铝合金搅拌摩擦焊焊缝形成的物理机制  

Physical Mechanism of Friction Stir Weld Formation of Aluminum Alloy

作　　者：柯黎明[1] 潘际銮[1] 邢丽[2] 秦占领[2] 

机构地区：[1]清华大学先进成形制造教育部重点实验室,北京100084 [2]南昌航空大学材料科学与工程学院,南昌330063

出　　处：《材料工程》2008年第4期33-37,共5页Journal of Materials Engineering

基　　金：江西省自然科学基金项目(0450090)

摘　　要：研究了一种铝合金焊缝成形的物理机制及焊接工艺参数对焊核尺寸的影响。结果表明:搅拌摩擦焊焊缝是由焊核、在前进边后方沿板材厚度方向流动的金属、由搅拌针两侧向其后方流动的金属组成,四个方向的金属流会在焊缝横截面上出现一交汇区,若金属流动不足,易在此区出现焊接缺陷。焊核的形成及其大小取决于搅拌针表面的螺纹和焊接工艺参数,若单位长度焊缝中有较多的金属在螺纹的驱动下向下流动,则会在焊缝下部出现较大的焊核。过高的搅拌头旋转速度或过低的焊接速度,使搅拌针周围金属易于朝焊缝上部流动,焊核尺寸减小。The physical mechanism of the weld formation during friction stir welding and the influence of welding parameters on the size of weld nugget were investigated. The results shown that, the friction stir weld is composed of three parts of metals, that is, the weld nugget, the metal flowing along the thickness of the workpiece at the trail of the advancing side, and the from the two sides of the stir pin. There exist a confluence region to which the metal flows from four directions on the weld cross section. If the metal flowing is not enough, the weld defects would form in this region. The formation of the nugget and its size are dependent on the screw threads on the stir pin surface and the welding parameters. The more the metal flowing to the bottom of the workpiece under the driving of the screw threads in unit weld length, the larger the weld nugget near the bottom is. If the rotation speed of stir tool is too high or the travel velocity of the tool is too low, the metal around the stir pin would be easy to flow to the upper part of the weld, and this will decrease the size of the nugget.

关 键 词：搅拌摩擦焊 焊核 焊缝成形 物理机制 

分 类 号：TG453.9[金属学及工艺—焊接]