The impact of dual ceramic components (WC/B4C) on the friction performance of copper-based powder metallurgy friction materials and wear mechanism

The copper-based powder metallurgy friction material, modified with dual ceramic components (WC/B4C), underwent friction experiments paired with custom-made carbon ceramic discs. The overall findings are as follows: The judicious addition of dual ceramic components (WC/B4C) can enhance the mechanical, thermal, and frictional performance of copper-based powder metallurgy friction materials. When the WC/B4C ratio is 5:3, the material exhibits the optimal mechanical, thermal, and frictional properties. B4C and WC, after braking, form friction films of B2O3 and WO3. Additionally, the friction film of copper-based powder metallurgy friction materials can be categorized into an oxide layer, a deformation layer, and a matrix layer. The oxide layer primarily consists of Fe2O3, the deformation layer is mainly composed of WO3 and B2O3, and the matrix layer is primarily composed of CuO and Cu2O. With the increase in the WC/B4C ratio, the primary wear mechanisms of copper- based powder metallurgy friction materials shift from abrasive wear to mild fatigue wear, mild fatigue wear progressing to severe fatigue wear, adhesive wear, and fatigue wear, accompanied by a gradual intensification of oxidative wear.