The most commonly used abrasives are brown alumina (A) and white alumina (WA), followed by black silicon carbide (C) and green silicon carbide (GC), followed by chrome alumina (PA), single crystal alumina (SA), microcrystalline alumina (MA) and zirconium alumina (ZA).
Brown alumina grinding wheel: brown alumina has high hardness and toughness, and is suitable for grinding metals with high tensile strength, such as carbon steel, alloy steel, malleable iron, hard bronze, etc., this kind of abrasive has good grinding performance, wide adaptability, and is often used to cut off the coarse grinding with a large margin, cheap price, and can be widely used.
White alumina grinding wheel: the hardness of white alumina is slightly higher than that of brown alumina, and its toughness is lower than that of brown alumina. In grinding, the abrasive particles are easy to break, so the grinding heat is small, suitable for the manufacture of fine tempered steel, high carbon steel, high speed steel and thin wall parts grinding wheel, the cost is higher than that of brown alumina.
Black silicon carbide grinding wheel: black silicon carbide is crisp and sharp, with higher hardness than white alumina. It is suitable for grinding materials with lower mechanical strength, such as cast iron, brass, aluminum and refractory.
Green silicon carbide grinding wheel: the hardness and brittleness of green silicon carbide is higher than that of black silicon carbide, the abrasive grain is sharp, the thermal conductivity is good, suitable for grinding hard alloy, optical glass, ceramics and other hard and brittle materials.
2. Grain selection
When grinding with coarse grain grinding wheel, the production efficiency is high, but the workpiece surface is rough. When grinding with fine-grained grinding wheel, the surface roughness of the workpiece is better and the productivity is lower.On the premise of satisfying the roughness requirement, the coarse-grained grinding wheel should be selected as far as possible to ensure high grinding efficiency. Generally, coarse-grained grinding wheel is used for rough grinding and fine-grained grinding wheel is used for fine grinding. Abrasive particle size general use range 36 # ~ 46 # general flat grinding, cylindrical grinding and centerless grinding 60 # ~ 100 # fine grinding and tool grinding
3. Selection of hardness
When grinding soft material, choose the hard grinding wheel, while when grinding hard material, choose the soft grinding wheel.
When grinding soft and large toughness of nonferrous metals, hardness should be selected soft;