JPS58126953A - Sintered tungsten carbide tool material and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture a tool material having a sintered structure free from segregation by forming an imprefectly sintered body from a molded body consisting of tungsten carbide powder and cobalt powder in a specified ratio, pulverizing the sintered body, and forming a perfectly sintered body by an ordinary- pressure sintering method. CONSTITUTION:A mixture of 70-95wt% tungsten carbide powder with 30- 5wt% cobalt powder is compression-molded and heated at 800-1,300 deg.C in vacuum for 10-60min to form an imperfectly sintered body. The sintered body is pulverized to homogeneous imperfectly sintered powder, and the powder is compression-molded under about 300-1,000kg/cm<2> pressure and heated at about 1,300-1,600 deg.C in vacuum to form a perfectly sintered body by an ordinary- pressure sintering method. Thus, a spongy sintered structure made of cobalt powder is filled into the gaps among uniformly dispersed tungsten carbide particles and bonded to the separate particles to prevent the ununiform distribution of carbide particles.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing powder sintered tungsten carbide-based tool material by homogeneously mixing powder obtained by pulverizing an incompletely sintered tungsten carbide body in a precursor process for manufacturing a powdered sintered tungsten carbide tool material. Completely sintered tungsten carbide based completely sintered powder! This invention relates to tool materials and their manufacturing methods.

In the present invention, the raw materials for producing the powder sintered tungsten carbide tool material of the present invention include single tungsten carbide powder, tungsten carbide double carbide powder, or tungsten carbide powder with other types of hard carbide powder. A mixed powder obtained by adding nickel powder to cobalt powder is used as a tungsten carbide-based powder, and cobalt powder or a cobalt-nickel mixed powder obtained by adding nickel powder to cobalt powder is used as a material for bonding such tungsten carbide-based powder.

The present invention involves compression molding a mixed powder obtained by adding cobalt powder or cobalt-nickel mixed powder to the above-described tungsten carbide powder, and molding the compression molded product at 800°C to 1.
An incomplete sintered body is produced by heating at a temperature within a range of 300°C, the incomplete sintered body is pulverized to produce a powder of the incomplete sintered body, and the incomplete sintered body is powdered. The particles of the incompletely sintered body are sufficiently mixed to eliminate the distortion of the individual incompletely sintered particles forming the incompletely sintered body powder, and the homogeneously mixed incompletely sintered body powder is sintered under normal pressure. A method for producing a powder sintered tungsten carbide tool material by performing complete sintering using a pressure sintering method, a pressure sintering method, or an isostatic pressure sintering method; This invention relates to a powder sintered tungsten carbide tool material that prevents distortion and eliminates segregation.

As explained above, an object of the present invention is to provide a powder sintered tungsten carbide tool material with excellent cutting performance that prevents sintered tungsten carbide particles from shifting and eliminates segregation. The present invention aims to provide an industrially viable method for manufacturing a tungsten carbide tool material.Next, the process and operation of manufacturing a powder sintered tungsten carbide tool material by the method of the present invention will be described. The powder sintered tungsten carbide tool material produced together with the above will be explained.

