A Study on the Mechanical Properties and Residual Stresses of the Thermally Sprayed Alumina Ceramic Coating Layer

J. Ocean Eng. Technol. 1996;10(2):88-97.

알루미나 세라믹(Alumina Ceramic) 코팅층의 기술적인 특성과 잔류응력의 해소에 관한 연구

김영식

부산수산대학교 자동차공학과

Key Words: Alumina Ceramic, Residual Stress, Strengthening Heat Treatment, Finite Difference Method, Finite Element Method, Thermoelastic Analysis

핵심용어: 알루미나 세라믹, 잔류응력, 강화열처리, 유한차분법, 유한요소법, 열탄성해석

Abstract

The pupose of this study is to improve the mechanical properies and to evaluate the residual stresses of flame-sprayed Alumina ceramic coating layer. The first work in this study is to investigate the effects of strengthening heat treatments on the mechanical properties of coating layer. Strengthening heat treatments for sprayed specimens were carried out in vaccum furnace. The mechanical properties such as microhardness, thermal shock resistance, adhesive strength and erosion resistance were tested for the sprayed specimens after strengthening heat treatments. And it was clear that the mechanical properties of coating layer were much improved by strengthening heat treatments. The second work in this study is to evalute the residual stresses in coating lsyer by numerical analysis. FDM and FEM were used to analyze temperature distribution and residul stresses in coating layer. It was proved that are tensile stresses in coating layer and that residual stresses can be controlled by the appropriate selection of the spraying parameters such as preheat temperature, coating thickness and bond coat thickness.