Effect of Dimple Texture on the Fretting Wear Behavior of Ti-6Al-4V under Dry and Oil-Lubricated Conditions

Abstract

This study investigated the fretting wear behavior of Ti-6Al-4V ball-on-flat laser-textured surfaces using a self-designed experiment platform. Dimple textures with area ratios of 10%, 30%, and 50% were tested under dry and lubricated conditions, 4 N and 20 N loads, and displacement amplitudes ranging from 25 μm to 200 μm. It was observed that under dry friction, textures did not alter the sliding regime. The energy wear rate increased monotonically with the area ratio under a load of 4 N, but it demonstrated an initially increasing and then decreasing trend under a load of 20 N due to the increased contact stress and restricted debris evacuation. Under oil lubrication, the synergistic effect of lubrication and surface texture modified the sliding regime, expanded the effective friction-reduction range, and shortened the running-in time. This synergy was load-dependent: low-area-ratio surfaces excelled under the low load, while high-area-ratio surfaces performed better under the high load due to the superior oil storage and load-bearing. Furthermore, lubrication complicated the wear mechanisms, with the energy wear rate governed by the coupling of load and displacement amplitude.