High-wear-resistance wedge-shaped chopper and preparation method thereof

Abstract

The invention discloses a high-wear-resistance wedge-shaped chopper and a preparation method thereof. The material for producing the wedge-shaped chopper comprises the following components in percentage by mass: 80-95% of matrix carbide and 5-20% of binding phase high-entropy alloy, the matrix carbide is a mixture of tungsten carbide and titanium carbide, the mass percent of tungsten carbide in the mixture is 50-99%, and the balance is titanium carbide. The preparation method of the wedge-shaped chopper comprises the steps that carbide-high-entropy alloy powder is mixed, a carbide-high-entropy hard alloy block is prepared through spark plasma sintering (SPS), and the wedge-shaped chopper is prepared through electric machining. According to the wedge-shaped chopper, the problems of tungsten carbide-cobalt hard alloy can be effectively solved, so that the mechanical property and the wear resistance of the wedge-shaped chopper are improved, and the service life of the wedge-shaped chopper is prolonged. According to the wedge-shaped chopper, the processing efficiency can be greatly improved by adopting an electromachining grinding method for the handle and the conical surface of the chopper head, and meanwhile, the dimensional accuracy of the fine structure of the wedge-shaped chopper can be ensured by adopting an electromachining forming method for the lead hole and the CG groove of the chopper head.

Description

Technical Field

[0001] The invention relates to the technical field of wedge-shaped splitting cutter production, in particular to a highly wear-resistant wedge-shaped splitting cutter and a preparation method thereof. Background Art

[0002] Tungsten carbide-cobalt cemented carbide is the earliest material used in wedge cutters. However, the hardness of the binder phase Co contained in tungsten carbide-cobalt cemented carbide is relatively low, which will affect the hardness and wear resistance of the material, thereby reducing the service life of the wedge cutter; tungsten carbide-cobalt cemented carbide will undergo grain coarsening during the sintering process, affecting the hardness of the material and causing the wear resistance of the wedge cutter to decrease. In order to improve the wear resistance of the wedge cutter, it is necessary to improve the wear resistance of tungsten carbide.

[0003] Compared with the bonding phase cobalt, high entropy alloy not only has higher hardness and wear resistance, but also because of the slow diffusion effect of high entropy alloy, there is no need to add grain growth inhibitors during the sintering process of cemented carbide, which can effectively prevent the grain coarsening of tungsten carbide particles. The wear resistance of titanium carbide is better than that of tungsten carbide. Therefore, using carbide-high entropy cemented carbide as the material of wedge cutter can effectively improve its wear resistance. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the object of the present invention is to provide a highly wear-resistant wedge-shaped riving cutter, which has excellent mechanical properties and wear resistance, thereby being able to extend the service life of the wedge-shaped riving cutter.

[0005] Another object of the present invention is to provide a method for preparing the highly wear-resistant wedge-shaped splitter.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A high wear-resistant wedge-shaped splitter, wherein the material used to produce the wedge-shaped splitter comprises, by mass percentage, 80% to 95% of matrix carbide and 5% to 20% of a bonding phase high entropy alloy; the matrix carbide is a mixture of tungsten carbide and titanium carbide, wherein the mass percentage of tungsten carbide in the mixture is 50% to 99% and the rest is titanium carbide.

[0007] Preferably, the binder phase high entropy alloy is composed of five elements: Cr, Fe, Ni, Al, and Ti, and the atomic ratio of the five elements is in the range of 1 to 1.5.

[0008] A method for preparing the highly wear-resistant wedge-shaped splitter comprises the following steps: (1) Selecting raw materials of high entropy alloy according to molar ratio and placing them into a vacuum induction gas atomization powder making furnace for smelting, atomizing the molten liquid under an inert gas condition of 3-5 MPa to obtain high entropy alloy powder; (2) Weighing carbide and high entropy alloy powders according to the weight ratio, placing them into a ball mill, adding anhydrous ethanol as a ball milling medium, and ball milling to obtain a product slurry; (3) placing the product slurry obtained in step (2) into a vacuum stirring dryer for drying, and after the product slurry is dried and cooled, sieving it through a vibrating machine to obtain a carbide-high entropy alloy powder; (4) Weigh the carbide-high entropy alloy powder according to the predetermined loading amount and place it into the mold of the spark plasma sintering furnace, and evacuate to 10 -2 Pa, after heating to 1350~1550 ℃ at a heating rate of 100 ℃ / min, pressurizing to 30~50 MPa, keeping the temperature and pressure for 30~60 min, cooling to room temperature at a cooling rate of 50 ℃ / min to release the pressure, and prepare the blank; (5) The four conical surfaces of the wedge-shaped splitting cutter handle and the cutter head are processed by electro-machining grinding, and the lead and CG groove of the wedge-shaped splitting cutter are processed by electro-machining forming.

