Hard alloy applied to cutting tool and preparation method of hard alloy

Abstract

The invention relates to the technical field of cutting tool materials, and discloses a hard alloy applied to a cutting tool and a preparation method thereof.The hard alloy is prepared from, by weight, 70-80 parts of tungsten carbide powder, 5-10 parts of cobalt powder, 2-6 parts of copper powder, 1-5 parts of silver powder, 0.2-0.5 part of tantalum carbide powder, 0.2-0.5 part of titanium carbide powder and 0.1-0.3 part of nickel powder, and the particle size of all the components is smaller than 10 micrometers. The copper powder and the silver powder are added into the raw materials, half of the silver powder is ground to be finer in particle size in the production process, the silver powder is evenly mixed with other powder, the mixture is pressed into a blank through a mold, and after sintering is conducted, copper and silver elements can be evenly distributed on the inner layer and the outer layer of the hard alloy; by means of the excellent heat conduction effect of copper and silver, heat generated when the cutting tool made of the hard alloy is used can be well carried away by cutting fluid, abrasion of the tool is reduced, and the service life of the tool is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of cutting tool materials, in particular to a cemented carbide used for cutting tools and a preparation method thereof. Background Art

[0002] Cutting tools are important tools used for cutting in mechanical manufacturing. They use the blade to cut off chips to achieve the purpose of processing workpieces. Cutting tools can be made of different materials, including but not limited to tool steel, ceramics and superhard materials. Among them, cemented carbide is currently the most important type of tool in the world. It is made of hard compounds of refractory metals and bonding metals through powder metallurgy. The hardness of cemented carbide is extremely high, usually up to HRC60-80, or even higher, which enables it to maintain a sharp cutting edge during cutting, grinding and other processing. The cutting speed of cemented carbide tools is much higher than that of traditional high-speed steel tools, which improves processing efficiency and precision.

[0003] In order to achieve the purpose of lubrication, cleaning and cooling of the tool during the cutting process, cutting fluid will be sprayed at the cutting position and the tool during the cutting process to achieve lubrication and cleaning while cooling the tool. The cutting tool is constantly in the cutting work with the material, and its heat generation is huge. In order to ensure its strength, the tool has a certain thickness or a large diameter. The heat dissipation effect of the tool will be affected by the thickness or diameter of the tool. The heat transferred to the inside is not easy to dissipate to the outside, which eventually causes serious wear of the tool and reduces the service life of the tool. Therefore, we propose a cemented carbide for cutting tools and a preparation method thereof. Summary of the invention

[0004] The object of the present invention is to provide a cemented carbide for cutting tools and a preparation method thereof. By adding copper powder and silver powder to the raw materials, grinding half of the silver powder to a finer particle size during production, uniformly mixing with other powders, pressing into a blank through a mold and sintering, the copper and silver elements can be evenly distributed in the inner and outer layers of the cemented carbide. When in use, the excellent thermal conductivity of copper and silver can be utilized, so that the heat of the cutting tool made of cemented carbide during use can be better carried away by the cutting fluid, thereby reducing the wear of the tool and increasing its service life, thereby solving the problems raised in the background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a cemented carbide for cutting tools and a preparation method thereof, wherein the raw materials include the following raw materials and their weight fractions in parts by weight: tungsten carbide powder: 70-80 parts, cobalt powder: 5-10 parts, copper powder: 3-10 parts, silver powder: 5-15 parts, tantalum carbide powder: 0.2-0.5 parts, titanium carbide powder: 0.2-0.5 parts, nickel powder 0.1-0.3 parts, wherein the particle size of each component is less than 10 μm.

[0006] As a preferred embodiment of the present invention, tungsten carbide powder: tungsten carbide powder: 80 parts, cobalt powder: 5 parts, copper powder: 8 parts, silver powder: 6 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, nickel powder: 0.3 parts.

[0007] As a preferred embodiment of the present invention, tungsten carbide powder: 70 parts, cobalt powder: 9.5 parts, copper powder: 10 parts, silver powder: 10 parts, tantalum carbide powder: 0.2 parts, titanium carbide powder: 0.2 parts, nickel powder: 0.1 parts.

[0008] As a preferred embodiment of the present invention, tungsten carbide powder: 75 parts, cobalt powder: 10 parts, copper powder: 8 parts, silver powder: 6 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, nickel powder: 0.3 parts.

