Non-ferrous metals are difficult to weld as compared to the ferrous metals. Copper is one of the non-ferrous metals using worldwide in different manufacturing and other metal processing industries. This paper focuses on the processing of copper under friction stir welding (FSW) and the study of mechanical properties of friction stir welded (FSWed) copper joints. Different parameters of FSW have been studied with the help of L₉ orthogonal array (OA). Rotational speed and traverse speed of the tool with three different tool materials have undergone for the parametric optimization. Tensile strength and impact strength have been optimized using the grey relational method. Results show a significant effect of parameters on responses. Finally, it has been concluded that the grey relational method is a robust method to optimize the combined set of responses in a single attempt. From results, it has been observed that the higher rotational speed and lower traverse speed with H13 tool material give better results for mechanical properties. Analysis of variance (ANOVA) has been used to find the percentage contribution of each parameter on mechanical properties. P-value has been found less than 0.05 which shows that the effect of each selected parameter on the result is significant. Microstructure study has been performed on scanning electron microscopy (SEM) and the change in grain size within the weld zone has been observed.

中文翻译：

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铜的摩擦搅拌焊接：加工和多目标优化

与黑色金属相比，有色金属难以焊接。铜是世界范围内在不同制造业和其他金属加工行业中使用的有色金属之一。本文主要研究搅拌摩擦焊（FSW）下铜的加工以及搅拌摩擦焊（FSWed）铜接头的机械性能的研究。在L ₉的帮助下研究了FSW的不同参数正交数组（OA）。使用三种不同工具材料的工具的旋转速度和移动速度已进行参数优化。拉伸强度和冲击强度已使用灰色关联方法进行了优化。结果显示参数对响应的显着影响。最后，得出的结论是，灰色关联方法是在一次尝试中优化组合响应组合的可靠方法。从结果可以看出，H13工具材料的较高旋转速度和较低的移动速度为机械性能提供了更好的结果。方差分析（ANOVA）已用于查找每个参数对机械性能的百分比贡献。发现P值小于0。05表示每个选定参数对结果的影响都很大。在扫描电子显微镜（SEM）上进行了微结构研究，并观察到焊接区内晶粒尺寸的变化。