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CN-122012974-A - WC-based hard alloy with high hardness and high toughness

CN122012974ACN 122012974 ACN122012974 ACN 122012974ACN-122012974-A

Abstract

A WC-based hard alloy with high hardness and high toughness is characterized in that the hard alloy material is prepared by ball milling, spray drying and sintering an interface reinforcing phase, recovered WC and TiCN, wherein the interface reinforcing phase is solid solution powder prepared by vacuum melting and plasma rotating electrodes. The invention solves the problem of poor wettability of Ni and WC matrix interfaces, achieves the purposes of dispersion strengthening and purifying grain boundaries through the synergistic effect of Ni, mo and Zr, thereby remarkably improving the hardness and the toughness of the alloy material, realizing the dual-high effect of improving the toughness of the alloy material while improving the hardness of the alloy material, ensuring that the hardness reaches 94.2HV, the bending strength reaches 3500MPa, and the fracture toughness reaches more than 13.7MPa.m 1/2 , thereby ensuring that the alloy material meets the service performance requirements in the mining field.

Inventors

  • DENG YING
  • SHEN KUN
  • GUO CHAOZHONG
  • WU XIANG
  • JIANG ZHONGTAO
  • XIONG WAN
  • He Miaojin

Assignees

  • 重庆文理学院

Dates

Publication Date
20260512
Application Date
20240701

Claims (7)

  1. 1. A WC-based hard alloy with high hardness and high toughness is characterized in that the hard alloy material is prepared by ball milling, spray drying and sintering an interface reinforcing phase, recovered WC and TiCN, wherein the interface reinforcing phase is solid solution powder prepared by vacuum melting and plasma rotating electrodes.
  2. 2. The WC-based hard alloy with high hardness and high toughness according to claim 1, wherein the mass percentage of the interfacial reinforcing phase is 6-15 wt%, the recovered WC is 60-70 wt%, the TiCN is 15-25 wt%, and the mass ratio of Ni, zr and Mo in the solid solution powder is 8-10:2-4:2-4.
  3. 3. The WC-based hard alloy with high hardness and high strength and toughness according to claim 1 or 2, wherein the vacuum smelting is to add simple substance metal blocks (metal purity is more than 99%) of Ni, zr and Mo into a vacuum induction smelting furnace for smelting, wherein the vacuum degree of the smelting furnace is 0.005-0.05Pa, the smelting temperature is 1400-1500 ℃, the metal is stirred after being melted to ensure that the components are uniform, then the mixture is refined for 2-5 min to obtain cast ingots, and the cast ingots are processed to obtain alloy bars with the size range of 0-90 multiplied by 300-500 mm.
  4. 4. The WC-based hard alloy with high hardness and high toughness according to any one of claims 1 to 3, wherein the atomization working current prepared by the plasma rotary electrode is 1500 to 2000A, the feeding speed is 1 to 3mm/s, the plasma arc length formed by the plasma gun is 60 to 90mm, the main arc current range is 1500 to 2000A, the pilot arc current is 280 to 350A, and the main shaft rotating speed is 6000 to 13000 rpm.
  5. 5. The WC-based hard alloy with high hardness and high toughness according to any one of claims 1 to 4, wherein the ball milling is to mix solid solution powder, recovered WC powder and TiCN, put the mixture into a planetary ball mill, add WC balls with a ball-to-material ratio of 5 to 10:1, add absolute ethyl alcohol according to 0.1 to 0.2L/kg, then perform planetary ball milling at a rotational speed of 100 to 200rpm and a ball milling time of 48 to 60 h.
  6. 6. The WC-based hard alloy with high hardness and high toughness according to claim 5, wherein the sintering treatment is divided into two sections of sintering, the first section of sintering is carried out by raising the temperature to 600 ℃ for 8-10 min, preserving the heat for 5-8 min and then raising the temperature to 1050 ℃ within 3-5 min, the pressure of the instrument on the die at the first section is slowly raised to 9.5KN from 6KN, the second section of sintering is carried out by raising the temperature to 1100 ℃ for 1-2 min, then raising the temperature to 1200 ℃ for 2-3 min, and finally preserving the heat for 8-10 min at 1200 ℃, and the pressure of the instrument on the die at the second section is raised to 15.7KN from 9.5KN in stages.
  7. 7. The preparation method of the hard alloy material for the mining with the reinforced interface comprises the following steps: Preparing solid solution composite powder: (1) Weighing corresponding simple substance metal blocks (metal purity is greater than 99%) according to the weight ratio of Ni to Mo to Zr of 10:3:3, feeding the simple substance metal blocks into a vacuum induction smelting furnace for smelting, wherein the vacuum degree of the smelting furnace is 0.02Pa, the smelting temperature is 1450 ℃, stirring after melting the metal to ensure that the components are uniform, feeding the metal blocks into a refining furnace for refining for 4min to obtain cast ingots, and processing the cast ingots to obtain alloy bars with the size range phi 50-90 multiplied by 300-500 mm; (2) The alloy rod is placed on a feeding device of a plasma rotary electrode device, the alloy rod is inserted into an atomization chamber, the atomization working current is 1800A, and the feeding speed is 2mm/s. The plasma arc length formed by the plasma gun of the equipment is 80mm, the main arc current range is 1700A, the pilot arc current is 300A, the main shaft rotating speed is 12000 rpm, after the alloy powder is atomized, the alloy powder is collected, and the average particle size of the prepared powder is controlled within the range of 0.8-2.0 mu m; Preparing a mixture: (1) Mixing interface strengthening phase solid solution with the content of 12 wt%, WC powder with the content of 68 wt% and TiCN with the content of 20 wt%, putting into a planetary ball mill, adding WC balls with the ball-to-material ratio of 8:1, adding absolute ethyl alcohol according to the ratio of 0.15L/kg, and then performing planetary ball milling at the rotating speed of 150 r/min for 50 h; (2) Discharging the slurry after ball milling, atomizing the slurry under the pressure of 10 MPa, and mixing and drying the atomized slurry under the hot air at 70 ℃ to prepare a hard alloy mixture; Sintering: The mixture is put into a graphite die for sintering treatment, and is specifically divided into two-stage sintering, wherein the first-stage sintering is carried out at the temperature of 8min liters to 600 ℃, the temperature is kept for 6min, then the temperature is increased to 1050 ℃ within 4min, the pressure of an instrument for the die at the stage is slowly increased to 9.5KN from 6KN, the second-stage sintering is carried out at the temperature of 2min liters to 1100 ℃, then the temperature is increased to 1200 ℃ again for 2min, and finally the temperature is kept for 9min at the temperature of 1200 ℃, and the pressure of the instrument for the die at the stage is gradually increased to 15.7KN from 9.5 KN.

