Grindarbility of Sintered Alumina with Different Porosity

抄録

Several kinds of sintered alumina with different porosity were produced by a cold press and a normal sintering using fine alumina powers. The grindarbility was undergone for these specimens using 2 kinds of diamond wheels with different abrasive grain sizes. To consider for effects of residual pore on grindarbility and grinding mechanism, normal grinding force were measured and ground surfaces were observed with SEM. The results were summarized as follows:
(1) The grinding mechanism of alumina with different porosity was changed by abrasive grain size of used grinding wheel. That is, in case of using grinding wheel with 800-mesh size, the grinding mechanism was dominated by plastic flow. On the other hand in case of using grinding wheel with 170-mesh size, that was governed by brittle fracture with large-scale cracks.
(2) The sintered alumina with high porosity gave a low normal grinding force, while the grinding mechanism was dominated by plastic flow in using grinding wheel with 800-mesh size.
(3) In chip generation by brittle fracture with large-scale cracks and plastic flow, using grinding wheel with 170-mesh size, the large-scale cracks were obstructed by residual pore, and the normal grinding force increased with increasing porosity at over 3.1vol% porosity.