Triboxidation and softening induced by dry sliding of copper coupling with steel at 3.36 m s −1 speeds

Abstract In this paper, the copper coupled with steel under dry sliding are comparatively sdudied at 0.56 m s −1 and 3.36 m s −1 condition from the morphology, structure and composition of tribolayer of the copper. It is found that the wear rate of Cu at 3.36 m s −1 is twice that at 0.56 m s −1 , and the temperature of Cu block at 3.36 m s −1 (240 °C) is much higher than that at 0.56 m s −1 (75 °C). The results show that when the grinding speed is 0.56 m s −1 , the grain distortion occurs in the top area of the subsurface layer of Cu block. When the grinding speed is 3.36 m s −1 , the grain refinement zone appears below the subsurface layer of Cu block wear. The study further proves that the softening caused by friction heat occurs in the grain refinement zone, and a large number of softened metal copper tends to transfer to the opposite side. At the same time, the friction heat changes the mechanical and thermal deformation, material transfer and friction oxidation of the contact surface, which has a great influence on the dry sliding behavior of Cu.