A high-hardness, high-toughness WC-based cemented carbide

Abstract

A high-hardness, high-strength, and high-toughness WC-based cemented carbide is characterized by the following: the cemented carbide material is prepared by ball milling and spray drying of an interface-reinforcing phase, recycled WC, and TiCN, followed by sintering. The interface-reinforcing phase is a solid solution powder of Ni, Zr, and Mo prepared by vacuum melting and plasma rotating electrode deposition. This invention solves the problem of poor wettability at the Ni-WC matrix interface. Through the synergistic effect of Ni, Mo, and Zr, dispersion strengthening and grain boundary purification are achieved, resulting in a significant improvement in both the hardness and toughness of the alloy material. This achieves a dual effect of increased hardness and high toughness, with a hardness of 94.2 HV, a bending strength of 3500 MPa, and a fracture toughness of 13.7 MPa·m. 1 / 2 The above ensures that the alloy material meets the performance requirements for use in the mining field.

Description

[0001] This patent is a divisional application of invention patent number 202410868035.0, entitled "An interface-strengthened cemented carbide material for mining and its preparation method". Technical Field

[0002] This invention relates to the field of cemented carbide materials technology, specifically to a high-hardness, high-strength and high-toughness WC-based cemented carbide. Background Technology

[0003] Hard alloys are composite materials composed of one or more high-hardness, high-modulus carbides and transition metals or alloys (such as Fe, Co, Ni, etc.). Currently, hard alloy materials are used extensively in mining equipment, with WC (tungsten carbide) accounting for over 80% of the materials. Tungsten (W) is a strategic resource, and existing tungsten reserves will soon be depleted. Besides increasing tungsten ore yield, recycling waste hard alloys is an effective way to replenish tungsten resources. Utilizing recycled hard alloys to produce WC not only significantly reduces costs but also shortens the smelting process, reduces CO2 emissions, and aligns with the requirements of developing a circular economy.

[0004] However, WC prepared from recycled waste alloys has fatal drawbacks such as high impurity content (oxygen, carbon, etc.) and damaged crystal structure (dislocations or defects), affecting the product's microstructure and making quality control difficult. Large-scale application of recycled WC requires unique innovations in impurity control and microstructure optimization. Alternatively, replacing WC with TiCN is another approach. However, TiCN is brittle and has low strength, and is not yet widely used in mining tools. If TiCN is used to partially replace WC, the matrix must be strengthened. Hard alloys used in mining tools need to achieve both high hardness and high strength and toughness. However, during the preparation process, it has been found that increasing the toughness of the material leads to a decrease in hardness, while increasing the hardness sacrifices toughness. Therefore, it is extremely important to find a way to simultaneously enhance the hardness and toughness of the alloy material to meet the performance requirements of mining applications. Summary of the Invention

[0005] The purpose of this invention is to provide an interface-strengthened cemented carbide material for mining, specifically a high-hardness, high-strength and high-toughness WC-based cemented carbide.

[0006] Another objective of this invention is to provide a method for preparing the aforementioned interface-strengthened cemented carbide material for mining.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A high-hardness, high-strength and high-toughness WC-based cemented carbide is characterized in that: the cemented carbide material is prepared by ball milling and spray drying of an interface-reinforcing phase, recycled WC and TiCN, and finally sintering. The interface-reinforcing phase is a solid solution powder of Ni, Zr and Mo prepared by vacuum melting and plasma rotating electrode.

[0009] Furthermore, by mass percentage, the interface reinforcing phase is 6~15wt%, the recovered WC is 60~70wt%, and TiCN is 15~25wt%, and the mass ratio of Ni, Zr and Mo in the solid solution powder is 8~10:2~4:2~4.

[0010] Furthermore, the vacuum melting process involves adding elemental metal blocks of Ni, Zr, and Mo (with a metal purity greater than 99%) into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.005-0.05 Pa, the melting temperature is 1400-1500℃, and after the metal melts, it is stirred to make the composition uniform. Then, it is refined for 2-5 minutes to obtain an ingot, which is then processed to obtain an alloy rod with a size range of 0-90×300-500mm.

