Diamond tool for high-speed dry stone carving and preparation process thereof

Abstract

The invention discloses a diamond tool for high-speed dry stone carving and a preparation process thereof, and belongs to the technical field of diamond tools. A plurality of diamond tool bits are evenly distributed on the outer edge of a base body of the diamond tool. An arc-shaped notch is formed in the tool bit gap position; the section of each diamond tool bit in the radial direction of the base body is trapezoidal. The diamond tool bit is prepared from the following raw materials: 16 to 34 parts of iron, 10 to 32 parts of copper, 2 to 11 parts of nickel, 9 to 21 parts of cobalt, 5 to 15 parts of iron-copper alloy, 11 to 23 parts of nickel-chromium-boron alloy, 0.03 to 0.11 part of liquid paraffin and 1.1 to 2.4 parts of diamond. When the tool is prepared, firstly, raw materials of the tool bit are subjected to cold press molding and hot pressed sintering, and then the tool bit and the base body are connected together through laser welding. The diamond tool bit structure is improved, the tool bit sintering process and the tool welding process are optimized, the cutting resistance is reduced, the impact resistance of the tool bit is improved, and the safety coefficient is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond blades, and particularly to a diamond tool for high-speed dry stone carving and its preparation process. Background Art

[0002] Under the background of the continuous development of the world economy, especially with global warming, low-carbon environmental protection has become an inevitable trend. The economic construction and infrastructure construction are inseparable from diamond tools. In the processes of stone carving, municipal engineering, tombstone carving, bridge columns, and engineering construction, with the increase in labor costs, high-efficiency and safe tools are bound to be favored by users. Summary of the Invention

[0003] The purpose of the present invention is to provide a diamond tool for high-speed dry stone carving and its preparation process. By improving the structure of the diamond tool bit, optimizing the tool bit sintering process and the tool welding process, the cutting resistance is reduced, the impact resistance of the tool bit is improved, and the safety factor is higher.

[0004] To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0005] A diamond tool for high-speed dry stone carving includes a circular base body and a plurality of diamond tool bits evenly arranged on the outer edge of the base body; there is a gap between adjacent diamond tool bits, and an arc-shaped notch is opened towards the inside of the base body at the gap position; the cross-section of each diamond tool bit along the radial direction of the base body is trapezoidal.

[0006] Further, the width of the outer end face of the trapezoidal tool bit is smaller than the width of the inner end face, and there is a V-shaped notch on the outer end face of the tool bit.

[0007] Further, an installation hole is provided at the center of the base body of the diamond tool for installing the diamond tool on a cutting machine; heat dissipation holes are also provided on the base body. The heat dissipation holes are arrow-shaped, with the arrow pointing outwards, and the width of the arrow is 1.5 - 3 times the width of the arrow shaft; the number of heat dissipation holes is 4 - 6, and they are evenly distributed between the diamond tool bits and the installation hole.

[0008] Further, the material of the base body is 45# steel; the tool bit contains diamond, and the diamond particle size is 35 / 40, 40 / 45 or 45 / 50, and the compressive strength is 25 - 35 kg.

[0009] Further, the raw material composition of the diamond tool bit by weight is as follows:

[0010] 16 - 34 parts of iron, 10 - 32 parts of copper, 2 - 11 parts of nickel, 9 - 21 parts of cobalt, 5 - 15 parts of iron-copper alloy, 11 - 23 parts of nickel-chromium-boron alloy, 0.03 - 0.11 parts of liquid paraffin, and 1.1 - 2.4 parts of diamond.

[0011] Further, the raw material composition of the diamond cutting head by weight parts is preferably as follows:

[0012] 19 - 32 parts of iron, 11 - 31 parts of copper, 4 - 8 parts of nickel, 12 - 20 parts of cobalt, 7 - 15 parts of iron - copper alloy, 14 - 23 parts of nickel - chromium - boron alloy, 0.04 - 0.10 parts of liquid paraffin, and 1.3 - 1.8 parts of diamond.

[0013] Further, the raw material composition of the diamond cutting head by weight parts is more preferably as follows:

[0014] 25 parts of iron, 22 parts of copper, 6 parts of nickel, 12 parts of cobalt, 15 parts of iron - copper alloy, 20 parts of nickel - chromium - boron alloy, 0.15 parts of liquid paraffin, and 1.6 parts of diamond.

