A study of the structure, mechanical and corrosion properties of the copper matrix composites with CNTs/Cu foams as 3-dimensional skeleton reinforcements

In this paper, inhomogeneous copper matrix composite with carbon nanotube reinforced copper foam (CNTs/Cuf) as the three-dimensional (3-D) skeleton is designed to overcome the paradox between strength and ductility or conductivity. The open cell composite foams with uniformly embedded CNTs are filled with dense copper phase in the foam pores by spark plasma sintering (SPS) to form the inhomogeneous composites. The inhomogeneous composite reinforced with CNTs/Cuf shows a combination of high electrical conductivity (93.4% IACS), tensile strength (366.7 MPa), and fracture elongation (31.78%) with a quite low CNTs content (0.2414 vol%). In addition, the polarization curves and AC impedance (EIS) tests show that the best corrosion resistance is achieved with the CNTs content of 0.2414 vol%, and the corrosion rate is reduced by 71.9% and 49.1% compared with the Cu and Cuf®Cu samples, respectively.