2A14 T6铝合金FSW及VP-TIG焊接对比分析

Comparative analysis of FSW and VP-TIG for 2A14 T6 aluminum alloy

采用FSW及VP-TIG两种方法对5mm厚2A14 T6铝合金进行焊接,并对比分析焊缝。试验结果表明,两种焊接方法均可获得满足相应标准I级要求的焊缝,VP-TIG接头内部存在微小孔洞,且晶粒较为粗大,FSW接头组织致密,晶粒细小,后退侧热影响区晶粒尺寸明显大于前进侧热影响区晶粒尺寸。VPTIG接头硬度最低值为92.8 HV0.2/20,位于焊缝中心,FSW接头硬度最低值为104.2 HV0.2/20,位于后退侧热机影响区与热影响区交界处。VP-TIG接头强度系数0.63,延伸率4.7%,断裂发生在热影响区,FSW接头强度系数0.8,延伸率5%,断裂发生在后退侧热机影响区及热影响区交界处,两者均为韧性断裂。

The 2A14 T6 aluminum alloy with a thickness of 5mm is welded by FSW and VP-TIG respectively,and the characteristics of the welds are studied.The results show that both welding methods can obtain welds that meet the requirements of the corresponding standard level I.There are tiny holes inside the VP-TIG welded joint,and the grains are coarse.The microstructure of FSW welded joints is dense,the grains are fine,and the grain size of the HAZ on the retreating side is significantly larger than that on the advancing side.The minimum hardness of the VP-TIG welded joint is 92.8 HV0.2/20,which is located in the center of the weld.The minimum hardness of FSW welded joint is 104.2 HV0.2/20 and is located at the junction of TMAZ and HAZ on the retreating side.The VP-TIG welded joint has a strength coefficient of 0.63 and an elongation of 4.7%,the fracture occurs in the HAZ.The FSW welded joint has a strength coefficient of 0.8 and an elongation of 5%,the fracture occurs at the junction of TMAZ and HAZ on the retreating side.These two kinds of fractures are ductile fracture.