Abstract
Lubricant additives are chemical compounds that are added to lubricating fluids to enhance their performance. Sulfur-containing additives are an important family of these compounds that increase the life of mechanical components by creating protective films on surfaces in relative motion to prevent direct metal-metal contact. These additives are widely used in the industry whenever a mechanical system is subject to extreme pressure or wear, but the mechanisms and conditions by which they form protective films are not yet fully understood. This dissertation seeks to address this from an atomistic point of view by investigating the tribochemical reactions between additives and surfaces using reactive molecular dynamics simulations. Overall, the results presented in this dissertation contribute to improving the understanding of the mechanisms by which sulfur-containing additives function and are an important step towards rational design of lubricants for more energy efficient and longer lasting mechanical systems.

Biography

Karen Mohammadtabar is a Ph.D. candidate in the Department of Mechanical Engineering. Karen joined Martini Research Lab (fundamental tribology) in 2017. Karen received his B.Sc. in Physics from the University of Tehran and his M.Sc. in Physics from The University of Akron, Ohio. Karen’s research focuses on investigating the mechanisms of film formation from tribochemical reactions on surfaces in relative motion and the effects of operational conditions such as temperature and contact pressure on reaction rates and pathways.