Achieving ultra-low wear of Ti6Al4V alloy by introducing a sinusoidal nitriding layer via nanosecond pulsed laser irradiation

Abstract

Introducing wear-resistant layers or constructing microtextures is normally employed to improve the wear resistance of materials. However, single role of the wear-resistant layer or microtexture still could not effectively address the wear issue of titanium alloys. In this study, a sinusoidal nitriding layer is directly fabricated on the Ti6Al4V surface by one-step laser irradiation. Chemical composition and microstructure analysis indicate that the nitriding layer contains TiN and α-Ti phases, and it is metallurgically bonded to the heat-affected zone. Friction wear tests show a 96.9 % reduction in wear rate with dry sliding and 99.6 % with oil lubrication, without exhibiting groove orientation dependence. The wear mechanism is discussed by scrutinizing the morphology of the wear scars and their corresponding cross-sections.