Crack-healing function of metal/Al2O3 hybrid materials

Abstract

Nano-Ni/Al2O3 hybrid materials have the crack-healing function by thermal oxidation process such as 1200°C for 6 h in air. In this hybrid material system, crack was filled up by an oxidation product, NiAl2O4, via outward diffusion of cations along grain boundaries of Al2O3 matrix. Ni/Al2O3 with Y2O3 doping and SiC+Ni/Al2O3 nano-hybrid materials have similar crack-healing performance with better oxidation resistance at high temperatures than Ni/Al2O3 nano-hybrid materials. Mo/Al2O3 hybrid materials were studied on a candidate with crack-healing function via thermal oxidation process at temperatures as low as 700°C. © 2011 Ceramic Society of Japan.