Research On Preparation Process And Properties Of Graphene Reinforced Iron Matrix Powder Metallurgy Materials

Iron-based powder metallurgy sintered material and parts are widely used in powder metallurgy industry.One of the research targets for powder metallurgy technique is developing the iron-based sintered material with high performance.Graphene is an ideal reinforcing filler in composites with high strength,high toughness,low density and high temperature resistance.In this paper,graphene with excellent performance was used to substitute the precious metal elements for the preparation of Graphgne/ iron – based powder metallurgy materials.The main research contents and achievements are as follows:(1)The graphene was characterized by scanning electron microscopy,atomic force microscopy,Raman spectroscopy and X-ray diffraction and then the graphene with low layer of the layered structure and excellent performance was selected as the reinforcing material of iron-based powder metallurgy material.(2)The preparation technology of graphene reinforced iron powder metallurgy material was studied.The Fe-C,GNSs / Fe and GNSs / Fe-C materials and their test pieces were prepared by reasonable process parameters such as unidirectional pressing pressure,sintering temperature and holding time.And the microstructure of the three groups of materials was observed by metallographic microscope.(3)The mechanical properties of the three groups of materials were tested by uniaxial tensile test.And the effects of graphene content on the tensile strength,elastic modulus and elongation were studied.The results show that: 0.4wt.%GNSs/Fe-0.4C has the best comprehensive properties,the density is 6.75g/cm3,the apparent hardness is 123.02HV0.5,the tensile strength is 437.14 MPa,which is 43.15% higher than that of Fe-0.4C.The elongation is 1.92% and the elastic modulus is 132 GPa.And the analysis of tensile fracture of the 0.4wt.%GNSs/Fe-0.4C shows that: fracture characteristics is mainly toughness-brittle fracture,there is a large number of dimples in the fracture,but also a large dissociation surface appears,Comprehensive performance of the materal is better with both good apparent hardness and high strength.