Effects of laser shock peening with contacting foil on micro laser texturing surface of Ti6Al4V

Ti6Al4V samples with micro-dimple arrays were subjected to laser shock peening in contact with foil (HCLSP). The surface roughness, micro-hardness, the residual stress distribution and the surface morphology of the micro dimple arrays were studied to evaluate the effects of HCLSP. Moreover, the surface topography of the foils in contact was also analyzed. The gap existence between the foil and the to-be treated surface led the mechanism of HCLSP to be different compared to regular laser shock peening. The surface roughness reduction, the work hardening effects, the compressive residual stress and the micro crack enclosure were achieved. A simplified ball hitting-surface model was utilized to analyze the HCLSP impact. The model could well explain the experimental results. When treated by the HCLSP with H62 foil at the laser power density of 4.24 GW/cm(2), the Ti6Al4V samples with micro-dimple arrays exhibit well surface topography and mechanical performance. (C) 2017 Elsevier Ltd. All rights reserved.