Abstract: Aiming at improving the bearing capacity of composite transmission shaft manufactured by microwave curing, the material enhancement method with hybrid fiber as reinforcement and alumina particle reinforced epoxy as matrix was proposed. The microwave curing process was optimized simultaneously. The optimal hybrid volume ratio, Al₂O₃ content and microwave curing parameters were determined by comparing the interlaminar shear, tensile and dynamic impact properties of plate specimens. On that basis, the reduced transmission shaft was manufactured by wet winding with fabrics. The mechanical property difference between thermal and microwave curing was compared by bending and torque test. The experimental results showed that ① the interlaminar shear strength of specimen could be enhanced by low-power preheat and high-power curing on the premise of efficiency. ② With the increase of CF/GF hybrid ratio, the interlaminar shear strength and tensile properties increased, while the impact toughness was reduced. ③ When the Al₂O₃ content increased from 0 to 30%, the interlaminar shear strength, tensile strength and module increased by 8.7%, 27.9% and 12.5%, respectively. However, further increase in Al₂O₃ content resulted in the reduction of properties. ④ The maximum torque, bending strength and module of composite transmission shaft manufactured by microwave curing showed the same level with those by thermal curing.

Key words: composite material transmission shaft, microwave curing, particle reinforcement, hybrid fiber, mechanical properties