintering process of hot pressing molding and sintering is as follows: the first stage is to raise the temperature from 30℃ to 500℃ within 90 minutes; the second stage is to hold the temperature at 500℃ for 60 minutes; the third stage is to raise the temperature from 500℃ to 800℃ within 120 minutes; the fourth stage is to hold the temperature at 800℃ for 180 minutes; the fifth stage is to lower the temperature from 800℃ to 500℃ within 120 minutes; and the sixth stage is to allow the temperature to drop naturally from 500℃ to 25℃.

[0054] Comparative Example 1: This comparative example provides a diamond cutting tool, the only difference from Example 1 is that the hydroxyl iron powder in the metal binder raw material is replaced with iron powder (300 mesh), and the other raw materials and preparation methods are the same.

[0055] Comparative Example 2: This comparative example provides a diamond cutting tool, the only difference from Example 2 is that the hydroxyl iron powder in the metal binder raw material is replaced with iron powder (300 mesh), and the other raw materials and preparation methods are the same.

[0056] Comparative Example 3: This comparative example provides a diamond cutting tool, the only difference from Example 3 is that the hydroxyl iron powder in the metal binder raw material is replaced with iron powder (300 mesh), and the other raw materials and preparation methods are the same.

[0057] Performance Testing: 1. The Rockwell hardness (HRB) and ultimate flexural strength of the diamond cutting tools provided in Examples 1-3 and Comparative Examples 1-3 were tested according to relevant industry standards; the results are as follows: The diamond cutting tools provided in Examples 1-3 have Rockwell hardness HRB of 81, 88 and 96, respectively, and ultimate flexural strength of 546 MPa, 561 MPa and 577 MPa, respectively. The diamond cutting tools provided in Comparative Examples 1-3 have Rockwell hardness HRB of 72, 76 and 81, respectively, and ultimate flexural strength of 501 MPa, 512 MPa and 525 MPa, respectively. Based on the above test results, it can be seen that under the same pressing and sintering conditions, the three formulations of Examples 1-3 are higher than those of Comparative Examples 1-3 in terms of both hardness and flexural strength. This indicates that the sharpness and processing life of the diamond cutting tool provided by the embodiments of the present invention are better than those of Comparative Examples 1-3.

[0058] II. To further verify the practicality of the metal binder used in Example 2 and Comparative Example 2, diamond blanking tools with finished specifications of Φ157*Φ153*122*2 were produced according to the methods provided in Example 2 and Comparative Example 2, and the silicon carbide crystal blanks were rounded. Figure 1 The image shows a cross-sectional view of a diamond extraction tool. After machining silicon carbide crystals, the ground surfaces of the diamond extraction tools prepared in Example 2 and Comparative Example 2 are shown below. Figure 2 and Figure 3 As shown.

[0059] according to Figure 2 and Figure 3 It can be seen that both of these formulations can be used to make diamond cutting tools, and neither produced significant clogging during use; however, from Figure 3 It can be seen that the diamond adhesion of the diamond cutting tool prepared in Comparative Example 2 is weak and it is prone to premature detachment, resulting in a short processing life. This indicates that the metal bond matrix layer used in it is too soft. Figure 2 It can be seen that the metal binder matrix layer provided in this embodiment of the invention has good holding force for diamonds, high cutting rate, and each diamond has a matrix support after grinding, indicating strong diamond adhesion. This shows that the metal binder matrix layer has moderate hardness, long processing life, and high processing efficiency.

[0060] Furthermore, under the same conditions, the diamond rounding tools prepared in Example 2 and Comparative Example 2 were compared with the traditional brazed diamond rounding tool in terms of rounding effect. The results are shown in Table 1.

[0061] Table 1 The results in the table show that, under the same conditions, the diamond rounding tool provided in this embodiment of the invention has the best performance when rounding silicon carbide crystals.

[0062] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.

Claims

1. A metal binder, characterized in that, It includes metal powder and rare earth oxides; the metal powder includes the following components by mass percentage: cobalt 51%-84%, tin 4%-8%, silver 2%-6%, copper 8%-20%, and ferric hydroxide 2%-15%.

2. The metal binder according to claim 2, characterized in that, The metal powder comprises the following components by mass percentage: cobalt 58%-78%, tin 5%-7%, silver 3%-5%, copper 10%-18%, and ferric hydroxide 4%-12%.

3. The metal binder according to claim 1 or 2, characterized in that, The cobalt is ultrafine cobalt powder with an average particle size of 15-20 μm; the copper is ultrafine copper powder with an average particle size of 15-20 μm; the tin is tin powder with a particle size of 300-500 mesh; the silver is silver powder with a particle size of 300-500 mesh; and the hydroxyl iron is hydroxyl iron powder with an average particle size of 3-5 μm.

4. The metal binder according to claim 1, characterized in that, The mass of the rare earth oxide is 2%-5% of the mass of the metal powder.

5. The metal binder according to claim 1 or 4, characterized in that, The rare earth oxide is cerium oxide.

6. A diamond cutting tool comprising the metal binder according to any one of claims 1-5.

7. A method for preparing a diamond boring tool as described in claim 6, characterized in that, Includes the following steps: After mixing metal powder and rare earth oxides, diamond particles are added and mixed evenly to obtain a mixture. The mixture is placed in a mold and hot-pressed and sintered under a protective atmosphere to form a matrix layer. After cooling, a diamond cutting tool is obtained.

8. The method for preparing a diamond boring tool according to claim 7, characterized in that, The concentration of diamond particles in the matrix layer is 150%-250%.

9. The method for preparing a diamond boring tool according to claim 7, characterized in that, The sintering process of the hot pressing forming sintering is as follows: the first stage is to raise the temperature from 25-35℃ to 450-550℃ within 80-100 minutes; the second stage is to hold the temperature at 450-550℃ for 50-70 minutes; the third stage is to raise the temperature from 450-550℃ to 750-850℃ within 100-150 minutes; the fourth stage is to hold the temperature at 750-850℃ for 150-200 minutes; the fifth stage is to lower the temperature from 750-850℃ to 450-550℃ within 100-150 minutes; and the sixth stage is to allow the temperature to cool naturally from 450-550℃ to 25-35℃.

10. The application of the diamond cutting tool according to claim 6 in the processing of semiconductor crystal materials.

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