Study On Thermal Forming And Thermal Deformation Of CF/PEEK Thermoplastic Composites

Composite materials are characterized by light weight,high strength,corrosion resistance,fatigue resistance and strong designable ability,so they are widely used in aviation,aerospace,automobile,energy and other fields.Among all this composite materials,the resin-based composite is most representative in aerospace filed.With the continuous improvement of the requirements for lightweight and high strength properties materials in the aerospace field,the traditional thermosetting resin matrix composites can no longer meet the existing requirements.Therefore,scientists have turned their attention to thermoplastic composites with good toughness,high fatigue strength and high impact damage tolerance.However,thermoplastic resin has high melting point and high melt viscosity,which makes that difficult to prepare thermoplastic composites.In this paper,CF/PEEK thermoplastic composites are used as raw materials to carry out research on thermal forming and thermal deformation process.The main contents are as follows:The process parameters of hot pressing were determined and optimized,and the CF/PEEK composite prepreg was made into laminated composite plates to test basic properties including mechanical properties and thermal properties.After that,using water cooling system to increase the cooling rate of thermoplastic composites preparation process,which can improve the efficiency of the preparation process and reduce the cost of molding.The crystallinity and mechanical properties of thermoplastic composite which prepared under different cooling rate were tested to discuss the effect of cooling rate on properties of materials.Thermal deformation of materials often occurs in thermoplastic composites forming process.And the forming temperature is one of the most importan t factors influencing the thermal deformation properties of thermoplastic composites.Taking continuous fiber reinforced thermoplastic composite curved beam as a typical structure,the four-point bending strength and maximum radium stress of the composite curved beam prepared at different molding temperature were studied.Simultaneously,the four-point bending strength and failure mode of composite curved beam are simulated by finite element method.By the above methods,the influence of forming temperature on the thermal deformation properties of thermoplastic composites was analyzed.