Effect of Laser Shock Peening on Commercially Pure Titanium-1 Weldment Fabricated by Gas Tungsten Arc Welding Technique

Abstract

This research work investigates the effect of laser shock peening (LSP) on commercially pure titanium grade 1 (CP Ti-1) weldment. The welding was done using gas tungsten arc welding (GTAW) with ERTi-2 filler wire. LSP was carried out on the cap surface of the weldment. The optical microstructure showed the Widmanstatten-type martensitic structure in the fusion zone (as-welded). The LSP fusion zone showed a refined microstructure compared to that of as-welded condition. Scanning electron microscope (SEM) of LSP weldment showed the indentation on the surface of the weld. This was a result of the surface ablation that occurred during LSP. X-ray diffraction analysis showed the absence of transformation of phases in the weldment. A reduction of 14.8% of crystalline size was observed in LSP weldment. A higher compressive residual stress was observed in LSP weldment than the as-welded condition. Tensile test showed the occurrence of failure in the base metal region in the case of LSP weldment, as against the failure in the case of as-welded condition in the fusion zone.