Effects of surface chemical modifications on the adhesion of metallic interfaces. An high-throughput analysis

Abstract

Chemical interactions between two surfaces in contact play a crucial role in determining the mechanical and tribological behavior of solid interfaces. These interactions can be quantified via adhesion energy, that is a measure of the strength by which two surfaces bind together. Several works in literature report how the presence of chemisorbed atoms at homo- and heterogeneous solid-solid interfaces drastically change their proprieties. A precise evaluation of how different species at solid contacts modulates their adhesion would be extremely beneficial for a range of different technological fields: from metallurgy to nuclear fusion. In this work we have used and high-throughput approach to systematically explore the effects of the presence of non-metallic elements, at different concentrations, on the adsorption and adhesion energies of different homogeneous metallic interfaces. Together with the databases for the adsorption and the adhesion energies, we calculated several other properties such as the charge transferred at the interface, the d-band edge shift for the substrate the Bond order and the interfacial density redistribution for the hundreds of systems analyzed. These values were used to define different trends with respect to chemical and concentration parameters that could be useful for the development of engineered interfaces with selected properties. In particular we noticed how the substrate with low filling of d-band are the most prone to adsorb ad-atoms and how the adsorption of almost all non-metallic elements decreases the adhesion energy of solid interfaces, particularly in the case of Fluorine. Carbon and Boron were the only two ad-atoms species that showed an opposite trend increasing the adhesion energy instead.