Preparation And Research Of Graphene Reinforced Aluminum Matrix Composites

Compounding is an effective means to improve the properties of metal materials and promote the application of metal materials to a wider range of fields.As a new type of two-dimensional carbon material with excellent mechanical and physical properties,graphene may make graphene an ideal reinforcing phase in metal-based composites.In this paper,the bio-multilayer graphene produced by Shengquan Group is selected as the reinforcement,and it is added to four aluminum substrates(pure aluminum,2024,6061,7075)by solid-state method to prepare composites with different graphene contents.In order to speed up the industrial production of graphene composites,some explorations have been made on the preparation of graphene aluminum-based composites by liquid stirring.Designed and manufactured liquid stirring equipment with different stirring methods,and prepared graphene/pure aluminum composite materials by liquid stirring.The average number of layers of bio-multilayer graphene used in this paper is 10-20 layers,and the sheet diameter is 0.5?m??m.Although the performance is not as good as single-layer or few-layer graphene,it has extremely high cost performance.If a good reinforcement effect can be obtained,it has the potential for industrial production of graphene aluminum-based composite materials.The graphene-reinforced aluminum-based composite material prepared by the solid-state method adopts a vacuum ball mill mixing powder + vacuum hot pressing sintering+hot extrusion process.Ball milling process parameters:The weight ratio of the grinding ball to the material is 5:1,the rotation speed is 300 rpm/min,and the ball milling time is 2h.The vacuum hot-pressing sintering pressure was 20 MPa.The sintering temperatures of pure aluminum,2024,6061,and 7075 substrates are 560 ?,520? C,560 ?,and 460 ?,respectively,and the extrusion temperatures are 480 ?,450?,480,and 420 ?,and the extrusion ratio is 16:1.By observing the microstructure of the composite material,the distribution of graphene on the surface of aluminum powder after ball milling and the distribution of graphene in the final composite matrix were synthesized.It is concluded that for several different Al-matrix,0.5wt%graphene is a reasonable addition amount.At this time,graphene was uniformly distributed in the aluminum matrix,and no obvious agglomeration was found.Graphene was distributed in a stripe shape in the matrix,and most of the thickness was about 100 nm.As the content continues to increase,the distribution of graphene in the matrix obviously appears as agglomeration,with a size of 1 ?m-5?m.In the case where graphene is added to the four substrates,the composite material has the best comprehensive performance when 0.5wt%graphene is added.After adding 0.5wt%graphene to the matrix of pure aluminum,2024,6061,7075,the tensile strength of several composite materials relative to their respective substrates increased by 36.9%,13.9%,27.6%,and 6.4%respectively(tensile strength reached 136.9 MPa,367.8 MPa,190.6 MPa,and 373.5 MPa),the hardness increased by 33.4%,15.7%,basically equal,7.16%(the hardness was 46.37HV,90.3HV,50.5HV,and 82.3HV).When the graphene content is 0.5%by weight,the elongation and electrical conductivity of the composite materials show only a small decrease compared to the respective matrix.The liquid agitation for the preparation of graphene aluminum-based composite materials was explored.The blade agitation equipment and the column slit agitation equipment for the preparation of composite materials were designed.Although the graphenel pure aluminum composite material prepared by the blade type stirring device still has heterogeneity.However,effective stirring methods are provided for follow-up researchers to continue research and improvement.The structure and principle.of the cylindrical slot-type stirring device are analyzed,and a new stirring idea is provided.In summary,In summary,this paper use four kinds of aluminum substrates(pure aluminum,2024,6061,7075)were added with different contents of graphene by solid state method.The best performance was achieved when the graphene content of the four aluminum-based composite materials was 0.5wt%.Graphene's reinforcement effect on 7075 aluminum matrix is not as good as other aluminum matrix.Some researches have been made on the preparation of graphene aluminum matrix composites by liquid stirring.