Experimental and Simulation Investigation on the Mechanical Properties of Carbon Nanotubes/Cu Composites Doped with Ti and Cr Elements

To disclose the effect of doping Ti and Cr elements on the interface bonding of carbon nanotubes (CNTs)/Cu composites, the CNTs/Cu, Ti‐doped CNTs/Cu, and Cr‐doped CNTs/Cu composites are prepared by powder metallurgy. The microstructure is characterized and the mechanical properties are tested. Moreover, the interface bonding energy, interfacial stability, charge density difference, density of states, and Mulliken bond population of the studied composites are calculated by first principles, and the interfacial bonding mechanism is discussed as well. The results show that the Ti and Cr elements are enriched at the interface between Cu and CNT. The tensile strength of Ti‐doped CNT/Cu and Cr‐doped CNT/Cu composites is, respectively, increased by 35.5% and 20.4% as compared to CNTs/Cu composites. Density functional theory reveals that after doping Ti and Cr atom, the interfacial bonding energy ( E _b ) increases to −5.668 and −5.662 eV/atom, respectively. The density of states, charge density difference, and Mulliken bond population analysis indicate that the strong covalent bonds of TiC and CrC formed between doped atom and CNT contribute to the enhancement of interfacial bonding strength and interfacial stability of CNT/Cu. The research is of great significance for the design and fabrication of CNT/Cu composite with better performance.