SUS321不锈钢和6061铝合金激光搭接焊接头的组织和力学性能

焊接参数对钢铝异种接头质量影响明显。主要研究不同的激光功率和焊接速度对SUS321不锈钢和6061铝合金焊缝成形的影响,分析异种接头的微观形貌特征及组成,并对接头的断口形貌和力学性能进行了试验研究。结果表明,不同焊接速度和激光功率对于焊缝成形有着重要影响:当激光功率为2 200~2 400 W,焊接速度为30~35 mm/s时可以获得质量较高的焊缝;在焊接过程中,接头界面形成了FeAl、Fe_2Al_3和Fe_3Al等金属间化合物,它们的存在影响了接头的力学性能;接头在拉伸试验中发生韧性断裂,且裂纹最先在金属间化合物中萌生,并沿着钢铝反应界面进行扩展,直至整个接头发生断裂。

Microstructure and mechanical properties of welded joints of laser lap welding for SUS321 stainless steel and 6061 aluminum alloy

Welding parameters have an important influence on the quality of dissimilar joints.In this paper,the effects ot laser power and welding speed on the weld formation of SUS321 stainless steel and 6061 aluminum alloy were studied.The morphology and composition of the dissimilar joints were analyzed,and the fracture morphology and mechanical properties were studied.Through welding test,it is found that different welding speed and laser power have important influence on weld formation.When the laser power is from 2 200～2 400 W and the welding speed is about 30～35 mm/s,the weld with higher quality can be obtained.In the welding process,intermetallic compounds such as FeAl,Fe2Al3 and Fe3Al are formed at the interface of the joints,and their existence influences the mechanical properties of the joints.Ductile fracture occurs in the tensile test,and the crack initiates in intermetallic compound and expands along the steel aluminum reaction interface until the joint is broken.