[0009] Furthermore, in the step (1), the smelting temperature is 1400°C to 1500°C.

[0010] Furthermore, in the step (2), the ball-to-material ratio is 3:1-5:1, the ball milling time is 36-48 h, and the ball milling speed is 50-100 r / min.

[0011] Furthermore, in step (3), the drying temperature is 80°C to 100°C, the vacuum degree is 0 to 5 Pa, and the stirring drying time is 2 to 3 h.

[0012] Furthermore, the hardness of the blank obtained in step (4) is 1800~2100 HV 10 , the grain size is 0.2~0.5 μm, and the wear rate is less than 6×10 -7 mm 3 / N·m.

[0013] Beneficial technical effects of the present invention: 1. The material used to produce the wedge-shaped splitter of the present invention is carbide-high entropy cemented carbide material, and the high entropy alloy is used as a bonding phase. Since the high entropy alloy has a slow diffusion effect, it can effectively inhibit the coarsening of tungsten carbide grains during the sintering process. The wear resistance of titanium carbide is better than that of tungsten carbide, so the alloy system has excellent performance.

[0014] 2. The carbide-high entropy cemented carbide material used in the production of the wedge-shaped splitter of the present invention can effectively solve the problem of low hardness of metal Co in tungsten carbide-cobalt cemented carbide, thereby improving the mechanical properties and wear resistance of the wedge-shaped splitter and extending the service life of the wedge-shaped splitter.

[0015] 3. The wedge-shaped splitting cutter handle and the cone surface of the cutter head are grinded by electro-machining method, which can greatly improve the processing efficiency. At the same time, the lead hole and the transverse groove (CG groove) of the cutter head are formed by electro-machining method, which can ensure the dimensional accuracy of the fine structure of the wedge-shaped splitting cutter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the overall structure of the wedge-shaped splitter.

[0017] Figure 2 It is a schematic diagram of the structure of a wedge-shaped riving cutter head. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but this does not limit the protection scope of the present invention.

[0019] Figure 1 It is a schematic diagram of the overall structure of the wedge-shaped splitter; Figure 2 Figure 2 is a schematic diagram of the wedge-shaped splitter head structure. Figure 1 , 2 As shown, the wedge-shaped riving tool comprises a handle 1 and a cutter head 2 , wherein the cutter head 2 has four conical surfaces 21 , 22 , 23 , 24 , a lead 25 and a transverse groove (CG groove) 26 .

[0020] The friction and wear test described in the following examples uses silicon nitride balls as the wear parts. The test conditions are: load 10N, grinding speed 30mm / s, grinding time 60min, dry friction at room temperature. The wear rate is calculated as wear rate = wear volume / (load · total stroke).

[0021] Example 1 In this embodiment, the raw materials and proportions for preparing the wedge-shaped splitter are tungsten carbide-47.5wt.% titanium carbide-5wt.% high entropy alloy CrFeNiAlTi, that is, the raw material composition is: WC-47.5TiC-5CrFeNiAlTi.

[0022] The preparation method of the wedge-shaped splitter comprises the following steps: (1) Selecting raw materials of high entropy alloy according to molar ratio and placing them into a vacuum induction gas atomization powder making furnace for smelting at a smelting temperature of 1400°C, atomizing the molten liquid obtained by smelting under an inert gas condition of 3 MPa to obtain high entropy alloy powder; (2) Carbide and high entropy alloy powders were weighed according to the weight ratio and loaded into a ball mill with a ball-to-material ratio of 3:1. Anhydrous ethanol was added as a ball milling medium. The ball milling time was 36 h and the ball milling speed was 50 r / min to obtain a product slurry. (3) placing the product slurry obtained in step (2) into a vacuum stirring dryer for drying at a temperature of 80° C., a vacuum degree of 1 Pa, and a stirring and drying time of 2 h. After the product slurry is dried and cooled, it is sieved by a vibrating machine to obtain a carbide-high entropy alloy powder; (4) Weigh the carbide-high entropy alloy powder according to the predetermined loading amount and place it into the mold of the spark plasma sintering furnace, and evacuate to 10 -2 Pa, after heating to 1350℃ at a heating rate of 100℃ / min, pressurizing to 30MPa, keeping the temperature and pressure for 30min, cooling to room temperature at a cooling rate of 50℃ / min to release the pressure, and preparing the blank; (5) The four conical surfaces of the wedge-shaped splitting cutter handle 1 and the cutter head 2 are processed by electro-machining grinding, and the four conical surfaces are 21, 22, 23, and 24 respectively. The lead wire 25 and the CG groove 26 of the wedge-shaped splitting cutter are processed by electro-machining forming (such as Figure 1 , 2 as shown).

