焊接速度对厚板5083铝合金搅拌摩擦焊接头组织与性能的影响

Influence of welding speed on the microstructure and properties of FSW 5083 thick plate aluminum alloy

对厚度12 mm的5083铝合金板材进行搅拌摩擦焊对接试验,在旋转速度为600 r/min的条件下,对比研究焊接速度为100 mm/min和300 mm/min时的对接接头的宏观形貌及微观组织、力学性能、断裂形式的差异。结果表明,当焊速为100 mm/min时,洋葱环间距较小,焊接接头内无明显缺陷,力学性能接近母材,能获得质量较高的焊接接头,断裂位置发生在热影响区,模式为韧性断裂;当焊速为300 mm/min时,洋葱环间距较大,接头根部出现未焊合缺陷,严重降低接头力学性能,断裂位置发生在焊核区,断裂模式为韧-脆性混合断裂。

The 12 mm thick cold-rolled sheets of 5083 aluminum alloy were butt jointed by friction stir welding（FSW）at a rotation rate of 600 r/min. Then compare the effort of microstructure,mechanical properties and fracture pattern with the different welding speeds of 100 mm/min and 300 mm/min. The results show that when welding speed is 100 mm/min,the spacing of onion rings is bigger than the 300 mm/min＇s. There is no obvious defect in the welded joint and the mechanical property is close to the parent material,which show the welding quality is high. The fracture position occurs in the HAZ,and the model is ductile fracture of the welds. When welding speed is 300 mm/min,there is the unwelded joint defect at the root of weld joint,which causes a serious decline in the mechanical properties of the joint. The fracture position occurs in the NZ,and the model is a mixture of ductile and brittle fracture of the welds.