[0011] Furthermore, the plasma rotating electrode has an atomization working current of 1500-2000A, a feed speed of 1-3mm / s, a plasma arc length of 60-90mm formed by the plasma gun, a main arc current range of 1500-2000A, a secondary arc current of 280-350A, and a spindle speed of 6000-13000 rpm.

[0012] Furthermore, the ball milling process involves mixing the solid solution powder, recovered WC powder, and TiCN, placing them in a planetary ball mill, adding WC balls at a ball-to-material ratio of 5-10:1, adding anhydrous ethanol at 0.1-0.2 L / kg, and then performing planetary ball milling at a speed of 100-200 rpm for 48-60 h.

[0013] Furthermore, the sintering process is divided into two stages. The first stage of sintering involves raising the temperature to 600°C in 8-10 minutes, holding it at that temperature for 5-8 minutes, and then raising it to 1050°C in 3-5 minutes. During this stage, the pressure on the mold is slowly increased from 6 kN to 9.5 kN. The second stage of sintering involves raising the temperature to 1100°C in 1-2 minutes, then raising it to 1200°C in 2-3 minutes, and finally holding it at 1200°C for 8-10 minutes. During this stage, the pressure on the mold is gradually increased from 9.5 kN to 15.7 kN.

[0014] Hard alloys are used in harsh environments during mining operations. Equipment collides with rocks, generating high temperatures and wear. Mining often involves complex environments with acids and alkalis, requiring alloys with high hardness and corrosion resistance. Based on these performance requirements, Ni, with its high-temperature red hardness and corrosion resistance, is used instead of Co as the binder phase in the preparation of the alloy material. Ni is also more cost-effective than Co. However, a technical challenge with using Ni as the binder phase is that, compared to Co, the wettability between Ni and WC alloys is poor. Furthermore, since WC is recycled, its interface is more disordered, with an incomplete crystal structure and numerous defects, further reducing the wettability of the Ni-WC interface.

[0015] In this invention, vacuum melting is followed by plasma rotary sintering. Centrifugal force generated by the plasma rotating electrode ejects the liquid film, forming droplets. These droplets are then atomized in an inert gas atmosphere to form spherical Ni-Mo-Zr solid solution powders. During this process, the spherical shape possesses high surface energy, while the face-centered cubic (fcc) structure of Ni requires high free energy. Ni undergoes a high free energy conversion to a 100% fcc structure (fcc-Ni), inhibiting its transformation into a hexagonal structure. The fcc-structured Ni, due to its greater slip system, significantly improves the strength and toughness of the matrix, effectively enhancing the strength and toughness of the alloy material. Furthermore, during the formation of fcc-Ni, fcc-Ni forms a solid solution with Zr and Mo in a specific ratio. This solid solution is added as an interface strengthening phase to the alloy powder composed of WC and TiCN. After ball milling and sintering, the solid solution powder is dispersed around the WC and TiCN grains. As a strengthening phase, fcc-Ni, along with Mo and Zr, promotes the formation of a continuous transition from incoherent to coherent states at the fcc-Ni phase interface by improving interface wettability and strengthening the matrix. This reduces the pile-up of interface dislocations. The synergistic effect of Mo, Zr, and fcc-Ni achieves dispersion strengthening and grain boundary purification, thereby significantly improving the hardness and toughness of the alloy material.

[0016] A method for preparing an interface-strengthened cemented carbide material for mining, characterized in that: a solid solution powder is prepared by vacuum melting and plasma rotating electrode of Ni, Zr and Mo; the solid solution powder, recycled WC and TiCN are mixed, ball-milled and spray-dried to form a mixture; and finally sintered. The mass ratio of Ni, Zr and Mo in the solid solution powder is 8~10:2~4:2~4.

