Strengthening copper matrix composites by in situ synthesized amorphous carbon nanosheet reinforcements

Abstract

Graphene-like carbon nanosheets with large specific surface areas present a great potential to enhance the mechanical properties of copper matrix composites. To achieve the homogeneous dispersion of nanosheet reinforcements in the copper matrix, in-situ synthesis strategies using solid carbon sources have been developed in recent years. However, the influence of in-situ synthesis factors on the microstructures of carbon nanosheets and the corresponding mechanical behaviors are far from clear. In this work, an amorphous carbon nanosheets reinforced copper matrix composite with significantly enhanced strength had been in-situ synthesized. The dependence of the microstructures and tensile mechanical properties of the composite on the amorphous carbon nanosheet concentration was investigated. The in-situ grown amorphous carbon nanosheets induced remarkably refined Cu grains and they could effectively bear the loads transferring from the matrix. Consequently, the copper matrix composite with 0.6 wt% amorphous carbon nanosheets showed the highest yield strength and ultimate tensile strength of 196.5 MPa and 306.4 MPa, respectively, which are 2.56 and 1.51 folds of the pure copper bulk. The strengthening mechanisms of the amorphous carbon nanosheets/Cu composite were further revealed through the microstructure characterizations and theoretical model analysis. The load transfer was considered as a dominant mechanism for the strengthening.