Compelling mechanical properties of carbon nanotubes reinforced pure magnesium composite by effective interface bonding of Mg2Ni

Abstract

In this study, a kind of nickel coated carbon nanotubes (Ni-CNTs) reinforced pure magnesium (Mg) matrix composite was prepared using two-step process. The nano-Mg2Ni phase at the interface was in-situ formed to improve the interface bonding between CNTs and Mg matrix. Results indicated that the yield and ultimate tensile strength of 2.0 wt. % Ni-CNTs/Mg composite were 278.3 MPa and 304.5 MPa, respectively, showing 77% and 48% increase in comparison with those of 2.0 wt. % CNTs/Mg composite. The remarkably enhanced mechanical properties were attributed to the strong interface bonding due to the in-situ formed nano-Mg2Ni phase. The corresponding strengthening mechanisms were regarded as the coupling interface effect of the coherent interface and the interstitial solid solution. Moreover, the CNTs acted as a bridging role in load transfer and obstructed the growth of cracks in Ni-CNTs/Mg composites.