[0009] As a preferred embodiment of the present invention, tungsten carbide powder: 75 parts, cobalt powder: 8 parts, copper powder: 6 parts, silver powder: 10 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, nickel powder: 0.3 parts.

[0010] As a preferred embodiment of the present invention, the preparation steps are as follows:

[0011] a. Weigh the above raw materials in parts by weight;

[0012] Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw material powders evenly mixed together;

[0013] Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, then grind the other half of the separated silver powder to a particle size of less than 0.5 μm, then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use;

[0014] Step 3: Put the mixed powder into the mold, apply pressure through the pressing equipment to form it into a blank of the desired shape, and stir and mix the powder each time before adding it to the mold, and then add the powder into the mold;

[0015] Step 4: Place the formed blank into a sintering furnace for high-temperature sintering to allow metallurgical bonding between the powder particles to form a dense cemented carbide structure, and conduct quality inspection on the finished product.

[0016] As a preferred embodiment of the present invention, the ball milling equipment in step 2 uses a ball mill, and the mixed powder and the separated silver powder use different ball mills.

[0017] As a preferred embodiment of the present invention, in step three, a hydraulic press is used for pressing, and the powder is stirred for no less than 5 seconds each time it is mixed.

[0018] As a preferred embodiment of the present invention, the high-temperature sintering environment in step 4 is a vacuum environment, the sintering temperature is between 1300-1500° C., and the sintering time is 2-3 hours.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention adds copper powder and silver powder to the raw materials, grinds half of the silver powder to a finer particle size during production, uniformly mixes with other powders, presses into blanks through a mold, and sintered, so that copper and silver elements can be evenly distributed in the inner and outer layers of the cemented carbide. When in use, the excellent thermal conductivity of copper and silver can be utilized, so that the heat of the cutting tool made of cemented carbide during use can be better carried away by the cutting fluid, thereby reducing the wear of the tool and increasing the service life.

[0021] 2. The present invention utilizes vacuum sintering to sinter the blank, which makes it difficult to react with oxygen in the air to generate metal oxides under high temperature conditions, thereby ensuring that various parameters and performances of the cemented carbide are not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0023] Figure 1 The present invention is a flow chart of a cemented carbide used for cutting tools and a preparation method thereof. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0025] See also Figure 1 The present invention provides a technical solution: a cemented carbide for cutting tools, wherein the raw materials include the following raw materials and their weight fractions in parts by weight: tungsten carbide powder: 70-80 parts, cobalt powder: 5-10 parts, copper powder: 3-10 parts, silver powder: 5-15 parts, tantalum carbide powder: 0.2-0.5 parts, titanium carbide powder: 0.2-0.5 parts, nickel powder 0.1-0.3 parts, wherein the particle size of each component is less than 10μm.

[0026] Furthermore, tungsten carbide powder: 80 parts, cobalt powder: 5 parts, copper powder: 8 parts, silver powder: 6 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, and nickel powder: 0.3 parts.

[0027] Furthermore, tungsten carbide powder: 70 parts, cobalt powder: 9.5 parts, copper powder: 10 parts, silver powder: 10 parts, tantalum carbide powder: 0.2 parts, titanium carbide powder: 0.2 parts, and nickel powder: 0.1 parts.

[0028] Furthermore, tungsten carbide powder: 75 parts, cobalt powder: 10 parts, copper powder: 8 parts, silver powder: 6 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, and nickel powder: 0.3 parts.

[0029] Furthermore, tungsten carbide powder: 75 parts, cobalt powder: 8 parts, copper powder: 6 parts, silver powder: 10 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, and nickel powder: 0.3 parts.

[0030] Further, the preparation steps are as follows:

[0031] a. Weigh the above raw materials in parts by weight;

[0032] Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw materials evenly mixed together. When the stirring equipment is working, keep its silo sealed to prevent the powder from leaking out;

[0033] Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, and then grind the other half of the separated silver powder to a particle size of less than 0.5 μm. The ball milling equipment uses a ball mill. In order to improve the ball milling efficiency, the mixed powder and the separated silver powder use at least two different ball mills, and then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use;

[0034] Step 3: Put the mixed powder into the mold and apply pressure through the pressing equipment, that is, use the pressure head at the bottom of the hydraulic press that matches the mold to press it to form a blank of the required shape. Then, the blank is ejected from the mold by the ejection structure, and the powder is stirred and mixed before each addition to the mold to avoid stratification due to the different densities of different raw material powders and vibration during the continuous pressing process. Then, the powder is added to the mold. Each time it is mixed, the powder is stirred for no less than 5 seconds.

