Evaluation of Characteristics for CoNiCrAlY Coating Layer by Atmospheric Pressure Plasma Coating Method

摘要

With recent technological progress, industrial machinery and equipment are being exposed to severe environments. Thus, materials having better durability are required. However, there are almost no single materials that can satisfy the functional requirements in various conditions. Therefore, various surface treatment methods are being developed not only to diversify and enhance material functions, but also to present inherent characteristics of the material and repair its defects. Among them, thermal spray coating is widely used in various industrial applications, but the porosity formed in the thermally sprayed coating degrades corrosion resistance by the penetration of corrosive solution into it. In this study, aluminum-bronze alloy was used as a substrate, which is excellent in corrosion resistance and cavitation resistance characteristics, and thus applies to the marine environment. To improve durability and prevent damages, the alloy was coated with CoNiCrAlY by atmospheric pressure plasma coating (APPC) technology and the coating underwent post-treatment with C-Si sealer, and then its electrochemical characteristics were evaluated. As a result, the coating layer containing Ni and Cr represented better corrosion resistance than the aluminum-bronze alloy (ALBC3) whose main elements are Cu and Al.