Analysis and Characterization of Axially Joined Friction-Welded Ti6Al4V Alloy Rods

The effect of process inputs in the friction welding of Ti6Al4V alloy rods was investigated through the analysis of residual stresses, microstructure, chemical phases and hardness testing of the weld joints. The rods were welded using different combinations of process inputs. The results revealed variations in residual stresses, hardness and microstructure of the weld joints when weld inputs were varied. Peak compressive residual stresses were obtained at the centre of the weld interface, where the grains were very fine. The joints with a greater volume fraction of martensitic grains had elevated residual stress values. The maximum compressive residual stress values were obtained at the weld interface, with high hardness results. A further investigation was conducted to study the relationship between the residual stresses, microstructure and mechanical properties of the weld joint.