Interfacial effect on oxidation resistance of TiC/hastelloy composites applied for intermediate-temperature solid oxide fuel cell interconnects

Better interfacial bonding with fewer dislocations is observed between in-situ TiC and hastelloy than that between ex-situ TiC and hastelloy, which slows down the diffusion rate of Ti and O during oxidation process. Mass gain (800 °C/100 h) of in-situ TiC/hastelloy composites is 2.60 mg cm−2 with oxidation rate 6.84 × 10−8 g2 cm−4 h−1, much lower than 4.17 mg cm−2 with oxidation rate of 1.75 × 10−7 g2 cm−4 h−1 of ex-situ TiC/hastelloy composites. Besides, smaller TiO2 area is formed on in-situ TiC/hastelloy composites with smaller interparticle spacing of TiC, against the prediction that the decrease of interparticle spacing of TiC accelerates the formation of continuous TiO2 area.