ZnO@GNPs/ZK60复合材料制备及其性能研究OA

Magnesium alloys possess advantages such as low density,high specific strength,and good thermal conductivity,but their relatively low strength and ductility limit broader engineering applications.To enhance their overall performance,ZnO-coated graphene nanoplatelets(ZnO@GNPs)were introduced as reinforcements into a ZK60 magnesium alloy matrix.ZnO@GNPs/ZK60 composites containing 0 wt.%,0.1 wt.%,0.3 wt.%,0.5 wt.%,and 0.7 wt.%ZnO@GNPs were fabricated via an ultrasonic-assisted mechanical stirring-casting method.The microstructure,mechanical properties,and thermal conductivity of the composites were examined via optical microscopy,scanning electron microscopy equipped with EDS,X-ray diffraction,microhardness testing,tensile testing,and laser flash analysis.The results show that appropriate additions of ZnO@GNPs are uniformly distributed within the magnesium matrix,effectively promoting grain refinement and improving interfacial bonding.When the ZnO@GNPs content reaches 0.7 wt.%,the ultimate tensile strength and elongation of the composite increase to 210 MPa and 5.3%,representing improvements of 19.3%and 39.5%over those of the base alloy,respectively.The hardness attains a peak value of 83.32 HV at 0.5 wt.%,whereas the highest thermal conductivity of 112.19 W/(m·K)is achieved at 0.3 wt.%,which is 13.7%higher than that of the ZK60 matrix.Overall,the enhancement in the mechanical and thermal properties is attributed to the combined effects of dispersion strengthening,grain refinement,improved interfacial bonding,and a reduction in the interfacial thermal resistance induced by the ZnO@GNPs.