Equipment and method for improving hardness of WC-Co hard alloy

Abstract

The invention relates to the technical field of hard alloy preparation, in particular to equipment and a method for improving the hardness of WC-Co hard alloy, according to the method for improving the hardness of the WC-Co hard alloy, superfine WC powder and superfine Co powder are adopted for preparing the WC-Co hard alloy, a proper amount of yttrium salt water solution of rare earth elements is added, and therefore the microstructure of the hard alloy can be improved, and the hardness of the hard alloy can be improved. Meanwhile, according to the method for improving the hardness of the WC-Co hard alloy, the raw material powder is subjected to ball milling through a ball mill, after ball milling, the obtained ball milling material is dried and sieved, and then a sintering furnace is adopted for sintering a pressed blank formed through pressing, so that the porosity of the hard alloy can be effectively reduced, and the hardness of the hard alloy is improved. In addition, according to the method for improving the hardness of the WC-Co hard alloy, the hard alloy is subjected to heat treatment again, so that the wear resistance, plasticity and hardness of the hard alloy are greatly improved, the service life of the hard alloy is prolonged, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of cemented carbide preparation, and particularly to an apparatus and method for enhancing the hardness of WC-Co cemented carbide. Background Art

[0002] Cemented carbide is a multiphase composite material composed of one or more refractory metal carbides (WC, TiC, Cr2C3) with high hardness and high modulus as the matrix and transition metals (Fe, Co, Ni, etc.) or other alloys as the binder phase. This composite structural material has the high hardness, high wear resistance, and red hardness of ceramics, and also has relatively high hardness and toughness of metals. It is widely used in wire drawing dies, cutting tools, corrosion-resistant parts, and structural components, such as the plungers and cylinders of high-pressure vessels, precision rolling rolls, anvils for synthesizing diamond, rolling rolls of wire rolling mills, paper cutters, etc., as well as nozzles for oilfield drilling.

[0003] When the existing WC-Co cemented carbide is processed, WC is produced by the solid-phase reaction of W powder and C powder at 1400 to 1600 °C, and then Co powder is mixed and ball-milled, cold-pressed into shape, and finally densified by liquid-phase sintering at a temperature of 1400 °C. The grain size of the alloy made by this method cannot be smaller than the size of the original particles, and there are usually problems of large brittleness, low hardness, and work softening. Summary of the Invention

[0004] The purpose of the present invention is to provide an apparatus and method for enhancing the hardness of WC-Co cemented carbide, which solves the technical problems that when the existing WC-Co cemented carbide is processed, WC is produced by the solid-phase reaction of W powder and C powder at 1400 to 1600 °C, and then Co powder is mixed and ball-milled, cold-pressed into shape, and finally densified by liquid-phase sintering at a temperature of 1400 °C. The grain size of the alloy made by this method cannot be smaller than the size of the original particles, and there are usually problems of large brittleness, low hardness, and work softening.

[0005] To achieve the above purpose, the present invention provides a method for enhancing the hardness of WC-Co cemented carbide, including the following steps:

[0006] Select ultra-fine WC powder and ultra-fine Co powder as raw materials. After preprocessing the WC powder and the Co powder, mix them to obtain a mixed powder material;

[0007] Use a ball mill to ball-mill the mixed powder material. After ball-milling, dry, screen, and press the screened ball-milled material into shape to obtain a green compact;

[0008] Put the green compact into a sintering furnace, and let the sintering furnace sinter the green compact. After sintering is completed, obtain WC-Co cemented carbide;

[0009] Place the WC-Co cemented carbide into a heat treatment equipment again for heat treatment, and after the heat treatment is completed, cool it to room temperature to obtain the required high-hardness WC-Co cemented carbide.

[0010] Among them, the specific steps of selecting ultrafine WC powder and Co powder as raw materials, pretreating the WC powder and the Co powder, and then mixing them to obtain a mixed powder are as follows:

[0011] Select ultrafine WC powder and ultrafine Co powder as raw materials, and weigh appropriate amounts of the WC powder and the Co powder;

[0012] Put the WC powder into a mixing box, add 0.4 wt% yttrium salt aqueous solution into the mixing box, and perform preliminary wet mixing treatment to obtain a wet mixture;

[0013] After that, add the Co powder to the wet mixture, and mix the wet mixture with the Co powder to obtain a mixed powder.

