Corrosion Performance of Medical Titanium Alloy with Different Surface Morphology

Abstract

[Objective] The purpose of this study was to evaluate the variation of surface morphology of titanium alloy after sand blasting with different particle sizes of Al2O3sand and acid etching, and its corrosion resistance property. [Methods] The surfaces of titanium alloy were first treated with the different sands and then acid etched with mixture of 18% HCl and 48% H2SO4. The morphology of samples was investigated by scanning electron microscopy (SEM). The potentiodynamic polarization curves of the various surfaces were obtained by electrochemical workstation (CHI 660E) in simulated body fluid (SBF). [Results and conclusions] It is observed that pore sizes on surface increases with the increase of sand grain diameter while there is no obvious change after acid etching. After sand blasting and acid etching, the corrosion resistance of titanium alloy was improved. However, as the pore size of the surface increases, the corrosion resistance gradually degrades and this becomes even more obvious after acid etching. The investigation of the corrosion rate indicates there is an increasing trend with the emergence of small pores.