Microstructure, mechanical, and corrosion properties of electron beam-welded commercially pure titanium after laser shock peening

Surface properties play a critical role in the structural integrity of any component and this becomes even more critical for weld joints. Laser shock peening (LSP) is one of the non-contact methods which is getting popular in industries to enhance surface properties for improving service life, mainly fatigue of engineering components. In the present study, electron beam welding (EBW) of commercially pure (cp) titanium was carried out at constant line energy with varying scan speeds ranging from 1000 to 1600 mm/min and welding currents from 25 to 40 mA. The influence of the EBW parameters on microstructure, surface micro-hardness, tensile, and fatigue strength was investigated. The effect of LSP on mechanical and corrosion properties of EBW cp titanium was studied. LSP induced a significant amount of compressive residual stresses at the surface through plastic deformation and led to significant improvement in micro-hardness (7–10%) at the sub-surface region of the fusion zone due to finer grain structure. Further, appreciable enhancement in tensile strength (~ 15%) and fatigue life (~ 43%) due to strain hardening and changes in microstructure like twinning within grains was realized.