Effect of Fe and Cr on the Macro/Micro Tribological Behaviours of Copper-Based Composites

Fe and Cr are regarded as two of the most important friction components in Cu-based composites (Cu-BCs). In this study, the microstructural detection and micro- and macro-tribology evaluation of Cu-BCs containing Fe and Cr were performed. The results indicated that both Fe and Cr formed diffusion interfaces with the copper matrix. Because of the generation of a defect interface layer, the Cr/Cu interface exhibited a low bonding strength. Owing to the excellent binding interface between Fe and Cu, the high coefficient of friction (COF) of Fe, and the formation of a mechanical mixing layer promoted by Fe, the Cu-BCs containing Fe presented better friction performance under all braking energy per unit area (BEPUA) values. The main wear mechanism of Cu-BCs containing Fe and Cr changed from abrasion to delamination with an increase in BEPUA, and the delamination of Cu-BCs containing Fe was induced by breaks in the mechanical mixed layer (MML).