Internal oxidation of laminated Hf–Ru coatings

Abstract

This study explored the internal oxidation of laminated Hf–Ru coatings by using cyclical gradient chemical concentration distribution along the growth direction. Hf-rich, near-equiatomic, and Ru-rich Hf–Ru coatings were prepared using direct-current magnetron cosputtering. Oxidation was examined by annealing the coatings at 500 and 600 °C in a 1% O2–99% Ar atmosphere for 30 min. The results indicated that internally oxidized laminated Hf–Ru coatings formed after annealing at 600 °C. Hf preferentially oxidized and formed monoclinic HfO2. The Ru-rich Hf0.11Ru0.89 coatings exhibited a higher oxidation resistance and superior mechanical properties.