Mechanical Properties of Graphene Reinforced AZ91 Mg Alloy Based Composite

The AZ91 Mg alloy based composite powder and materials were prepared with graphene oxide and graphene nanosheet as strengthening phase respectively and the interface reaction mechanism of graphene oxide with AZ91 Mg alloy was analyzed. The mechanical properties of the composites were tested and the tensile fracture surfaces were observed. The results show that the yield strength, elongation and microhardness of the composite with graphene oxide as strengthening phase reached 224.85 MPa, 8.15% and 70.14 HV, which were improved by 39.7%, 35.4% and 31.8% respectively comparing to those of AZ91 Mg alloy and also much higher than those of the composite with graphene nanosheet as strengthening phase. The graphene oxide was easy to disperse uniformly with the AZ91 Mg alloy powder due to its oxygen groups; the interface bonding between graphene and Mg alloy matrix can be strengthened by MgO produced by the reaction between the Mg alloy and the oxygen groups, resulting in the improvement of mechanical properties of the composite.