Corrosive Fretting Wear Behavior of a Titanium Alloy TC11 in Artificial Seawater

By using the ball-on-flat configuration at 30Hz frequency in SRV tribo-tester with various normal loads and amplitudes, the corrosive fretting wear behavior of a titanium alloy TC11 flat against a high carbon bearing steel counter ball was investigated in artificial seawater and distilled water respectively at room temperature for 1h. The worn surfaces of TC11 were observed by scanning electron microscopy (SEM) and analyzed by energy dispersive spectroscopy (EDS). The influences of the load, amplitude and aqueous medium on the friction coefficient and wear resistance of TC11 were analyzed. It is clear that the friction coefficient curve undulates in the fretting proceeding and fluctuates from 0.2 to 0.6 in the seawater, while it shows better stability in the distilled water which fluctuates from 0.5 to 0.6. The friction coefficient curve gets more stable as the amplitude decreasing in both the aqueous media. Results from the SEM and EDS analysis revealed that compared with that in distilled water, the lubrication surface film formed on the wear scar in the artificial seawater could reduce the friction coefficient greatly, even to 50%. The wear volume-loss of TC11 in the artificial seawater is always lower than that in the distilled water. It demonstrates the dominant roll action of the lubrication of seawater and therefore presents a negative synergy ratio between corrosion and wear. The wear mechanism of TC11 is delamination fatigue associated with abrasion at short amplitude, whereas it is only abrasive wear at long amplitude.