[0017] Furthermore, the vacuum melting process involves adding elemental metal blocks of Ni, Zr, and Mo (with a metal purity greater than 99%) into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.005-0.05 Pa, the melting temperature is 1400-1500℃, and after the metal melts, it is stirred to make the composition uniform. Then, it is refined for 2-5 minutes to obtain an ingot, which is then processed to obtain an alloy rod with a size range of 0-90×300-500mm.

[0018] Furthermore, the plasma rotating electrode has an atomization working current of 1500-2000A, a feed speed of 1-3mm / s, a plasma arc length of 60-90mm formed by the plasma gun, a main arc current range of 1500-2000A, a secondary arc current of 280-350A, and a spindle speed of 6000-13000 rpm.

[0019] The average particle size of the obtained powder is controlled within the range of 0.8-2.0 μm.

[0020] Furthermore, the solid solution powder is 6-15 wt% by mass, the recovered WC is 60-70 wt%, and the TiCN is 15-25 wt%.

[0021] Furthermore, the ball milling process involves mixing the solid solution powder, recovered WC powder, and TiCN, placing them in a planetary ball mill, adding WC balls at a ball-to-material ratio of 5-10:1, adding anhydrous ethanol at 0.1-0.2 L / kg, and then performing planetary ball milling at a speed of 100-200 rpm for 48-60 h.

[0022] Furthermore, the sintering process is divided into two stages. The first stage of sintering involves raising the temperature to 600°C in 8-10 minutes, holding it at that temperature for 5-8 minutes, and then raising it to 1050°C in 3-5 minutes. During this stage, the pressure on the mold is slowly increased from 6 kN to 9.5 kN. The second stage of sintering involves raising the temperature to 1100°C in 1-2 minutes, then raising it to 1200°C in 2-3 minutes, and finally holding it at 1200°C for 8-10 minutes. During this stage, the pressure on the mold is gradually increased from 9.5 kN to 15.7 kN.

[0023] A method for preparing an interface-strengthened cemented carbide material for mining, characterized by comprising the following steps:

[0024] Preparation of solid solution composite powder:

[0025] (1) Weigh the corresponding elemental metal blocks (metal purity greater than 99%) according to the weight ratio of Ni:Mo:Zr of 8~12:2~4:2~4 and put them into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.005-0.05Pa and the melting temperature is 1400~1500℃. After the metal melts, stir to make the composition uniform, and then refine for 2~5 minutes to obtain ingots. After processing, alloy rods with a size range of φ50-90×300-500mm are obtained.

[0026] (2) Place the alloy rod into the feeding device of the plasma rotating electrode equipment, insert the alloy rod into the atomization chamber, the atomization working current is 1500-2000A, the feeding speed is 1-3mm / s, the plasma arc length formed by the plasma gun of the equipment is 60-90mm, the main arc current range is 1500-200A, the secondary arc current is 280-350A, the spindle speed is 6000-13000 rpm, after the alloy powder is atomized, collect the alloy powder, and the average particle size of the powder obtained is controlled within the range of 0.8-2.0 μm;

[0027] Preparation of the mixture:

[0028] (1) Mix 6~15wt% solid solution powder, 60~70wt% WC powder and 15~25wt% TiCN powder, put them into a planetary ball mill, add WC balls, the ball-to-material ratio is 5~10:1, add anhydrous ethanol at 0.1~0.2L / kg, and then perform planetary ball milling at 100-200rpm for 48-60h;

[0029] (2) After ball milling, the slurry is discharged and atomized under a pressure of 2 to 15 MPa. The atomized slurry is mixed and dried under hot air at 60 to 80°C to produce a cemented carbide mixture.

