Study On Preparation And Properties Of Carbon Fiber Surface Coated With Nickel Plating

With the development of science and technology and the demand of national defense,the development of single material is difficult to meet the demand.Among them,carbon fiber of aluminum alloy and other metal matrix composites has excellent comprehensive properties such as high specific strength,specific modulus,high temperature resistance,fatigue resistance,low expansion and self-lubrication.The excellent comprehensive properties of carbon fiber make it an ideal reinforcing material for aluminum matrix composites.However,there is a poor wetting property between carbon fiber and molten aluminum,and carbon fiber is prone to damage in the process of high temperature forming,resulting in the failure of carbon fiber reinforced aluminum matrix composites to achieve the expected strengthening effect.In order to solve the above problems,this paper focuses on the nickel plating process on carbon fiber surface and the influence of carbon fiber surface coating on the mechanical properties and interface properties of carbon fiber.Through the comparison and analysis of the micro-structure of the nickel coating on the surface of carbon fiber,the optimum process range of electroplating was determined.The influence of coating thickness on the tensile mechanical properties of carbon fiber was discussed by the tensile test of single wire and the micro-structure analysis.The main contents and conclusions are as follows:(1)Research on nickel plating process of carbon fiber surface.The effects of electroplating temperature,electroplating current and electroplating time on the deposition efficiency and surface morphology of nickel plating were analyzed.The proper electroplating formula and reasonable electroplating process range were determined: the electroplating current was0-0.7a,the electroplating temperature was normal temperature,the electroplating time and the coating thickness were linear.(2)Interface study of continuous carbon fiber reinforced aluminum matrix composites.Based on the study of the interface micro-structure of carbon fiber reinforced aluminum matrix composites,it is found that the interface wetting performance of carbon fiber and aluminum matrix can be improved by nickel plating on the surface of carbon fiber.The effects of coating thickness,interface products and forming temperature on the interface properties of Cf/Al composites were studied.(3)Study on the influence law and mechanism of surface electroplating nickel on tensilemechanical properties of carbon fiber monofilaments.Nickel-plated carbon fiber with different thickness of coating was obtained by changing the plating process,and the influence of coating on the tensile mechanical properties of the fiber was studied by single wire drawing and SEM analysis.The results show that the maximum tensile force of single wire increases first and then decreases with the increase of nickel coating thickness,and reaches the maximum when the coating thickness is 2.2 μm.(4)Study on the influence of nickel plating on the high temperature resistance of carbon fiber.The tensile mechanical properties of carbon fiber coated with nickel coating thickness of0.7μm after treatment at different temperatures and for different periods of time were tested.It was found that nickel coating on the surface of carbon fiber could significantly improve the antioxidant properties of carbon fiber and reduce the damage of carbon fiber during high-temperature molding.Through different thickness of nickel plating carbon fiber for transient high temperature treatment(700 ℃,15 s)to simulate the forming process of high temperature on the influence of nickel plating carbon fiber,will process after the carbon fiber monofilament tensile test and SEM analysis,and high-temperature processing of nickel plated with carbon fiber,known: nickel plating carbon fiber after high temperature manager pulled the biggest change trend;After high temperature treatment,the maximum tension loss of nickel-coated carbon fiber decreases with the increase of coating thickness.Therefore,increasing the coating thickness can improve the oxidation resistance of carbon fiber.