AZ31镁合金搅拌摩擦焊接头力学性能

Mechanical properties of friction stir welds on AZ31 magnesium alloy

成功实现了2.5mm厚AZ31镁合金的搅拌摩擦焊接。焊接参数的选择决定接头的力学性能,通过拉伸和弯曲试验,分析了焊接参数的选择对接头性能的影响。试验结果表明,当焊接速度为75～150mm/min,旋转速度为900～1500 r/min之间时,可以得到性能好的接头。为简化焊接参数的选择,同时考虑焊接速度和旋转速度的相互影响,提出一个新的评定参数R/υ,即单位长度上的旋转次数,并分析R/υ与接头性能之间的关系。结果表明,当R/υ=8～15时,接头性能良好,可知,当焊接速度和旋转速度的选择在一个比较合理的范围时,R/υ可以作为搅拌摩擦焊接参数选择的依据。

A series of controlled friction stir welds had been successfully made using 2.5 mm thick AZ31 magnesium alloy. The mechanical property of friction stir welds is largely depends on the welding parameters and welding process. The relationship between the rotation speed the traverse speed and the ultimate strength of as-welded joint was studied using tensile and bend testing. The results show that sound joints had been made at welding speed 75-150 mm/min and rotation speed 900-1500 r/min. The paper presented a new evaluating parameter, the ratio of the rotation speed and the welding speed (R/v) - the rotation amount per unit length, and combined this new parameter with the joint quality in place of the total effect caused by the rotation speed and the welding speed. Results indicated that sound joint can be made when R/v=8-15, and the new evaluating parameter can be regarded as reliable when the value of v and R are in good range.