Influence of Electron Beam Welding Parameters on the Microstructure Formation and Mechanical Behaviors of the Ti and Ni Dissimilar Metals Welded Joints

Commercially pure titanium Ti Grade 2, 2 mm in thickness, was welded to thick nickel alloy 201 with electron beam welding. Various welding parameters were used create the butt-welded joints. The innovation herein consists of two dissimilar metals that are declared non-weldable. current for 40–70 mA and speeds 20–50 mm/s. In this experiment, we tested offsets beam, which 100–300 μm side 200 side. It observed offset had no effect on weld joint’s strength. samples subjected a visual test longitudinal transverse cracks recorded along whole weld. Only four retained integrity joint. Microstructures joints examined by scanning confocal microscopy. Energy dispersive spectroscopy (EDS) analysis confirmed phase constitution inside regions fusion interfaces. Tensile strength microhardness tests evaluate mechanical Ti/Ni results showed cracking brittle Ni–Ti intermetallic phases occurred. microstructure zone’s center part primarily NiTi Ti2Ni. No clear correlation found between heat input or parameters—welding speed—and tensile strain–tensile curve resulted fracturing. hardness zone five times higher than base metal heat-affected zone. amount into is as critical large asymmetry transport controls process solidification from each metal.