Oxidation Resistance Optimization of TiC/Hastelloy Composites by Designing Composition

TiC/Hastelloy composite has been proposed as one of promising intermediate temperature solid oxide fuel cell interconnects, and the oxidation resistance is one key property for its application. TiC/Hastelloy composites with 50vol% and 58vol% metal matrix were prepared by reactive infiltration method. Results show that high metal content results in the increase in Cr content, which optimizes the oxidation resistance of TiC/Hastelloy composites by promoting formation of continuous Cr2O3 layer to inhibit external diffusion of Ni and Ti. The content of Ti and Ni oxides in oxide scale obviously decreases. The mass gain reduces from 2.03 to 0.55 mg center dot cm(-2). Meanwhile, in order to inhibit the migration of Cr, Co is extra introduced into the composites with 58vol% metal. During the oxidation process, Co and Fe (in metal matrix) show high external diffusion rate through Cr2O3, and generate in-situ CoFe2O4 layer outmost the oxide scale.