Electron Beam Welding and Gas Tungsten Arc Welding Studies on Commercially Pure Titanium Sheets

Commercially pure titanium (CP-Ti) sheets have been welded through gas tungsten arc welding (GTAW) using Ti6Al4V-ELI filler wire and through electron beam welding (EBW). Microhardness is found to be higher in the weld fusion zone as compared to the parent metal. The strength of the weldments of GTAW and EBW are found to be nearly same. Although GTAW weldments are expected to exhibit lower strength compared to that of EBW, the use of Ti6Al4V-ELI filler wire contributed to a higher strength in the GTAW weldment. Failure of the tensile test specimens was found to occur in the parent metal indicating the weld efficiency ~100% in both the cases. However, a marginal reduction in ductility of welded samples is observed. Widmanstätten microstructure is observed in the weld fusion zone of both the weldments. The microstructure is found to be relatively finer in EBW which is attributed to the lower heat input and higher cooling rate as compared to that in GTAW. Coarse and fine dimples are observed in the fractographs of the tensile tested samples indicating good ductility in both the weldments.