PREPARATION OF HIGH-STRENGTH (MG,Y)-PARTIALLY STABILIZED ZIRCONIA BY HOT ISOSTATIC PRESSING

Fine-grained (Mg, Y)-PSZs containing small amounts of spinel as a seco nd phase have been produced by pressureless sintering and hot isostati c pressing. Their mechanical proper ties have been optimised by judici ous adjustment of processing parameters such as sintering temperature, cooling Pare and holding time of eutectoid heat treatments. Hot isost atic pressing reduces the internal defect size in comparison with conv entional sintering. Without exploiting transformation toughening, high strength values of more than 700 MPa are obtained which rise to about 900 MPa after eutectoid ageing. Failure mechanisms are discussed in t erms of defect size, defect type and R-curve behaviour. (C) 1997 Elsev ier Science Limited.