[0014] Among them, the specific steps of using a ball mill to ball mill the mixed powder, drying, sieving after ball milling, and pressing the sieved ball milled material into a shape are as follows:

[0015] Put the mixed powder into a rolling ball mill, and use the rolling ball mill to perform ball milling on the mixed powder to obtain ball milled material;

[0016] After the ball milling process, transfer the ball milled material to a dryer, let the dryer dry the ball milled material, and after drying, sieve the ball milled material;

[0017] After sieving, load the ball milled material into a mold, and let the mold press the ball milled material into a shape to obtain a green compact.

[0018] Among them, the specific steps of putting the green compact into a sintering furnace, letting the sintering furnace sinter the green compact, and obtaining WC-Co cemented carbide after sintering are as follows:

[0019] Put the green compact into a sintering furnace, let the sintering furnace sinter the green compact, and during the whole sintering process, introduce flowing ammonia gas into the sintering furnace;

[0020] When the sintering temperature of the sintering furnace rises to 650 °C, dewax for 20 min, then continue to heat up to 1350 °C, keep warm for 15 min, and after sintering is completed, obtain WC-Co cemented carbide.

[0021] Among them, the specific steps of reheating the WC-Co cemented carbide in a heat treatment device and cooling it to room temperature after the heat treatment to obtain the required high-hardness WC-Co cemented carbide are as follows:

[0022] Place the WC-Co cemented carbide in a heat treatment device and let the heat treatment device perform heat treatment on the WC-Co cemented carbide;

[0023] After the heat treatment is completed, cool the heat-treated WC-Co cemented carbide to room temperature to obtain the required high-hardness WC-Co cemented carbide.

[0024] Among them, the specific steps of placing the WC-Co cemented carbide in a heat treatment device and letting the heat treatment device perform heat treatment on the WC-Co cemented carbide are as follows:

[0025] Place the WC-Co cemented carbide in a heat treatment device and heat the WC-Co cemented carbide from room temperature to 1200 °C at a heating rate of 150 °C / min in an isopropanol atmosphere;

[0026] Keep it at this temperature for 60 min to ensure that the internal structure of the WC-Co cemented carbide can be fully homogenized;

[0027] Subsequently, introduce liquid nitrogen into the heat treatment device for rapid cooling until the temperature of the WC-Co cemented carbide drops to 400 °C;

[0028] At this temperature, introduce nitrogen or argon for heat preservation and keep it for 30 min to further stabilize the organizational structure of the WC-Co cemented carbide.

[0029] The present invention also provides a device for improving the hardness of WC-Co cemented carbide, including a mixing tank, a rolling ball mill, a dryer, a mold, a sintering furnace and a heat treatment device. The mixing tank, the rolling ball mill, the dryer, the mold, the sintering furnace and the heat treatment device are all placed on the ground;

[0030] The mixing tank is used to mix WC powder, Co powder and yttrium salt solution to obtain mixed powder;

[0031] The rolling ball mill is used to perform ball milling on the mixed powder to obtain ball-milled material;

[0032] The dryer is used to dry and screen the ball-milled material;

[0033] The mold is used to press the sieved ball mill into a shape to obtain a green compact;

[0034] The sintering furnace is used to sinter the green compact to obtain WC-Co cemented carbide.

[0035] The heat treatment equipment is used to heat-treat the WC-Co cemented carbide to obtain the required high-hardness WC-Co cemented carbide.

[0036] An equipment and method for improving the hardness of WC-Co cemented carbide according to the present invention. The method for improving the hardness of WC-Co cemented carbide prepares WC-Co cemented carbide by using ultrafine WC powder and ultrafine Co powder, and adding an aqueous solution of yttrium salt of a suitable rare earth element, thereby being able to improve the microstructure of the cemented carbide. At the same time, the method for improving the hardness of WC-Co cemented carbide mills the raw material powder by a ball mill, and after ball milling, dries and sieves the obtained milled material, and then sinters the green compact formed by pressing by using a sintering furnace, thereby being able to effectively reduce the porosity of the cemented carbide, enabling the cemented carbide to have good comprehensive mechanical properties. In addition, the method for improving the hardness of WC-Co cemented carbide greatly improves the wear resistance, plasticity and hardness of the cemented carbide by performing secondary heat treatment on the cemented carbide, extends the service life of the cemented carbide, and reduces the production cost. Brief Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art.

