阅读说明：本技术 一种低成本高性能聚晶立方氮化硼刀具材料 (Low-cost high-performance polycrystalline cubic boron nitride cutter material ) 是由 朱玉梅 李志宏 纪焕丽 孙坤 于 2019-11-20 设计创作，主要内容包括：本发明公开了一种低成本高性能聚晶立方氮化硼刀具材料,原料组成及质量百分比为70～90wt％的立方氮化硼粉体、2～10wt％的六方氮化硼粉体、8～28wt％的添加剂粉体。立方氮化硼由0.1～20μm中的至少2～3种不同粒度级配构成；六方氮化硼的粒度小于1μm；添加剂的粒度小于0.5μm；添加剂的原料组成为：①Al、Nb、Ti、Zr、Ni、Si金属单质的至少两种；②Al、Nb、Ti、Zr、Ni、Si金属单质的硼化物、氮化物或碳化物粉体中的至少两种；③氧化锂、氮化锂、氧化镁、氧化硼粉体中的至少两种；均按任何比例混合；①、②、③类原料按照2～10︰2～8︰4～10的质量份数复合。本发明抗弯强度为750～900MPa,硬度为42～70GPa,断裂韧性为7～10MPam<Sup>1/2</Sup>,在150m/min的切削速度下可以切削1250～3000米。(The invention discloses a low-cost high-performance polycrystalline cubic boron nitride cutter material which comprises, by mass, 70-90% of cubic boron nitride powder, 2-10% of hexagonal boron nitride powder and 8-28% of additive powder, wherein cubic boron nitride is composed of at least 2-3 different particle size gradations in 0.1-20 micrometers, the particle size of hexagonal boron nitride is smaller than 1 micrometer, the particle size of additive is smaller than 0.5 micrometer, the raw material composition of additive is at least two of ① Al, Nb, Ti, Zr, Ni and Si metal simple substances, at least two of boride, nitride or carbide powder of ② Al, Nb, Ti, Zr, Ni and Si metal simple substances, at least two of ③ lithium oxide, lithium nitride, magnesium oxide and boron oxide powder, the raw materials are mixed according to any proportion, and ①, ② and ③ raw materials are compounded according to the mass ratio of 2-10: 2-8: 4-10The bending strength is 750-900 MPa, the hardness is 42-70 GPa, and the fracture toughness is 7-10 MPam 1/2 And cutting can be carried out at a cutting speed of 150m/min for 1250-3000 m.)

1. A low-cost high-performance polycrystalline cubic boron nitride cutter material comprises the following raw materials in percentage by mass: 70-90 wt% of cubic boron nitride powder, 2-10 wt% of hexagonal boron nitride powder and 8-28 wt% of additive powder;

the cubic boron nitride powder is composed of at least 2-3 different particle size compositions in 0.1-20 μm;

the particle size of the hexagonal boron nitride is less than 1 μm;

the particle size of the additive powder is less than 0.5 mu m;

the additive powder comprises the following raw materials:

① mixing at least two of Al, Nb, Ti, Zr, Ni and Si simple substances according to any proportion;

② mixing at least two of boride, nitride or carbide powder of Al, Nb, Ti, Zr, Ni and Si metal simple substance according to any proportion;

③ mixing at least two of lithium oxide, lithium nitride, magnesium oxide and boron oxide powder at any ratio;

the ①, ② and ③ raw materials are compounded according to the mass ratio of 2-10: 2-8: 4-10.

The preparation method of the polycrystalline cubic boron nitride cutter material comprises the following steps:

(1) according to the requirement that the particle size of the additive powder is less than 0.5 mu m and is the composition of at least two of Al, Nb, Ti, Zr, Ni and Si metal simple substances and at least two of boride, nitride or carbide powder thereof as well as at least two of lithium oxide, lithium nitride, magnesium oxide and boron oxide powder, firstly preparing the additive powder, placing the additive powder into a ball milling tank, adding zirconia balls, and fully and uniformly mixing;

(2) mixing the dry-mixed and uniform additive powder in the step (1) according to the raw material composition and the mass percentage content of 70-90 wt% of cubic boron nitride powder, 2-10 wt% of hexagonal boron nitride powder and 8-28 wt% of additive powder, placing the mixture into a ball milling tank, adding zirconium balls and ethanol, and wet-mixing uniformly;

(3) putting the wet-mixed uniformly-mixed raw materials obtained in the step (2) into a low-temperature drying box, and drying at 60-80 ℃;

(4) putting the dried raw material in the step (3) into a vacuum furnace, and carrying out vacuum drying treatment for 8-14 hours at the temperature of 300-400 ℃ with the vacuum degree of 10^-2～10^-4MPa；

(5) Treating the mixed raw material subjected to vacuum drying treatment in the step (4) in a hydrogen atmosphere furnace at 1000-1200 ℃ for 2-5 hours;

(6) putting the raw materials treated in the step (5) into a graphite die, coating pyrophyllite outside the graphite die, and performing compression molding and sintering at high temperature and high pressure by using a cubic press to prepare the polycrystalline cubic boron nitride cutter material;

the pressure of the cubic press is 4-10 GPa, and the sintering temperature is 1400-1700 ℃.

2. The low-cost high-performance polycrystalline cubic boron nitride cutter material as claimed in claim 1, wherein the ball milling in step (1) is carried out on a power ball mill by using a nylon ball milling tank, and the rotation number of the ball mill is 350-450 rpm.

3. The low-cost high-performance polycrystalline cubic boron nitride cutter material as claimed in claim 1, wherein the mass ratio of the zirconia balls in the step (1) to the raw materials is 2.5: 1.

