Microwave curing of composite material

Abstract: Microwave curing has become a trend in composite processing due to its efficiency in energy consumption compared to the traditional curing method. However, as commonly found in every composite processing, controlling the microwave curing process remains challenging. The most feasible control method is to build a numerical model. In this report, the numerical model was developed to simulate the microwave heating of cured and uncured glass/epoxy samples. The objective of cured sample simulation was to obtain the average electric field intensity generated in the composite, which was then used in the uncured sample simulation. Meanwhile, three methods of microwave heating to the uncured samples were suggested, i.e. heating with constant electric field intensity, heating with non-constant electric field intensity, and heating with concentrated electric field intensity. The simulation was further expanded by combining microwave heating with contact heating to improve the curing state on the corner section. The simulation showed a reasonable temperature evolution trend for all three microwave-heated methods of an uncured sample. However, they are all different from the experiment result. Meanwhile, a high temperature in the core layer was observed in all simulations with a gradual temperature decline toward the outer layer, as expected from a microwave heated object. Finally, a decent degree of cure was obtained by employing additional contact heating without involving microwaves.