Tribology in Full View

Northwestern University, Evanston IL

Investigators

Abstract

The primary focus of the proposed work is a combination of in-situ transmission electron microscopy studies of sliding surfaces and materials-science based modelling of the nanoscale processes taking place in the triboactive region using primarily dislocation-based analytic models. The main focus of the experimental work will be to directly resolve in real time the processes taking place, ranging from the motion of dislocations and sliding of interfaces to tribologically induced chemical or structural transitions. This will exploit all the different modes of electron microscope imaging ranging from conventional low-resolution imaging through electron-energy loss spectroscopy to atomic scale imaging. The thrust of the analytical component will be to marry conventional materials science ideas such as the effect of barriers on dislocation motion with what is taking place in the triboactive layer, to develop parameter-free analytic models which have predictive power so can be used in the future to estimate what will be taking place in new tribological problems or systems. If successful, the work will establish a solid materials science foundation for tribological processes taking place at the nanoscale in the triboactive region. In addition, the theoretical models and the predictive analytical models can be then used to estimate issues in real engineering situations, leading to rational designs to reduce frictional energy losses and improve the reliability of mechanical systems at the nanoscale. In terms of education, the research will help support both local outreach to high-school students as part of the existing programs with Chute and Nichols Middle Schools and the HANDS program in Evanston, as well as more international outreach efforts involving efforts to run schools and workshops on electron crystallography in places such as Mongolia, Qatar and South Africa via the International Union of Crystallography.