Experimental investigations on rolling contact fatigue of artificially dented surfaces under grease elastohydrodynamic lubrication

摘要

The first aim of this work was to analyse the use of artificial dents as a technique to evaluate rolling contact fatigue (RCF) performance. The second aim was to study the influence of grease composition on RCF damage using the artificial dents technique. A tribological investigation with three greases and corresponding base oils was conducted. The following parameters were varied: base oil viscosity, percentage of soap composition and the presence of additives. Tests were carried out on a twin-disc machine originally designed for tests using oils and later re-designed to allow tests using greases. Artificial dents were printed on the surface of one of the contacting discs and the damaged area around the dents was analysed using video-microscopy. It was found that tests using different lubricants resulted in different damaged areas around the dents. Based on this, a comparison of this area growth throughout the fatigue cycles was used as a way to compare the influence of grease composition on RCF.