Microstructure, mechanical and electrical properties of laser-welded overlap joint of CP Ti and AA2024

The study results of an overlap welded joint of Commercially Pure Titanium Grade 4 (CP Ti) and Aluminum-Copper Alloy 2XXX series (AA2024) obtained by laser welding without defects in the form of pores and cracks are presented. A microstructure using optical and scanning electron microscopes, a phase composition using X-Ray Diffraction, an electrical resistivity of welded joints were studied. It was found that at tensile shear strength (TSS) testing, failure occurs not only in the brittle intermetallic zone of the welded joint but also in the columnar heat affected zone (HAZ) of aluminum. A 1% of titanium does not have time to diffuse from the HAZ of aluminum at a higher welding speed (150 mm/s), whereas, at a speed of 20% less titanium is not observed in the HAZ of aluminum. The tensile shear strength of samples welded on the titanium side is in the range of 80-120 MPa, depending on the rate of input energy.