The raw material for the incomplete sintered body is 70% to 95% by weight of tungsten carbide powder, tungsten carbide double carbide powder, or tungsten carbide mixed powder obtained by adding other types of hard carbide powder to tungsten carbide powder. , a mixture of cobalt powder or a cobalt-nickel mixed powder obtained by adding nickel powder to cobalt powder in a ratio selected from within the ratio range of 30% by weight to 5% by weight is used. The raw material for the incomplete sintered body prepared by adding an adhesive such as paraffin to the raw material for the incomplete sintering prepared in this manner and mixing the raw material for the incomplete sintered body is molded into an appropriate shape using a molding device such as a compression molding device or a compression extrusion device. The molded body is heated in vacuum or in a hydrogen atmosphere at a temperature selected from a range of 800°C to 300°C for 10 to 60 minutes to produce an incompletely sintered body. . The resulting incompletely sintered body is crushed to produce incompletely sintered body powder. Next, the incompletely sintered powder is sufficiently mixed using a mixer to produce a homogeneously mixed incompletely sintered powder. Next, the homogeneously mixed incompletely sintered powder is subjected to normal pressure sintering, pressure sintering, or isostatic pressure sintering to produce a completely sintered body. In the case of the pressureless sintering method, 3 times the incompletely sintered powder is mixed evenly.
00kf, /+! A molded body is made by compression molding using a pressure selected from a range of 1.000 kg/d to 1.000 kg/d,
The molded body is heated to 1.300 in vacuum or hydrogen atmosphere.
Heating is performed at a temperature selected from the range of 1,600°C to 1,600°C, and when using the pressure sintering method, the incompletely sintered compact powder mixed homogeneously is filled into the pressure heating chamber to a temperature of 300°C. 9/d
Pressure is applied at a pressure selected from a range of 97 to 1,000°C, and heated at a temperature selected from a range of 1.300°C to 1.500°C, and the isostatic pressure sintering method is performed. In this case, homogeneously mixed incompletely sintered powder is filled into a container formed with a soft plate such as a soft iron plate, and the sealed container is loaded into a hydrostatic pressure heating chamber and heated at 300 dazz/d to 1. ,000 to a pressure selected from the range of 97- and heated at a temperature selected from the range of 1,300°C to 1,500°C to produce a completely sintered body. Manufacture of sintered tungsten carbide tool materials
It is a law.

The powder-sintered tungsten carbide-based tool material manufactured by the method described above is made of single tungsten carbide powder, tungsten carbide-based double carbide powder, or tungsten carbide powder prepared by adding other types of hard carbide powder to tungsten carbide powder. The system mixed powder is homogeneously dispersed, and the gaps between the individual carbide particles are filled with sintered bodies with a spongy structure made of cobalt powder or cobalt-nickel mixed powder, and the individual particles are This powder-sintered tungsten carbide-based tool material is characterized by forming a state in which the tungsten carbide particles are bonded to carbide particles, preventing the carbide particles from shifting, and forming a sintered structure that eliminates segregation.

Next, the process of manufacturing a powder sintered tungsten carbide tool material according to the method of the present invention and the powder sintered tungsten carbide tool material obtained by manufacturing will be explained.

Example 1 A mixture of 85% by weight of single tungsten carbide powder and 15% by weight of cobalt powder was used as a raw material for producing an incompletely sintered body. The raw material for the incomplete sintered body prepared in this manner is mixed with paraffin for bonding, and the raw material for the incomplete sintered body is made into a compression molded body using a compression molding device. The compression molded body was heated in a hydrogen atmosphere for 1,
An incompletely sintered body was produced by heating at a temperature of 150° C. for 30 minutes. Next, the incomplete sintered body was used in a pulverizer to produce incomplete sintered body powder. Next, pensol was added to the incomplete sintered body powder and the mixture was charged into a ball mill and further pulverized and homogeneously mixed to create an incompletely sintered body powder. A pressure of 900) cp/cJ was applied to the incomplete sintered body powder using a compression molding device to form a compression molded body of the incomplete sintered body powder. Next, the compression molded body was heated to 1,37% in a hydrogen atmosphere.
A sintered body was produced by heating at a temperature of 0° C. for 50 minutes. The sintered body obtained after the sintering process is a sponge in which tungsten carbide powder is homogeneously dispersed, and cobalt powder is sintered in the gaps between the individual tungsten carbide particles that are homogeneously dispersed. The cobalt powder sintered structure is filled with a sintered structure having a shaped structure, and the filled cobalt powder sintered structure binds individual tungsten carbide particles, forming a sintered structure with no distortion of the tungsten carbide particles. We have developed a powdered sintered tungsten carbide tool material that can exhibit high productivity as a tool material.

Example 2 Raw materials for producing an incomplete sintered body include 83% by weight of tungsten carbide-titanium carbide double carbide powder, which has a ratio of 80% by weight of tungsten carbide and 20% by weight of titanium carbide. 78% by weight cobalt powder and 2% nickel powder
A mixture was used in which a cobalt-nickel mixed powder having a proportion of 2% by weight was mixed with a proportion of 17% by weight.