[0030] Sintering treatment:

[0031] The mixture is loaded into a graphite mold and sintered. The sintering process is divided into two stages. The first stage involves raising the temperature to 600℃ in 8-10 minutes, holding it for 5-8 minutes, and then raising it to 1050℃ in 3-5 minutes. During this stage, the pressure on the mold is slowly increased from 6KN to 9.5KN. The second stage involves raising the temperature to 1100℃ in 1-2 minutes, then raising it to 1200℃ in 2-3 minutes, and finally holding it at 1200℃ for 8-10 minutes. During this stage, the pressure on the mold is gradually increased from 9.5KN to 15.7KN.

[0032] The present invention has the following technical effects:

[0033] This invention prepares an alloy material by adding Ni-Mo-Zr solid solution powder and mixing it with recycled WC and TiCN. This solves the problem of poor wettability at the Ni and WC matrix interface. Through the synergistic effect of Ni, Mo, and Zr, dispersion strengthening and grain boundary purification are achieved, resulting in a significant improvement in both the hardness and toughness of the alloy material. This achieves a dual effect of increased hardness and improved toughness, with a hardness of 94.2 HV, a bending strength of 3500 MPa, and a fracture toughness of 13.7 MPa·m. 1 / 2 The above ensures that the alloy material meets the performance requirements for use in the mining field. Attached Figure Description

[0034] Figure 1 XRD pattern of Ni-Mo-Zr solid solution powder prepared in this invention.

[0035] Figure 2 SEM morphology images and TEM images of the Ni-Mo-Zr solid solution powder prepared by this invention.

[0036] Figure 3 : KIC and HRA four-dimensional color mapping diagram of the alloy material prepared in Example 3 of this invention.

[0037] Figure 4 TEM images of the interface of the alloy materials prepared in Example 3 and the comparative example of this invention. Detailed Implementation

[0038] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0039] Example 1

[0040] A method for preparing a high-hardness, high-strength, and flexible WC-based cemented carbide material includes the following steps:

[0041] Preparation of solid solution composite powder:

[0042] (1) Weigh the corresponding elemental metal blocks (metal purity greater than 99%) according to the weight ratio of Ni:Mo:Zr of 12:2:2 and put them into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.005Pa and the melting temperature is 1400℃. After the metal melts, stir to make the composition uniform, and then refine for 5 minutes to obtain ingots. After processing, alloy rods with a size range of φ50-90×300-500mm are obtained.

[0043] (2) Place the alloy rod into the feed device of the plasma rotating electrode equipment, insert the alloy rod into the atomization chamber, set the atomization current to 1500A, and the feed speed to 1-3mm / s. The plasma arc length formed by the plasma gun of the equipment is 60~90mm, the main arc current range is 1500A, the secondary arc current is 350A, and the spindle speed is 13000 rpm. After the alloy powder is atomized, collect the alloy powder, and control the average particle size of the obtained powder within the range of 0.8-2.0 μm;

[0044] Preparation of the mixture:

[0045] (1) Mix 6wt% solid solution powder, 70wt% WC powder and 24wt% TiCN powder, put them into a planetary ball mill, add WC balls, the ball-to-material ratio is 5:1, add anhydrous ethanol at 0.2L / kg, and then perform planetary ball milling at 100rpm for 60h.

[0046] (2) After ball milling, the slurry is discharged and atomized under a pressure of 2 MPa. The atomized slurry is mixed and dried under hot air at 60 ℃ to produce a cemented carbide mixture.

[0047] Sintering treatment:

[0048] The mixture is loaded into a graphite mold and sintered. The sintering process is divided into two stages. The first stage involves raising the temperature to 600℃ in 10 minutes, holding it for 5 minutes, and then raising it to 1050℃ within 5 minutes. During this stage, the pressure on the mold is slowly increased from 6KN to 9.5KN. The second stage involves raising the temperature to 1100℃ in 1 minute, then raising it to 1200℃ in 2 minutes, and finally holding it at 1200℃ for 8 minutes. During this stage, the pressure on the mold is gradually increased from 9.5KN to 15.7KN.

