Strengthening mechanism of Nd: Yag laser shock peening for commercially pure titanium (CP-TI) on surface integrity and residual stresses

In the present work, an attempt has been made to investigate the effect of generating shock waves through direct and confined ablation modes of plasma method of massive laser shock peening (MLSP) on surface integrity of cast dumbbell shaped and cylindrical cast specimens of commercially pure titanium (CP-Ti) and to compare with those of untreated CP-Ti. The MLSP is usually performed in a massively peening mode to induce uniform compressive residual stress and surface deformation across the entire specimens. After MLSP, tensile testing was carried out to obtain the tensile strength, modulus of elasticity and percentage elongation. The microstructural and surface topography investigations of the laser shock peened material were carried out using digital, optical microscopy and SEM equipped with an energy dispersive spectrometer (EDS) and XRD. The results show that laser shock peened with confined ablation make the surface of CP-Ti with improved change in microstructure, increase in tensile strength, microhardness (73.08%), surface roughness and compressive residual stresses (-420 MPa) which prolongs the mastication ability and dimensional stability of dental implant restorative materials. (C) 2019 Elsevier Ltd. All rights reserved.