Microwave absorbing and mechanical properties of carbon fiber/bismaleimide composites imbedded with Fe@C/PEK-C nano-membranes

An effective approach is proposed to fabricate hybrid multilayer stealth composite composed of carbon fiber/bismaleimide composites containing carbon coated Fe (Fe@C)/phenolphthalein polyetherketone (PEK-C) nano-membranes as interlaminar electromagnetic absorbing agents. Dynamic mechanical analysis and interlaminar shear strength tests were carried out to evaluate mechanical properties. Special attention was paid to the permittivity, permeability and microwave absorbing properties. The results indicated that the radar-absorbing structural materials (RASs) showed a minimum reflection loss (RL) value of -16.85dB observed at 11.5GHz at a thickness of 1.7mm, with the values exceeding -10dB achieved in 9.7-16.7GHz with increasing thicknesses. The measured RL values were in good agreement with the calculated ones. This strategy may be extended as a versatile approach to achieve high performance RASs, thereby promoting their engineering applications at low cost in aerospace industry.