Effect of Scan Strategy on Dissimilar Bi-Metal Cladding through Laser Directed Energy Deposition: A Numerical Study

Bi-metallic components having diverse properties are essential for improved functionality in hot-condition applications such as aeroplanes, boilers, and nuclear reactors. Hybrid components such as copper-steel (SS316) with improved thermal conductivity and high strength are attracting attention for their improved thermal performance. However, cladding of Cu on SS316 using laser-directed energy deposition (L-DED) is challenging due to differences in their thermo-physical properties, resulting in residual stress and distortion. While various studies exist for scanning strategies on similar metal deposition, there is limited literature for dissimilar bi-metallic cladding using L-DED. In this study, a one-way coupled thermo-mechanical analysis has been performed using Finite Element Method (FEM). SS316 steel is taken as the substrate, and copper is the deposited part. The analysis is performed for six different scanning patterns: raster, zig-zag, alternate line, out-in spiral, in-out spiral and a novel S scan. The peak and average temperature are calculated for six different scanning strategies and correlated with the residual stresses and warpage. The results provide insight into the effective scanning strategies for dissimilar bi-metallic cladding with reduced residual stresses and warpage.