Structure Analysis of Friction Layer of Copper Matrix Composites Reinforced by Composite Ceramic (Tic-B4c) Powder

To alleviate the issues of matrix softening and excessive wear faced by copper-based composites matched with C/ C-SiC disc during high-speed braking, the research was conducted to investigate the impact of composite ceramic (TiC-B4C, TB) powder on copper matrix composites prepared through conventional powder metallurgy method. TiC-B4C powder was produced using the high-energy ball milling method, and a suitable milling time (48 h) was established to obtain the maximum disorder degree. The results revealed that TB2 (6% TB) had the highest densification and the best mechanical and thermal performance, as compared to other composites. However, there were differences in tribological properties, with TB4 (10% TB) achieving the maximum friction coefficient, while TB2 (6% TB) exhibited more stable friction performance. As the TB powder content increased, larger tribofilms were formed on the worn surface. However, the influence of TB powder content (less than 10% TB) on friction performance was mainly due to mechanical strength and structural tightness, rather than the formation of tribo-films. The friction layer consisted of three parts: the top nanostructure layer composed of nanoparticles (C, Cu, Fe, B, O, and Ti), the middle tribo-film composed of graphite and B2O3, and the lower elastic deformation zone.