Electron Beam Welding Studies on Nb-Hf-Ti Refractory Alloy

Niobium, a refractory metal is mainly used as alloying addition in steels, superalloys, titanium and copper alloys. Being lightest refractory metal with high melting temperature, niobium based alloys are developed for high temperature applications of aerospace systems. However, poor oxidation resistance at elevated temperature limits its fabrication options and also requires oxidation protection in service. Among the fabrication methods, electron beam welding has been found to be a realistic option and the same has been studied in the present work. The paper presents the details of the Electron Beam Welding study carried out in developing the welding procedure for this alloy. An attempt has been made to correlate the weldment microstructure with the mechanical properties.