Tribological Investigation of Wear-Resistant Friction Pairs for Miniature Linear Ultrasonic Motors

To solve the drawbacks of conventional long-cycle wear tests for miniature standing- wave linear ultrasonic motors, an accelerated equivalent wear model and test system were proposed in this work. After primary screening of multiple friction pair materials, graphite and Al2O3 were adopted to modify epoxy films. The optimal friction pair is composed of 6061 hard anodic oxidation film and ECA105 composite film. The matched pair exhibits excellent driving stability and low wear loss, with fatigue wear as the main wear form. Graphite and Al₂O₃ exert synergistic anti-wear and load-bearing effects via forming a stable transfer film on the friction interface. Experimental results confirm that the accelerated test is equivalent to full-life durability test. The presented method and optimized friction pair can effectively guide the development of high-performance ultrasonic motors.