Particle size: When the grains are relatively small, the wear mechanism is mainly plastic deformation and partial transgranular fracture, resulting in slight wear. When the grains are relatively coarse, the wear mechanism is mainly due to the fracture of the grain boundary and serious wear, so the smaller the grain, the better the wear resistance of the ceramic grinding ball. Therefore, aluminum oxide raw materials with small particle size should be used as much as possible to reduce the grain size of ceramic grinding balls. In addition, small particles have a larger specific surface area or surface energy than large particles, so the driving force for sintering is large, the sintering temperature is low, and the sintering density is high.
A suitable sintering aid reduces the sintering temperature, improves the microstructure of the ceramic grinding balls, improves the mechanical properties, and thus increases the wear resistance of the ceramic balls. The quality of sintering aids includes quantity, phase composition, chemical composition and fineness. The sintering aid is generally formulated using the SiO2-CaO-MgO ternary system. It is necessary to avoid the use of sintering aids that emit gas and phase change at high temperature to avoid new defects, which affects the densification and pass rate of the product, and reduces the competitiveness of the product.
