LAUSR

Homogenized intermetallic compound (IMC) layer at interface was achieved in laser-arc hybrid butt welded Al/steel dissimilar metals through beam oscillation. The beam oscillation reduced the macrosegregation of Fe element in the weld, which increased the uniformity of IMC layer by 443 times as its thickness variance (δ) decreased from 0.9767 to 0.0022. It was found that the tensile properties of weld were not only related to the thickness (τ) of IMC as claimed in most previous literatures, but also linked with its uniformity along interface. A new relationship between interface uniformity and tensile properties was established based on quantitative analysis of interface homogenization. The ultimate tensile strength was more than 130 MPa when δ ≤ 0.1156 and 0.9 μm ≤ τ ≤ 1.8 μm. Beam oscillation not only homogenized melt flow in molten pool, but also promoted to form turbulent flows at interface, which benefited for the interface homogenization.