[0049] Example 2

[0050] A method for preparing a high-hardness, high-strength, and flexible WC-based cemented carbide material includes the following steps:

[0051] Preparation of solid solution composite powder:

[0052] (1) Weigh the corresponding elemental metal blocks (metal purity greater than 99%) according to the weight ratio of Ni:Mo:Zr of 8:4:4 and put them into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.05Pa and the melting temperature is 1500℃. After the metal melts, stir to make the composition uniform, and then refine for 2 minutes to obtain ingots. After processing, alloy rods with a size range of φ50-90×300-500mm are obtained.

[0053] (2) Place the alloy rod into the feed device of the plasma rotating electrode equipment, insert the alloy rod into the atomization chamber, the atomization working current is 2000A, and the feed speed is 1-3mm / s. The plasma arc length formed by the plasma gun of the equipment is 60~90mm, the main arc current range is 2000A, and the secondary arc current is 280A. The spindle speed is 6000rpm. After the alloy powder is atomized, collect the alloy powder, and the average particle size of the obtained powder is controlled within the range of 0.8-2.0 μm;

[0054] Preparation of the mixture:

[0055] (1) Mix 15wt% solid solution powder, 70wt% WC powder and 15wt% TiCN powder, put them into a planetary ball mill, add WC balls, the ball-to-material ratio is 10:1, add anhydrous ethanol at 0.1L / kg, and then perform planetary ball milling at 200rpm for 48h.

[0056] (2) After ball milling, the slurry is discharged and then atomized under a pressure of 15MPa. The atomized slurry is mixed and dried under hot air at 80°C to produce a cemented carbide mixture.

[0057] Sintering treatment:

[0058] The mixture is loaded into a graphite mold and sintered. The sintering process is divided into two stages. The first stage involves raising the temperature to 600℃ in 8 minutes, holding it for 8 minutes, and then raising it to 1050℃ in 3 minutes. During this stage, the pressure on the mold is slowly increased from 6 kN to 9.5 kN. The second stage involves raising the temperature to 1100℃ in 2 minutes, then raising it to 1200℃ in 3 minutes, and finally holding it at 1200℃ for 10 minutes. During this stage, the pressure on the mold is gradually increased from 9.5 kN to 15.7 kN.

[0059] Example 3

[0060] A method for preparing a high-hardness, high-strength, and flexible WC-based cemented carbide material includes the following steps:

[0061] Preparation of solid solution composite powder:

[0062] (1) Weigh the corresponding elemental metal blocks (metal purity greater than 99%) according to the weight ratio of Ni:Mo:Zr of 10:3:3 and put them into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.02Pa and the melting temperature is 1450℃. After the metal melts, stir to make the composition uniform, and then refine for 4 minutes to obtain ingots. After processing, alloy rods with a size range of φ50-90×300-500mm are obtained.

[0063] (2) Place the alloy rod into the feed device of the plasma rotating electrode equipment, insert the alloy rod into the atomization chamber, the atomization working current is 1800A, and the feed 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 secondary arc current is 300A, and the spindle speed is 12000 rpm. After the alloy powder is atomized, collect the alloy powder. The average particle size of the powder obtained is controlled within the range of 0.8-2.0 μm.

[0064] Preparation of the mixture:

[0065] (1) Mix 12wt% interface-strengthened phase solid solution, 68wt% WC powder, and 20wt% TiCN, put them into a planetary ball mill, add WC balls, the ball-to-material ratio is 8:1, add anhydrous ethanol at 0.15L / kg, and then perform planetary ball milling at 150 rpm for 50 h.

[0066] (2) After ball milling, the slurry is discharged and atomized under a pressure of 10 MPa. The atomized slurry is mixed and dried under hot air at 70°C to produce a cemented carbide mixture.

[0067] Sintering treatment:

[0068] The mixture was loaded into a graphite mold and sintered. The sintering process was divided into two stages. The first stage involved raising the temperature to 600°C in 8 minutes, holding it for 6 minutes, and then raising it to 1050°C in 4 minutes. During this stage, the pressure on the mold was gradually increased from 6 kN to 9.5 kN. The second stage involved raising the temperature to 1100°C in 2 minutes, then raising it to 1200°C in another 2 minutes, and finally holding it at 1200°C for 9 minutes. During this stage, the pressure on the mold was gradually increased from 9.5 kN to 15.7 kN.