[0038] Figure 1 It is a flowchart of the steps of the method for improving the hardness of WC-Co cemented carbide in the first embodiment of the present invention.

[0039] Figure 2 It is a detailed flowchart of the method for improving the hardness of WC-Co cemented carbide in the first embodiment of the present invention, which selects ultrafine WC powder and ultrafine Co powder as raw materials, pre-treats the WC powder and the Co powder, and then mixes them to obtain a mixed powder material.

[0040] Figure 3 It is a detailed flowchart of the method for improving the hardness of WC-Co cemented carbide in the first embodiment of the present invention, which mills the mixed powder material by a ball mill, and after ball milling, dries, sieves, and presses the sieved milled material into a green compact to obtain a green compact.

[0041] Figure 4 It is a detailed flowchart of the method for improving the hardness of WC-Co cemented carbide in the first embodiment of the present invention, which puts the green compact into a sintering furnace, allows the sintering furnace to sinter the green compact, and after sintering is completed, obtains WC-Co cemented carbide.

[0042] Figure 5It is a specific step diagram of the method for improving the hardness of WC-Co cemented carbide in the first embodiment of the present invention, which involves placing the WC-Co cemented carbide in a heat treatment device for heat treatment again, and after the heat treatment is completed, cooling it to room temperature to obtain the required high-hardness WC-Co cemented carbide.

[0043] Figure 6 It is a specific step diagram of the method for improving the hardness of WC-Co cemented carbide in the first embodiment of the present invention, which involves placing the WC-Co cemented carbide in a heat treatment device and allowing the heat treatment device to perform heat treatment on the WC-Co cemented carbide.

[0044] Figure 7 It is a schematic structural diagram of the overall device for improving the hardness of WC-Co cemented carbide in the second embodiment of the present invention.

[0045] In the figure: 101 - mixing tank, 102 - rolling ball mill, 103 - dryer, 104 - mold, 105 - sintering furnace, 106 - heat treatment device, 107 - sieve mesh. Detailed implementation manners

[0046] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0047] First embodiment:

[0048] Please refer to Figures 1 to 6 , the present invention provides a method for improving the hardness of WC-Co cemented carbide, including the following steps:

[0049] S1. Select ultrafine WC powder and ultrafine Co powder as raw materials. After pre-treating the WC powder and the Co powder, mix them to obtain a mixed powder material.

[0050] Specifically, the specific steps of selecting ultrafine WC powder and Co powder as raw materials, pre-treating the WC powder and the Co powder, and then mixing them to obtain a mixed powder material are as follows:

[0051] S11. Select ultrafine WC powder and ultrafine Co powder as raw materials, and weigh appropriate amounts of the WC powder and the Co powder;

[0052] Specifically, the grain size of the WC powder is 0.4 - 0.8 μm, and the grain size of the Co powder is 0.8 - 1.5 μm.

[0053] S12. Put the WC powder into the mixing tank 101, add 0.4 wt% yttrium salt aqueous solution into the mixing tank 101, and perform preliminary wet mixing treatment to obtain a wet mixture;

[0054] S13. After that, add the Co powder to the wet mixture, and mix the wet mixture with the Co powder to obtain a mixed powder material.

[0055] S2. Use a ball mill to ball-mill the mixed powder material, and after ball-milling, dry, screen it, and press the screened ball-milled material into a compact to obtain a green compact.

[0056] Specifically, the specific steps of using a ball mill to ball-mill the mixed powder material, and after ball-milling, drying, screening it, and pressing the screened ball-milled material into a compact are as follows:

[0057] S21. Put the mixed powder material into a rolling ball mill 102, and use the rolling ball mill 102 to perform ball-milling processing on the mixed powder material to obtain ball-milled material;

[0058] S22. After ball-milling processing, transfer the ball-milled material to a dryer 103, let the dryer 103 dry the ball-milled material, and after drying, screen the ball-milled material;

[0059] Specifically, after the ball-milled material is dried, use a screen 107 in the dryer 103 to screen the ball-milled material to obtain the ball-milled material with uniform particles of 100 - 200 mesh.

