Passivation of the HAYNES® 214® Nickel-Based Superalloy via Pulsed Laser Deposition of Alumina and Chromia Coatings for Enhanced Corrosion Resistance at Intermediate Temperatures

The role of using pulsed laser deposition (PLD) as a means for applying alumina (Al2O3) and chromia (Cr2O3) coatings to the HAYNES® 214® alloy was investigated to provide oxidation resistance in air at 800 °C. Using various material characterization techniques, it was found that an amorphous Cr2O3 coating approximately 150 nm thick could promote and maintain the formation of a protective α-Al2O3 scale for durations of at least 100 h of exposure. The Cr2O3-coated alloy also provided superior protection under thermal cycling conditions. The Al2O3-coated alloy provided results comparable to the uncoated alloy in all isothermal oxidation tests performed; however, it appeared to provide some benefit under thermal cycling conditions.