[0023] The carbide-5wt.% high entropy cemented carbide prepared in this example has a particle size of 0.2µm and a Vickers hardness of 1800 HV 10 The wear rate is 6×10 -7 mm 3 / N·m.

[0024] Example 2 In this embodiment, the raw materials and proportions used to prepare the wedge-shaped splitter are tungsten carbide-9wt.% titanium carbide-10wt.% high entropy alloy CrFe 1.5 Ni 1.5 AlTi, that is, the raw material composition is: WC-9TiC-10CrFe 1.5 Ni 1.5 AlTi.

[0025] The preparation method of the wedge-shaped splitter comprises the following steps: (1) Selecting raw materials of high entropy alloy according to molar ratio and placing them into a vacuum induction gas atomization powder making furnace for smelting at a smelting temperature of 1450°C, atomizing the molten liquid obtained by smelting under an inert gas condition of 4 MPa to obtain high entropy alloy powder; (2) Weigh carbide and high entropy alloy powders according to the weight ratio and put them into a ball mill with a ball-to-material ratio of 4:1. Add anhydrous ethanol as a ball milling medium. The ball milling time is 40 h and the ball milling speed is 70 r / min to obtain a product slurry. (3) placing the product slurry obtained in step (2) into a vacuum stirring dryer for drying at a temperature of 90° C., a vacuum degree of 3 Pa, and a stirring and drying time of 3 h. After the product slurry is dried and cooled, it is sieved by a vibrating machine to obtain a carbide-high entropy alloy powder; (4) Weigh the carbide-high entropy alloy powder according to the predetermined loading amount and place it into the mold of the spark plasma sintering furnace, and evacuate to 10 -2 Pa, after heating to 1450℃ at a heating rate of 100℃ / min, pressurizing to 40MPa, keeping the temperature and pressure for 50min, cooling to room temperature at a cooling rate of 50℃ / min to release the pressure, and preparing the blank; (5) The four conical surfaces of the wedge-shaped splitting cutter handle 1 and the cutter head 2 are processed by electro-machining grinding, and the four conical surfaces are 21, 22, 23, and 24 respectively. The lead wire 25 and the CG groove 26 of the wedge-shaped splitting cutter are processed by electro-machining forming (such as Figure 1 , 2 as shown).

[0026] The carbide-10wt.% high entropy cemented carbide prepared in this example has a particle size of 0.3µm and a Vickers hardness of 2100 HV 10 The wear rate is 5×10 -7 mm 3 / N·m.

[0027] Example 3 In this embodiment, the raw materials and proportions used to prepare the wedge-shaped splitter are tungsten carbide-0.8wt.% titanium carbide-20wt.% high entropy alloy CrFeNi 1.5 AlTi 1.5 , that is, the raw material composition is: WC-0.8TiC-20CrFeNi 1.5 AlTi 1.5 .

