Friction properties of Cu-SiO_2 sintered friction materials

To improve the wear resistance while maintaining a stable friction coefficient of Cu-based friction materials under high-speed dry friction conditions,Cu-SiO_2 friction materials were prepared through the powder metallurgy method.The effects of content and granularity of SiO_2,and the mode of friction on friction and wear properties of the materials were studied at friction speeds of 1.6～47.1 m/s.The research demonstrates that: the friction coefficient and the wear rate increase slightly with the increase of SiO_2content;the change of SiO_2particle size has no significant impact on the friction coefficient;the friction mode has considerable influence on friction and wear properties.The increase of friction coefficient with the increasing SiO_2content is ascribed to the increased number of high-hardness particles on the friction surfaces.A key factor affecting friction and wear properties of the materials under dry friction conditions is the friction mode.The dense and continuous morphology of the third bodies formed at high friction speed helps to lower the wear rate,and apparently decreases the fluctuation of the friction coefficient caused by the friction speed variation.