Effect of Al_2O_3 Addition on Mechanical Properties of SiC-platelet/Y-TZP Composites
Hong Jinsheng; Huang Xiaoxian; Gao Lian(Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai 200050 China)Ghompson D. P.(Department of Mechanical, Material Manufacturing Engineering,University of Newcastle upon Tyne, U. K.)
SiC-platelet /yttria-stabilized tetragonal zirconia polycrystal (Y- T Z P ) and A12 O 3 /S iC- platelet /YTZP composites were fabricated using SiC--platelet, ZrOC12.SHZO, Y(NO3)3 and AIC13 solution as starting materials by chemical co-precipitation mixing followed by hot-pressing technique. Adding SiC-platelets to Y-TZP matrix resulted in losses of both strength and toughness. Its eleVated temperature strength also revealed no particular benefit compared with that of monolithic matrix material (Y-TZP). Addition of Allot to SiC -platelet/TZP composite system was useful to enhance the strength and toughness at room temperature strength, and its elevated tempertaure strength can also be improved. The XRD results showed that the addition of A12O3 can promote tetragonal to monoclinec phase transformation of ZrO2 during fracture.