Microwave uniformity regulation and its influence on temperature field distribution of composite materials

Microwave heating technology is currently a prominent area of research in the field of composites curing due to its advantages, including selective heating, energy saving and high efficiency. However, the uneven distribution of electric field inside the cavity leads to asynchronous heating of composite components. This, in turn, results in severe deformation and curing defects, posing a major challenge that hinders the widespread industrial application of microwave process. In this paper, by combining nonlinear electromagnetic constitutive equations and power density functions, the correlation between the uniformity of electric field and the temperature distribution in composite components during microwave heating was elucidated. Finite element simulations were employed to investigate the influence of various regulation methods, such as the setting of generators, the introduction of mode stirrers, and the relative movement of loading platform, on the uniformity of electric field distribution. An experimental apparatus for regulating microwave heating uniformity was independently designed and developed, and a series of experiments were conducted to validate the accuracy of the simulation analysis and investigate the temperature variation in microwave-cured components under different regulation modes. Finally, an analysis was performed on the influence of temperature distribution during the curing process on the performance of composites.