Influence of synergistic strengthening effect of B4C and TiC on tribological behavior of copper-based powder metallurgy

• Published in: Ceramics international 2023-01, Vol.49 (2), p.2978-2990
• Main Authors: Wu, Jiaqi, Li, Zhuan, Luo, Yong, Gao, Zonglong, Li, Ye, Zhao, Yibo, Liao, Yanxia, Wu, Cuiwei, Jin, Min
• Format: Article
• Language: English
• Subjects: B2O3 tribo-film; Dual ceramic particles (B4C–TiC); Tribological behavior; Wear mechanism
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2022.09.282

High-speed rail brake pads mainly face the lack of stability of tribological performance under high temperature. An effective approach that is often employed is to reinforce copper-based powder metallurgy (PM) with single ceramic particle to obtain superior properties. In this paper, preparation of the dual ceramic particles (B4C–TiC) reinforced copper-based PM by powder metallurgy route, and paired as friction discs using the self-made carbon-ceramic composite. Influence of synergistic strengthening effect of B4C and TiC on tribological behavior and wear mechanisms were investigated. The result reveals that the more content of TiC (less 5%) in B4C–TiC, the greater the performance improvement, especially when the ratio of TiC/B4C is 5:3, the copper-based PM obtains exceptional mechanical and thermal performance, but different tribological behavior at different braking speed. The main factor affecting the tribological behavior at middle-speed (4500 rpm) is TiC, while is B4C at high-speed (6000 rpm) due to the generation of B2O3 tribo-film. With the ratio of TiC/B4C increases, the generation of B2O3 tribo-film goes through a change of first increased to the maximum, and then disappeared. While wear mechanism of copper-based PM goes through the transitional stage from abrasive wear to slight oxidative wear, severe oxidative wear, abrasive wear and adhesive wear, respectively.