Stress distribution of near the interface on high temperature fatigue in ceramic/metal bonded joints

J. Ocean Eng. Technol. 1996;10(2):106-119.

세라믹/금속접합재의 고온피로에 따른 접합계면의 응력분포

박영철,허선철,윤두표,김광영

동아대학교 기계공학과,동아대학교 기계공학과,동아대학교 기계공학과,한국기계연구원 선박해양공학연구센터 해양기술연구부장

Keywords: Ceramic/Metal Joint, Residual Stress Distribution, Finite Element Method, Elastoplastic Analysis

핵심용어: 세라믹/금속접합, 잔류응력분포, 유한요소법, 탄소성 해석

Abstract

The ceramic has various high mechanical properties such as heat, abrasion, corrosion resistance and high temperature strength compared with metal. It also has low speciffic weight, low thermal expansibillity, low thermal conductivity. However, it could not be used as structural material since it is brittle and difficult for the machining. Therefore, there have been many researches to attempt to join ceramic with metal which is full of ductillity in order to compensate the weakness of ceramic.The problem is that residual stress develops around the joint area while the ceramic/metal joint material is cooled from high joining temperature to room temperature due to remarkable difference of thermal expansion coefficients between ceramic and metal. Especially, the residual stress at both edges of the specimen reduces the strngth of joint to a large amount by forming a singular stress field. In this study, two dimensional finite element method is attempted for the thermal elastic analysis. The joint residual stress of ceramic/metal developed in the cooling process is investigated and the change of joint residual stress resulted from the repetitive heat cycle is also examined. In addition, it is attempted to clarify the joint stress distribution of the case of tensile load and of the case of superposition of residual stress and actual loading stress.