Microstructure and mechanical properties of zirconia-toughened ZrB2-MoSi2 composites prepared by hot-pressing

ZrO2-doped ZrB2-20 vol.% MoSi2 composites were prepared by hot-pressing. Compared with ZrB2-MoSi2 composite the addition of ZrO2 caused an obvious improvement in microstructure as well as in mechanical properties. Due to the phase transformation toughening of ZrO2, the toughness of ZrB2-MoSi2 composites was clearly advanced by 50% from similar to 4.3 to similar to 6.3 MPa m(1/2) regardless of the method of testing. Such enhancement, especially in toughness, indicates that it is an effective way to design ZrB2-MoSi2 composites with phase transformation toughening of ZrO2. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.