A comparative evaluation of friction and electron beam welds of near-α titanium alloy

Electron beam and friction welding studies have been carried out on a TIMET 834 a near-α titanium alloy. The study was also focused on the post-weld heat treatment aspects and their influence on mechanical properties. The influence of parent metal microstructure on the toughness has been evaluated to explain the trends observed on the toughness of welds. Electron beam welds contained micro-porosity while friction welds were free from such solidification related defects. Friction welds exhibited very fine equiaxed prior β grains as compared to electron beam welds. Electron beam welds exhibited better creep and stress rupture properties and marginally higher strength. The impact toughness of both the welds was comparable. Post-weld ageing of welds resulted in reduction in impact toughness due to precipitation of silicides along the martensite lath boundaries.