[0035] Step 4: Place the formed blank into a sintering furnace for high-temperature sintering. In order to prevent the metal powder from reacting with oxygen in the air under high-temperature conditions during the sintering process, the high-temperature sintering environment is preferably a vacuum environment. The sintering temperature is between 1300-1500°C and the sintering time is 2-3h. Metallurgical bonding occurs between the powder particles to form a dense cemented carbide structure. The finished product is then quality inspected to determine whether the quality of the finished hard aluminum alloy meets the requirements for producing cutting tools.

[0036] Embodiment 1

[0037] The hard alloy comprises the following raw materials and their weight fractions: 80 parts of tungsten carbide powder, 5 parts of cobalt powder, 8 parts of copper powder, 6 parts of silver powder, 0.3 parts of tantalum carbide powder, 0.4 parts of titanium carbide powder, and 0.3 parts of nickel powder.

[0038] The preparation steps are as follows:

[0039] a. Weigh the above raw materials in parts by weight;

[0040] Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw materials evenly mixed together. When the stirring equipment is working, keep its silo sealed to prevent the powder from leaking out;

[0041] Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, and then grind the other half of the separated silver powder to a particle size of less than 0.5 μm. The ball milling equipment uses a ball mill. In order to improve the ball milling efficiency, the mixed powder and the separated silver powder use at least two different ball mills, and then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use;

[0042] Step 3: Put the mixed powder into the mold and apply pressure through the pressing equipment, that is, use the pressure head at the bottom of the hydraulic press that matches the mold to press it to form a blank of the required shape. Then, the blank is ejected from the mold by the ejection structure, and the powder is stirred and mixed before each addition to the mold to avoid stratification due to the different densities of different raw material powders and vibration during the continuous pressing process. Then, the powder is added to the mold. Each time it is mixed, the powder is stirred for no less than 5 seconds.

[0043] Step 4: Place the formed blank into a sintering furnace for high-temperature sintering. In order to prevent the metal powder from reacting with oxygen in the air under high-temperature conditions during the sintering process, the high-temperature sintering environment is preferably a vacuum environment. The sintering temperature is 1300°C and the sintering time is 3 hours. Metallurgical bonding occurs between the powder particles to form a dense cemented carbide structure. The finished product is then quality inspected to determine whether the quality of the hard aluminum alloy product meets the requirements for producing cutting tools.

[0044] Embodiment 2

[0045] The cemented carbide comprises the following raw materials and their weight fractions: 70 parts of tungsten carbide powder, 9.5 parts of cobalt powder, 10 parts of copper powder, 10 parts of silver powder, 0.2 parts of tantalum carbide powder, 0.2 parts of titanium carbide powder, and 0.1 parts of nickel powder.

[0046] The preparation steps are as follows:

[0047] a. Weigh the above raw materials in parts by weight;

[0048] Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw materials evenly mixed together. When the stirring equipment is working, keep its silo sealed to prevent the powder from leaking out;

[0049] Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, and then grind the other half of the separated silver powder to a particle size of less than 0.5 μm. The ball milling equipment uses a ball mill. In order to improve the ball milling efficiency, the mixed powder and the separated silver powder use at least two different ball mills, and then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use;

[0050] Step 3: Put the mixed powder into the mold and apply pressure through the pressing equipment, that is, use the pressure head at the bottom of the hydraulic press that matches the mold to press it to form a blank of the required shape. Then, the blank is ejected from the mold by the ejection structure, and the powder is stirred and mixed before each addition to the mold to avoid stratification due to the different densities of different raw material powders and vibration during the continuous pressing process. Then, the powder is added to the mold. Each time it is mixed, the powder is stirred for no less than 5 seconds.