[0069] Figure 1 The image shows the XRD pattern of the fcc-Ni-Mo-Zr solid solution powder prepared in this embodiment. Figure 2 Image A is a scanning electron microscope (SEM) image of the solid solution powder. It can be seen that the alloy composition of the solid solution powder is uniformly distributed, and the particles are spherical with uniform particle size distribution. This lays the foundation for the subsequent structural optimization of the cemented carbide preparation. Image B is a transmission electron microscope (TEM) image of the interface of the prepared alloy material. It can be seen from the image that the alloy material has good interface bonding, structural crystal faces, and uniform grains.

[0070] During the preparation process, through continuous experimentation, it was found that the ratio of Ni, Mo and Zr in the solid solution has a significant impact on the hardness and toughness of the final alloy material. If the ratio is not reasonable, it is impossible to achieve the dual effect of increasing the hardness and toughness of the alloy material at the same time. Instead, when one of the hardness and toughness increases, the other decreases. Figure 3 The diagram shows a four-dimensional graph of KIC and HRA, where colors represent the values ​​of KIC and HRA. Red indicates that KIC and HRA have reached their maximum values, with Ni, Mo, and Zr weight ratios of 11.5:2.5:3 and 8:3.5:3.2, respectively. The graph shows that as Ni increases, KIC and HRA exhibit opposite trends. Therefore, to ensure dual enhancement of KIC and HRA, it is necessary to find a balance point in the Ni, Mo, and Zr ratio within this range.

[0071] To verify the effect of the ratio of Ni, Mo and Zr on the properties of alloy materials, this invention prepared different alloy materials by changing the ratio of Ni, Mo and Zr based on Example 3. Some experimental results are shown in Table 1.

[0072] Table 1:

[0073]

[0074] It is evident that the ratio of Ni, Mo, and Zr in a solid solution is crucial. When the ratio is unbalanced, whether it is Ni, Mo, or Zr, the dual enhancement of hardness and toughness cannot be achieved.

[0075] Comparative Example 1

[0076] Compared to Example 3, in the preparation of the solid solution powder, Ni was replaced with Co, while the remaining steps were the same as in Example 3.

[0077] The prepared alloy material has a hardness of 94.1 HRA, a bending strength of 3258 MPa, and a fracture toughness of 12.3 MPa·m. 1 / 2 By observing the interface TEM images of the alloy material prepared in Comparative Example 1, such as... Figure 4 As shown, A is the interface of the alloy material prepared in Example 3, and B is the interface of the alloy material prepared in Comparative Example 1. It can be seen that the alloy material prepared in Example 3 forms a continuous transition state from incoherent to coherent, while no continuous transition state is formed in Comparative Example 1.

[0078] During the research, when either Mo or Zr was absent from the solid solution, the resulting alloy materials did not form a continuous transition structure from incoherent to coherent. Replacing Mo in the solid solution with other components that can improve interfacial wettability, such as Ti, also failed to create a continuous transition structure from incoherent to coherent.

Claims

1. A high-hardness, high-strength, high-toughness WC-based cemented carbide, characterized in that: The cemented carbide material is prepared by ball milling and spray drying of an interface-reinforcing phase, recycled WC, and TiCN, followed by sintering. The interface-reinforcing phase is a solid solution powder of Ni, Zr, and Mo prepared by vacuum melting and plasma rotating electrode process. By mass percentage, the interface-reinforcing phase is 6-15 wt%, the recycled WC is 60-70 wt%, and the TiCN is 15-25 wt%. The mass ratio of Ni, Zr, and Mo in the solid solution powder is 8~10:2~4:2~4; the sintering process is divided into two stages. The first stage of sintering involves raising the temperature to 600℃ in 8~10 minutes, holding it at that temperature for 5~8 minutes, and then raising it to 1050℃ in 3~5 minutes. During this stage, the pressure of the instrument on the mold is slowly increased from 6KN to 9.5KN. The second stage of sintering involves raising the temperature to 1100℃ in 1~2 minutes, then raising it to 1200℃ in 2~3 minutes, and finally holding it at 1200℃ for 8~10 minutes. During this stage, the pressure of the instrument on the mold is gradually increased from 9.5KN to 15.7KN.

