铝合金激光-MIG双面焊接接头组织和性能研究

针对16mm厚1561铝合金(俄罗斯牌号),采用不开坡口无间隙的双面激光-MIG复合焊接工艺,并研究焊接接头的拉伸性能、显微硬度和微观组织。结果表明,采用较大的激光功率使双面焊道交叉面积增大,有利于减少焊道根部缺陷,提高拉伸性能;接头中存在着基体相α-Al和第二相Fe(Mn Al)6,第二相经焊接热循环重熔后弥散分布,其中单独激光作用区弥散度最高;焊缝硬度在激光单独作用区相对于母材升高,而在激光-电弧复合作用区相对于母材降低,这与焊缝显微组织中的第二相数量和形态密切相关。

Study on microstructure and mechanical properties of laser-MIG double-sided welded joints of aluminum alloy

For the 16 mm thick 1561 aluminum alloy (Russian brand),the double laser-MIG hybrid welding process without groove and gap was adopted,and the tensile properties,micro-hardness and microstructure of the welded joint were studied.The results show that,with larger laser power,the intersect area of double side welding bead is increased,which is helpful to reduce the defect of bead root and improve the tensile properties;the joints contain the matrix phase αt-Al and the second phase Fe (MnA1)6,the second phase is dispersed after welding thermal cycling,where the dispersion of the laser welded area is the highest;compared with the base metal,the hardness of the laser welded area increases,and the hardness of the hybrid welded area decreases,which due to the number and shape of the second phase in the microstructure.