Changes in the structure and composition of automobile big-end bearing materials and their relation to bearing failure

Abstract

Changes in the composition and structure of automobile big end bearings during operation were examined by X-ray diffraction and electron probe X-ray microanalysis. It was found that evolution of heat and severe plastic flow of the surface layer caused diffusion of Sn into Cu, resulting in the formation of intermetallic compounds such as ε-Cu 3Sn. Similar changes were obtained by heating an unused bearing at 170°C for 120 h. It is suggested that the formation of intermetallic compounds such as ε-Cu 3Sn is a contributory factor in bearing failure.