Effects of speed sequence on friction properties of sintered Cu–SiO 2

Abstract

The effects of the speed sequence and SiO₂ content of Cu–SiO₂, sintered by powder metallurgy method, on friction and wear properties have been investigated at fixed speeds. The results indicate that the sequence of speeds employed in the tests plays great roles in the friction and wear properties. When the tests are executed from a lower speed to a higher speed, friction coefficients decrease and oscillate dramatically as the speed goes up, resulting in a severe wear. On the contrary, as the speed starts from a higher value, the friction coefficients are stable and wear is small. These phenomena can be explained by states of third bodies formed in the friction. The third body formed at lower friction speeds is usually granular, which is responsible for the coefficient oscillations and larger wear loss. At higher speeds, the third body formed is rather dense, leading to stable friction coefficients and lower wear loss.