Research On Rivet Free CFRTP/Al Connection Technology And Performance Control

Advanced composite materials represented by carbon fiber have excellent mechanical properties and designability,and are widely used in the field of aerospace.In recent years,with the improvement of the manufacturing process and the reduction of the price of composite materials,it has been extended to vehicles,ships,wind power and other large civil mechanical products.No matter any structural design,including aircraft,ships,vehicles and wind turbines,it is desirable to adopt integrated design and manufacturing as far as possible in order to reduce connections and improve structural efficiency.However,it is not possible to completely avoid connections.In general,it is necessary to arrange certain separation surfaces.The development and application of thermoplastic composites are expanding rapidly.Along with the application of thermoplastic composites,it is necessary to develop and adapt new joint technology.Aiming at the problem of CFRTP/Al rivet free connection and combining with the traditional metal rivet free stamping connection technology,a new rivet free connection technology is designed in this paper.The forming mechanism of the rivet free CFRTP/Al process was revealed through the mechanical property test and microscopic microstructure observation.The main research contents are as follows:Firstly,the rivet-free joint die of CFRTP/Al was designed,and the process parameters of making and forming CFRTP composite laminate were explored,as well as the process method of rivet-free joint of thermoplastic carbon fiber composite material and aluminum alloy.According to the principle of rivet-free connection,the best process route is developed to realize reliable connection.Secondly,different surface treatment methods and interface treatment methods,such as grinding with different mesh number,anodizing phosphoric acid,KH560 silane coupling agent and adding aluminum powder medium in the connection area,were used to enhance the connection strength of CFRTP/Al rivet free connection.Finally,the CFRTP and a variety of surface treated Al plates were connected by rivet stamping,tensile experiments were carried out on the connectors,the connection strength and performance were analyzed,and the connection area was cut off for microscopic observation,and the connection mechanism was explored.The optimal sandpaper mesh number suitable for grinding was analyzed,and the anodic oxidation process parameters were determined.The mechanism of adding silane coupling agent and aluminum powder to promote interface bonding was investigated.It provides some reference for realizing high strength CFRTP/Al connection.