DENSIFICATION AND MECHANICAL-PROPERTIES OF SHOCK-TREATED ALUMINA AND ITS COMPOSITES

The effects of shock treatment and consolidation method on densificati on behaviour and mechanical properties of Al2O3, Al2O3-ZrO2, Al2O3-SiC (whisker), and Al2O3-ZrO2-SiC (whisker) have been studied. It was est ablished that shock treatment does not improve the sintering kinetics of alumina or alumina-based composites. On the other hand, partial sho ck compaction followed by sintering provided higher densities compared to sintering alone. Unshocked and pressureless sintered materials pos sessed better mechanical properties than shock-treated materials, in g eneral. No significant difference was noted in the mechanical properti es of hot-pressed Al2O3-ZrO2 composites with regard to shock treatment . Improved mechanical properties were occasionally found in shock-trea ted and hot-pressed whisker-reinforced alumina, although a direct rela tionship with shock pressure was not observed. The improvement was att ributed to decreased whisker aspect ratios upon shock treatment, leadi ng to enhanced microstructural uniformity.