[0051] Step 4: Place the formed blank into a sintering furnace for high-temperature sintering. In order to prevent the metal powder from reacting with oxygen in the air under high-temperature conditions during the sintering process, the high-temperature sintering environment is preferably a vacuum environment. The sintering temperature is between 1400°C and the sintering time is 2.5 hours. Metallurgical bonding occurs between the powder particles to form a dense cemented carbide structure. The finished product is then quality inspected to determine whether the quality of the hard aluminum alloy product meets the requirements for producing cutting tools.

[0052] Embodiment 3

[0053] The cemented carbide comprises the following raw materials and their weight fractions: 75 parts of tungsten carbide powder, 10 parts of cobalt powder, 8 parts of copper powder, 6 parts of silver powder, 0.3 parts of tantalum carbide powder, 0.4 parts of titanium carbide powder, and 0.3 parts of nickel powder.

[0054] The preparation steps are as follows:

[0055] a. Weigh the above raw materials in parts by weight;

[0056] Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw materials evenly mixed together. When the stirring equipment is working, keep its silo sealed to prevent the powder from leaking out;

[0057] Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, and then grind the other half of the separated silver powder to a particle size of less than 0.5 μm. The ball milling equipment uses a ball mill. In order to improve the ball milling efficiency, the mixed powder and the separated silver powder use at least two different ball mills, and then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use;

[0058] Step 3: Put the mixed powder into the mold and apply pressure through the pressing equipment, that is, use the pressure head at the bottom of the hydraulic press that matches the mold to press it to form a blank of the required shape. Then, the blank is ejected from the mold by the ejection structure, and the powder is stirred and mixed before each addition to the mold to avoid stratification due to the different densities of different raw material powders and vibration during the continuous pressing process. Then, the powder is added to the mold. Each time it is mixed, the powder is stirred for no less than 5 seconds.

[0059] Step 4: Place the formed blank into a sintering furnace for high-temperature sintering. In order to prevent the metal powder from reacting with oxygen in the air under high-temperature conditions during the sintering process, the high-temperature sintering environment is preferably a vacuum environment. The sintering temperature is between 1500°C and the sintering time is 2 hours. Metallurgical bonding occurs between the powder particles to form a dense cemented carbide structure. The finished product is then quality inspected to determine whether the quality of the hard aluminum alloy product meets the requirements for producing cutting tools.

[0060] Embodiment 4

[0061] The cemented carbide comprises the following raw materials and their weight fractions: 75 parts of tungsten carbide powder, 8 parts of cobalt powder, 6 parts of copper powder, 10 parts of silver powder, 0.3 parts of tantalum carbide powder, 0.4 parts of titanium carbide powder, and 0.3 parts of nickel powder.

[0062] The preparation steps are as follows:

[0063] a. Weigh the above raw materials in parts by weight;

[0064] Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw materials evenly mixed together. When the stirring equipment is working, keep its silo sealed to prevent the powder from leaking out;

[0065] Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, and then grind the other half of the separated silver powder to a particle size of less than 0.5 μm. The ball milling equipment uses a ball mill. In order to improve the ball milling efficiency, the mixed powder and the separated silver powder use at least two different ball mills, and then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use;

[0066] Step 3: Put the mixed powder into the mold and apply pressure through the pressing equipment, that is, use the pressure head at the bottom of the hydraulic press that matches the mold to press it to form a blank of the required shape. Then, the blank is ejected from the mold by the ejection structure, and the powder is stirred and mixed before each addition to the mold to avoid stratification due to the different densities of different raw material powders and vibration during the continuous pressing process. Then, the powder is added to the mold. Each time it is mixed, the powder is stirred for no less than 5 seconds.

[0067] Step 4: Place the formed blank into a sintering furnace for high-temperature sintering. In order to prevent the metal powder from reacting with oxygen in the air under high-temperature conditions during the sintering process, the high-temperature sintering environment is preferably a vacuum environment. The sintering temperature is between 1500°C and the sintering time is 2.5 hours. Metallurgical bonding occurs between the powder particles to form a dense cemented carbide structure. The finished product is then quality inspected to determine whether the quality of the hard aluminum alloy product meets the requirements for producing cutting tools.

