Research On The Process And Properties Of Carbon Fiber Reinforced Nylon 6 Composites Formed By Compression Molding Process With Self-resistance Electric Heating Technology

Automotive lightweight is an important means of energy saving and emission reduction to cope with global climate change and energy crisis.Carbon fiber reinforced thermoplastic composites are a kind of automotive lightweight materials with great potential due to their advantages of light weight,high strength and good designability.Its efficient and energy-saving forming process has become a research hotspot at present.This study proposed a new process which combine the selfresistance electric heating technology with traditional film-stacking molding process,and successfully prepared carbon fiber reinforced PA 6composite laminates with excellent performance.The main work of this paper is as follows:1.The experimental platform of compression molding combined with self-resistance electric heating was built at first.Based on this experimental platform,the carbon fiber surface physicochemical properties,quality of impregnated,crystallization properties,mechanical properties and energy consumption of the carbon fiber reinforced PA 6 laminates manufactured by the new process and conventional compression molding process under the same process conditions were compared.It was found that compared with the conventional process,the carbon fiber reinforced PA 6 laminates fabricated by the self-resistance electric heating method can achieve similar or even better impregnation quality and mechanical properties,and significantly reduce the molding cycle and energy consumption.2.The compression molding with self-resistance electric heating process was optimized by the orthogonal test.The experimental results show that the forming temperature,forming pressure and impregnation time have significant effects on the impregnation quality and flexural properties of carbon fiber reinforced PA 6 laminates,but have no significant effects on the impact properties.The optimum process conditions are obtained as forming temperature of 270 ℃,forming pressure of 2.5 MPa and impregnation time of 15 min.3.The cooling rate was controlled through different power adjustment method to adjust the crystal and mechanical properties of carbon fiber reinforced PA 6 laminates.It was found that with the decrease of cooling rate,the crystallinity of matrix increases gradually.Compared with the natural cooling mode,the flexrual strength of the laminates with current reduction rate of 0.6 A/min increased by 29.45%,and the impact property of laminates is weakened,while the high temperature environment improves the impact property of laminates to some extent.This study compared the comprehensive properties of continuous carbon fiber reinforced PA 6 fabricated by the self-resistance electric heating compression molding process and the conventional compression molding process.The new process has been optimized,and carbon fiber reinforced PA 6 laminates with high quality,excellent mechanical properties have been successfully manufactured.This study provides a new way to manufacture carbon fiber reinforced thermoplastic composites with high efficiency and energy saving.