Surface modification of biomedical titanium alloy using hydroxyapatite-fine particle peening

In this study, a hydroxyapatite (HAp) surface layer was generated at room temperature on a beta-titanium alloy (Ti-29Nb-13Ta-4.6Zr, TNTZ) for use in bio-implants using fine particle peening (FPP) by transfer and microstructural modification of the shot particles. The elemental composition and thickness of the HAp layer on TNTZ followed by aging tended to increase with the FPP treatment time. The rate of increase in the HAp layer thickness in TNTZ followed by aging was lower than that in solution-treated TNTZ. In addition, FPP using HAp shot particles formed a work-hardened layer with high compressive residual stress on TNTZ followed by aging.