JPS592729B2 - Manufacturing method of cubic boron nitride solids - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cubic boron nitride solid for use as a cutting tool material.

The present invention uses cubic boron nitride powder with extremely high hardness or a mixed powder of cubic boron nitride powder and titanium nitride powder with high hardness as the main material, hydrolyzes it, and then heats it to form a nascent state. Aluminum ethoxide powder or aluminum methoxide powder, which produces fine alumina powder, is used as a binder material, and aluminum powder is used as a bonding aid, and a mixture of these main materials and the binder material and bonding aid is prepared. Used as a basic raw material, water is added to the basic raw material and heated to transform the aluminum ethoxide powder or aluminum methoxide powder in the basic raw material to produce fine alumina powder in a nascent state; A hard tool characterized in that a sintered body is produced by directly performing a sintering operation using a mixed powder in which the produced fine alumina powder is mixed instead of aluminum ethoxide powder or aluminum methoxide powder as a raw material. A method for producing cubic boron nitride solids to be used as a material, the method comprising combining cubic boron nitride powder or a mixed powder of cubic boron nitride powder and titanium nitride powder with nascent fine alumina powder and aluminum powder. The object of the present invention is to provide an effective method for manufacturing cubic boron nitride solids to be used as cutting tool materials that can perform cutting operations with high productivity by bonding together mixed powders.

Next, the process and operation of manufacturing a cubic boron nitride solid body to be used as a hard tool material by the method of the present invention will be explained.

There are a first method and a second method for manufacturing a cubic boron nitride solid body.

When manufacturing by the first method, 40 parts by weight to 60 parts by weight of cubic boron nitride powder is added to the basic raw materials,
171 parts by weight to 102 parts by weight of aluminum ethoxide powder
A mixture of 125 parts by weight to 74 parts by weight of aluminum methoxide powder and 10 parts by weight of aluminum powder is used, and water is added to the basic raw materials. to hydrolyze the aluminum ethoxide powder or aluminum methoxide powder in the basic raw material, and then heat to remove the evaporated content to produce fine alumina powder in the nascent state. A state in which fine alumina powder is mixed with cubic boron nitride powder and aluminum powder is produced, and the mixture in this state is directly used as a raw material.

When manufacturing by the second method, the basic raw materials include 40 parts by weight to 60 parts by weight of cubic boron nitride powder, 30 parts by weight to 20 parts by weight of titanium nitride powder, and aluminum ethoxide powder. 68 parts by weight to 34 parts by weight or 49 parts by weight to 25 parts by weight of aluminum methoxide powder
parts by weight and 10 parts by weight of aluminum powder, and water is added to the basic raw material to form aluminum ethoxide powder or aluminum methoxide in the basic raw material. The powder is hydrolyzed and subsequently heated to eliminate the evaporated content to produce nascent alumina fine powder, and the resulting nascent alumina fine powder is transformed into cubic boron nitride powder and titanium nitride powder. A mixture of aluminum powder and aluminum powder is produced, and this mixture is used directly as a raw material.

The operation of sintering the direct raw material used in the first method described above and the operation of sintering the direct raw material used in the second method are performed by the same sintering operation.

The sintering work is performed in two stages: preliminary sintering work and main sintering work, and the pre-sintering temperature used in the preliminary sintering work is 1,200℃ to 1. ,400℃
Temperature within the range of 41,000℃kg/ffl to 43
．． Pressure within the range of 000 to 9/to 11t,
The main sintering temperature and main sintering pressure used in the main sintering work are within the range of 1.400°C to 1,600°C and 43.00 ok/= to 50.000 kg/
In addition, the temperature for main sintering and the pressure for main sintering are selected in a correlation that satisfies the stable temperature and pressure conditions for cubic boron nitride.

Next, to start the work of sintering the direct raw material in the container loaded into the high temperature and high pressure generating chamber, first, the selected pre-sintering pressure is applied to the direct raw material in the container.

Subsequently, the raw material under presintering pressure is gradually heated and the heating necessary to maintain the selected presintering temperature is maintained for 10 to 50 minutes.

