In-vitro characterization of boronized titanium alloy by means of corrosion and electrochemical impedance spectroscopy methods in simulated body fluids

Titanium and titanium alloys are becoming the backbone of medical implants and prosthetics. Titanium alloys are used because of its high biocompatibility and similarity to bone. However, titanium and titanium alloys have a low wear resistance. Titanium and titanium alloys are susceptible to particle erosion, which can cause inflammation, infection, and even implant rejection. Boronizing titanium alloy improves titanium\u27s wear resistance and also improves corrosion resistance. The target of this research was to characterize the corrosion characteristics of both unboronized and boronized titanium using both electrochemical corrosion methods and Electrochemical Impedance Spectroscopy (ELS) in simulated body fluid. Using electrochemical methods the corrosion rate of boronized titanium decreased from 1.5 x 10-4 MPY to 8.67 x 10-5 MPY, while the corrosion rate of unboronized titanium decreased from 1.62 x 10-4MPY to 3.42 x 10-6MPY. Unboronized titanium alloy exhibited pining corrosion while boronized titanium remained unchanged. BIS testing for boronized titanium alloy proved the existence of a protective layer, while the unboronized titanium alloy exhibited the formation of a passive layer over the course of testing. Moreover, boronized titanium alloy has shown an ability to withstand corrosive environments and pitting corrosion, which was not seen in unboronized titanium alloy