On the Effect of Nano-particles on Real Area of Contact, Friction and Wear

Conference Name: Society of Tribologists and Lubrication Engineers (STLE)
Location: St. Louis, MO
Date: 5/2012

List of Authors:

Hamed Ghaednia, Rober L. Jackson

Abstract

The nanoparticles suspended in lubricants (nano-lubricant) can alter the tribology of the contacting rough surfaces. The active mechanisms of the particles are divided into two main categories. Particles can affect the bulk properties of the lubricant or particles can actively participate inside the contact region. The former mostly affects the full film lubrication cases whereas the latter is more important for the boundary lubrication regime. In the boundary lubrication regime the mechanisms which govern particles performance are uncertain. The goal of this study is to investigate particles operating in the boundary lubrication regime using a contact model that considers the effects of size, distribution and concentration. The model employs a statistical method for the nanoparticles inside the contact region and a multi-scale method for rough surface contact. Comparison with friction and wear tests suggest that the friction coefficient is altered as the result of changes in the real area of contact and that wear is mostly governed by peak pressures in the particle/substrate interface.