This study explores the thermal distribution of high-strength engineering alloys during the friction stir welding process (FSW). Materials which are difficult to weld or are unweldable by conventional welding processes can be successfully welded by FSW. The specific analysis and modification of the process require an understanding of the actual mechanism of the process. Therefore, a transient, three-dimensional, thermo-mechanical finite element model (FEM) for FSW was developed. The model calculates the temperature distribution during the welding process considering various boundary conditions such as rotational speed, linear speed, normal pressure, tool diameter and material properties. The thermo-mechanical FEM calculations consider the effects of conduction and convection heat transfer. The numerical results are successfully compared and validated by experimental results published in the literature for aluminium alloy, titanium alloy and steel (mild and bainitic) as workpiece materials. The model was found to be useful for understanding the effects of changes in different system parameters, and for selecting the optimum welding conditions before undertaking high-cost physical testing.

这项研究探讨了高强度工程合金在搅拌摩擦焊过程中的热分布。FSW可以成功焊接传统焊接工艺难以焊接或无法焊接的材料。对过程的特定分析和修改要求了解过程的实际机制。因此，开发了用于FSW的瞬态三维热机械有限元模型（FEM）。该模型在考虑各种边界条件（例如转速，线速度，法向压力，工具直径和材料特性）的情况下计算焊接过程中的温度分布。热机械有限元计算考虑了传导和对流传热的影响。数值结果已通过文献中针对铝合金，钛合金和钢（低碳和贝氏体）作为工件材料的实验结果成功进行了比较和验证。发现该模型对于了解不同系统参数变化的影响以及在进行高成本的物理测试之前选择最佳焊接条件非常有用。