The development history and prospects of boron nitride cBN

The development history of boron nitride CBN

Boron nitride came out more than 100 years ago. The earliest application was hexagonal boron nitride as a high-temperature lubricant. Not only its structure but also its properties are very similar to graphite, and its own whiteness, so it is commonly known as: white graphite.

Boron nitride (BN) ceramics is a compound discovered as early as 1842. A lot of research work has been done on BN materials abroad since the Second World War, and it was not developed until the BN hot pressing method was solved in 1955. The American Diamond Company and Union Carbon Company were the first to put into production, and in 1960 they had produced more than 10 tons.

In 1957, R·H·Wentrof took the lead in successfully trial-manufacturing CBN. In 1969, General Electric Company sold the product as Borazon. In 1973, the United States announced the production of CBN tools.

In 1975, Japan imported technology from the United States and also produced CBN tools.

In 1979, the pulse plasma technology was used for the first time to prepare a collapsed c-BN film at low temperature and low pressure.

At the end of the 1990s, people have been able to use a variety of physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods to prepare c-BN films.

From the perspective of China, the development is advancing by leaps and bounds. The research on BN powder began in 1963, was successfully developed in 1966, and was put into production in 1967 and used in China's industry and cutting-edge technology.

Future prospects of boron nitride CBN

Due to the high hardness of steel materials, a lot of heat will be generated during processing. Diamond tools are easy to decompose at high temperatures and easily react with transition metals. C-BN materials have good thermal stability and are not easy to react with iron group metals or alloys. Reaction, can be widely used in precision processing, grinding, etc. of steel products. In addition to excellent wear resistance, c-BN also has excellent heat resistance. It can also cut heat-resistant steel, ferroalloys, hardened steel, etc., and can cut high-hardness chilled rolls and infiltrating steels at relatively high cutting temperatures. Carbon quenching materials and Si-Al alloys which are very serious for tool wear. In fact, cutting tools and abrasive tools made of sintered body of c-BN crystal (synthesized at high temperature and high pressure) have been used in high-speed precision machining of various cemented carbide materials.

As a wide band gap (band gap of 6.4 eV) semiconductor material, c-BN has high thermal conductivity, high resistivity, high mobility, low dielectric constant, high breakdown electric field, can achieve dual-type doping and has good It is called the third-generation semiconductor material after Si, Ge and GaAs together with diamond, SiC and GaN. Their common feature is the wide band gap, which is suitable for the production of electronic devices used under extreme conditions. Compared with SiC and GaN, c-BN and diamond have more excellent properties, such as wider band gap, higher mobility, higher breakdown electric field, lower dielectric constant and higher heat Conductivity. Obviously as extreme electronics materials, c-BN and diamond are better. However, as a semiconductor material, diamond has its fatal weakness, that is, the n-type doping of diamond is very difficult (the resistivity of n-type doping can only reach 102 Ω·cm, which is far from the device standard), while c-BN Can achieve dual-type doping. For example, in the process of high temperature and high pressure synthesis and thin film preparation, adding Be can obtain p-type semiconductor; adding S, C, Si, etc. can obtain n-type semiconductor. Therefore, in general, c-BN is the third-generation semiconductor material with the most excellent performance. It can not only be used to prepare electronic devices that work under extreme conditions such as high temperature, high frequency, and high power, but also has advantages in deep ultraviolet luminescence and detectors. Wide application prospects. In fact, it was first reported that c-BN light-emitting diodes made under high temperature and high pressure conditions can work at a temperature of 650°C. Under forward bias, the diode emits blue light visible to the naked eye. Spectral measurement shows that its shortest wavelength is 215. nm (5.8 eV). c-BN has a thermal expansion coefficient similar to that of GaAs and Si, high thermal conductivity and low dielectric constant, good insulation performance, and good chemical stability, making it a heat sink material and insulating coating for integrated circuits. In addition, c-BN has a negative electron affinity and can be used as a cold cathode field emission material. It has a wide range of application prospects in the field of large-area flat panel displays.

In terms of optical applications, due to the high hardness of c-BN film and the high transmittance in the entire wavelength range from ultraviolet (approximately from 200 nm) to far-infrared, it is suitable as a surface coating for some optical components, especially as Coating of window materials such as zinc selenide (ZnSe) and zinc sulfide (ZnS). In addition, it has good thermal shock resistance and commercial hardness, and is expected to become an ideal window material for high-power lasers and detectors.

