Novel insight into the self-lubricating mechanism of Cu-Pb bearing alloy during sliding friction with the guidance of molecular dynamics

The self-lubricating mechanism of Cu-Pb bearing alloy is discussed by molecular dynamics (MD). MD friction tests are conducted on the pure Cu and Cu-Pb models. The Pbrich secondary phases (PSPs) melt due to the frictional heat. The solid-liquid phase transition of Pb is characterized by the radial distribution function (RDF) and the potential energy. An obvious drop of motion resistance of the abrasive debris is observed in Cu-Pb alloy once the debris moves close to the soft PSP which protect the matrix from abrasion by embedding the debris and promoting the formation of a liquid lubricant film. The synchrotron radiation technology is employed to in-situ observe the phase transition of Pb, and the MD results match the experimental results well.& COPY; 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).