Al/Cu薄板高转速搅拌摩擦点焊工艺及接头微观组织研究

Study on High Rotation Speed Friction Stir Spot Welding Technology and Joint Microstructure of Al/Cu Thin Sheet

采用高转速搅拌摩擦焊对1 mm厚的6061铝合金及T2紫铜板开展点焊工艺试验,研究了焊接停留时间、Zn中间层及冷却方式对焊点宏观界面及微观组织的影响规律。结果表明:在焊接停留时间为1s、中间层Zn厚度0.2 mm、无水冷的焊接工艺参数下,焊点宏观形貌成形良好,无明显焊接缺陷产生,接头力学性能最优;焊点中间界面层主要由Al_(2)Cu、Al-Zn共晶和α-Al组成;随着焊接停留时间的增大,焊接热输入增加,焊点抗剪切性能降低;Zn中间层的加入能够提高接头力学性能;水冷使得焊接峰值温度降低,减小了焊接热输入,提高了接头力学性能。

The high rotation speed friction stir welding experiment of 1mm thick 6061 aluminum alloy and T2 copper sheets was carried out, and the influence of welding residence time, Zn intermediate layer and cooling mode on the macroscopic interface and microstructure of spot joints was studied. The results show that: under the welding process parameters of 1s welding residence time, 0.2 mm thick Zn intermediate layer and no water cooling, the macroscopic shape of the welding spot is well formed, no obvious welding defects are formed, and the mechanical properties of the joint are best.The intermediate interface layer of the spot joints is mainly composed of Al2Cu, Al-Zn eutectic and α-Al. With the increase of welding residence time, the welding heat input increases, the shear resistance of spot joint decreases gradually;the addition of Zn intermediate layer can improve the mechanical properties of the joint. The water cooling can reduce the peak welding temperature, reduces the welding heat input and improves the joint’s mechanical properties.