Influence of the Lubricating Grease on the Properties of Fretting Friction and Wear of an Applicative Metallic Material(<Special Issue>M & P 2009 The 9th Materials and Processing Conference)

Abstract

Objective of the present experimental investigation is to clarify the influence of the moist air relative humidity (RH=10-70%) on the properties of fretting friction and wear of steels under grease lubrication. Ball (bearing steel, JIS SUJ 2) on disk (carbon steel, JIS S15C) type fretting tests, for various amounts of grease supplied before each test at the punctual contact between ball and disk, were conducted at 50μm relative slip amplitude. Maximum values of the friction coefficient and the disk wear rate decrease at augmentation of the grease amount. Wear rate appears as unaffected by the RH variation for an amount of grease exceeding 0.02g, this representing the minimum amount necessary to avoid the grease film breakdown.