Microstructure and mechanical properties of dissimilar metal joints of copper/aluminum using FeCoCrNiMn filler material

• Published in: Welding in the world Vol. 68; no. 3; pp. 543 - 555
• Main Authors: Liu, Dejia, Ni, Chongling, Ma, Zhe, Li, Bin, Tang, Yanchuan, Wang, Xiangjie
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2024; Springer Nature B.V
• Subjects: Alloy powders; Aluminum; Chemistry and Materials Science; Copper; Dissimilar material joining; Dissimilar materials; Dissimilar metals; Fillers; Hardness; High entropy alloys; Intermetallic compounds; Laser beam welding; Laser deposition; Materials Science; Mechanical properties; Metal joints; Metallic Materials; Research Paper; Solid Mechanics; Tensile strength; Theoretical and Applied Mechanics; Welded joints; Welding parameters; FeCoCrNiMn high-entropy alloy; Dissimilar metal welding; Laser deposition welding; Microstructure; Hardness; Tensile strength
• ISSN: 0043-2288; 1878-6669
• DOI: 10.1007/s40194-023-01608-1

FeCoCrNiMn high-entropy alloy powder was used as the filler material to achieve the dissimilar metal joining of pure copper to pure aluminum through laser deposition welding. The feasibility of using FeCoCrNiMn filler material for dissimilar metal welding of copper/aluminum was investigated. It was found that a dissimilar joint without defects, such as cracks or pores, could be achieved using FeCoCrNiMn filler material with the appropriate welding parameters. An environment with a high mixing entropy (
ΔS
mix
) value was achieved in both the weld center and the weld zone on the copper side. However, in the weld zone near the aluminum side, a significant amount of Al was introduced, resulting in the formation of Al-Cu intermetallic compounds. Extremely high hardness, reaching 710 HV
0.1
, was found in the weld zone located ~ 375 μm away from the welding interface on the aluminum side. The tensile sample was fractured near the region with extremely high hardness, which resulted in a low tensile strength (~ 51 MPa) for the welded joint using FeCoCrNiMn filler material. Cleavage steps and tearing ridges were observed in the fracture morphology.
Graphical Abstract