University of Alberta, Canada
Dr. D.Y. Li is a professor at department of Chemical & Materials Engineering and an adjunct professor at the department of Biomedical Engineering, University of Alberta. His research interests include surface science and engineering, tribology and materials, computational materials science, photocatalysts, and bacteria-metal interfaces. Dr. Li has more than 250 publications including in excess of 200 refereed journal publications. Dr. Li is the editor-in-chief of the International Journal of Nano & Biomaterials and a member of editorial board for seven other journals in areas of materials, tribology, wear, and corrosion.
Properties of materials are fundamentally dependent on their electron state, which is largely reflected by the electron work function (EWF). A higher work function corresponds to a more stable electronic state with a higher resistance to any attempt of changing the state or related states of a material, such as crystal structure or microstructure caused by mechanical and electrochemical processes. In this talk, close correlation between EWF and material properties will be demonstrated. With this simple characteristic parameter, many material intrinsic properties and processes could be analyzed without involving complex theoretical treatments. Particular attention will be put on the possibility of using EWF as a fundamental parameter for material design, which provides information or clues in a simple or straightforward way for material modification and development. Using Cu-Ni alloy as an example, the correlation between the electron work function (EWF) and mechanical and tribological properties will be demonstrated. One may see that properties of the alloy vary with the electron work function when composition changes, implying that properties of a material can be modified using elements with appropriate work functions. This should also be applicable for tailoring inter-phase boundaries or interfaces.