Fabrication and characterization of few-layer graphene oxide reinforced magnesium matrix composites

In this study, few-layer graphene oxide (FLGO) reinforced Mg matrix composite was successfully fabricated by the hetero-agglomeration method and spark plasma sintering (SPS) process. The microstructure, mechanical properties, and strengthening behavior of these composites were comprehensively investigated. A unique amorphous MgO/ultrafine MgO + reduced FLGO/amorphous MgO sandwich-like grain boundary of the α-Mg matrix grain was confirmed in FLGO/Mg matrix composites. This kind of grain boundary indicated the strongly interfacial bonding between the reduced FLGO and Mg matrix. The low mismatch between the d{2 0 0}_MgO and d{1 0 0}_graphene and the instantaneous elevated temperature during the SPS process could contribute to the formation of these unique grain boundaries. The mechanical strength and Vickers hardness were apparently increased with increasing FLGO concentration. The 0.5 vol%FLGO/Mg composite exhibits the maximum increase in the mechanical properties. The uniaxial compressive strength (UCS) of 373.2 MPa, yield strength (YS) of 140.7 MPa, failure strain of 14.9% and Vickers hardness of 57.6 was achieved in this composite. Quantitative analysis of the strengthening behavior in these composite was performed, and a high strengthening efficiency was achieved in the FLGO/Mg matrix composites. Therefore, FLGO could be considered as a promising candidate as reinforcement for the Mg matrix.