Study On Laser Welding Joining Technology Of Carbon Fiber Reinforced Peek Prepreg

With the development of the composites,the traditional metal materials have been gradually replaced by composite material because of their excellent performance,and it shows good application future.Carbon fiber reinforced polyether-ether-ketone(CFRP)prepreg combines the advantages of polyether-ether-ketone(PEEK)and carbon fiber(CF),which gradually applied to the civil industry.However,the connection method has many limitations when manufacturing parts because of high melting point.The laser welding technology which has the advantages of high-efficient and pollution-free,provides a new possibility for the connection of CFRP composite material.It is suitable for industrial automation production.Therefore,it is important to study the connection process of CFRP prepreg.In this paper,the orthogonal test is designed to optimize the three main welding parameters based on the mechanism of laser welding.The mechanical properties ? morphology and the thermal properties of the welded joint are characterized.In order to optimize the process parameters,the lap-shear strength of the specimen was used to evaluate the quality of the joint.The degree of influence is obtained by using the range method:laser power ? welding speed ? clamping force.The suitable welding temperature interval was analyzed based on the results of infrared temperature measurement and shear strength.In order to investigate the effect of laser welding on the welded joint,the microstructure and shear fracture morphology of the welded joint were observed.The chemical bonds and the formation of functional groups at the interface were studiedby infrared spectroscopy.The change of the crystallinity and thermal decomposition temperature of the material after the heat cycle of laser welding was analyzed by DSC and TGA.The optimum combination of process parameters was obtained by adding the preheating device to improve the thermal performance of the joint.