[0060] S23. After screening, load the ball-milled material into a mold 104, and let the mold 104 press the ball-milled material into a compact to obtain a green compact.

[0061] Specifically, after the ball-milled material is loaded into the mold 104, press the ball-milled material into a compact under a pressure of 150 - 250 MPa to obtain the required green compact.

[0062] S3. Put the green compact into a sintering furnace 105, and let the sintering furnace 105 sinter the green compact. After sintering is completed, WC-Co cemented carbide is obtained.

[0063] Specifically, the specific steps of putting the green compact into a sintering furnace 105, and let the sintering furnace 105 sinter the green compact. After sintering is completed, WC-Co cemented carbide is obtained are as follows:

[0064] S31. Put the green compact into a sintering furnace 105, and let the sintering furnace 105 sinter the green compact, and during the whole sintering process, introduce flowing ammonia gas into the sintering furnace 105;

[0065] S32. When the sintering temperature of the sintering furnace 105 rises to 650 °C, dewax for 20 min, then continue to heat up to 1350 °C and hold for 15 min. After sintering is completed, WC-Co cemented carbide is obtained.

[0066] Specifically, the heating rate of the sintering furnace 105 is 350 °C / min.

[0067] S4. Place the WC-Co cemented carbide into the heat treatment equipment 106 again for heat treatment, and after the heat treatment is completed, cool it to room temperature to obtain the required high-hardness WC-Co cemented carbide.

[0068] Specifically, the specific steps of placing the WC-Co cemented carbide into the heat treatment equipment 106 again for heat treatment and, after the heat treatment is completed, cooling it to room temperature to obtain the required high-hardness WC-Co cemented carbide are as follows:

[0069] S41. Place the WC-Co cemented carbide into the heat treatment equipment 106 and let the heat treatment equipment 106 perform heat treatment on the WC-Co cemented carbide.

[0070] Specifically, the specific steps of placing the WC-Co cemented carbide into the heat treatment equipment 106 and letting the heat treatment equipment 106 perform heat treatment on the WC-Co cemented carbide are as follows:

[0071] S411. Place the WC-Co cemented carbide into the heat treatment equipment 106. Under the atmosphere of isopropanol, heat the WC-Co cemented carbide from room temperature to 1200 °C at a heating rate of 150 °C / min.

[0072] S412. Hold at this temperature for 60 min to ensure that the internal structure of the WC-Co cemented carbide can be fully homogenized.

[0073] S413. Subsequently, introduce liquid nitrogen into the heat treatment equipment 106 for rapid cooling until the temperature of the WC-Co cemented carbide drops to 400 °C.

[0074] S414. At this temperature, introduce nitrogen or argon for heat preservation and hold for 30 min to further stabilize the organizational structure of the WC-Co cemented carbide.

[0075] S42. After the heat treatment is completed, cool the heat-treated WC-Co cemented carbide to room temperature to obtain the required high-hardness WC-Co cemented carbide.

[0076] Second Embodiment:

[0077] Based on the first embodiment, please refer to Figure 7, the present invention also provides a device for improving the hardness of WC-Co cemented carbide, including a mixing tank 101, a rolling ball mill 102, a dryer 103, a mold 104, a sintering furnace 105 and a heat treatment device 106.

[0078] In this embodiment, through the combined use of the mixing tank 101, the rolling ball mill 102, the dryer 103, the mold 104, the sintering furnace 105 and the heat treatment device 106, WC-Co cemented carbide with high strength and high toughness can be prepared as required.

[0079] Among them, the mixing tank 101, the rolling ball mill 102, the dryer 103, the mold 104, the sintering furnace 105 and the heat treatment device 106 are all placed on the ground; the mixing tank 101 is used to mix WC powder, Co powder and yttrium salt aqueous solution to obtain a mixed powder; the rolling ball mill 102 is used to ball-mill the mixed powder to obtain a ball-milled material; the dryer 103 is used to dry and screen the ball-milled material; the mold 104 is used to press and form the sieved ball mill to obtain a green compact; the sintering furnace 105 is used to sinter the green compact to obtain WC-Co cemented carbide; the heat treatment device 106 is used to heat-treat the WC-Co cemented carbide to obtain the required high-hardness WC-Co cemented carbide.

