Enhancing mechanical properties of pure copper-based materials with Cr x O y nanoparticles and CNT hybrid reinforcement

Pure Cu matrix composite reinforced by CrxOy-CNT hybrid was prepared via powder metallurgy in the present work. Microstructural analysis revealed that the formation of Cu2O nanoparticles at the interface is contributed to the interfacial bonding. The CrxOy-CNT/Cu composite of 1.0 vol% hybrid reinforcement exhibited excellent ultimate strength of 402.6 MPa, which was ~ 90.0% higher than that of unreinforced Cu (211.9 MPa). Meanwhile, the ultimate strength of the hybrid reinforcement was much higher than those of the separate components, which were 238.4 MPa of 1.0 vol% CNT/Cu composite and 339.1 MPa of 1.0 vol% CrxOy/Cu composite, respectively. Furthermore, the quantitative analysis indicated that Orowan looping system contributed the most to strength in CrxOy/Cu and CrxOy-CNT/Cu composites, whereas load transfer then contributed the most strength for CNT/Cu composite.