Dry Sliding Tribological Behavior of TC11 Titanium Alloy Subjected to the Ultrasonic Impacting and Rolling Process

The dry sliding friction and wear behaviors of TC11 titanium alloy subjected to the ultrasonic impacting and rolling process (UIRP) were studied in the present work. The microstructure of the deformation layer and the morphology of the worn surfaces were observed. The results clearly show that the wear performance of TC11 alloy after UIRP is better than that of TC11 alloy before UIRP under the same testing conditions. This can be attributed to the gradient nanostructure, work hardening, and low surface roughness of the treated surface layer. For the untreated samples, wear resistance first decreases and then increases with the increase of the sliding speed. Both the friction coefficient (FC) and wear rate reach a maximum value at a sliding speed of 478 r/min, and the corresponding worn surface is the most serious. While for UIRP treated samples, better friction and wear behaviors are obtained at a sliding speed of 478 r/min. This is because the deformation layer plays a protective role against wear