[0015] Further, the chemical composition of the iron - copper alloy is: Fe 5 - 10wt.%, and the balance is Cu; the chemical composition of the nickel - chromium - boron alloy is: Ni 50 - 63wt.%, B 7.0 - 12.0wt.%, C 1.4 - 2.0wt.%, Cr 20 - 25wt.%, Fe 0 - 5wt.%.

[0016] Further, the preparation process of the diamond tool for high - speed dry - type stone carving includes the following steps:

[0017] (1) Substrate processing:

[0018] According to the drawing requirements, the steel plate is machined by turning to cut the substrate of the required shape.

[0019] (2) Sintering and forming of the diamond cutting head:

[0020] After the diamond cutting head raw materials are mixed evenly, they are first cold - pressed into a shape with a cold - pressing pressure of 3 - 10MPa, and then hot - pressed and sintered to obtain a cutting - head blank. The cutting - head blank is polished by a grinding wheel and sand belt to obtain the diamond cutting head; among them, the hot - pressing sintering process is as follows: the cold - pressed sample is placed in a hot - pressing steel mold, the mold is installed in a hot - pressing furnace, hydrogen is first introduced, and after the air in the furnace chamber is exhausted, sintering is started. First, it is heated and raised to 825 - 850°C, the pressurizing mold is started, the pressure is increased to 20 - 30KN, after heat preservation and pressure maintenance for 30 - 45min, heating is stopped and the pressure is released, and after natural cooling to room temperature, the obtained cutting - head blank is taken out of the furnace; the heating rate is 500 - 650°C / hour.

[0021] (3) Laser welding:

[0022] Place the diamond bit at the corresponding position on the substrate, start the laser welding machine for welding to weld the bit and the substrate together; use a CO2 laser, with a laser spot diameter of 0.3 - 0.5 mm, a laser power of 1120 - 1160 W, a welding speed of 1.0 - 1.5 m / min, a defocus amount of -1 mm, and an offset amount of 0.15 mm; the shielding gas is argon, and the shielding gas flow rate is 2 - 3 L / min;

[0023] (4) Sandblasting and painting:

[0024] Sandblast the inner side of the bit of the diamond tool obtained after welding the bit to remove the oxide scale on the substrate surface caused by welding, then grind the working surface of the diamond bit with a grinding wheel to expose the diamond, and then grind the tool with a grinder to make the substrate surface bright. Finally, perform surface painting and drying to prevent surface rusting.

[0025] The design mechanism and beneficial effects of the present invention are as follows:

[0026] 1. The present invention improves the structure of the diamond bit and designs it in an anti-collision style, which is beneficial to improving the connection strength between the bit and the substrate. At the same time, when the tool is cutting, there is a large opening angle between the bit intervals, which is beneficial to the tool to exclude sediment outside the cutting gap. During the cutting process, on the one hand, the bit can reduce the contact area between the bit and the cutting material, reduce the cutting resistance, and on the other hand, reduce the collision with the material during cutting to improve the durability of the substrate, so that the tool can complete the cutting more smoothly.

[0027] 2. The substrate of the diamond tool of the present invention is designed with a new type of arrow-shaped heat dissipation hole with the arrow facing outwards. The area of the hole on the outer circle side is larger. When engraving stone at high speed, due to the mutual friction between the bit and the stone, a large amount of heat is generated. The larger heat dissipation hole can effectively dissipate heat, thereby preventing heat from being transferred to the inner circle side of the tool body, and can maintain the rigidity of the substrate unchanged to the greatest extent and stably exert the cutting performance.

[0028] 3. The diamond bit of the present invention adopts a hot pressing sintering process, which has high output, low carbon and energy saving. The organizational structure after hot pressing sintering is more uniform, can maintain the original characteristics of the powder, has better self-sharpening of the matrix, better bonding strength between the matrix and the diamond part, and a relatively higher safety factor, ensuring that the bit can stably exert its performance during high-speed engraving.

[0029] 4. Generally, W, WC, etc. are added to increase the hardness and wear resistance of the bit. However, due to the too large specific gravity of W and WC, it is easy to cause uneven organization of the bit, resulting in a decrease in wear resistance. The present invention adds an appropriate amount of nickel-chromium-boron alloy powder to the diamond engraving bit to increase wear resistance. At the same time, in combination with other components, the organization of the bit can be made more impact-resistant. Engraving is often winding. If the bit is too brittle, it is easy to cause tissue cracking and endanger personal safety. Therefore, the appropriate introduction of nickel-chromium-boron alloy powder can improve the safety factor of the diamond engraving bit.

