Thermal stress behaviour of yttria, scandia and AIN ceramics

Abstract

Results of an investigation of ceramics based on yttria (Y₂O₃), scandia (Sc₂O₃) and aluminum nitride (AIN) are given. Test procedures used for evaluating their mechanical behaviour as well as their thermal shock resistance on quenching and monotonic heating are described. Special emphasis was placed on yttria from which one- and two-phase materials were fabricated. It was found that, of the materials studied, ceramics of AIN possessed the highest strength and thermal shock resistance. The analysis involved also the use of data from fractographic studies.