Fabrication And Properties Of Gaphene Reinforced Copper Matrix Composites

Graphene is a two-dimensional(2D)material.It is a single atomic layer of sp~2 hybridized carbon atoms packed densely in a honeycomb lattice.It has excellent mechanical,thermal and electrical properties and is considered to be the ideal reinforcement for copper metal matrix composite(MMC).High-energy ball-milling is a solid-state powder processing technique,which is cost-effective and widely used to prepare copper matrix composites conveniently.However,as all these research works were focusing on discussing the effectiveness of the fabrication method,the impacts of graphene content and milling time on the properties of copper/graphene composites were seldom studied.Therefore,it is of primary importance to study the graphene dispersion under different ball-milling times and to produce the graphene/copper composites with good mechanical properties by optimizing the ball-milling time.In this work,we prepared graphene oxide(GO)with Hummers method,and then use the method of high-energy ball mill to make graphene oxide evenly dispersed in the copper substrate.Finally we used the method of hot pressing sintering to prepare the graphene reinforced copper matrix composites.The GO and composite were characterized by metallographic microscope(OM),X-ray diffraction(XRD)and scanning electronmicroscopy(SEM)and other methods were studied the dispersion of graphene and the structure,mechanical properties of composite with different surfactant and graphene contents.It was found that the graphite has been effectively stripped and have fewer layers of graphene oxide using XRD?SEM and FT-IR.And the presence of large amounts of oxygen containing groups on the graphene oxide makes graphene oxide have a strong ability of interface bonding.Graphene was evenly dispersed and the structure of graphene is relatively complete with 5 h of ball-milling time.We found that when the content of graphene was 0.5 wt.%,the performance of the composite material reached the best,the tensile strength increased by 28 % and coefficient of thermal conductivity increased by 33.8 % with the study of different content of graphene.And the elongation is not clear declined.The fracture morphology of the composite material analysis found that brittle fracture and ductile fracture characteristics,the combination of graphene is mainly distributed in the order of the composite material,see the phenomenon of pull out and fracture state.The composite material has both of brittle fracture and ductile fracture and the graphene are mainly distributed in the order of the composite material.The graphene was obviously pulled out and broken.