アルミナ板状粒子の粒成長に及ぼすMgO添加効果とその焼結体の機械的特性 Effect of Addition of MgO on Platelike Grain Growth in Alumina Sintered Bodies and Their Mechanical Properties
Effect of addition of MgO on growth behavior of platelike grains in alumina sintered bodies was investigated and also their mechanical properties were investigated. The growth of platelike grains in the direction of long axis were restrained by addition of MgO, so the aspect ratio of the grains decreased with increasing amount of MgO. However, platelike grain growth mechanism with any amount of MgO up to 0.1mass% was considered to be similar, because the slopes of growth isotherms in log-log plot of platelike grain size of long axis versus sintering time were nearly equivalent. Although the bending strength of alumina sintered bodies with 20-30vol% platelike grains was almost. the same in comparison with the bodies which did not contain platelike grains, the fracture toughness of the former bodies were about 10-40% larger than the latter bodies. The mechanism of increasing fracture toughness in this study was considered to be the crack deflection process. The fracture toughness increased with aspect ratio of platelike grains in sintered bodies.
粉体および粉末冶金 45(11), 1018-1023, 1998-11-15
Japan Society of Powder and Powder Metallurgy