铝合金可回抽搅拌摩擦焊接头组织和性能

针对8 mm 厚2219 铝合金进行可回抽搅拌摩擦焊工艺试验,详细分析了回抽过程中搅拌针运动

轨迹、不同回抽位置的接头组织形态及力学性能。结果表明:搅拌针的运动轨迹是焊接速度与搅拌针相对于轴

肩回抽速度的合成运动轨迹,并呈现出一定的线性关系。回抽结束处和回抽起始处的接头组织形貌为典型的

常规搅拌摩擦焊接头,位于中间回抽区域的焊接接头可以认为是100% 焊透的焊接接头与“相同直径的轴肩+

(100% ~0%) ×L 的搅拌针”形成的焊透深度逐渐变浅的常规搅拌摩擦焊接头复合形成的。接头力学性能测

试结果表明:回抽结束处的性能最高,回抽起始处的性能次之,中间回抽区域的力学性能最低,并且随着回抽距

离的逐渐增加,中间回抽区域的力学性能逐渐增加。不同回抽位置的搅拌摩擦焊接头均呈现出典型的韧性断

裂形貌。

Retractable Friction Stir Welding Technology of 2219 Aluminium Alloy

An extensive investigation was carried out on the retractable friction stir welding of 2219 aluminium

alloy with the thickness of 8 mm, and the retractable track, microstructure and mechanical properties of the welding

joint at the different locations have been analyzed. The results indicated that the actual trajectory of the RPT is the

combination of welding speeed and retracting speed, and showed a linear relationship. The morphology at the beginning

and end of the retractable FSW welded seam showed a typical conventional FSW microstructure, while the joint

located in the middle of the retractable FSW welded seam can be considered as the composite of a 100% penetration

welded joint and a joint with gradually shallower depth. The results of the tensile test indicated that the mechanical

property of the joint at the end of weld seam is the highest, followed by the joint loacated at the beginning and middle

of the retractable FSW welded seam. With the retracting distance increasing gradually, the performance of the joint in

the middle of the retractable FSW welded seam also gradually increased. The fracture mechanism of the joint at different

position is all ductile fracture.