Development of thermo conductive analysis simulation in order to aid laser welding of dissimilar metals

点击翻译按钮获取中文摘要

Steel and aluminum alloy were chosen as a combination of dissimilar metals in this study. Boundary element analysis program was developed. Laser welding condition was obtained by the analysis, assuming of solid state / liquid state reaction at the interface. A joint between steel and aluminum alloy was welded under the condition predicted by BEM analysis. Intermetallic phase between Fe and Al was formed at the interface of the joint. Strength of the joint was controlled by this intermetallic phase, because this phase has poor mechanical properties. Even if brittle reaction layer exists at the interface, increase of bonded area could be a way to improve failure load of the joint. According to BEM analysis, change of shape of joint part and/or applying contact pad at welding zone can control temperature distribution at the interface and increase bonded area. In this case also, the welding condition was predicted by BEM analysis. Increase of failure load of joint and bonded area was recognized by tensile test and cross-sectional observation at the interface. The BEM simulation with assumption of interface state as mentioned above also predicted the size of bonded area. In conclusion, the computer aiding method for dissimilar metals laser welding was developed and its availability was shown in this study.