Microstructure characterization and mechanical properties of linear friction welded Ti-6Al-4V alloy

Microstructure characterization and mechanical properties of linear friction welding (LFW) Ti-6Al-4V alloy welded under an appropriate condition have been reported. Typical microstructure of the Ti-6Al-4V consisted of a bimodal structure in the form of elongated grains and intergranular mixture of lamellar grains. It was observed that a sound weld could be obtained under specific processing parameters. An obvious flash consisting of many small ridge was observed as a result of the oscillating extrusion process during LFW. A very thin weld of around 65-115 μm was formed with a superfine bimodal microstructure and much limited thermomechanically affected zone (TMAZ), which is associated with the quick heating and cooling processes involved in LFW. It was also observed that the tensile properties of LFW processes Ti-6Al-4V alloy were comparable to or higher than those of the parent Ti-6Al-4V alloy because the fracture occurred in the parent material.