PREPARATION OF HIGH-STRENGTH AND TRANSLUCENT ALUMINA BY HOT ISOSTATIC PRESSING

A vacuum-pressure slip-casting technique and hot isostatic pressing (HIPing) were used to prepare high-strength and translucent alumina ceramics. A low-viscosity and high-solids-content slurry (46 vol% solids) was prepared, and a dense green compact was formed. The samples were sintered and subjected to capsule-free HIPing. Extremely high-density (99.9%) and fine-grained (0.7 to 15-mu-m in diameter) alumina ceramics were obtained. The HIPed samples showed high bend strength and translucency with in-line transmittance of 30% to 46% (1 mm thick).