Evaluation of ZrO₂-Dispersed Al₂O₃ Ceramics Prepared by Coprecipitation Technique

抄録

Al₂O₃-ZrO₂composite powder has been prepared using the coprecipitation technique. Al₂O₃particles in the powder were surrounded with ZrO₂ particles whose sizes were about 50nm. Al₂O₃-20mass%ZrO₂ bulk ceramics, made from the Al₂O₃-ZrO₂ composite powder, using hot isostatic pressing (HIP) after pressureless sintering attained a mean bending strength of about 1.3GPa. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for analyzing the microstructure of the composites. Both a homogeneous dispersion of ZrO₂ particles in the Al₂O₃-ZrO₂ composite ceramics and the existence of fine ZrO₂ particles remaining at grain boundaries of the Al₂O₃ matrix might be two important factors to strengthen the Al₂O₃-Al₂O₃grains coupling.