Preparation and Mechanical Properties of zirconia-mullite nano-comoposites from TiO_2-doped Si-Al-Zr-O amorphous bulk

摘要

Zirconia-mullite nanocomoposites were prepared from TiO_2-doped Si-Al-Zr-O amorphous bulks according to a two-step heating treatment between 880 and 1250°C. Effects of TiO_2 amount and heat treatment conditions on the mechanical properties have been investigated. The fracture toughness was much more affected by the heat treatment processing than by amount of TiO_2. With increasing amount of TiO_2 (2.5～10 wt%), the fracture toughness gradually decreases. Nucleating temperature and time and crystallization temperature and time are interrelated. The fracture toughness of the sample with 5 wt% TiO_2 nucleated at 920°C for 2.0 h and crystallized 1150°C for 4.0 h is 7.48 MPa·m~(1/2).