Poster Session

Ni/LaCO3 Composite Coatings for Ferritic Stainless Steels

Nima Shaigan, PhD student in Materials Engineering

Supervisor - Dr. D. G. Ivey and Dr. W. Chen

To increase the conductivity of the surface oxide forming on the surface of the ferritic stainless steel used as solid oxide fuel cell interconnects, a Ni/LaCrO3 composite layer is electrodeposited onto a ferritic stainless steel substrate. Annealing is subsequently performed to change the surface composition of the coating to a Cr-rich, Fe-Ni-Cr alloy. Chromium, at the surface, promotes the formation of a protective chromia scale. The LaCrO3 particles are incorporated into the chromia scale and provide an electronic conduction path through the oxide layer. Kinetics of diffusion as well ad structural changes is studied by means of scanning electron microscopy (SEM) along with energy dispersive x-ray (EDX) spectroscopy. After annealing of a ~15 m thick Ni/LaCrO3 coating at 1000°C for 9 hours a maximum of ~8 at% chromium approached. After 170 hours of oxidation in air at 800°C, presence of conductive particles on and inside the oxide scale was evident.