Ageing has been known to affect the performance of lubricants. However, there is a lot of debate as to whether ageing is beneficial or detrimental to the wear performance of lubricants.
The purpose of this research is to evaluate the effect of ageing on the viscosity, total acid number and Fourier-transform infrared spectroscopy information of a series of lubricants. The tribological performance (friction and wear) of the aged lubricants is also studied, followed by X-ray photoelectron spectroscopy analysis on the selected post-test samples to study the tribochemical features of the tribofilm.
The results show that ageing has a different impact on lubricants and tribological performances based on the physical and chemical properties.
These findings will be compared with the research on the role of water in lubricant ageing (Part II of this study).
