Friction and wear on titanium alloy surface machined by ultrasonic vibration-assisted milling

Abstract

With the development of the feasibility study on ultrasonic vibration-assisted machining in difficult cutting materials, its surface microstructure and the use performance get more and more attention. In this paper, the 3D roughness and surface residual stress are analyzed based on the experiments of common milling (CM) and ultrasonic vibration-assisted milling (UVAM) TC4 titanium alloy. Besides, the surface friction and wear properties machined by CM and UVAM are compared. The results show that, although arithmetic average deviation ($${s_\mathrm{a}}$$) and root-mean-square deviation ($${s_\mathrm{q}}$$) increase slightly because of the high-frequency vibration, the uniformity and consistency of the surface texture improve obviously. Moreover, the surface residual compressive stress increases with the increasing of the ultrasonic current. Additional, the friction coefficient and wear volume are reduced obviously by the surface microstructure machined by UVAM under oil lubrication. Because there are many continuous pits distribution on the surface, which can not only store the debris but also generate the hydrodynamic effect. However, there is no obvious difference in surface tribological properties machined by CM and UVAM under dry friction, due to the disappearance of hydrodynamic effect.