JPS581002A - Production of consolidated body of cubic boron nitride - Google Patents

Abstract

PURPOSE:To produce a titled solidified body used as a cutting tool material by sintering mixed powders of cubic boron nitride powder, fine powder of alumina in a nascent state, and Al powder under specific conditions. CONSTITUTION:Mixed materials, by weight, of 40-60pts. cubic boron nitride powder, 171-102pts. Al ethoxide powder or 125-75pts. Al methoxide powder and 10pts. Al powder are used as basic raw materials. The mixture formed by adding water to these basic raw materials and heating formed by adding water to these basic raw materials and heating the same to convert ethoxide or methoxide to alumina powder is used as a direct raw material. Such direct raw material is packed in a vessel, which is loaded into a high temp. high pressure generating chamber, where it is presintered under 41-43t/cm<2> pressures at 1,200-1,400 deg.C, then it is subjected to normal sintering under 43-50t/cm<2> pressures at 1,400-1,600 deg.C. At this time, the heating temps. for the presintering and normal sintering are maintaind respectively for 10 or 50min. While said normal sintering pressures are maintained, the temp. in the chamber is decreased down to 300 deg.C, then the pressure is returned to the atmospheric pressure and the sintered body is removed from the chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cubic boron nitride solid body used as a four-ply 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, and hydrolyzes and heats it to form alumina in a nascent state. Aluminum ethoxide powder or aluminum methoxide powder that produces fine powder is used as a binder material, aluminum powder is used as a binding aid, and a mixture of these main materials, binder material, and binding aid is used as the basic raw material. The aluminum ethoxide powder or aluminum methoxide powder in the basic raw material is modified by adding water to the basic raw material and heating it to produce fine alumina powder in the nascent state. The produced alumina fine powder is aluminum methoxide powder ti, which is characterized in that the sintered body is produced by directly using the mixed powder as a raw material instead of the aluminum methoxide powder. A method for producing cubic boron nitride solids to be used as a hard tool material, the method comprises converting cubic boron nitride powder or a mixed powder of cubic boron nitride powder and titanium nitride powder into 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 sushi feeding tool materials that can perform highly productive cutting operations by combining them with mixed powders. It is.

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, the basic raw materials include 40 to 50 parts by weight of cubic boron nitride powder and 17 parts by weight of aluminum ethoxide powder.
1 part by weight to 102 parts by weight'=! For this purpose, a mixture of aluminum methoxide powder and 10 parts by weight is used, and water is added to the basic raw material to mix the aluminum ethoxide powder or aluminum methoxide powder in the basic raw material. Aluminum methoxide powder is hydrolyzed and then heated to remove the evaporated content to produce fine alumina powder in a nascent state, and the resulting fine alumina powder in a rainy season state; cubic boron nitride powder and A mixture with aluminum powder is produced, and the mixture is directly used as a raw material. When manufacturing by the second method, 40 parts by weight to 6 parts by weight of cubic boron nitride powder is added to the basic raw material.
0 parts by weight, 60 parts by weight to 20 parts by weight of titanium nitride powder, and 68 parts by weight to 34 parts by weight of aluminum ethoxide powder.
Parts by weight or a mixture of 49 parts by weight to 25 parts by weight of aluminum methoxide powder and 10 parts by weight of aluminum powder are used, and water is added to the basic raw materials. The aluminum ethoxide powder or aluminum methoxide powder in the basic raw material is hydrolyzed and then heated 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, titanium nitride powder, and aluminum powder is produced, and the mixture in this state is directly used as a raw material. The operation of sintering the direct raw material used in the above-described first method 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 carried out in two stages: preliminary sintering work and main sintering work. , 400
Temperatures within the range of 41.000°C to 43°C,
000 degrees Celsius/d and a temperature within the range of 1,400°C to 1,600°C for the main sintering temperature and main sintering pressure used in the main sintering operation. and 45,
0 [Pressure within the range of 10 kf/crl to 50,0001 w/d is selected, and the main sintering temperature and main sintering temperature are selected in a correlation that satisfies the stable temperature and pressure conditions for cubic boron nitride. Select the pressure. Next, in order to start the work of sintering the direct raw material in the container loaded into the high temperature and high pressure generation chamber, first, the selected direct raw material in the container is applied with pre-sintering pressure.