2. The high-hardness, high-strength and high-toughness WC-based cemented carbide as described in claim 1, characterized in that: The vacuum melting process involves adding elemental metal blocks of Ni, Zr, and Mo with a purity greater than 99% into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.005-0.05 Pa, and the melting temperature is 1400-1500℃. After the metal melts, it is stirred to make the composition uniform, and then refined for 2-5 minutes to obtain an ingot. After processing, alloy rods with a size range of φ50-90×300-500mm are obtained.

3. A high-hardness, high-strength, high-toughness WC-based cemented carbide as described in claim 1 or 2, characterized in that: The plasma rotating electrode has an atomization working current of 1500-2000A, a feed speed of 1-3mm / s, a plasma arc length of 60-90mm formed by the plasma gun, a main arc current range of 1500-2000A, a secondary arc current of 280-350A, and a spindle speed of 6000-13000 rpm.

4. The high-hardness, high-strength and high-toughness WC-based cemented carbide as described in claim 3, characterized in that: The ball milling process involves mixing solid solution powder, recovered WC powder, and TiCN, placing them in a planetary ball mill, adding WC balls at a ball-to-material ratio of 5-10:1, adding anhydrous ethanol at 0.1-0.2 L / kg, and then performing planetary ball milling at a speed of 100-200 rpm for 48-60 hours.

5. A method for preparing an interface-strengthened cemented carbide material for mining, comprising the following steps: Preparation of solid solution composite powder: (1) Weigh out the corresponding elemental metal blocks with a purity greater than 99% according to the weight ratio of Ni:Mo:Zr of 10:3:3 and put them into a vacuum induction melting furnace for melting. The vacuum degree of the melting furnace is 0.02Pa and the melting temperature is 1450℃. After the metal melts, stir to make the composition uniform, and then refine for 4 minutes to obtain ingots. After processing, alloy rods with a size range of φ50-90×300-500mm are obtained. (2) Place the alloy rod into the feeding device of the plasma rotating electrode equipment, insert the alloy rod into the atomization chamber, the atomization working current is 1800A, 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 secondary arc current is 300A, the spindle speed is 12000 rpm, after the alloy powder is atomized, collect the alloy powder, and the average particle size of the powder obtained is controlled within the range of 0.8-2.0 μm; Preparation of the mixture: (1) Mix 12wt% interface-strengthened phase solid solution, 68wt% WC powder, and 20wt% TiCN, put them into a planetary ball mill, add WC balls, the ball-to-material ratio is 8:1, add anhydrous ethanol at 0.15L / kg, and then perform planetary ball milling at 150 rpm for 50 h. (2) After ball milling, the slurry is discharged and then atomized under a pressure of 10 MPa. The atomized slurry is mixed and dried under hot air at 70°C to produce a cemented carbide mixture. Sintering treatment: The mixture is loaded into a graphite mold and sintered. The sintering process is divided into two stages. The first stage involves raising the temperature to 600℃ in 8 minutes, holding it for 6 minutes, and then raising it to 1050℃ in 4 minutes. During this stage, the pressure on the mold is slowly increased from 6 kN to 9.5 kN. The second stage involves raising the temperature to 1100℃ in 2 minutes, then raising it to 1200℃ in another 2 minutes, and finally holding it at 1200℃ for 9 minutes. During this stage, the pressure on the mold is gradually increased from 9.5 kN to 15.7 kN.

Images