The oxidation resistance optimization of titanium carbide/hastelloy (Ni-based alloy) composites applied for intermediate-temperature solid oxide fuel cell interconnects

Abstract

Titanium carbide/hastelloy (TiC/hastelloy) composites are potential candidates for intermediate-temperature solid oxide fuel cell interconnects. In this work, TiC/hastelloy composites with suitable coefficient of thermal expansion are fabricated by in-situ reactive infiltration method, and their properties are optimized by adjusting TiC particle size (dTiC). The oxidation process of TiC/hastelloy composites is comprehensive performance of TiC and Ni-Cr alloy and determined by outward diffusion of Ti and Ni atoms and internal diffusion of O2. The oxidation resistance of composites could be improved by the decrease of dTiC through accelerating the formation of continuous and dense TiO2/Cr2O3 oxide scale. Moreover, the electrical conductivity of composites at 800 °C for 100 h is 5600–7500 S cm−1 and changes little with the prolongation of oxidation time. The decrease of dTiC is favorable for the properties optimization, and composites with 2.16 μm TiC exhibits good integrated properties.