Microstructure development, hardness, toughness and creep behaviour of pressureless sintered alumina/SiC micro–nanocomposites obtained by slip-casting

Al2O3–SiC micro–nanocomposites are much more resistant materials than monolithic alumina regarding some mechanical properties. In order to study the possibility of obtaining creep resistant alumina/SiC micro–nanocomposites using inexpensive forming methods, alumina 1 and 5 vol% SiC materials were produced by slip-casting and pressureless sintering. Well-densified alumina–SiC pressureless sintered materials were obtained at 1700 °C for 2 h and attained 97–99% of the theoretical density. The microstructure, hardness and toughness were examined and 4-point flexure creep tests were performed at 1200 °C and 100 MPa in air. Compared with pure alumina materials, the creep resistance, toughness and hardness were enhanced drastically in materials containing 5 vol% of SiC.