Deoxidized oxygen free copper C12200, 1 mm in thickness, was welded to 1-mm thick AISI 304 stainless steel with disk laser. The butt-welded joints were produced with different welding parameters. Full factorial design of experiment (DoE) approach consisting of three factors and two levels was utilized. Laser powers used for welding were 1.3 and 1.9 kW and welding speeds of 20 and 30 mm/s. Two beam offsets were tested, namely, 100 μm toward copper side and 200 μm toward AISI 304 steel. It was found that beam offset possesses the largest influence on the welded joints’ tensile strength. Tensile strengths attained values more than 3.7 times higher in comparison to the AISI 304 steel beam offset. When lower laser power was used, the higher tensile strength was attained for copper sheet offset. Higher microhardness was observed when laser beam was offset to AISI 304 steel side. The average microhardness of the weld metal was higher than that of the weaker base material, copper sheet. Energy dispersive X-ray spectroscopy (EDS) analysis confirmed the heterogeneity in elemental composition across the welded joint interface, being lower when laser beam was offset to AISI 304 steel side. On the other hand, the copper content dropped to the average composition of weld metal at the distance of about 140 μm from copper-weld metal interface.

An innovative Wire and Arc Additive Manufacturing combines the well-studied process of arc welding with direct energy deposition. Effect of travel speed 5.0 and 7.5 mm/s on the microstructure and mechanical properties of 5087 aluminum alloy was investigated. Five thousand eighty-three aluminum alloy was used as a substrate material and 5087 aluminum alloy was utilized as a filler material for the walls fabrication. The presence of pores reducing the strength of the overlay weld metal was detected on both overlay welds. The lower welding speed (5 mm/s) resulted in the smaller amount of porosity in comparison to higher welding speed (7.5 mm/s). Average pore area of wall No. 1 was 0.66% and wall No. 2 was 1.13%. It was found that higher welding speed affected the wall width and overlay weld bead geometry. Increase in welding speed led to a narrowing of wall width from 10.23 to 8.44 mm. The microstructure of weld metal matrix consisted of a α-Al substitution solid solution. The tensile strength of parallel to welding direction removed samples exceeded the tensile strength of perpendicular removed samples. It is a result of the cohesion of the layers in the overlay welding direction compared to the non-uniformity of the layers in the perpendicular direction. Furthermore, the tensile strength was higher in the case of travel speed of 5 mm/s in comparison to that of 7.5 mm/s.

In this article, the effect of process parameters on the microstructure and mechanical properties of AW5083 aluminum alloy weld joints welded by a disk laser were studied. Butt welds were produced using 5087 (AlMg4.5MnZr) filler wire, with a diameter of 1.2 mm, and were protected from the ambient atmosphere by a mixture of argon and 30 vol.% of helium (Aluline He30). The widest weld joint (4.69 mm) and the highest tensile strength (309 MPa) were observed when a 30 L/min shielding gas flow rate was used. Conversely, the narrowest weld joint (4.15 mm) and the lowest tensile strength (160 MPa) were found when no shielding gas was used. The lowest average microhardness (55.4 HV0.1) was recorded when a 30 L/min shielding gas flow rate was used. The highest average microhardness (63.9 HV0.1) was observed when no shielding gas was used. In addition to the intermetallic compounds, β-Al₃Mg₂ and γ-Al₁₂Mg₁₇, in the inter-dendritic areas of the fusion zone (FZ), Al₄₉Mg₃₂, which has an irregular shape, was recorded. The application of the filler wire, which contains zirconium, resulted in grain refinement in the fusion zone. The protected weld joint was characterized by a ductile fracture in the base material (BM). A brittle fracture of the unshielded weld joint was caused by the presence of Al₂O₃ particles. The research results show that we achieved the optimal welding parameters, because no cracks and pores were present in the shielded weld metal (WM).