Currently, the research on BN is mainly focused on its hexagonal phase (h-BN) and cubic phase (c-BN). The former has lubricity, thermal conductivity, and good high-temperature performance. The latter is also in thermodynamic equilibrium at room temperature and pressure.
Application of Hexagonal Boron Nitride
Hexagonal boron nitride is a material with high-temperature resistance, corrosion resistance, high thermal conductivity, high insulation, and excellent lubrication performance. At present, simplifying the process, reducing production costs, and increasing the service life of components are the more active research directions of this type of material.
1 Taking advantage of the excellent chemical stability of hexagonal boron nitride, it can be used as a crucible, boat, liquid metal delivery pipe, rocket nozzle, high-power device base, molten metal pipe, pump parts, cast steel mold, etc.
2 Taking advantage of the heat and corrosion resistance of hexagonal boron nitride, it can be used to manufacture high-temperature components, rocket combustion chamber linings, spacecraft heat shields, and corrosion-resistant parts of magnetic flow generators.
3. Taking advantage of the insulation of hexagonal boron nitride, it is widely used in insulators of high-voltage and high-frequency electricity and plasma arcs, insulators of various heaters, heating tube sleeves, and high-temperature, high-frequency, and high-voltage insulation and heat dissipation components, and materials for high-frequency application electric furnaces.
4. Taking advantage of the lubricity of hexagonal boron nitride, when boron nitride is used as a lubricant, it can be dispersed in heat-resistant grease, water, or solvent; sprayed on the friction surface, and the solvent evaporates to form a dry mold; filled in the surface layer of resin, ceramic, and metal as a high-temperature resistant self-lubricating composite material. Boron nitride suspension oil is white or yellow, so it does not pollute fiber products on textile machinery. It can be used in large quantities to lubricate synthetic fiber textile machinery.
5. Hexagonal boron nitride can also be used as an additive for various materials. Boron nitride fiber made from boron nitride is a medium-modulus high-functional fiber. It is an inorganic synthetic engineering material that can be widely used in the chemical industry, textile industry, aerospace technology, and other cutting-edge industrial sectors.
Application of cubic boron nitride
1 Used as abrasive: Small particles of cBN single crystal can be used as abrasive. cBN abrasive is a superhard material that uses a binder to bond cBN abrasive grains into products with a certain geometric shape.
cBN abrasive has good grinding performance for ferrous metals, especially materials with high hardness, high toughness, high-temperature strength, and low thermal conductivity. Its metal removal rate is 10 times that of diamond, which solves the processing problem of tough materials.
Cubic boron nitride abrasive is used for high-speed and high-efficiency grinding and honing, which can greatly improve grinding efficiency; high grinding accuracy, long grinding wheel life, saving a lot of auxiliary time such as grinding wheel replacement and dressing, machine tool adjustment, workpiece inspection, etc.
2 Used as tool material: PcBN overcomes the shortcomings of cBN single crystal such as easy cleavage and anisotropy, and is mainly used to make tool materials. PcBN tools are particularly suitable for high-speed cutting and high-precision cutting. They have been widely used in CNC machine tools and are ideal for cutting high-hardness materials, especially high-hardness difficult-to-cut materials that could only be processed by grinding before. Turning and milling can be used instead of grinding to obtain better workpiece surface quality, eliminate the annealing process, and greatly improve production efficiency.