Fretting Corrosion Wear of Titanium-Based Alloy (Ti-6Al-4V) in 0.9 wt.% NaCl Solution

Abstract

In this study, a high-precision fretting tribo-corrosion tester used to analyze the wear and corrosion behavior of Ti alloys in a fretting motion condition. The tester, operated in a ball-on-plate mode, was employed in the fretting corrosion study of metallic bio-materials (Ti and Ti-6Al-4V) under different loads (0 and 10 N), electrolytes (0.9 wt% NaCl and SBF) and fixed displacement frequency (1 Hz). Using profilometer, optical microscope in the experimental analysis and three-body mechanism in the theoretical analysis, the fretting corrosion performances of these biomedical metals, such as velocity accommodation characteristics, friction, wear, and scratch profile were examined in depth. The dynamic polarization curves indicated that under the same electrolyte and displacement amplitude the mass loss was more severe in fretting corrosion than in simple corrosion. Under different applied potentials -0.5 mVSCE, +0 mVSCE and +1.5 mVSCE, it was found that the friction coefficient and cross-sectional area of worn trace increased with the corrosion potential. Both the mechanisms of adhesive wear and fatigue wear contributed mainly to the wear loss of pure Ti while fatigue wear and abrasive wear were more responsible for the wear loss of Tie6Ale4V alloy.