[0068] The data parameters of traditional cemented carbide are shown in Table 1:

[0069] Test items strength Wear resistance Thermal conductivity Parameters high high generally

[0070] Example 1 Cemented carbide data parameter table 2 is as follows:

[0071] Test items strength Wear resistance Thermal conductivity Parameters high high good

[0072] Example 2 Cemented carbide data parameter table 3 is as follows:

[0073] Test items strength Wear resistance Thermal conductivity Parameters high high good

[0074] Example 3 Cemented carbide data parameter table 4 is as follows:

[0075] Test items strength Wear resistance Thermal conductivity Parameters high high excellent

[0076] Example 4 Cemented carbide data parameter table 5 is as follows:

[0077]

[0078]

[0079] In summary, referring to the data comparison of Table 1, Table 2, Table 3, Table 4 and Table 5, it can be obtained that the present invention adds copper powder and silver powder to the raw material, and grinds half of the silver powder to a finer particle size during production, uniformly mixes it with other powders, presses it into a blank through a mold and sintered it, and the copper and silver elements can be evenly distributed in the inner and outer layers of the cemented carbide. When in use, the excellent thermal conductivity of copper and silver can be utilized, so that the heat of the cutting tool made of cemented carbide during use can be better carried away by the cutting fluid, thereby reducing the wear of the tool and increasing the service life.

[0080] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0081] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A cemented carbide for cutting tools, characterized in that: The invention comprises the following raw materials and their weight fractions: tungsten carbide powder: 70-80 parts, cobalt powder: 5-10 parts, copper powder: 3-10 parts, silver powder: 5-15 parts, tantalum carbide powder: 0.2-0.5 parts, titanium carbide powder: 0.2-0.5 parts, nickel powder: 0.1-0.3 parts, wherein the particle size of each component is less than 10 μm.

2. The cemented carbide for cutting tools according to claim 1, characterized in that: Tungsten carbide powder: tungsten carbide powder: 80 parts, cobalt powder: 5 parts, copper powder: 8 parts, silver powder: 6 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, nickel powder: 0.3 parts.

3. The cemented carbide for cutting tools according to claim 1, characterized in that: Tungsten carbide powder: 70 parts, cobalt powder: 9.5 parts, copper powder: 10 parts, silver powder: 10 parts, tantalum carbide powder: 0.2 parts, titanium carbide powder: 0.2 parts, nickel powder: 0.1 parts.

4. The cemented carbide for cutting tools according to claim 1, characterized in that: Tungsten carbide powder: 75 parts, cobalt powder: 10 parts, copper powder: 8 parts, silver powder: 6 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, nickel powder: 0.3 parts.

5. The cemented carbide for cutting tools according to claim 1, characterized in that: Tungsten carbide powder: 75 parts, cobalt powder: 8 parts, copper powder: 6 parts, silver powder: 10 parts, tantalum carbide powder: 0.3 parts, titanium carbide powder: 0.4 parts, nickel powder: 0.3 parts.

6. The method for preparing cemented carbide for cutting tools according to claim 1, characterized in that: The preparation steps are as follows: a. Weigh the above raw materials in parts by weight; Step 1: First weigh the silver powder in the raw materials, separate half of the silver powder and keep it for later use, mix the other components with the other half of the silver powder, and stir the powders sufficiently to make the raw material powders evenly mixed together; Step 2: Grind the mixed raw material powders to a particle size of less than 1 μm for later use, then grind the other half of the separated silver powder to a particle size of less than 0.5 μm, then mix the silver powder into the mixed raw material powders, and mix the powders evenly again for later use; Step 3: Put the mixed powder into the mold, apply pressure through the pressing equipment to form it into a blank of the desired shape, and stir and mix the powder each time before adding it to the mold, and then add the powder into the mold; Step 4: Place the formed blank into a sintering furnace for high-temperature sintering to allow metallurgical bonding between the powder particles to form a dense cemented carbide structure, and conduct quality inspection on the finished product.

7. The method for preparing cemented carbide for cutting tools according to claim 6, characterized in that: The ball milling equipment in step 2 uses a ball mill, and the mixed powder and the separated silver powder use different ball mills.

8. The method for preparing cemented carbide for cutting tools according to claim 6, characterized in that: In the step 3, a hydraulic press is used for pressing, and the powder is stirred for no less than 5 seconds each time it is mixed.

9. The method for preparing cemented carbide for cutting tools according to claim 6, characterized in that: The high-temperature sintering environment in step 4 is a vacuum environment, the sintering temperature is between 1300-1500° C., and the sintering time is 2-3 hours.

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