Abstract
An ultrafine α-alumina powder was consolidated by spark plasma sintering (SPS) and the effect of microstructure on mechanical properies of the sintered compact was examined. In the sintering temperature at 1473K, the sintering was incomplete at the central part, and the periphery was fine microstructure. On the other hand, in the sintering temperature at 1773 K, many fine pores observed in the grains and/or on the grain boundaries. Further, the martens hardness indicated a low value at the central part.
