Acoustic Emission Characteristics of Plasma Sprayed Ceramic Coating Layer after Salt Spray

J. Ocean Eng. Technol. 2001;15(3):69-74.

플라즈마용사 세라믹코팅 피막부식재의 음향방출 특성

김귀식,박경석,홍용의

제주대학교 기계공학과,제주대학교 기계공학과,제주대학교 기계공학과

Keywords: Plasma spray, Ceramic coating, Coating layer corrosion, Adhesiveness, Acoustic emission, Tensile testing

핵심용어: 플라즈마 용사, 세라믹 코팅, 코팅 피막 부식, 밀착성, 음향방출, 인장시험

Abstract

This paper was to investigate of a adhesiveness for the plasma sprayed coating materials did salt spray by acoustic emission method in tensile loadings. The powders used for the coating were nickel aluminum composite powder Ni-4.5wt.%Al and titanium dioxide powder $TiO_2$. These powders were coated on a carbon steel S45C by plasma spray method. The result solution was a 5% NaCl and the slat spray times were 2, 5 and 10 hours respectively. The salt solution penetrated into the surface of the substrate through pore of the coating layer built in the process of plasma spay. Corrosion productions formed on the surface of substrate. The adhesiveness between the substrate and the coating layer is weaken by corrosion and the exfoliation initiated chiefly at the corrosion surface of the substrate. The AE events and energy of the corroded coating specimens decreased as the salt spray times increased.