Hexagonal BN

Hexagonal BN (h-BN) is the most widely used polymorph. It is a good lubricant at low and high temperatures (up to 900 °C, even in an oxidizing atmosphere). H-BN lubricant is particularly useful when graphite's electrical conductivity or chemical reactivity (alternative lubricant) is problematic. In internal combustion engines, where graphite could be oxidized and turned into carbon sludge, h-BN can be added to engine lubricants with its superior thermal stability. As with all nano-particle suspensions, Brownian-motion settlement is a problem. Settlement can clog engine oil filters, which limits solid lubricant applications in a combustion engine to automotive racing, where engine re-building is common. Since carbon has appreciable solubility in certain alloys (such as steels), which may lead to degradation of properties, BN is often superior for high-temperature and high-pressure applications. Another advantage of h-BN over graphite is its lubricity does not require water or gas molecules trapped between the layers. Therefore, h-BN lubricants, such as space applications, can be used in a vacuum. The lubricating properties of fine-grained h-BN are used in cosmetics, paints, dental cement, and pencil leads. Hexagonal BN was first used in cosmetics around 1940 in Japan. Because of its high price, h-BN was abandoned for this application. Its use was revitalized in the late 1990s with the optimization of h-BN production processes. Currently, h-BN is used by nearly all leading producers of cosmetic products for foundations, make-up, eye shadows, blushers, kohl pencils, lipsticks, and other skincare products. If you are looking for high quality, high purity, and cost-effective Boron nitride, or if you require the latest price of Boron nitride, please feel free to email contact mis-asia.

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