Abstract：Copper based brake pads have the problems of matrix softening and friction film breaking during high-speed cycle braking. Cu-based brake pads with boron carbide (B4C) mass fraction of 0-6% were prepared using powder metallurgy (PM) method, and C/C-SiC brake discs were selected as dual components to study the effect of B2O3 friction film formed during the braking process on friction and wear performance, and to analyze the wear mechanism. The results show that the density of copper based friction materials can be reduced by modifying with B4C. When the mass fraction of B4C is 4% and 6%, the material density significantly decrease and the strength increase, and the most excellent thermal degradation resistance and the lowest wear rate are obtained, respectively. During the braking process, B2O3 formed by B4C oxidation has a layered crystal structure similar to MoS2 and graphite, which is easy to shear at the sliding interface, thereby improving the mean friction stability coefficient and reducing wear rate. B2O3 formed on the surface of B4C combines well with the Cu matrix. When the mass fraction of B4C exceeds 4%, the wear mechanism of Cu-based brake pads shifts from delamination wear to oxidation wear.
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2023, Vol. 28 
