THERMAL SHOCK RESISTANCE OF ZIRCONIA /IRON-ALUMINIDE COMPOSITES EVALUATED BY INDENTATION-QUENCH TECHNIQUES

The thermal shock resistance of ZrO₂(3Y) and ZrO₂(3Y)/Fe₃Al composite was studied using indentation-quench technique. The results show that the pattern of crack growth is similar for the two materials. Low crack growth in a stable manner happened when ΔT<ΔT_U, and cracks grew unstably when ΔT>ΔT_U. The ΔT_U of ZrO₂(3Y)/Fe₃Al composite is higher than that of ZrO₂(3Y), indicating the improved thermal shock resistance. The higher fracture toughness and thermal conductivity and lower elastic modulus and Poisson's ratio of ZrO₂(3Y)/Fe₃Al composite compared with monolith ZrO₂ are the main reasons for the elevated ΔT_U value of ZrO₂(3Y)/Fe₃Al composites.