Oxidation Resistance of Vacuum Plasma Sprayed CoNiCrAlY Coatings Modified by Filtered Cathodic Vacuum Arc Deposition Aluminizing.

The vacuum plasma sprayed CoNiCrAlY coatings are modified by filtered cathodic vacuum arc deposition aluminizing. The microstructure and oxidation resistance of the coatings are investigated. The parabolic law is obeyed for the aluminized coatings after oxidation at 1100 °C for 100 h. Its parabolic kinetic constant is 0.080 mg/cm h, which is lower than that of as-sprayed coatings. The continuous and dense AlO scale is formed earlier due to the increase of Al concentration, and the spinels hardly exist. The oxidation resistance is improved obviously after filtered cathodic vacuum arc deposition aluminizing. [ABSTRACT FROM AUTHOR]