1. Differences in raw material purity and crystal structure determine the different properties of green silicon carbide and black silicon carbide. Green silicon carbide is mainly made from petroleum coke and quartz sand, refined with the addition of salt. This process minimizes impurities, resulting in a regular hexagonal crystal system with sharp edges. Black silicon carbide, on the other hand, has a simpler raw material processing method, without the addition of salt. Residual impurities such as iron and silicon in the raw material cause its crystal particles to have irregular shapes and rounded edges.
2. Differences in raw materials and structure lead to different physical properties. In terms of hardness, green silicon carbide has a Mohs hardness of approximately 9.5, second only to diamond, and can be used to process high-hardness materials; black silicon carbide has a Mohs hardness of approximately 9.0, slightly lower. In terms of density, green silicon carbide has a density of 3.20-3.25 g/cm³, with a dense structure; black silicon carbide has a density of 3.10-3.15 g/cm³, with a relatively loose structure. In terms of performance, green silicon carbide has high purity, excellent thermal and electrical conductivity, and high-temperature resistance, but it is brittle and easily breaks into new sharp edges. Black silicon carbide has slightly weaker thermal and electrical conductivity, lower brittleness, and stronger impact resistance.
3. Performance differences determine their application focuses. Green silicon carbide has high hardness and sharp particles, making it suitable for processing high-hardness, low-toughness materials: in the non-metallic field, it can be used for glass grinding, ceramic cutting, and semiconductor silicon wafer and sapphire polishing; in metal processing, it performs excellently in high-precision machining of materials such as cemented carbide and hardened steel, and is widely used in products such as grinding wheels and cutting discs. Black silicon carbide is mainly used for processing low-hardness, high-toughness materials, and is suitable for processing non-ferrous metals such as cast iron, copper, and aluminum, as well as refractory materials. In rough scenarios such as deburring castings and rust removal of steel, it has become a common industrial choice due to its high cost-effectiveness. Although green silicon carbide and black silicon carbide belong to the same silicon carbide material system, their physicochemical properties and application characteristics differ significantly. With the continuous innovation of materials science and processing technology, green silicon carbide and black silicon carbide are expected to achieve wider application in high-tech fields such as semiconductor manufacturing, precision grinding, and new energy, providing key material support for the high-quality development of modern industry.
