About the structural dependence of mechanical behaviour of (Al2O3 + ZrO2) ceramics

The elucidation of influences like sintering atmosphere, dotating and mixing technology upon the mechanical behaviour of Al2O3-ZrO2 dispersion ceramics was the aim of experimental investigations. Higher grain boundary strength of Al2O3 attainable by means of sintering in air proves favourable for the macroscopic properties at medium grain size of ZrO2, whereas structures with fine-grained ZrO2 with respect to their diffusion behaviour will be sintered advantageously under reducing atmosphere. Special dotations probably can increase strength and fracture toughness by means of heterogenizing the grain boundary structure. Strength values above the range of 600 MPa require an extraordinaryly high homogeneity of distribution of the dispersed ZrO2, which has to be secured in all the stages of technological running between powder preparation and moulding. (author)