Deformation and Grain Growth of Low-Temperature-Sintered High-Purity Alumina
نویسندگان
چکیده
9 = 0.6 I / s ' 7 = 6.0 0 7 = 2 4 i ti 3 = 6 0 Through close control over green-state powder processing, pure alumina ceramics of 0.5-pm grain size were obtained by sintering at 1250°C. The static grain growth of this material was modest at temperatures below 1300°C. However, dynamic grain growth occurred rapidly during superplastic deformation. Therefore, although the ultrafine-grained alumina exhibited rather low initial flow stress at relatively low deformation temperatures, dynamic grain-growth-induced strain hardening gave rise to high flow stress causing cavitation and cracking. As a result, superplastic deformation could not be achieved for the ultrafine-grained pure alumina. [
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