Tribochemical study of micropitting in tribocorrosive lubricated contacts: The influence of water and relative humidity

Abstract

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.

The evolution of hardness and tribofilm growth during running-in of case carburized steel under boundary lubrication

“…shown by Soltanahmadi et al [50]. Using a modified MPR, similar to the device used in the present study, the researchers provided evidence that micropitting surface area and abrasive wear increased with the amount of water present the lubricant [50].…”

“…Using a modified MPR, similar to the device used in the present study, the researchers provided evidence that micropitting surface area and abrasive wear increased with the amount of water present the lubricant [50]. The variance in tribofilm development due to environmental and operating conditions indicate close attention must be paid to the design of running-in with respect to tribofilms.…”

The evolution of hardness and tribofilm growth during running-in of case carburized steel under boundary lubrication

“…to affect the time in which tribofilm thickness reached a steady state as all conditions maximized film thickness around 30 minutes of rubbing time. The influence of water within a tribosystem negatively impacts the effectiveness of the tribofilm which was shown by Soltanahmadi et al[50]. Using a modified MPR, similar to the device used in the present study, the researchers provided evidence that micropitting surface area and abrasive wear increased with the amount of water present the lubricant[50].…”

“…The influence of water within a tribosystem negatively impacts the effectiveness of the tribofilm which was shown by Soltanahmadi et al[50]. Using a modified MPR, similar to the device used in the present study, the researchers provided evidence that micropitting surface area and abrasive wear increased with the amount of water present the lubricant[50]. The variance in tribofilm development due to environmental and operating conditions indicate close attention must be paid to the design of running-in with respect to tribofilms.…”

Surface Reaction Films from Amine-Based Organic Friction Modifiers and Their Influence on Surface Fatigue and Friction

“…multiple region analysis, incorporated in Vision64 software was used to quantify surface fatigue damageto understand and compare the OFM performance. This technique is explained in our previous paper [7]. A Carl Zeiss Supra 55 Field Emission Gun (FEG) and a Carl Zeiss EVO MA15 Scanning Electron Microscope (SEM) were used to examine wear scars/rolling tracks and surface reaction films in wear scars/rolling tracks.…”