[0080] When using the device for improving the hardness of WC-Co cemented carbide in this embodiment, ultrafine WC powder and ultrafine Co powder are selected as raw materials. The grain size of the WC powder is 0.4 - 0.8 μm, and the grain size of the Co powder is 0.8 - 1.5 μm. An appropriate amount of WC powder and Co powder are weighed. The WC powder is put into the mixing tank 101, and 0.4 wt% of yttrium salt aqueous solution is added into the mixing tank 101 for preliminary wet mixing treatment to obtain a wet mixture. Then, Co powder is added to the wet mixture to mix the wet mixture with the Co powder to obtain a mixed powder.

[0081] Put the mixed powder into the rolling ball mill 102, and use the rolling ball mill 102 to grind the mixed powder to obtain the milled material. After the grinding process, transfer the milled material to the dryer 103, let the dryer 103 dry the milled material, and after drying, screen the milled material. After screening, load the milled material into the mold 104, and let the mold 104 press and form the milled material to obtain a green compact. Among them, after the milled material is dried, use the screen 107 in the dryer 103 to screen the milled material to obtain milled material with uniform particles of 100-200 mesh. At the same time, after the milled material is loaded into the mold 104, press and form the milled material under a pressure of 150-250 MPa to obtain the required green compact.

[0082] Put the green compact into the sintering furnace 105, and let the sintering furnace 105 sinter the green compact. During the entire sintering process, introduce flowing ammonia gas into the sintering furnace 105. When the sintering temperature of the sintering furnace 105 rises to 650 °C, dewax for 20 min, then continue to heat up to 1350 °C and hold for 15 min. After sintering is completed, WC-Co cemented carbide is obtained. Among them, the heating rate of the sintering furnace 105 is 350 °C / min.

[0083] Place the WC-Co cemented carbide in the heat treatment equipment 106. Under an isopropanol atmosphere, heat the WC-Co cemented carbide from room temperature to 1200 °C at a heating rate of 150 °C / min, and hold at this temperature for 60 min to ensure that the internal structure of the WC-Co cemented carbide can be fully homogenized. Subsequently, introduce liquid nitrogen into the heat treatment equipment 106 for rapid cooling until the temperature of the WC-Co cemented carbide drops to 400 °C. At this temperature, introduce nitrogen or argon for heat preservation and hold for 30 min to further stabilize the tissue structure of the WC-Co cemented carbide. After heat treatment is completed, cool the heat-treated WC-Co cemented carbide to room temperature to obtain the required high-hardness WC-Co cemented carbide.

[0084] In summary, through the combined use of the mixing box 101, the rolling ball mill 102, the dryer 103, the mold 104, the sintering furnace 105 and the heat treatment equipment 106, it is possible to prepare the required WC-Co cemented carbide with high strength and high toughness. This cemented carbide can have good comprehensive mechanical properties (including wear resistance, plasticity, hardness and toughness), and extends the service life of the cemented carbide, and reduces the production cost.

[0085] The above-disclosed is only one or more preferred embodiments of the present application, and the scope of rights of the present application cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A method for improving the hardness of WC-Co cemented carbide, characterized in that: The following steps are involved: Selecting ultrafine WC powder and ultrafine Co powder as raw materials, pre-treating the WC powder and the Co powder, and then mixing them to obtain a mixed powder; The mixed powder is ball-milled by a ball mill, and after ball-milling, the mixed powder is dried and sieved, and the sieved ball-milled powder is pressed into a shape to obtain a compact; Putting the compact into a sintering furnace, allowing the sintering furnace to sinter the compact, and obtaining a WC-Co cemented carbide after sintering; The WC-Co cemented carbide is placed in a heat treatment device again for heat treatment, and after the heat treatment is completed, it is cooled to room temperature to obtain the desired high-hardness WC-Co cemented carbide.