In the direct raw material that has been subjected to this preliminary sintering operation, the mixed powder of fine aluminum oxide powder and aluminum powder or the mixed powder of fine aluminum oxide powder, titanium nitride powder, and aluminum powder in the direct raw material has a cubic crystal structure. A state is created in which the individual cubic boron nitride particles in an aggregate consisting of a large number of boron nitride particles are filled with a liquid phase-containing incompletely combusted tissue having a spongy structure.

Next, the pre-sintering pressure that had been applied is increased to the selected main sintering pressure.

Subsequently, the heating applied to maintain the preliminary sintering temperature is increased to the selected main sintering temperature, and the main sintering temperature is maintained for 10 to 50 minutes.

In the container subjected to this main sintering operation, the incompletely sintered tissue containing a liquid phase with a spongy structure generated in the preliminary sintering operation in the previous step is heated at the main sintering temperature and the main sintering pressure. The liquid phase-containing completely sintered structure is exposed to heat to produce a liquid-phase-containing completely sintered structure, and the resulting liquid-phase-containing completely sintered structure is bonded to individual cubic boron nitride particles.

Next, while maintaining the applied main sintering pressure, only the heating was stopped, and the high temperature and high pressure generation chamber was further cooled.
The temperature inside the room is lowered to 300°C.

Through this cooling process, the completely sintered structure containing a liquid phase with a spongy structure, which was filled between the individual cubic boron nitride particles in the aggregate consisting of a large number of cubic boron nitride particles, is cooled inside the container. This produces a solid state fully sintered body with a spongy structure, and the solid state fully sintered body is sintered into individual cubic boron nitride particles.

A solid-phase completely sintered structure in this state can be obtained by hydrolyzing aluminum ethoxide powder or aluminum methoxide powder and further heating to remove volatile components when using the basic raw materials in the first method. In the case of a solid phase completely sintered structure consisting of fine alumina powder and aluminum powder, and using the basic raw materials in the second method,
It is a solid phase completely sintered structure consisting of fine alumina powder, titanium nitride powder, and aluminum powder obtained by hydrolyzing aluminum ethoxide powder or aluminum methoxide powder and further heating to remove volatile components.

Next, the main sintering pressure that had been maintained was returned to normal pressure,
The container is pushed out from inside the high temperature and high pressure generation chamber, and the sintered body is taken out from inside the container.

The obtained sintered body contains solid particles formed from a mixed powder of fine alumina powder and aluminum powder between individual cubic boron nitride particles in an aggregate consisting of a large number of cubic boron nitride particles. A binder region is a phase completely sintered structure or a binder region is a solid phase completely sintered structure produced from a mixed powder of fine alumina powder, titanium nitride powder, and aluminum powder, A cubic boron nitride solid that can be used as a cutting tool material is formed by bonding individual cubic boron nitride particles in an aggregate consisting of a large number of cubic boron nitride particles. It is a body.

Next, an example of manufacturing a cubic boron nitride solid body according to the present invention will be described.

Example 1 As a basic raw material, a mixed powder was used in which 50 parts by weight of cubic boron nitride powder, 136 parts by weight of aluminum ethoxide powder, and 10 parts by weight of aluminum powder were mixed.

Water is added to the mixed powder, which is its basic raw material, to hydrolyze the aluminum ethoxide in the mixed powder to produce aluminum hydroxide, and then the produced aluminum hydroxide is converted into cubic boron nitride powder. The resulting mixture is then heated to convert the aluminum hydroxide into nascent finely powdered alumina, and the heating further converts the aluminum hydroxide into finely powdered alumina. The generated moisture and the moisture mixed in the mixture are separated, and a state in which the generated alumina fine powder in a nascent state is mixed with cubic boron nitride powder and aluminum powder is produced, and that state is The mixture was used as the direct raw material used in the sintering operation.

The raw material directly prepared in this manner was filled into a container, and the container was loaded into a high temperature and high pressure generation chamber in a high temperature and high pressure generation device.

