Simulation and Experimental Investigation of Tortional Wear Corrosion at Constant Temperature

In order to reveal the wear and corrosion characteristics of metal materials under torsional contact in liquid medium at constant temperature, a new device for torsional wear corrosion test was developed. Using the test system, torsional wear corrosion tests of Ti6Al4V were carried out in saline solution at 37℃ under a normal load of 50 N, a torsional angular displacement amplitude of ±3°, and a frequency of 0.5 Hz. The results showed that the friction torque curves of the Ti6Al4V alloy in saline solution could be divided four stages: the friction torque was very low at first; it increased gradually to a peak value; after the peak, it decreased slightly; and then increased gradually to a relatively stable value at last. Three types of torques vs angular displacement curves in shapes of line, elliptical, and quasi-parallelogram presented during the tests. At the beginning of torsion, the free corrosion potential of the Ti6Al4V alloy had a rapid negative shift, followed by a slow positive shift to a relatively stable value lower than before torsion. Simultaneously, the corrosion current increased rapidly and then decreased to a relatively stable value higher than before torsion. The damage of Ti6Al4V alloy was typically caused by coupled wear and corrosion.