Overview of Boron Nitride CBN Powder

Boron nitride is a crystal composed of nitrogen atoms and boron atoms. The chemical composition is 43.6% boron and 56.4% nitrogen, with four different variants: hexagonal boron nitride (HBN), rhombohedral boron nitride (RBN), cubic boron nitride (CBN) and wurtzite nitrogen Boron (WBN)

As the most potential III-V compound, cBN has been one of the most interesting topics for researchers in the world in recent years. There are four main structures of cBN, namely hBN which is similar to rhombohedral graphite, cBN which is similar to diamond, rBN which corresponds to hexagonal graphite, and wBN which corresponds to hexagonal diamond. In addition, there is also a nearly disordered tBN. The most interesting thing is the cubic phase structure (cBN), which is similar to or even better than diamond in structure and properties.

Physical properties

CBN is usually black, brown or dark red crystals with sphalerite structure and good thermal conductivity. Hardness is second only to diamond, it is a super hard material, often used as tool materials and abrasives. Boron nitride has chemical resistance properties and is not corroded by inorganic acids and water. The boron-nitrogen bond is broken in the hot concentrated alkali. Above 1200℃, it will start to oxidize in the air. It begins to decompose at about 2700°C under vacuum. Slightly soluble in hot acid, insoluble in cold water, relative density 2.29. The compressive strength is 170MPa. The maximum operating temperature is 900°C in an oxidizing atmosphere, while it can reach 2800°C in an inactive reducing atmosphere, but the lubrication performance is poor at room temperature. Most of the properties of boron nitride are better than carbon materials. For hexagonal boron nitride: low friction coefficient, good high temperature stability, good thermal shock resistance, high strength, high thermal conductivity, low expansion coefficient, high electrical resistivity, corrosion resistance, microwave or microwave permeability Infrared.

Material structure

Hexagonal boron nitride crystals, the most common is graphite lattice, there are also amorphous variants, in addition to the hexagonal crystal form, there are other crystal forms of boron nitride, including: rhombohedral boron nitride (r-BN), cubic Boron nitride (c-BN), wurtzite type boron nitride (w-BN). People have even discovered two-dimensional boron nitride crystals like graphene.

Application of Boron Nitride CBN Powder

Cubic boron nitride (c-BN) is a superhard material second only to diamond. It has excellent chemical stability, high electrical resistivity and high thermal conductivity. It can become a semiconductor when it is doped with certain impurities. Cubic boron nitride film can be synthesized by a method similar to the formation of diamond film by low-pressure gas phase. There are three isomers of boron nitride (BN): h-BN, c-BN and w-BN. The performance between them is very different. h-BN has a layered structure very similar to graphite and has a very soft texture. Both B and N atoms in w-BN and c-BN form a four-coordinate structure with each other, and there is little difference in hardness between the two. Both are hard films and can be used for cutting tools.

Cubic boron nitride (CBN) is a synthetic high-temperature stable phase structure of face-centered cubic zinc sphalerite. It has a series of excellent physical and chemical properties similar to diamond. It has extremely high hardness and good wear resistance ( Hardness is second only to diamond), wide band gap, high resistivity. It is much higher than the thermal and chemical stability of diamond, and overcomes the problem of carbon diffusion when processing iron-based metals with diamond-coated tools. In addition, CBN has a wide optical band gap, high thermal conductivity, good insulation, a wide spectrum from infrared to ultraviolet, including visible light, and has good light transmittance.

Boron nitride CBN powder price

The price of boron nitride CBN powder will vary randomly with the production cost. The demand for boron nitride CBN powder, transportation cost, international situation, exchange rate and market supply and demand. Tanki New Materials Co., Ltd. aims to help various industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals by providing a full set of customized services. If you are looking for boron nitride CBN powder, please feel free to send an email to get the latest boron nitride CBN powder price.

Boron Nitride CBN Powder Supplier

As a global boron nitride CBN powder supplier, Tanki New Materials Co., Ltd. has extensive experience in the performance, application and cost-effective manufacturing of advanced engineering materials. The company has successfully developed a series of powder materials (molybdenum disilicide, nitrogen lanthanum powder, calcium silicide, iron boride), high-purity targets, functional ceramics and structural devices, and provides OEM services.