Paraffin for adhesion was added to the raw material for the incomplete sintered body prepared in this way and mixed, and the raw material for the Tsushiko complete sintered body was then made into a compression molded body using a compression molding device. The compression molded body was heated in a wall at a temperature of 1,150° C. for 20 minutes to produce an incompletely sintered body. Next, the incomplete sintered body was used in a pulverizer to produce incomplete sintered body powder.

Next, the mixture obtained by adding Penzol to the incomplete sintered body powder is charged into a ball mill and further pulverized, and the incompletely sintered body powder is fully mixed. A pressure of 1,000 kf/d was applied to the incompletely sintered body powder using a compression molding device to form a compression molded body of the incompletely sintered body powder. Next, the compression molded body was heated in a vacuum at a temperature of 1.450° C. for 30 minutes to produce a sintered body. The sintered body obtained after the sintering process has tungsten carbide-titanium carbide double carbide powder dispersed homogeneously, and in the gaps between the individual tungsten carbide-titanium carbide double carbide particles that are homogeneously dispersed. , is filled with a sintered structure having a spongy structure formed by sintering a cobalt-nickel mixed powder, and the filled cobalt-nickel mixed powder sintered structure is filled with individual tungsten carbide-titanium carbide. It is a powdered sintered tungsten carbide tool material that binds double carbide particles and forms a sintered structure with no distortion of tungsten carbide-titanium carbide double carbide particles, and can demonstrate high productivity as a tool material. Ta.

Examples & Raw materials for producing an incomplete sintered body include 82% by weight of tungsten carbide-mental carbide mixed powder with a ratio of 70% by weight of tungsten carbide powder and 30% by weight of tantalum carbide powder, and cobalt. A raw material for an incomplete sintered body is prepared by adding paraffin for bonding to the mixed powder, which is a raw material for a Tsujiko complete sintered body, using a mixture of powders mixed at a ratio of 18% by weight. A compression molded body was produced using a compression molding device. The compression molded product was heated to 1.150℃ in a vacuum.
An incompletely sintered body was produced by heating at a temperature of 90 minutes for 20 minutes, and the incompletely sintered body was then used in a pulverizer to produce incompletely sintered body powder. Next, Penzol is added to the incompletely sintered powder and mixed, and the mixture is charged into a ball mill and further pulverized and thoroughly mixed to produce Tsushiko's completely sintered powder. Next, the homogeneously mixed incompletely sintered powder was filled into a container, and the container was loaded into a high temperature and high pressure generation chamber in a hot press. Next, the raw material for the incomplete sintered body in the container loaded into the high temperature and high pressure generation chamber was
The container was heated at a temperature of 1,420°C for 20 minutes while applying a pressure of 01f/i.Then, the container was pushed out of the high temperature and high pressure generation chamber, and the sintered body was taken out from inside the container.
The sintered body taken out has tungsten carbide powder and tantalum carbide powder homogeneously dispersed, and cobalt powder is added to the gaps between the individual tungsten carbide particles and the individual tantalum carbide particles that are homogeneously dispersed. The cobalt powder is filled with a sintered body having a spongy structure formed by sintering, and the filled cobalt powder sintered body binds individual tungsten carbide particles and individual tantalum carbide particles. It is a powdered sintered tungsten carbide tool material that has a uniform sintered structure of tungsten carbide particles and tantalum carbide particles, and can exhibit high productivity as a tool material.

A chip made of the powdered unsintered tungsten carbide tool material of the present invention manufactured in the example described above and a chip made of a tungsten carbide sintered body obtained by sintering tungsten carbide powder with only cobalt were used. The actual results when cutting work was carried out were as follows.

