Mechanical and Electrochemical Corrosion Behaviors of Porous Ti-6Al-4V Alloys Prepared by an Electrochemical Sintering Approach

Abstract

Titanium alloys have been widely used in bone implants, but the mechanical properties, elastic modulus mismatch between bone and metal, and stress shielding effects can occur. However, porous materials can effectively overcome this problem. In recent years, porous structures have attracted enough attention from researchers. Adjustment of the porous structure may make the titanium alloys better able to meet the requirements of the implant. In this study, we have successfully prepared Ti-6Al-4V alloys by combining powder metallurgy with electrolysis in molten salt. At the same time, CaCl2 was used as a sacrificial space holder to adjust the porosity and porous structure. The Ti-6Al-4V alloys prepared by this method contain 29-60% porosity and elastic modulus has been controlled between 1.8 GPa to 7.8 GPa, which is suitable for cancellous bone, trabecular, and other parts with low elastic modulus. In addition, the higher porosity also showed better corrosion resistance in the Hank’s solution. The potentiodynamic polarization curves show that the corrosion resistance increases significantly with an increase in porosity.