[0030] 5. In the matrix material of the tool bit of the present invention, nickel-chromium-boron alloy, FeCu alloy, etc. are added, which reduces the sintering temperature and the laser welding power. At the same time, an appropriate amount of cobalt is added to improve the strength, hardness and bonding characteristics. The synergistic effect of multiple elements increases the bonding force between the matrix material and the diamond. In addition, due to the use of 45# steel matrix material, it has good solubility with iron, copper, etc. in the matrix material of the tool bit. By optimizing the laser welding process, the weld strength between the tool bit and the matrix is increased, and the service life of the tool is improved.

[0031] 6. The diamond tool of the present invention can be used for engraving most natural stones, especially represented by granite and basalt, especially for garden landscapes, municipal engineering, tombstone engraving, bridge columns, bonsai art stones, etc. Brief Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of the diamond tool for high-speed dry stone engraving of the present application.

[0033] Wherein: 1 - matrix; 2 - tool bit; 3 - heat dissipation hole; 4 - mounting hole; 5 - arc-shaped notch. Detailed Embodiments

[0034] The technical solution of the present invention will be further described below through specific embodiments. Obviously, the embodiments are only for illustrative and helping understanding purposes and should not be regarded as specific limitations on the application of the present invention.

[0035] The present invention provides a diamond tool for high-speed dry stone engraving, and its structure is as Figure 1 shown. The diamond tool includes a circular matrix 1 and a plurality of diamond tool bits 2 uniformly arranged on the outer edge of the matrix; there is a gap between adjacent diamond tool bits 2, and an arc-shaped notch 5 is opened in the matrix at the gap position; the cross-section of each diamond tool bit along the radial direction of the matrix is trapezoidal. The width of the outer end face of the trapezoidal tool bit is smaller than the width of the inner end face, and there is a V-shaped notch on the outer end face of the tool bit.

[0036] A mounting hole 4 is provided at the center of the matrix of the diamond tool for mounting the diamond tool on a cutting machine; heat dissipation holes 3 are also provided on the matrix, and the heat dissipation holes are arrow-shaped, with the arrow pointing outwards, and the width of the arrow is 1.5 - 3 times the width of the arrow shaft; the number of heat dissipation holes is 4 - 6, and they are evenly distributed between the diamond tool bits and the mounting hole.

[0037] In the following embodiments, the chemical composition of the FeCu alloy is: Fe 8wt.%, and the balance is Cu; the chemical composition of the nickel-chromium-boron alloy is: Ni 62wt.%, B 10wt.%, C 1.6wt.%, Cr 25wt.%, Fe 1.4wt.%.

[0038] Example 1:

[0039] The process of preparing the diamond tool in this example is as follows:

[0040] 1. Preparation of diamond bit raw materials and cold pressing:

[0041] Take 2.2 kg of iron powder, 1.8 kg of copper, 0.7 kg of nickel, 1.6 kg of cobalt, 1.4 kg of iron - copper alloy powder, and 2.1 kg of nickel - chromium - boron alloy powder. Put them into the mixing barrel and mix for 60 minutes. Then add 0.010 kg of liquid paraffin and 0.15 kg of diamond, and continue to mix for 2 hours. Then pour the powder into the cold - pressing mold. Use a 200 - ton cold - pressing press. Send the mold into the cold - press and start the cold - press for pre - pressing. When the pressure reaches 5 MPa, relieve the pressure, demold and check whether the tool shows teeth. If it is qualified, place it in the qualified area for the next process.

[0042] 2. Hot - pressing sintering: Put the cold - pressed diamond tool into the hot - pressing steel mold, load the furnace, cover it with a steel furnace liner, and bury the gaps at the bottom of the furnace liner with yellow sand to prevent air from entering. First, pass hydrogen for 5 minutes. After the air in the furnace liner is exhausted, ignite the pure hydrogen discharged at the ignition port at the bottom of the sintering base. This ignition port is used to monitor whether the hydrogen supply is sufficient. Start sintering. First, heat for 1.5 hours. When the temperature rises to 820 °C, start the pressurizing mold and raise the pressure to 30 KN. Keep the temperature and pressure for 30 minutes, stop heating and relieve the pressure, and wait for natural cooling to room temperature before taking the product out of the furnace.

