Effect of nickel interlayer thickness on lap joint laser welding for aluminium-steel dissimilar materials
Tianyu Xu, Shaowei Zhou, Han Wu, Chunquan Hong, Xiuquan Ma
Abstract
Laser lap welding of steel and aluminium with different thickness nickel foil was carried out. The effects of nickel interlayer thickness (TNi) on penetration depth, phase transition, mechanical properties were investigated. As the TNi increased from 0 to 50 µm, the weld penetration depth was first increased and then decreased, reaching a maximum of 382 µm when TNi was 20 µm. There was a γ-phase transformed from δ-ferrite in welded nugget and the transformation of high-temperature δ-ferrite into austenite was promoted as the TNi increased. The shear resistance of the steel/Al joint reached the maximum value of 103 N mm−1 when TNi was 20 µm. Which was almost 92% higher than the strength of the joint without nickel foil added.