Preparation and mechanical properties of SiC whisker and nanosized mullite particulate reinforced TZP composites

The influence of the addition of nanometer mullite particulates and SiC whiskers coated with alumina on the mechanical properties of tetragonal zirconia polycrystals (TZP) was studied, With increasing mullite(p) content the high-temperature flexural strength increased, and a maximum value of 360 MPa at 1000 degrees C was reached at 15 vol% mullite(p). Furthermore, 10 vol% SiC(w) reinforced 15 vol% mullite/TZP composites improved the high-temperature strength up to 490 MPa at 1000 degrees C, 2.7 times that of pure TZP matrix. This high-temperature strengthening is attributed to load transfer from TZP matrix to SiC(w) and mullite particulates, Significant whisker pull-out and interface debonding were also observed on the fractured surfaces when SiC(w) was coated with Al2O3 film.