[0028] The preparation method of the wedge-shaped splitter comprises the following steps: (1) Selecting raw materials of high entropy alloy according to molar ratio and placing them into a vacuum induction gas atomization powder making furnace for smelting at a smelting temperature of 1500°C, atomizing the molten liquid obtained by smelting under an inert gas condition of 5 MPa to obtain high entropy alloy powder; (2) Weigh carbide and high entropy alloy powders according to the weight ratio and put them into a ball mill with a ball-to-material ratio of 5:1. Add anhydrous ethanol as a ball milling medium. The ball milling time is 48 h and the ball milling speed is 100 r / min to obtain a product slurry. (3) placing the product slurry obtained in step (2) into a vacuum stirring dryer for drying at a temperature of 100° C., a vacuum degree of 5 Pa, and a stirring and drying time of 3 h. After the product slurry is dried and cooled, it is sieved by a vibrating machine to obtain a carbide-high entropy alloy powder; (4) Weigh the carbide-high entropy alloy powder according to the predetermined loading amount and place it into the mold of the spark plasma sintering furnace, and evacuate to 10 -2Pa, after heating to 1550℃ at a heating rate of 100℃ / min, pressurizing to 50MPa, keeping the temperature and pressure for 60min, cooling to room temperature at a cooling rate of 50℃ / min to release the pressure, and preparing the blank; (5) The four conical surfaces of the wedge-shaped splitting cutter handle 1 and the cutter head 2 are processed by electro-machining grinding, and the four conical surfaces are 21, 22, 23, and 24 respectively. The lead wire 25 and the CG groove 26 of the wedge-shaped splitting cutter are processed by electro-machining forming (such as Figure 1 , 2 as shown).

[0029] The carbide-20wt.% high entropy cemented carbide prepared in this example has a particle size of 0.5µm and a Vickers hardness of 1900 HV 10 , the wear rate is less than 7×10 -7 mm 3 / N·m.

Claims

1. A highly wear-resistant wedge-shaped riving cutter, characterized in that: The materials used to produce the wedge-shaped splitter are composed of 80% to 95% matrix carbide and 5% to 20% high entropy alloy as a binder phase, in terms of mass percentage; the matrix carbide is a mixture of tungsten carbide and titanium carbide, in which the mass percentage of tungsten carbide is 50% to 99% and the rest is titanium carbide.

2. The highly wear-resistant wedge-shaped riving cutter according to claim 1, characterized in that: The binder phase high entropy alloy is composed of five elements: Cr, Fe, Ni, Al and Ti, and the atomic ratio of the five elements is in the range of 1 to 1.

5.

3. A method for preparing the highly wear-resistant wedge-shaped splitter according to claim 1 or 2, characterized in that: The following steps are involved: (1) Selecting raw materials of high entropy alloy according to molar ratio and placing them into a vacuum induction gas atomization powder making furnace for smelting, atomizing the molten liquid obtained by smelting under an inert gas condition of 3-5 MPa to obtain high entropy alloy powder; (2) Weighing carbide and high entropy alloy powders according to the weight ratio, placing them into a ball mill, adding anhydrous ethanol as a ball milling medium, and ball milling to obtain a product slurry; (3) placing the product slurry obtained in step (2) into a vacuum stirring dryer for drying, and after the product slurry is dried and cooled, sieving it through a vibrating machine to obtain a carbide-high entropy alloy powder; (4) Weigh the carbide-high entropy alloy powder according to the predetermined loading amount and place it into the mold of the spark plasma sintering furnace, and evacuate to 10 -2 Pa, after heating to 1350~1550 ℃ at a heating rate of 100 ℃ / min, pressurizing to 30~50 MPa, keeping the temperature and pressure for 30~60min, cooling to room temperature at a cooling rate of 50 ℃ / min to release the pressure, and prepare the blank; (5) The four conical surfaces of the wedge-shaped splitting cutter handle and the cutter head are processed by electro-machining grinding, and the lead and CG groove of the wedge-shaped splitting cutter are processed by electro-machining forming.

4. The method for preparing a highly wear-resistant wedge-shaped splitter according to claim 3, characterized in that: In the step (1), the smelting temperature is 1400°C to 1500°C.

5. The method for preparing a highly wear-resistant wedge-shaped splitter according to claim 3, characterized in that: In the step (2), the ball-to-material ratio is 3:1-5:1, the ball milling time is 36-48 h, and the ball milling speed is 50-100 r / min.

6. The method for preparing a highly wear-resistant wedge-shaped splitter according to claim 3, characterized in that: In step (3), the drying temperature is 80°C to 100°C, the vacuum degree is 0 to 5 Pa, and the stirring drying time is 2 to 3 h.

7. The method for preparing a highly wear-resistant wedge-shaped splitter according to claim 3, characterized in that: The hardness of the blank obtained in step (4) is 1800~2100 HV 10 , the grain size is 0.2~0.5 μm, and the wear rate is less than 6×10 -7 mm 3 / N·m.

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