Abstract: The stepwise fabrication method combines 125 keV low energy electron beam and fiber placement for polymer matrix composites is investigated to reduce the high energy consumption and curing time of the auto-clave process and to overcome the high shield investment of the high energy electron beam process, the properties of the composites is also evaluated. The experimental results show that the 125 keV electron beam can not penetrate the single layer prepreg with the thickness of 0.125 mm due to its low energy. But the consistent irradiation can be gotten in the prepreg by both-side irradiation. Because of the very low temperature of the prepreg during the irradiation process, the degree of curing and the glass transition temperature of the composites at the 250 kGy irradiation does level are only 60.71% and 48.34 ℃, respectively. But after heat postcure, the degree of curing and the glass transition temperature of the composites increase significantly. After being treated at 180 ℃ for 30 min, the degree of curing of the composites laminate irradiates both-side with 50 kGy does increased from 16.7% to 97.4%, and the glass transition temperature increases from –3.2 ℃ to 167.3 ℃, respectively. The test results exhibit that the interlaminar shear strength of the laminate is cured by low energy electron beam and heat treatment reaches 59.62 MPa, which is close to that of the composite laminate cured by high energy electron beam.

Key words: Composites, Fiber placement, Interlaminar shear strength, Low-energy electron beam, Stepwise fabrication