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

开发热传导分析模拟以辅助异种金属的激光焊接

• 批准号: 13650774
• 负责人: MUTOH Yoshiharu
• 金额: $ 1.86万
• 依托单位: Nagaoka University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650774/
• 关键词: Dissimilar metals joint; Laser welding; Non steady thermo conductive analysis; Simulation; Welding condition; レーザー溶接

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.

在本研究中，选择钢和铝合金作为异种金属的组合。编制了边界元分析程序。通过对界面固/液反应的分析，得到了激光焊接的工艺条件。在边界元分析预测的条件下，对钢-铝合金接头进行了焊接试验。在接头界面处形成了Fe和Al金属间化合物相。接头的强度受该金属间化合物相控制，因为该相的力学性能较差。即使在界面处存在脆性反应层，增加粘结面积也可以提高节点的破坏载荷。根据边界元分析，改变接头形状和/或在焊接区施加触头垫可以控制界面的温度分布，增加焊接面积。在这种情况下，还利用边界元分析对焊接条件进行了预测。通过拉伸试验和界面断面观察，证实了接头和粘结区破坏载荷的增加。上述界面状态假设下的边界元模拟也预测了粘结区的大小。综上所述，本研究开发了异种金属激光焊接的计算机辅助方法，证明了该方法的有效性。