AZ31镁合金搅拌摩擦焊接头焊核区域成型过程及影响因素

The weld nugget formation of friction stir welded AZ31 magnesium alloy and its affecting factors

接头焊核区域的形成是搅拌摩擦焊接的一个典型特征,其形状和大小对搅拌摩擦焊接头的性能有重要影响。以AZ31镁合金为母材,分析不同焊接参数(包括焊接压力、焊接速度、搅拌头倾斜角)条件下搅拌摩擦焊接头焊核成型的规律及特点,并建立焊核成型过程的简单模型。分析认为焊接压力和搅拌头倾斜角是影响焊核成型的重要因素,而焊接压力决定塑性材料的形成。焊核的形状主要由塑性材料的流动状态决定,搅拌头的形状和焊接速度影响塑性材料的流动,从而影响焊核的成型。掌握FSW焊核成型规律,可以选择合理的工艺参数。

The main character of friction stirred weld is the formation of the weld nugget. The shape and size of the weld nugget have great effect on the joint mechanical properties. AZ31 magnesium alloy used as base metal and the effect of welding parameters including welding pressure, welding speed and probe tilt angle on the weld nugget formation was studied and a simple model was built to explain the weld nugget formation process. The results showed that the welding pressure and the probe tilt angle are the most important factors on weld nugget formation and the formation of superplastic material depends on the welding pressure. The shape of the weld nugget was affected by the material flow pattern, and the flow movement was caused by the probe and the welding speed, then affecting the weld nugget formation. A good understanding of the weld nugget formation can be used to choose reasonable welding parameters.