[0043] 3. Laser welding:

[0044] Connect the diamond bit after hot - pressing sintering and the substrate by laser welding to obtain the diamond tool. The welding process is as follows: Place the diamond bit on the corresponding position of the substrate, start the laser welding machine for welding to weld the bit and the substrate together; use a CO2 laser, the laser spot diameter is 0.35 mm, the laser power is 1135 W, the welding speed is 1.2 m / min, the defocus amount is - 1 mm, and the offset amount is 0.15 mm; the shielding gas is argon, and the shielding gas flow rate is 2.5 L / min.

[0045] 4. Sandblasting and painting:

[0046] Sandblast the inner side of the bit of the diamond tool obtained after welding the bit to remove the oxide scale on the substrate surface caused by welding. Then use a grinding wheel to grind the working surface of the diamond bit to expose the diamond. Then grind the tool with a grinder to make the substrate surface bright. Finally, perform surface painting and drying to prevent surface rusting.

[0047] Example 2:

[0048] The process of preparing the diamond tool in this example is as follows:

[0049] 1. Preparation of diamond tool head raw materials and cold pressing forming:

[0050] Take 2.4 kg of iron powder, 1.9 kg of copper, 0.8 kg of nickel, 1.4 kg of cobalt, 1.5 kg of iron - copper alloy powder, and 1.6 kg of nickel - chromium - boron alloy powder. Put them into a mixing barrel and mix for 60 minutes. Then add 0.008 kg of liquid paraffin and 0.15 kg of diamond, and continue mixing for 2 hours. After that, pour the powder into a cold - pressing mold. Use a 200 - ton cold - pressing press, send the mold into the cold - press and start pre - pressing. When the pressure reaches 5 MPa, relieve the pressure, demold and check whether the tool shows teeth. If it is qualified, it can be placed in the qualified area for the next process.

[0051] 2. Hot - press sintering: The same as Example 1.

[0052] 3. Laser welding: The same as Example 1.

[0053] 4. Sandblasting and painting: The same as Example 1.

[0054] Example 3:

[0055] The process of preparing the diamond tool in this example is as follows:

[0056] 1. Preparation of diamond tool head raw materials and cold pressing forming:

[0057] Take 2.5 kg of iron powder, 2.2 kg of copper, 0.6 kg of nickel, 1.2 kg of cobalt, 1.5 kg of iron - copper alloy powder, and 2.0 kg of nickel - chromium - boron alloy powder. Put them into a mixing barrel and mix for 60 minutes. Then add 0.015 kg of liquid paraffin and 0.16 kg of diamond, and continue mixing for 2 hours. After that, pour the powder into a cold - pressing mold. Use a 200 - ton cold - pressing press, send the mold into the cold - press and start pre - pressing. When the pressure reaches 5 MPa, relieve the pressure, demold and check whether the tool shows teeth. If it is qualified, it can be placed in the qualified area for the next process.

[0058] 2. Hot - press sintering: The same as Example 1.

[0059] 3. Laser welding: The same as Example 1.

[0060] 4. Sandblasting and painting: The same as Example 1.

[0061] The diamond tools manufactured in the above Examples 1 - 3 are tested. The surfaces of the prepared diamond tools are flat, without defects such as cracks and chipping; the structure of the welding and melting zone between the tool head and the substrate is uniform, without cracks and pores, indicating good bonding between the tool head and the substrate.

[0062] Using a universal material testing machine, the flexural strength of the welds of the diamond tools manufactured in Examples 1-3 was tested. The flexural strengths of Examples 1-3 were 1265 MPa, 1285 MPa, and 1372 MPa in sequence. The relatively high flexural strength indicates a high bonding force between the diamond matrix and the diamond, good impact resistance, and fully meeting the operation requirements commercially.

[0063] The diamond tools manufactured in Examples 1-3 were used for granite cutting, with a sawing speed of 2.5 m·min -1 , a sawing depth of 35 mm, and a current of 16.5 A. The wear rate and service life are shown in Table 1. It can be seen that the wear rates of the tools are all small and the tool service life is high.

[0064] The test data of the above-mentioned example tools for cutting granite are shown in Table 1.

[0065] Table 1 Test data of the tools in Examples 1-3 for cutting granite

[0066]

[0067] The above specific examples are only further descriptions of the technical solutions of the present invention and cannot be regarded as specific limitations on the application of the present invention. Those skilled in the art can understand that equivalent substitutions or changes made without departing from the technical solutions of the present invention all fall within the scope claimed by the present invention.

