Change of Coefficient of Friction due to Ageing of Biological Esters

Abstract

In order to investigate the influence of a single tribo system on the ageing of lubricants, a so-called Tribo-Oxidationtest has been designed at IFAS. It consists of a disc on disc tribometer integrated into the pressure vessel of an oxidation test according to ASTM D 2112. The coefficient of friction μ of different friction partners is discussed in this paper. The attempts are done with biological esters which are synthesized in a collaborative research centre. Due to biological aspects they contain no additives. It has been shown that there is an influence of oil ageing on friction coefficient but also a big influence of viscosity on friction coefficient.