Optimized Preparation And Mechanical Property Studies On Carbon Fiber Reinforced Plastic Hybrid Laminates

Carbon fiber(CF)reinforced plastic laminate with high specific strength and modulus is a charming candidate in the airplanes,vehicles and clean energy fields.However,the application of traditional CF reinforced epoxy laminates is limited by its low elongation and brittle fracture properties.In order to satisfy actual requirements in industry,hybrid laminates are gradually paid attention by researchers,due to their excellent comprehensive performance,high flexible design and low cost.In this work,a novel hybrid laminate-CF reinforced thermosetting/thermoplastic laminate-is designed in order to optimize comprehensive mechanical properties.The traditional CF reinforced thermosetting laminates are used to be the major load carrier,while CF reinforced thermoplastic laminates with low CF content and high plasticity are selected to eliminate the defects in thermosetting laminate as far as possible.The mechanical properties of hybrid laminates normally depend on three aspects:original performance,adhesive property and stacking sequence of two laminates.Therefore,a series of research was conducted to optimize the manufacture technology of these hybird laminateFirstly,a two-step hot-press process was purpose to fabricate CF reinforced thermoplastic laminate,which was mainly based on the thermoplastic property of resin matrix.This process aimed to reduce the values of the hot-press parameters,and to achieve ideal effects on both effective resin impregnation and uniform CF orientation of the spreaf CF.Tensile,flexural and impact tests,along with the morphological characterization observed via SEM were employed to evaluate the effect of the hot-press parameters and the number of layers on the performance of fabricated laminates.In addition,the reliable of this method would be further vertifiedSecondly,a laser surface treatment on CF reinforced thermosetting laminate was used to enhance the adhesive property of hybrid laminates.Based on the weaving property of CF fabric,a novel mathematic equation was established to describe the status of the resin removal at outer surface of laminates with less CF damage.Then,a series of groove laser etching operation was carried out to further increase the adhesive area and to provide an anchoring effect in the as-obtained CF fabric surface.Single-lap shear tests,processing and failure morphology observation were used to reveal the groove enhancing mechanism and find the optimal laser parametersFinally,according to the optimized processing parameters obtaind above,hybrid laminates with different stacking sequences were successfully prepared.Then,the effect of stacking sequence on flexural and impact properties of hybrid laminates were investigated in detail.The results indicate that the tensile properties of hybrid laminates basically conform with the composite mixing rule.The thermosetting-thermoplastic stacking type possesses the best flexural and impact property,because it follows the stress distribution rule.The breaking process of thermosetting laminate is greatly mitigated by the thermoplastic laminate,and its impact property is further improved,which illustrate the synergetic enhancement ability of hybrid laminates.