Laser shock peening of laser powder bed fusion produced Ti6Al4V for potential improvements to implant performance

Abstract

Titanium alloy based implants are becoming more common with medical advancements and longer global life expectancy. With its geometrical design freedom, low material wastage, and mass customisation, additive manufacturing has found growing use in biomedical applications. In this study, laser shock peening without coating (LSPwC) was investigated as a means to enhance the surface and mechanical properties of selective laser melted Ti6Al4V implants. The application of LSPwC was found to induce a favourable surface oxide layer, increase the measured surface roughness and hardness, and reverse the tensile residual stresses imparting deep, high-magnitude compressive residual stresses. The combination of oxide layer, increased roughness, and induced compressive stress will potentially improve implant osseointegration and increase fatigue life.