Evaluating the effects of hydroxyapatite coating on the corrosion behavior of severely deformed 316Ti SS for surgical implants

The present work investigates the effects of severe plastic deformation by cold rolling on the microstructure, the mechanical properties and the corrosion behavior of austenitic stainless steel (SS) 316Ti. Hydroxyapatite coating (HA) was applied on the deformed material to improve their corrosion resistance. The martensitic transformation due to cold rolling was recorded by X-ray diffraction spectra. The effects of cold rolling on the corrosion behavior were studied using potentiodynamic polarization. The electrochemical tests were carried out in Ringer's solution at 37±1°C. Cold rolling markedly enhanced the mechanical properties while the electrochemical tests referred to a lower corrosion resistance of the deformed material. The best combination of both high strength and good corrosion resistance was achieved after applying hydroxyapatite coating. •Cold rolling markedly increases the hardness of SS 316Ti from 125 to 460 HV10.•Higher deformation degrees lead to lower corrosion resistance.•Application of HA-coating leads to significant improvement of the corrosion resistance.