Study On Preparation Technology Of Continuous Carbon Fiber Reinforced Aluminum Matrix Composite

Continuous carbon fiber reinforced aluminum matrix composite material has the advantages of light weight,high modulus,high specific strength,etc.It is an important material with great potential in aerospace and advanced weaponry,and has now developed into the most strategic significance in modern defense technology At present,domestic and foreign researchers and research institutions have conducted a lot of research on the preparation methods of continuous carbon fiber reinforced aluminum matrix composite materials,but they are limited to layered and plate materials,and the material properties are directional.As for how to obtain a continuous carbon fiber reinforced aluminum matrix composite material with uniformly dispersed reinforcement,so that the material has"isotropic"mechanical characteristics in performance,the literature has not yet been introduced.Therefore,it is necessary to optimize the preparation method and process and move closer to the production of large-volume,large-block and complex-shaped carbon fiber reinforced composite materials to make it easier for industrial production.In this paper,continuous carbon fiber is used as the reinforcement,and pure aluminum is used as the matrix to explore the method of preparing"isotropic"continuous carbon fiber reinforced aluminum matrix composites.Pretreatment of carbon fiber surface with chemical copper plating method,through continuous pretreatment of carbon fiber,and electroless copper plating on carbon fiber surface,successfully solved the problem of poor wettability of carbon fiber and aluminum alloy substrate surface,greatly enhancing the composite material The bonding strength between the substrate and the aluminum alloy substrate.Enhanced and improved the chemical compatibility of the substrate and the reinforcement.The pretreatment process of carbon fiber surface is:degumming→coarsening→neutralization→sensitization→activation→degumming→reduction→electroless copper plating.The ideal process conditions for electroless copper plating are:12 g/L CuSO₄,15 mL/L HCHO,48 g/L NaKC₄H₄O₆,pH 12.25,temperature 60°C,plating time 10 min,mechanical moderate speed stirring.Experiments show that electroless copper plating has a great influence on carbon fiber during pretreatment,and sensitization and activation have the greatest influence on copper plating.In the experiment,the"flexible mixing"method was used to uniformly disperse the carbon fibers,and the composite material was prepared by the traditional powder metallurgy method.The scanning electron microscope was used to observe the microstructure of the composite material and test the mechanical properties of the composite material.Experiments show that the flexible mixing method can effectively disperse carbon fibers and obtain uniformly distributed continuous carbon fiber reinforced aluminum-based composite materials,and the composite materials tend to be isotropic.Through tensile experiments and three-point bending experiments,it is proved that the composite material has the best mechanical properties when carbon fiber is added at 0.3%by mass.The tensile strength of the composite material has increased by 272%（from 104.55 to302.34 MPa）and the bending strength has been improved It increased by 289%（from 66.17 to246.09 MPa）.With the increase of carbon fiber mass fraction,the elongation of the composite increased by 58%.Microscopic analysis showed that the carbon fiber section was smooth and neat,and the appearance of drawing was not obvious.The surface of the fibers exposed on the tensile fracture surface leaves a matrix with marked deformation marks.The aluminum matrix is broken because the elongation of the carbon fiber is smaller than that of aluminum.Therefore,when the load is strained,the carbon fiber breaks first.After the carbon fiber is broken,the aluminum matrix only bears the load.The interface between the aluminum matrix and the carbon fiber is well integrated.Although a weak interfacial reaction has occurred,it has little effect on the mechanical properties of the composite.