Next, the work of sintering the raw materials in the container is carried out in two stages: a preliminary sintering operation and a seven-sintering operation. A temperature of 1,200°C and a pressure of 41,000 kg/cvi were selected for the pressure, and a temperature of 1.500°C was selected for the main sintering temperature and the main sintering pressure used in the main sintering work. and 48.0
A pressure of 0.00 kg/cri was selected.

Next, the work of sintering the direct raw material in the container loaded into the high-temperature and high-pressure generation chamber started. First, the pre-sintering pressure selected for the direct raw material was 41.000 kg/CI.
Added IL.

Next, the direct raw material to which pre-sintering pressure is applied is gradually heated to the selected pre-sintering temperature of 1,200°C, and the pre-sintering temperature is maintained. The required heating was maintained for 25 minutes.

Next, the pre-sintering pressure that had been applied was increased to the selected main sintering pressure of 48,000 kg/cvb.

The heating at the preliminary sintering temperature that had been added directly to the raw materials in the container was increased to the selected main sintering temperature of 1,500°C, and the temperature required to maintain the main sintering temperature was increased. Heating was continued for 30 minutes.

Next, only heating was stopped while maintaining the main sintering pressure that had been applied, and the high temperature and high pressure generation chamber was cooled with water from the outside to lower the temperature inside the chamber to 300°C.

Next, the main sintering pressure that had been maintained was returned to normal pressure,
The container was pushed out of the high-temperature, high-pressure generation chamber, and the sintered body was taken out from inside the container.

The obtained sintered body has a solid phase with a spongy structure consisting of a mixed powder of fine alumina powder and aluminum powder between individual cubic boron nitride particles in an aggregate consisting of a large number of cubic boron nitride particles. It has a binder region that is a completely sintered structure, and the binder region, which is a solid state completely sintered structure with a spongy structure, is a solid-phase completely sintered structure having a spongy structure. It was a cubic boron nitride solid that could be used as a cutting tool material and was made by combining crystalline boron nitride particles.

It was a cubic boron nitride solid whose composition was 50% by weight of cubic boron nitride, 40% by weight of alumina, and 10% by weight of aluminum.

Example 2 As the basic raw material, a mixed powder in which 60 parts by weight of cubic boron nitride powder, 75 parts by weight of aluminum methoxide powder, and 10 parts by weight of aluminum powder were mixed was used.

Water is added to the mixed powder, which is the basic raw material, and the aluminum methoxide in the mixed powder is hydrolyzed to generate aluminum hydroxide, and the resulting aluminum hydroxide and water are converted into cubic nitride. A mixed state of boron powder and aluminum powder is produced, and then the mixture formed in that state is heated to form aluminum hydroxide into fine powder alumina in a nascent state, and the heating generates aluminum hydroxide. The water mixed in the mixture is separated from the water mixed in the mixture to form a state in which fine alumina powder in a nascent state is mixed with cubic boron nitride powder and aluminum powder. The mixture was used as the direct raw material used in the sintering operation.

The raw material directly prepared in this manner was filled into a container, and the container was loaded into a high temperature and high pressure generating chamber.

The work of directly sintering the raw material in the container loaded into the high temperature and high pressure generating chamber was carried out in the same manner as in Example 1.

The sintered body obtained after the sintering operation was a cubic boron nitride solid that had the same structure as the sintered body produced in Example 1 and could be used as a cutting tool material.

The sintered body was a cubic boron nitride solid having a ratio of 60% by weight of cubic boron nitride powder, 30% by weight of alumina, and 10% by weight of aluminum.

Example 3 The basic raw materials were mixed at a ratio of 50 parts by weight of cubic boron nitride powder, 20 parts by weight of titanium nitride powder, 68 parts by weight of aluminum ethoxide powder, and 10% by weight of aluminum powder. A mixed powder was used.

Water is added to the mixed powder, which is the basic raw material, to hydrolyze the aluminum ethoxide in the mixed powder, which is the basic raw material, to generate aluminum hydroxide, and the resulting aluminum hydroxide and water are combined. and forming a mixture of cubic boron nitride powder, titanium nitride powder, and aluminum powder, and then heating the resulting mixture to form aluminum hydroxide into nascent finely powdered alumina. At the same time, the water generated from the aluminum hydroxide and the water mixed in the mixture are evaporated and separated by heating.
The resulting nascent fine alumina powder was mixed with cubic boron nitride powder, titanium nitride powder, and aluminum powder, and the mixture was used as a direct raw material for sintering.