When a tip made of tungsten carbide sintered body is used to cut a piston outer diameter of 80 mm in diameter and 25 mm in length, which is made of Silumin with a composition of 88% by weight of aluminum and 12% by weight of silicon, -490 pieces could be cut continuously in - times of polishing, whereas when using the tip made of the powder sintered tungsten carbide tool material of the present invention, 530 pieces could be cut continuously in - times of polishing. I was able to cut 590 pieces. In addition, in the process of cutting the inner diameter of a bearing metal with an inner diameter of 34 mm and a length of 75 mm, which is made of gunmetal with a composition of 88% by weight of copper, 8% by weight of tin, and 4% by weight of zinc, sintered tungsten carbide When using a tip made of the powdered sintered tungsten carbide tool material of the present invention, 63 pieces could be cut continuously in - times of polishing. - It was possible to cut 65 to 76 pieces in succession in three polishing sessions.As this cutting experiment clearly shows, when cutting aluminum alloy materials and copper alloy materials, tungsten carbide sintered The chips made of the powdered sintered tungsten carbide tool material of the present invention were able to achieve significantly higher productivity than the chips made of the powdered sintered tungsten carbide tool material of the present invention.

Claims (2)

[Claims] (1) 70% to 95% by weight of a single tungsten carbide powder, a tungsten carbide double carbide powder, or a tungsten carbide mixed powder obtained by adding other types of hard carbide powder to the tungsten carbide powder, and cobalt powder. Alternatively, a cobalt-nickel mixed powder obtained by adding nickel powder to cobalt powder in a proportion selected from 30% to 5% by weight is used as the raw material for incomplete sintering, and the A compact obtained by compression molding a sintered compact is heated at 800°C to 1,500°C in nitrogen or hydrogen atmosphere.
Generate an incomplete sintered body by heating at a temperature selected from within the range of ℃ for 10 to 60 minutes, and then crush the generated incomplete sintered body to generate incomplete sintered body powder. Next, the generated incompletely sintered powder is sufficiently mixed to generate a homogeneous incompletely sintered powder, and then the generated homogeneous incompletely sintered powder is subjected to pressureless sintering or pressure sintering. A completely sintered body produced by sintering using a sintering method or isostatic pressure sintering method, which is a powder of single tungsten carbide, a powder of tungsten carbide-based double carbide, or a powder of tungsten carbide and another type of hard carbide. A tungsten carbide mixed powder containing powder is homogeneously dispersed, and a spongy sintered structure made of cobalt powder or cobalt-nickel mixed powder is formed in the spaces between the individual carbide particles that are homogeneously dispersed. Powdered sintered tungsten carbide characterized by forming a sintered structure in which the bodies are filled and bonded to individual carbide particles, preventing the carbide particles from shifting and eliminating segregation. System tool material 0 (2) 70% to 95% by weight of single tungsten carbide powder, tungsten carbide double carbide powder, or tungsten carbide powder mixed with other types of hard carbide powder, and cobalt powder or Cobalt-nickel mixed powder, which is made by adding nickel powder to cobalt powder, is mixed in a ratio selected from 30% by weight to 5% by weight, and the mixed powder is used as a raw material for an incomplete sintered body. A molded body obtained by compression molding the raw material for sintering is heated to 800°C to '1, in a vacuum or in a hydrogen atmosphere.
10 minutes to 6 days at a temperature selected from within the range of 300℃
Heating for 0 minutes to generate an incomplete sintered body, then pulverizing the generated incomplete sintered body to generate incomplete sintered body powder, and then using an atmospheric pressure sintering method to generate an incomplete sintered body. Powder of incompletely sintered body is heated at 300 m/d to 1. D 00 kp/d
A compacted compact of incompletely sintered powder compacted at a pressure within the range of 1.300°C to 1,600°C in a vacuum or hydrogen atmosphere, By the pressure sintering method, the powder of the incompletely sintered body produced is filled into a pressurized heating chamber and the amount is 3001 g/i to 1.000 ume/i.
- pressurized at a pressure within the range of and heated at a temperature within the range of 1,500°C to 1,500'C, or
The powder of the incomplete sintered body produced by the hydrostatic pressure heating method was filled into a container formed from a soft iron plate, and the sealed container was loaded into a hydrostatic pressure heating chamber to produce a powder of 500 kg/i to 1. Powder sintering characterized by producing a sintered body by isostatic pressing at a pressure within the range of .0001 w/i and heating at a temperature within the range of 1,300'C to 1,500°C. Manufacturing method for carbide tungsten tool material.