Effect of Pre-oxidation and Al amount on the Oxidation Behavior of Healing Agents in YSZ-Mo(Si1-x,Alx)2 Composite

Abstract Efficient and easy to produce self-healing agents have significant role on the development of self-healing composites. Herein, we report preoxidized Self-propagating high-temperature synthesis (SHS) synthesized Al-alloyed MoSi2 for self-healing agent in thermal barrier coating system. The raw materials of Mo, Si and Al with molar aspect ratio of (1:1.6:0.4) and (1:1.2:0.8) were used to produce Mo(Si1-x,Alx) via SHS method. The healing agents were used to produce YSZ- Mo(Si1-x,Alx) composite by spark plasma sintering (SPS) method. Effect of peroxidation and Aluminum amount were studied after iso-thermal oxidation at 1050 °C with FE-SEM, EDX and XPS analysis. Oxide shell were grown on the surface of healing agent powders after preoxidizing. Oxide form of aluminum, silicon and molybdenum are available in oxide shell after preoxidation. Selective oxidation of Aluminum led to produce firm and continues Alumina oxide film on the surface of healing agents. Peroxidation is effective way to reserve the healing agent with molar aspect ratio of (1:1.2:0.8) by decreasing oxidation rates of them at working temperature and has not significant effect on healing agent with (1:1.6:0.4) molar aspect ratio. There is much prospect that this research will led to producing novel self-healing thermal barrier coatings by modification of healing agents composition in order to have the most appropriate properties at working condition.