Next, the raw material under the pre-sintering pressure is gradually heated to the selected pre-sintering temperature, and the pre-sintering temperature is maintained. - Maintain the required heating for 10 or 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 the aggregate consisting of a large number of boron nitride particles are filled with a liquid phase-containing incompletely sintered structure 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 minutes or 50 minutes. In the incinerator to which this main sintering process has been applied, the incompletely sintered structure containing a liquid phase with a spongy structure generated in the preliminary sintering process in the previous process is heated at the main sintering temperature and the main sintering temperature. Exposure to pressure to produce a liquid-phase-containing fully sintered structure, and the resulting liquid-phase-containing fully sintered structure is bonded to individual cubic boron nitride particles. . Next, only the heating is stopped while maintaining the applied pressure for 8-piece sintering, and the high-temperature and high-pressure generation chamber is further cooled to lower the temperature in the chamber to 300°C. Through this cooling operation, the completely sintered structure containing the cavernous structure 6 liquid phase, which was filled between the individual cubic boron nitride particles in the aggregate consisting of a large number of cubic boron nitride particles, was cooled in 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. In this state, the in-phase completely sintered structure is an alumina 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. A solid phase completely sintered structure consisting of fine powder and aluminum powder, when the basic raw material in the second method is used, aluminum ethoxide powder or aluminum methoxide powder is hydrolyzed and further heated to volatilize. It is a solid-phase completely sintered structure consisting of fine alumina powder, titanium nitride powder, and aluminum powder obtained by removing the components. Next, the main sintering pressure that had been maintained is returned to normal pressure, the container is pushed out of the high temperature and high pressure generation chamber, and the sintered body is taken out from inside the container. The sintered body obtained by taking out the solid phase formed from the mixed powder of fine alumina powder and aluminum powder is formed between the individual cubic boron nitride particles in an aggregate of a large number of cubic boron nitride powders. The binder region is a sintered structure or a solid-phase completely sintered structure produced from a mixed powder of alumina fine powder, titanium nitride powder, and aluminum powder, and the binder region is Cubic nitride is a solid-phase completely sintered structure that can be used as a flying tool material, which 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 boron solid.

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

Example 1 As the 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. and aluminum powder, and then the mixture in such a state was subjected to a pre-sintering pressure of 41,000 kg.
/cfl was added.

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 a selected main sintering pressure of 48,000) c
The pressure was increased to p/i. Next, 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 main sintering temperature was maintained. The heating required for this was maintained for 30 minutes. Next, 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 500°C. Next, the main sintering pressure that had been maintained was returned to normal pressure, 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 obtained sintered body has a solid structure with a spongy structure made of a mixed powder of fine alumina powder and aluminum powder between individual cubic boron nitride particles in an aggregate of many cubic boron nitride particles. It has a binder region which is a phase-completely sintered structure, and the binder region, which is a solid-phase 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 W splitting tool material and was composed of cubic boron nitride particles. Its composition was 50% by weight of cubic boron nitride, 40% by weight of alumina, and 10% by weight of aluminum, making it a cubic boron nitride solid.

Example 2゜The basic raw materials include 60 parts by weight of cubic boron nitride powder.
A mixed powder prepared by mixing 75 parts by weight of aluminum methoxide powder and 10 parts by weight of aluminum powder 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. , a mixture of boron powder and aluminum powder is formed, and the resulting mixture is then heated to form aluminum hydroxide into fine powder alumina in a nascent state, and the heating causes aluminum hydroxide to form a finely powdered alumina. The generated moisture and the moisture mixed in the mixture are separated, and a state in which the generated alumina particles in the nascent state is mixed with the cubic boron nitride powder and the aluminum powder is produced. 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 operation of directly sintering the raw material in the container loaded into the high temperature and high pressure generating chamber was performed in the same manner as in Example 1. The sintered body obtained after the sintering process was a cubic boron nitride solid body that had the same structure as the sintered body produced in Example 1 and could be used as a Pa tool material. The body consists of 60% by weight of cubic boron nitride powder and 3% by weight of alumina.
3゜The basic raw materials include 50 parts by weight of cubic boron nitride powder and titanium nitride powder. A mixed powder prepared by mixing 20 parts by weight of aluminum ethoxide powder, 68 parts by weight of aluminum ethoxide powder, and 10 parts by weight of aluminum powder was used. Aluminum in the mixed powder, which is the basic raw material, is added by adding water to the mixed powder, which is the basic raw material; Lamb ethoxide is hydrolyzed to generate aluminum hydroxide, and the resulting aluminum hydroxide and water are 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, and the resulting nascent alumina and fine powder are cubic boron nitride powder and titanium nitride powder. A mixture of aluminum powder and aluminum powder was produced, and this 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 nitride. It was composed of individual cubic boron nitride particles bonded together in an aggregate consisting of a large number of boron particles (7" 141) It was a cubic boron nitride solid that could be used as a tool material. It was a cubic boron nitride solid having a ratio of 50% by weight boron, 20% by weight titanium nitride, 20% by weight alumina, and 10% by weight aluminum.