The raw material directly prepared in this manner was filled into a container, and the container was loaded into a high temperature and high pressure generating chamber.

The work of sintering the raw material in the container loaded into the high temperature and high pressure generating chamber was carried out in the same manner as in Example 1.

The sintered body obtained after completing the sintering process contains titanium nitride powder, fine alumina powder, and aluminum powder between the individual cubic boron nitride particles in an aggregate consisting of a large number of cubic boron nitride particles. The binder region is a solid-phase completely sintered tissue with a spongy structure made of a mixed powder of cubic boron nitride. It was a cubic boron nitride solid that could be used as a cutting tool material, and was made by combining individual cubic boron nitride particles in an aggregate consisting of a large number of particles.

It was a cubic boron nitride solid having a composition of 50% by weight of cubic boron nitride, 20% by weight of titanium nitride, 20% by weight of alumina, and 10% by weight of aluminum.

Example 4 The basic raw materials were mixed at a ratio of 60 parts by weight of cubic boron nitride powder, 20 parts by weight of titanium nitride powder, 25 parts by weight of aluminum methoxide powder, and 10 parts by weight of aluminum powder. The mixture was used.

Water is added to the mixed powder, which is the basic raw material, and aluminum methoxide in the mixed powder is hydrolyzed to produce aluminum hydroxide, and the resulting aluminum hydroxide and water form cubic nitridation. Producing a mixed state of boron powder, titanium nitride powder, and aluminum powder, and then heating the resulting mixture to form aluminum hydroxide into fine powder alumina in a nascent state, and heating it. The water generated from aluminum hydroxide and the water mixed in the mixture are separated, and the resulting fine alumina powder in a nascent state is mixed with cubic boron nitride powder, titanium nitride powder, and aluminum powder. generate the state,
The mixture in that state was used as the direct raw material used in the sintering operation.

The raw material directly prepared in this manner was filled into a container, and the container was loaded into a high temperature and high pressure generation chamber.

The work of directly sintering the raw material in the container loaded into the high temperature and high pressure generating chamber was carried out in the same manner as in Example 3.

The sintered body obtained after the sintering operation had the same structure as the sintered body produced in Example 3, but was a cubic boron nitride solid that could be used as a cutting tool material.

The sintered body was a cubic boron nitride solid containing 60% by weight of cubic boron nitride, 20% by weight of titanium nitride, 10% by weight of alumina, and 10% by weight of aluminum.

When cutting work is performed using a tip made of a cubic boron nitride solidified body manufactured according to the example described above and a tip made of a tungsten carbide sintered body made by sintering tungsten carbide powder with cobalt. The results were as follows.

When cutting a ring-shaped body formed and hardened from chrome tool steel into an outer ring for a roller bearing with an outer diameter of 52 mm and a width of 15 mm, if a tip made of sintered tungsten carbide is used, While 26 pieces could be cut by polishing, when a tip made of cubic boron nitride solids was used, 1,728 pieces could be cut with the tip of Example 1 in one polishing. In the case of the chip in Example 2, 1
, 762 pieces can be cut, and the tip of Example 3 can cut 1,
It is possible to cut 710 pieces, and the tip of Example 4 can cut 1.7 pieces.
I was able to cut 45 pieces.

As is clear from this cutting experiment, compared to chips made of sintered tungsten carbide, chips made of cubic boron nitride solids were able to achieve significantly higher productivity.

