EFFECT OF WELDING PROCESSES ON MICROSTRUCTURE OF Ti6Al4V WELDMENTS

Abstract

The titanium alloys are widely used in aerospace, highly corrosive environments and prosthetics. Among the titanium alloys, Ti6Al4V is used much, due to its high strength to weight ratio and its ability to easy fabrication. The Ti6Al4V has good weldability, but it is susceptible to hydrogen embrittlement. The welding technique used for fabricating the Ti6Al4V makes a significant effect in the microstructure of the weldments. The microstructural changes are significant, since it determines the properties, behaviour and reliability of the welded joints. This investigation was done to determine the changes in the microstructure of butt joints prepared from 3 mm rolled plates. The welding was done using Gas-TungstenArc Welding (GTAW) and Laser Beam Welding (LBW) processes. In both the processes argon with 99.9% purity was used for shielding, to avoid any contamination. In this investigation it was found that the Laser Beam Welding produced weldments with smaller heat affected zone and associated high hardness.