Classification, Characteristics, and Applications of Corundum Materials
- JCT Abrasives
- Apr 22
- 2 min read
Corundum materials are crucial in grinding, polishing, and related industrial processes, valued for their distinctive physical and chemical properties. Based on composition, manufacturing process, and performance, corundum materials are divided into several main types, each with specific formation conditions, characteristics, and application fields.
Formation: Brown fused alumina is primarily produced from bauxite and coke through high-temperature smelting and crystallization. During this process, alumina reacts with carbon, forming corundum crystals and removing impurities.
Characteristics: It appears brown, features high hardness (Mohs 9), toughness, good self-sharpening ability, and efficient grinding. Its crystal structure allows abrasive particles to continually expose new cutting edges during use, maintaining grinding performance.
Applications: Brown fused alumina is widely used in metal processing, particularly for rough grinding and cutting of steel, cast iron, and other metals. It is also suitable for manufacturing grinding wheels, oil stones, abrasive heads, and sanding bricks, as well as for sandblasting, polishing, and producing refractory materials.
Formation: White fused alumina is made from high-purity alumina powder, melted in an electric arc furnace, then cooled, crushed, and screened.
Characteristics: It is white, slightly harder than brown fused alumina, has excellent self-sharpening, high grinding efficiency, and generates less heat during grinding, reducing the risk of workpiece burns.
Applications: White fused alumina is mainly used for precision grinding and polishing of automotive parts, aerospace components, and precision molds, where high accuracy and surface quality are required.
Formation: Pink fused alumina is produced by adding chromium oxide to alumina during high-temperature smelting, resulting in chromium-containing corundum crystals.
Characteristics: It is pink to deep ruby in color, with high hardness, thermal stability, and chemical resistance. The abrasive grains maintain sharp cutting edges, reducing abrasive consumption.
Applications: Pink fused alumina is ideal for grinding hard-to-machine materials like stainless steel and heat-resistant alloys, which demand high abrasive performance.
Formation: SG abrasive is synthesized from micron-sized alumina powder via sol-gel technology and sintering, resulting in a microcrystalline structure with grain sizes below 1 μm.
Characteristics: It offers extremely high hardness, sharpness, self-sharpening, shape retention, and long service life. Its structure allows continuous formation of new cutting edges during grinding.
Applications: SG abrasives are used in high-precision, high-efficiency metalworking, suitable for a wide range of metallic and non-metallic materials.
Selection and Use
Different types of corundum materials should be chosen based on specific processing requirements and workpiece materials to ensure optimal grinding efficiency and workpiece quality. For non-metallic materials, diamond and silicon carbide abrasives are often more suitable.
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