4. a low cost high performance polycrystalline cubic boron nitride cutter material as claimed in claim 1, wherein the sintering temperature of step (6) is 1550 ℃.

Technical Field

The invention belongs to a ceramic composition characterized by components, and particularly relates to a low-cost high-performance polycrystalline cubic boron nitride cutter material.

Background

In recent years, with the rapid development of CNC (computer numerical control) processing technology, new materials and difficult-to-process materials are emerging and are accompanied by strong market competition, so that the requirements on processing efficiency and processing precision are higher and higher, even in a cutting and belt grinding manner. Therefore, the requirements for the machining capability, machining efficiency, machining precision and service life of the tool material are higher and higher, so that the traditional metal or alloy tool is difficult to meet the requirements of the market at present. The superhard material, especially the cubic boron nitride (PcBN) material, has the characteristics of high hardness, high thermal conductivity, corrosion resistance, good thermal stability, no reaction with metal at high temperature and the like, so that the high-speed and high-efficiency cutting, even dry cutting, turning instead of grinding and other processing of various soft and hard metals can be realized, and the method is an important development direction of future cutters.

Disclosure of Invention

The invention aims to meet the development requirement of CNC (computerized numerical control) processing technology and provide a low-cost polycrystalline cubic boron nitride cutter material.

In order to achieve the purpose of the invention, the invention adopts the following technical scheme:

a low-cost high-performance polycrystalline cubic boron nitride cutter material comprises the following raw materials in percentage by mass: 70-90 wt% of cubic boron nitride powder, 2-10 wt% of hexagonal boron nitride powder and 8-28 wt% of additive powder;

the cubic boron nitride powder is composed of at least 2-3 different particle size compositions in 0.1-20 μm;

the particle size of the hexagonal boron nitride is less than 1 μm;

the particle size of the additive powder is less than 0.5 mu m;

the additive powder comprises the following raw materials:

① mixing at least two of Al, Nb, Ti, Zr, Ni and Si simple substances according to any proportion;

② mixing at least two of boride, nitride or carbide powder of Al, Nb, Ti, Zr, Ni and Si metal simple substance according to any proportion;

③ mixing at least two of lithium oxide, lithium nitride, magnesium oxide and boron oxide powder at any ratio;

the ①, ② and ③ raw materials are compounded according to the mass ratio of 2-10: 2-8: 4-10;

the preparation method of the polycrystalline cubic boron nitride cutter material comprises the following steps:

(1) according to the requirement that the particle size of the additive powder is less than 0.5 mu m and is the composition of at least two of Al, Nb, Ti, Zr, Ni and Si metal simple substances and at least two of boride, nitride or carbide powder thereof as well as at least two of lithium oxide, lithium nitride, magnesium oxide and boron oxide powder, firstly preparing the additive powder, placing the additive powder into a ball milling tank, adding zirconia balls, and fully and uniformly mixing;

(2) mixing the dry-mixed and uniform additive powder in the step (1) according to the raw material composition and the mass percentage content of 70-90 wt% of cubic boron nitride powder, 2-10 wt% of hexagonal boron nitride powder and 8-28 wt% of additive powder, placing the mixture into a ball milling tank, adding zirconium balls and ethanol, and wet-mixing uniformly;

(3) putting the wet-mixed uniformly-mixed raw materials obtained in the step (2) into a low-temperature drying box, and drying at 60-80 ℃;

(4) putting the dried raw materials in the step (3) into a vacuum furnace, carrying out vacuum drying treatment for 8-14 hours at the temperature of 300-400 ℃,

vacuum degree of 10^-2～10^-4MPa；

(5) Treating the mixed raw material subjected to vacuum drying treatment in the step (4) in a hydrogen atmosphere furnace at 1000-1200 ℃ for 2-5 hours;

(6) putting the raw materials treated in the step (5) into a graphite die, coating pyrophyllite outside the graphite die, and performing compression molding and sintering at high temperature and high pressure by using a cubic press to prepare the polycrystalline cubic boron nitride cutter material;

the pressure of the cubic press is 4-10 GPa, and the sintering temperature is 1400-1700 ℃.

The ball milling in the step (1) is carried out on a power ball mill by adopting a nylon ball milling tank, and the revolution of the ball mill is 350-450 r/min.

The mass ratio of the zirconia balls in the step (1) to the raw materials is 2.5: 1.

the sintering temperature of the step (6) is 1550 ℃.

The invention has the following beneficial effects:

the invention not only reduces the cost of the polycrystalline cubic boron nitride cutter material, but also realizes the high performance of the polycrystalline cubic boron nitride cutter material. The price per gram of cubic boron nitride powder is not less than one RMB, and the price per kilogram of cubic boron nitride powder is at least 5000 RMB. The price of the hexagonal boron nitride is not higher than 200 RMB per kilogram, so the price of the hexagonal boron nitride is at most 4% of that of the cubic boron nitride, and the raw material cost of the hexagonal boron nitride is saved by at least 96% for every 1% of the cubic boron nitride. According to the invention, the hexagonal boron nitride is used for partially replacing the cubic boron nitride, and the conversion from the hexagonal boron nitride to the cubic boron nitride in the preparation process is realized through proper additives and proportions, and meanwhile, the high performance of the polycrystalline cubic boron nitride cutter material is realized. The bending strength of the material is 750-900 MPa, the hardness is 42-70 GPa, and the fracture toughness is 7-10 MPam^1/2And cutting can be carried out at a cutting speed of 150m/min for 1250-3000 m.

Detailed Description

The technical solution of the present invention is further explained with reference to the following specific examples, but the scope of the present invention is not limited thereto.