Research On Preparation And Low-velocity Impact Performance Of Carbon Fiber Reinforced Magnesium Alloy Based Composite Laminates

Carbon fiber reinforced polymer/magnesium alloy hybrid laminates(Fiber Metal Laminates,FMLs)is the latest generation of laminates.They have many advantages such as high specific strength and modulus,good shock and energy absorption as well as fatigue resistance properties.Thus,they have been paid for more and more attention in the fields of electronics,vehicles,aerospace and other fields.However,due to the poor strength and toughness of magnesium alloy plate and weak bonding interface in the fiber/magnesium alloy hybrid laminate,the application of the laminate is limited.Therefore,it is of both theoretical and practical value to study the preparation process,basic mechanical properties and low velocity impact properties of novel fiber/magnesium alloy hybrid laminates.Surface plastic deformation treatment for magnesium(Mg)alloy sheet was firstly conducted for the purpose of its grain refinement and enhanced interfacial bonding strength and mechanical properties of Mg based laminates.The effects of different processing parameters on the microstructure and tensile properties of Mg alloy were then studied.Moreover,the constitutive parameters of each layer were fitted and verified by comparison with simulation predictions based on the tensile test data of gradient Mg alloy sheet.On this basis,a novel carbon fiber reinforced Mg based laminates bonded with low-melting Mg alloy was fabricated by vibration-assisted hot pressing method and basic mechanical properties of the laminates was evaluated.Simulation study on the novel carbon fiber/Mg based laminates under low-speed repeated impact conditions was finally conducted based on the basic mechanical performance parameters obtained from the experimental data of single layer ply.Meanwhile their impact behaviors were compared with those of carbon fiber reinforced polymer composites/Mg alloy laminates.Results are as follows:the yield strength and tensile strength of Mg alloy plate increases by 14%and 10.5%respectively after the surface treatment with grain refinement.The interfacial shear strength of carbon fiber/Mg alloy laminates manufactured by thermal pressing method could reach 5.37 MPa.The fracture toughness values of type ? and type ? could be up to 0.23kJ/m~2 and 2.45kJ/m~2,respectively.Compared with existing fiber/Mg laminates,it has more excellent comprehensive performance.The carbon fiber/gradient fine-grain Mg-based hybrid laminates bonded with Mg alloy solder in this paper has better impact resistance than that of the resin-bonded carbon fiber/magnesium alloy laminates under repeated low-speed impact loading.For resin-bonded carbon fiber/Mg alloy laminates,it has strong impact resistance under repeated impact conditions when the fiber layup sequence is0?/90?/90?/0?and the carbon fiber(C)and glass fiber(G)are mixed and alternately laid(such as Mg/C4/Mg/G4/Mg).