Example 4゜Basic raw materials include 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. A mixed 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 nascent alumina fine powder is transformed into cubic boron nitride powder, titanium nitride powder, and aluminum powder. A mixed state was produced and the mixed state was used as a direct raw material for use in the sintering operation. The intuitive raw material 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 3. 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 3 and could be used as an all-tool material. The sintered body contains 60% by weight of cubic boron nitride.
It was a cubic boron nitride solid having a ratio of 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, - In this cutting experiment, 26 pieces could be cut by polishing, whereas when using a tip made of cubic boron nitride solids, 1,710 to 1,760 pieces could be cut in - times of polishing. As is clear, compared to chips made of sintered tungsten carbide, chips made of cubic boron nitride solids were able to achieve significantly higher productivity.

Claims (2)

[Claims] (1) 40 parts by weight to 60 parts by weight of cubic boron nitride powder
parts by weight, and 171 parts by weight to 102 parts by weight of aluminum ethoxide powder, or 125 parts by weight to 74 parts by weight of aluminum methoxide powder, and 10 parts by weight of aluminum powder. The resulting mixture is used as the basic raw material, water is added to the basic raw material,
Next, 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 is directly used as the raw material. The raw material is filled into a container, the container is loaded into a high-temperature, high-pressure generation chamber, and the raw material directly filled into the container is then sintered in two stages: preliminary sintering work and main sintering work. The pre-sintering temperature and pre-sintering pressure used in the pre-sintering work are within the range of 1.200°C to 1.400°C and 41,000 klI/crIi to 43.00°C.
0 kg/, 1! (7) Pressure within the range of 43,000kg/di to 50,000kt/
cfIt, and also select a main sintering temperature and a main sintering pressure that have a correlation that satisfies the stable temperature and pressure conditions for cubic boron nitride, and then,
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. A certain direct raw material was gradually heated to a selected presintering temperature, the heating necessary to maintain the presintering temperature was sustained for 10 or 50 minutes, and then 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, and then the temperature was increased to the selected main sintering temperature. The heating necessary to maintain the main sintering temperature of The chamber is cooled to bring the temperature inside the chamber down to 300°C, then the main sintering pressure that was maintained is returned to normal pressure, and then the sintered body is taken out from the high temperature and high pressure generation chamber. A method for producing a cubic boron nitride solid body, characterized by: (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. Weight parts to 2
A mixture of 5 parts by weight of aluminum powder and 10 parts by weight is used as the basic raw material, water is added to the basic raw material, and then heated to form the base material. A mixture of alumina powder produced by metamorphosis of aluminum ethoxide or aluminum methoxide in one raw material mixed with cubic boron nitride powder, titanium nitride powder, and aluminum powder is used as a direct raw material, and the direct raw material is poured into a container. and load the container into a high temperature and high pressure generation chamber,
Next, the work of sintering the raw materials directly filled in the container is performed in two stages: preliminary sintering work and main sintering work, and the pre-sintering temperature and pre-sintering temperature used in the preliminary sintering work are The sintering pressure is selected from a temperature in the range of 1,200°C to 1,400°C and a pressure in the range of 41,000 kp/d to 43,000 to 9/d, and for the main sintering work. The main sintering temperature and main sintering pressure used in the ora are within the range of 1,400°C to 1,600°C and the pressure within the range of 43,000 kg/d to 50,000 kg/d. Select from
Moreover, the main sintering temperature and the main sintering pressure are selected in a correlation that satisfies the stable hot water temperature and pressure conditions for cubic boron nitride, and then the To start the work of sintering the direct raw material, first, the selected pre-sintering pressure was applied, and then the direct raw material with the pre-sintering pressure applied was gradually heated and selected. Raise the temperature to the temperature for pre-sintering, maintain the heating necessary to maintain the humidity for pre-sintering for 10 minutes or 50 minutes, then increase the pressure applied to the selected main sintering pressure. Then, in order to maintain the temperature for preliminary sintering, the heating that had been applied was increased to the selected temperature for main sintering, and in order to maintain the flow rate for main sintering. The heating required for
It lasts for 0 minutes or 50 minutes, then only the heating is stopped while maintaining the applied main sintering pressure, and then the high temperature and high pressure generation chamber is cooled down to 300 degrees Celsius. A method for producing a cubic boron nitride solid body, which comprises: then returning the main sintering pressure to normal pressure, and then ejecting the sintered body from a high-temperature, high-pressure generating chamber.