高强铝合金的MIG以及激光-MIG焊接工艺对比

以20 mm厚的2519-T87高强铝合金为研究对象,研究了熔化极惰性气体保护焊 (MIG焊)和CO2激光-MIG复合焊的焊接效率、组织以及力学性能之间的区别.结果表明,激光-MIG复合焊的焊接效率是MIG焊的5倍,焊接熔深更大,接头的抗拉强度也提高到母材的70%以上,而MIG焊接头抗拉强度仅仅只有母材的60%左右.由于复合焊的热输入比较小,而且熔池的熔融金属的流动情况以及温度梯度与MIG焊有很大的不同,复合焊的焊缝组织比MIG焊的更加细小,接头处的也没有发现MIG焊接头中出现的等轴晶区.

Comparison of MIG welding and laser -MIG welding of high strength aluminum alloy

The 20 mm thick 2519-T87 high strength aluminum plates were welded by MIG welding and CO2 laser-MIG hybrid welding process.And the welding efficiency,microstructure and mechanical properties of welded joint were compared.Results indicarte that the efficiency of laser-MIG hybrid welding is 5 times of that of MIG welding,and the tensile strength of the joints has been improved,reaching 70% of the tensile strength of base material,while the tensile strength of MIG welded joints is only 60% of that of the base material.Because of the low heat input of laster-MIG hybrid welding,the condition of the fluid flow and temperature gradient are different from that of MIG welding,resulting in the finer microstructure in weld center,and the equiaxed zone near the bond line which often occurs in MIG welding disappears.