Description

WC-based hard alloy with high hardness and high toughness The patent is a divisional application of the invention 202410868035.0, named as 'an interface reinforced hard alloy material for mining and a preparation method thereof'. Technical Field The invention relates to the technical field of hard alloy materials, in particular to a WC-based hard alloy with high hardness and high strength and toughness. Background Cemented carbides are composite materials composed of one or more high hardness, high modulus carbides and a transition metal or alloy (e.g., fe, co, ni, etc.). At present, the hard alloy material used in the mining equipment has large consumption, WC (tungsten carbide) accounts for more than 80% of the material proportion, W (tungsten) is a strategic resource, and the existing reserved tungsten is almost completely consumed. Besides improving the yield of tungsten ore, the recovery of waste hard alloy is an effective supplementing way of tungsten resources. The recycled hard alloy is utilized to produce WC, so that the cost is greatly reduced, the smelting link can be reduced, the emission of CO 2 is reduced, and the requirement of development of recycling ecological economy is met. But the WC prepared by recycling waste alloy has the fatal defects of high content of impurities such as oxygen, carbon and the like, damaged lattice structure, misplacement or missing of crystal structure, influence on the microstructure of the product, difficult control of the quality of the product and the like. To recycle WC for large volume applications, unique innovations in impurity control and product microstructure optimization are necessary. In addition, the substitution of TiCN for WC is also a way. However, tiCN has high brittleness and low strength, and is not widely applied to mining tools at present. If TiCN is used instead of part of WC, the matrix must be strengthened. As a cemented carbide for mining tools, it is desirable to achieve the dual advantages of high hardness and high toughness, but it has been found during the manufacturing process that enhancing the toughness of the material results in a reduction in hardness, an increase in hardness of the material, and a sacrifice in toughness of the material. Therefore, it is extremely important how to simultaneously enhance the hardness and toughness of the alloy material so that it meets the performance requirements of mining applications. Disclosure of Invention The invention aims to provide a hard alloy material for mining with reinforced interface, in particular to a WC-based hard alloy with high hardness and high strength and toughness. The invention also aims to provide a preparation method of the hard alloy material for mining with the interface reinforcement. The invention aims at realizing the following technical scheme: A WC-based hard alloy with high hardness and high toughness is characterized in that the hard alloy material is prepared by ball milling, spray drying and sintering an interface reinforcing phase, recovered WC and TiCN, wherein the interface reinforcing phase is solid solution powder prepared by vacuum melting and plasma rotating electrodes. Further, according to the mass percentage, the interfacial reinforcing phase is 6-15 wt%, the recovered WC is 60-70 wt%, the TiCN is 15-25 wt%, and the mass ratio of Ni, zr and Mo in the solid solution powder is 8-10:2-4:2-4. And further, the vacuum smelting is to add simple substance metal blocks (metal purity is more than 99%) of Ni, zr and Mo into a vacuum induction smelting furnace for smelting, wherein the vacuum degree of the smelting furnace is 0.005-0.05Pa, the smelting temperature is 1400-1500 ℃, the metal is stirred after being melted to ensure that the components are uniform, then the mixture is refined for 2-5 min, an ingot is obtained, and an alloy rod with the size range of 0-90 multiplied by 300-500mm is obtained after processing. Further, the atomization working current prepared by the plasma rotary electrode is 1500-2000A, the feeding speed is 1-3mm/s, the plasma arc length formed by the plasma gun is 60-90 mm, the main arc current range is 1500-2000A, the pilot arc current is 280-350A, and the main shaft rotating speed is 6000-13000 rpm. Further, the ball milling is to mix solid solution powder, recovered WC powder and TiCN, put the mixture into a planetary ball mill, add WC balls with a ball-to-material ratio of 5-10:1, add absolute ethyl alcohol according to 0.1-0.2L/kg, then perform planetary ball milling at a rotating speed of 100-200rpm for a ball milling time of 48-60 h. Further, the sintering treatment is divided into two-stage sintering, wherein the first-stage sintering is carried out at the temperature of 8-10 min to 600 ℃, the temperature is kept for 5-8 min, then the temperature is increased to 1050 ℃ within 3-5 min, the pressure of the instrument to the die is slowly increased to 9.5KN from 6KN, the second-stage sintering is carried out at the temperature o