2. The method for improving the hardness of WC-Co cemented carbide according to claim 1, characterized in that: The specific steps of selecting ultrafine WC powder and Co powder as raw materials, pre-treating the WC powder and the Co powder, and then mixing them to obtain a mixed powder are as follows: Select ultrafine WC powder and ultrafine Co powder as raw materials, and weigh appropriate amounts of the WC powder and the Co powder; Put the WC powder into a mixing box, add 0.4wt% yttrium salt aqueous solution into the mixing box, perform preliminary wet mixing treatment, and obtain a wet mixed material; Then, the Co powder is added to the wet mixture, and the wet mixture and the Co powder are mixed to obtain a mixed powder.

3. The method for improving the hardness of WC-Co cemented carbide according to claim 1, characterized in that: The specific steps of ball milling the mixed powder, drying and sieving the mixed powder after ball milling, and pressing the sieved ball milled powder into a mold are as follows: The mixed powder is put into a rolling ball mill, and the mixed powder is ball-milled by the rolling ball mill to obtain a ball-milled material; After the ball milling process, the ball mill material is transferred to a dryer, and the dryer is used to dry the ball mill material. After drying, the ball mill material is screened. After screening, the ball mill material is loaded into a mold, and the mold is used to press the ball mill material to obtain a compact.

4. The method for improving the hardness of WC-Co cemented carbide according to claim 1, characterized in that: The specific steps of placing the compact into a sintering furnace and allowing the sintering furnace to sinter the compact, and obtaining WC-Co cemented carbide after sintering are as follows: placing the compact into a sintering furnace, allowing the sintering furnace to sinter the compact, and introducing flowing ammonia gas into the sintering furnace during the entire sintering process; When the sintering temperature of the sintering furnace is increased to 650° C., dewaxing is performed for 20 minutes, and then the temperature is further increased to 1350° C. and kept for 15 minutes. After the sintering is completed, WC-Co cemented carbide is obtained.

5. The method for improving the hardness of WC-Co cemented carbide according to claim 1, characterized in that: The specific steps of placing the WC-Co cemented carbide in a heat treatment device again for heat treatment, and cooling it to room temperature after the heat treatment is completed to obtain the desired high-hardness WC-Co cemented carbide are: Placing the WC-Co cemented carbide in a heat treatment device, and allowing the heat treatment device to perform heat treatment on the WC-Co cemented carbide; After the heat treatment is completed, the WC-Co cemented carbide after the heat treatment is cooled to room temperature to obtain the desired high-hardness WC-Co cemented carbide.

6. The method for improving the hardness of WC-Co cemented carbide according to claim 5, characterized in that: The specific steps of placing the WC-Co cemented carbide in a heat treatment device and allowing the heat treatment device to heat treat the WC-Co cemented carbide are: Placing the WC-Co cemented carbide in a heat treatment device, and heating the WC-Co cemented carbide from room temperature to 1200° C. at a heating rate of 150° C. / min in an isopropanol atmosphere; Keeping the temperature at this temperature for 60 minutes ensures that the internal structure of the WC-Co cemented carbide can be fully homogenized; Subsequently, liquid nitrogen is introduced into the heat treatment equipment to perform a rapid cooling treatment until the temperature of the WC-Co cemented carbide drops to 400° C.; At this temperature, nitrogen or argon is introduced to keep the temperature for 30 minutes to further stabilize the microstructure of the WC-Co cemented carbide.

7. A device for improving the hardness of WC-Co cemented carbide, applied to the method for improving the hardness of WC-Co cemented carbide according to any one of claims 1 to 6, characterized in that: It includes a mixing box, a rolling ball mill, a dryer, a mold, a sintering furnace and a heat treatment device, wherein the mixing box, the rolling ball mill, the dryer, the mold, the sintering furnace and the heat treatment device are all placed on the ground; The mixing box is used to mix WC powder, Co powder and yttrium salt aqueous solution to obtain a mixed powder; The rolling ball mill is used to perform ball milling on the mixed powder to obtain ball milled material; The dryer is used to dry and sieve the ball mill material; The mold is used to press the screened ball mill into a compact to obtain a compact; The sintering furnace is used to sinter the compact to obtain WC-Co hard alloy; The heat treatment equipment is used to perform heat treatment on WC-Co hard alloy to obtain the required high-hardness WC-Co hard alloy.

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