Improving the strength-ductility synergy of carbon nanotubes reinforced Cu matrix composites through interfacial regulation

How to strengthen the interface bonding and alleviate the contradiction between the strength and ductility of metal matrix composites is a long-standing open issue. Herein, continuous and uniform nano Cu coating was decorated onto the CNTs and used to tailor the interface between CNTs and Cu matrix of CNTs reinforced Cu matrix composite. It is found that coating Cu on CNTs not only can promote the dispersion of CNTs and strengthen the CNTs-Cu interface but also lead to the uniform strain distribution of the fabricated composite and the formation of dislocation deleted region in the interfacial area, resulting in better strength-ductility synergy than uncoated CNTs reinforced Cu matrix composite. Moreover, with precoating Cu on CNTs, the proportion of strength contribution from load transfer strengthening to the overall strength improvement can be increased from 14% to 26.5%. The findings can guide the development of Cu matrix composites with high mechanical performances.