Claims (1)

[Claims] 1. 40 to 60 parts by weight of cubic boron nitride powder and 171 to 10 parts by weight of aluminum ethoxide powder.
2 parts by weight or 125 parts of aluminum methoxide powder
The basic raw material is a mixture of 74 parts by weight and 10 parts by weight of aluminum powder, water is added to the basic raw material, and then,
The alumina powder produced by heating and modifying the aluminum ethoxide or aluminum methoxide in the basic raw material is mixed with the cubic boron nitride powder and the aluminum powder, and the mixture in this state is directly used as the raw material. The process of filling the raw material directly into a container, loading the container into a high-temperature and high-pressure generation chamber, and then sintering the raw material filled in the container is called preliminary sintering and main sintering. The temperature and pressure for pre-sintering used in the pre-sintering work are 1,200°C to 1,200°C.
．． Temperature within the range of 400℃ and 41.000 kg/cI
The pressure within the range of IL to 43,000 kg/cvi was selected, and the main sintering temperature and pressure used in the main sintering work were 1,400°C to 1,600°C. Temperature within the range 43,000 kg/C11 to 50
,000 kg/crA, and also selected the main sintering temperature and main sintering pressure that have a correlation that satisfies the stable temperature and pressure conditions for cubic boron nitride. When starting the work of directly sintering the raw materials in the container loaded into the high-temperature and high-pressure generation chamber, first apply the selected pre-sintering pressure, and then apply the pre-sintering pressure. Gradually heat the direct raw material in the container to the selected presintering temperature, maintain the heating necessary to maintain the presintering temperature for 10 to 50 minutes, and then add The pressure was increased to the selected main sintering pressure, and then the heating that had been applied to maintain the preliminary sintering temperature was increased to the selected main sintering temperature. The heating required to maintain the main sintering temperature is 10
This lasts for 50 minutes, then only the heating is stopped while maintaining the applied main sintering pressure, and the high temperature and high pressure generation chamber is further cooled to bring the temperature inside the chamber to 300°C. A method for producing a cubic boron nitride solid body, which comprises lowering the temperature, then returning the main sintering pressure to normal pressure, and then taking out the sintered body from a high temperature and high pressure generating chamber. 2 40 to 60 parts by weight of cubic boron nitride powder, 30 to 20 parts by weight of titanium nitride powder, 68 to 34 parts by weight of aluminum ethoxide powder, or 49 parts by weight of aluminum methoxide powder. ~25
The basic raw material is a mixture of parts by weight and aluminum powder selected from within the ratio range of 10 parts by weight,
Water is added to the basic raw material, followed by heating, and the aluminum ethoxide or aluminum methoxide in the basic raw material is transformed and the alumina powder produced becomes cubic boron nitride powder, titanium nitride powder, and aluminum. A state mixed with powder is generated, the mixture in that state is used as a direct raw material, the direct raw material is filled into a container, the container is loaded into a high temperature and high pressure generation chamber, and then the container is filled. The work of sintering the raw material directly is divided into preliminary sintering work and main sintering work.
The pre-sintering temperature and pre-sintering pressure used in the pre-sintering process are set at 1,200 to 1.4.
Temperature within the range of 00℃ 41.000 ky/i to 4
3. Select the pressure within the range of 000 kg/ant, and set the main sintering temperature and pressure used in the main sintering work within the range of 1.400°C to 1,600°C. At a temperature of 43,000 p/cI? L~50,000
The pressure is within the range of kg/cyyY, and
Select the main sintering temperature and main sintering pressure that have a correlation that satisfies the stable temperature and pressure conditions for cubic boron nitride, and then sinter the raw materials directly in the container loaded into the high temperature and high pressure generation chamber. At the beginning of the process, first apply the selected pre-sintering pressure, then gradually heat the direct raw material to which the pre-sintering pressure is applied to the selected pre-sintering pressure. The heating required to maintain the preliminary sintering temperature is continued for 10 to 50 minutes, and then the applied pressure is increased to the selected main sintering pressure. Next, the heating that had been applied to maintain the preliminary sintering temperature was increased to the selected main sintering temperature, and then the heating necessary to maintain the main sintering temperature was increased. 10 minutes to 5
The heating continued for 0 minutes, then the heating was stopped while maintaining the applied main sintering pressure, and the high temperature and high pressure generation chamber was further cooled down to 300°C, and then A method for producing a cubic boron nitride solid body, which comprises returning the main sintering pressure to normal pressure, and then taking out the sintered body from a high-temperature, high-pressure generation chamber.