Semi-coherent interface strengthens graphene/zinc scaffolds

Abstract Reduced graphene oxide (RGO) shows great advantages as nano reinforcement for zinc (Zn) based implants owing to its excellent fracture strength, large specific surface area and good biocompatibility. Nevertheless, the poor interfacial bonding between Zn matrix and RGO impairs the strengthening efficiency. In this work, titanium carbide (TiC) was used as an interface bridging between Zn matrix and RGO to improve the interface adhesion. On one hand, TiC was in-situ generated on RGO plane through chemical vapor deposition, and tightly integrated together via chemical bond. On the other hand, a semi-coherent bonding was formed between TiC and Zn matrix, owing to the small lattice misfit and similar atomic arrangement between the (200)Zn plane and (002)TiC plane. Results showed that TiC@RGO offered an improved strengthening efficiency with tensile strength of scaffolds increasing from 30.6 to 59.9 MPa, as the TiC nanoparticles considerably enhanced the load transfer strengthening of RGO and contributed an Orowan strengthening. Significantly, it also improved the plasticity of Zn scaffolds, since the semi-coherent structure inhibited the premature stress concentration and dislocation accumulation. Moreover, TiC@RGO promoted the cell differentiation behavior of Zn scaffolds.