Self-healing of indentation damage in Ti2AlC MAX phase ceramics

Abstract

Although the crack-healing capacity of Ti2AlC ceramics has been sufficiently studied, the ability of Ti2AlC to self-heal large-scale damage, such as foreign object damage (FOD), remains unknown. This paper investigates the self-healing ability of Ti2AlC ceramics with large-scale damage (∼1000 μm in diameter). Extensive healing was observed even in the plastic damage and radial cracks. The damage and cracks caused by indentations made using a tungsten carbide sphere were filled and covered with newly formed oxides, such as titanium oxide and alumina, by the oxidation of Ti2AlC after heat treatment in air at 1000 °C. The strength, hardness, toughness, and elastic modulus of the Ti2AlC samples were measured before and after healing. The results show that the mechanical properties of Ti2AlC were similar or even slightly higher after the damage had been healed. Thus, Ti2AlC ceramics are attractive healing agents for foreign object damage in high-temperature applications.