Claims

1. A diamond tool for high-speed dry stone engraving, characterized in that: The diamond tool comprises a circular base and a plurality of diamond bits evenly arranged on the outer edge of the base; there are gaps between adjacent diamond bits, and arc-shaped notches are provided in the gaps; and the cross section of each diamond bit along the radial direction of the base is trapezoidal.

2. The high-speed dry stone engraving diamond tool according to claim 1, characterized in that: The width of the outer end surface of the trapezoidal cutter head is smaller than the width of the inner end surface, and a V-shaped notch is provided on the outer end surface of the cutter head.

3. The high-speed dry stone engraving diamond tool according to claim 1, characterized in that: A mounting hole is provided at the center of the base of the diamond tool for mounting the diamond tool on a cutting machine; a heat dissipation hole is also provided on the base, the heat dissipation hole is arrow-shaped, the arrow head faces outward, and the width of the arrow head is 1.5-3 times the width of the arrow handle; the number of the heat dissipation holes is 4-6, which are evenly distributed between the diamond cutter head and the mounting hole.

4. The high-speed dry stone engraving diamond tool according to claim 1, characterized in that: The material of the substrate is 45# steel; the cutter head contains diamonds with a diamond particle size of 35 / 40, 40 / 45 or 45 / 50 and a compressive strength of 25-35kg.

5. The high-speed dry stone engraving diamond tool according to claim 4, characterized in that: The raw material composition of the diamond segment by weight is as follows: 16-34 parts of iron, 10-32 parts of copper, 2-11 parts of nickel, 9-21 parts of cobalt, 5-15 parts of iron-copper alloy, 11-23 parts of nickel-chromium-boron alloy, 0.03-0.11 parts of liquid paraffin, and 1.1-2.4 parts of diamond.

6. The diamond tool for high-speed dry stone engraving according to claim 4, characterized in that: The raw material composition of the diamond segment by weight is as follows: 19-32 parts of iron, 11-31 parts of copper, 4-8 parts of nickel, 12-20 parts of cobalt, 7-15 parts of iron-copper alloy, 14-23 parts of nickel-chromium-boron alloy, 0.04-0.10 parts of liquid paraffin, and 1.3-1.8 parts of diamond.

7. The diamond tool for high-speed dry stone engraving according to claim 5 or 6, characterized in that: The chemical composition of the iron-copper alloy is: Fe 5-10wt.%, and the balance is Cu; the chemical composition of the nickel-chromium-boron alloy is: Ni 50-63wt.%, B 7.0-12.0wt.%, C 1.4-2.0wt.%, Cr 20-25wt.%, Fe 0-5wt.%.

8. The process for preparing a high-speed dry-type stone engraving diamond tool according to claim 1, characterized in that: The process includes the following steps: (1) Matrix processing: According to the drawing requirements, the steel plate is machined and the base body of the required shape is cut; (2) Diamond Segment Sintering: The diamond cutter head raw materials are mixed evenly, cold pressed at a pressure of 3-10 MPa, and then hot pressed to obtain a cutter head blank, and the cutter head blank is polished with a grinding wheel and abrasive belt to obtain the diamond cutter head; (3) Laser welding: Place the diamond cutter head on the corresponding position on the substrate, start the laser welding machine to weld the cutter head and the substrate together; use CO2 laser, laser spot diameter 0.3-0.5mm, laser power 1120-1160W, welding speed 1.0-1.5m / min, defocus -1mm, offset 0.15mm; shielding gas is argon, shielding gas flow 2-3L / min; (4) Sandblasting and painting: The inner side of the diamond tool obtained after welding the cutter head is sandblasted to remove the oxide scale on the substrate surface caused by welding, and then the working surface of the diamond cutter head is polished with a grinding wheel to expose the diamond. The tool is then polished with a grinder to make the substrate surface bright, and finally the surface is painted and dried to prevent rust on the surface.

9. The process for preparing a high-speed dry-type stone engraving diamond tool according to claim 8, characterized in that: In step (2), the hot pressing sintering process is as follows: the cold pressed sample is placed in a hot pressing steel mold, the mold is placed in a hot pressing furnace, hydrogen is introduced first, and sintering is started after the air in the furnace is exhausted. The temperature is first raised to 825-850°C, and the pressure mold is started to increase the pressure to 20-30KN. After keeping the temperature and pressure for 30-45 minutes, the heating is stopped and the pressure is released. After naturally cooling to room temperature, the obtained blade blank is taken out of the furnace; the heating rate is 500-650°C / hour.

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