Preparation And Corrosion Resistance Of Carbon Fiber Resin Matrix Composites By RTM

Carbon fiber resin matrix composites are widely used in the field of offshore wind turbine blades because of their excellent mechanical properties,lightweight,corrosion resistance and durability.Therefore,it is of great significance to study their corrosion resistance in marine environment.In this paper,the carbon fiber resin matrix composites with 692p-1k and 692-2k epoxy resin as matrix and 12K-T300 carbon fiber woven fabric as reinforcement were prepared by RTM(liquid transfer molding)process.In this paper,through the characterization of 692-2k and 692p-1k epoxy resin and 12KT300 carbon fiber,RTM process optimization and carbon fiber composite mechanical properties experiment,the optimal RTM process parameters were selected to prepare two kinds of carbon fiber epoxy resin composites,and the salt spray aging experiment was carried out to explore the durability of carbon fiber resin matrix composites in marine environment In order to provide a theoretical basis for the preparation of offshore wind turbine blades,the changes of mass,mechanical properties,surface and fracture morphology before and after aging test were studied.The intrinsic experiment shows that: DSC spectrum shows that the curing exothermic peak area of the two kinds of epoxy resin is large,and the exothermic is obvious,which indicates that the epoxy resin system is suitable;after cooling,the DSC curve shows that there is no curing exothermic peak,which indicates that the resin system is completely cured.During the heating process,the DSC curve of 12K-T300-T300 carbon fiber showed a steady rising trend,and there was no wave peak,indicating that the surface of carbon fiber was not modified by surface modifier.The process parameters of RTM are as follows: injection pressure is 2.5MPa,injection speed is 40 ml/min.The mechanical tests show that the tensile strength and flexural strength of 692-2k/12K-T300 carbon fiber resin matrix composites are 449.15 mpa and 500.94 mpa,respectively,and the tensile strength and flexural strength of 692p-1k/12K-T300 carbon fiber resin matrix composites are 358.44 mpa and 458.96 mpa,respectively,indicating that the former is superior to the latter in mechanical properties.SEM fracture morphology shows that RTM optimization process achieves full infiltration of resin and fiber interface between tow and fiber cloth.There are three main ways of energy absorption in the tensile fracture process: the fracture of carbon fiber,the brittle fracture of epoxy resin and the interface failure of carbon fiber and epoxy resin.The salt spray aging test shows that the weight gain of carbon fiber composite is mainly caused by the moisture absorption behavior,followed by the deposition of salt spray on the surface of composite samples.The effect of salt spray aging test on the bending specimen is greater than that on the tensile specimen.In the initial stage of salt spray aging test,there is no obvious change on the surface of the two composites,but cracks and debonding of resin and fiber appear in the later stage;the fracture morphology shows that the resin and fiber are well infiltrated,and the holes left by fiber pulling out become more and more,the wrapping property of resin to fiber becomes worse,and the interfacial adhesion between carbon fiber and resin weakens.DMA spectrum showed that after 10 days of accelerated salt spray aging test,the peak value of storage modulus of the two carbon fiber composites decreased,indicating that the hardness decreased.The peak value of Tan ? of the two kinds of carbon fiber composites is lower,which indicates that the interfacial properties between fiber and resin are better,and the energy loss is less under dynamic stress.After salt spray aging test,the glass transition temperature of the two carbon fiber composites decreased.