ADVANCES IN THE GRINDING EFFICIENCY OF SINTERED ALUMINA ABRASIVES

The study relates the grinding Fewer of different grades of sintered a lumina abrasives to their microstructures and to basic mechanical prop erties in comparison with conventionally fused electrocorundum and wit h an electrofused alumina/zirconia eutectic, Contrary to the tradition al approach of the Battelle test, the fracture toughness K-Ic of indiv idual grains is measured by a quantitative indentation analysis. Compa red with fused corundum, sintered alumina grits exhibit an increased t oughness and grinding efficiency, but the further increase of K-Ic in the eutectic does not improve the grinding performance. The key parame ter for grinding is the inherent hardness of the abrasive. The elimina tion of flaws by a new approach results in a strong increase in the gr inding power of sintered alumina abrasives.