28 research outputs found
Tribochemical Study of Micropitting in Tribocorrosive Lubricated Contacts: The Influence of Water and Relative Humidity
Water ingress into the lubricant as a contaminant affects performance leading to an alteration in wear, corrosion and fatigue behaviour of the tribological components especially in the rolling element bearings. The current study addresses the tribochemical phenomena involved in micropitting in tribocorrosion systems where different levels of dissolved-water are present in a model lubricant. In this study the effect of different temperatures, water concentrations and relative humidities have been investigated on micropitting under rolling-sliding contacts. The influence of free and dissolved water on tribocorrosive micropitting is clarified. The tribochemical change of the reaction films is studied using X-ray Photoelectron Spectroscopy (XPS) which confirmed that the (poly)phosphate chain length and tribofilm thickness are reduced with increased dissolved-water level
Evolution and phylogeny of the New Zealand cicada genus Kikihia Dugdale (Homoptera: Auchenorrhyncha: Cicadidae) with special reference to the origin of the Kermadec and Norfolk Islands' species
Further studies of the test-tube agglutination test for the diagnosis of Bang's disease (contagious abortion)
This archival publication may not reflect current scientific knowledge or recommendations
Studies of the test tube agglutination test for the diagnosis of Bang's disease (contagious abortion)
This archival publication may not reflect current scientific knowledge or recommendations
An experimental and analytical study of the effect of water and its tribochemistry on the tribocorrosive wear of boundary lubricated systems with ZDDP-containing oil
Water has long been recognised as a contaminant in lubricants. It can affect wear performance, especially in bearing systems, in complex ways. Water can also induce corrosion, which in turn can enhance wear. The individual parts of any tribocorrosion system are related to a complex mix of system parameters such as lubricant and additives, relative humidity and temperature. The effect of different water concentrations and different temperatures has been studied experimentally in this work. A modification to Archard[U+05F3]s wear coefficient was applied with respect to the experimental measurements. The new wear model considering the effect of water was implemented into the previously-reported numerical model to develop a new semi-deterministic numerical wear model adapted to the tribo-corrosion system in this work