陶瓷材料吸收微波的微观机制

分析带电粒子在微波电场中动力学方程的解,可知微波电场对带电粒子做的功一部分变成粒子为克服周围环境阻尼力做功,另一部分变成粒子向外辐射的电磁波能量.材料本身吸收的微波能量就是材料内部所有带电粒子克服阻尼做功之和.材料对微波的吸收能力与阻尼系数关系极大.在金属中,自由电子受到的阻尼力非常小,所以金属对微波几乎全反射.在陶瓷材料中,带电粒子受到的阻尼非常大,所以陶瓷也很难吸收微波,与金属的全反射相反,微波几乎全部穿透陶瓷材料.随着温度的升高,陶瓷材料中带电粒子受的阻尼力下降,其对微波的吸收能力也大大增强.

The micro-mechanism of microwave absorption of ceramic materials

By analyzing the solution of the dynamic equation of a charged particle in microwave electric field, we note that one part of the work done by microwave electric field to a charged particle becomes the work done by the charged particle to overcome the ambient damp force, the other part transforms into the energy irradiated by the charged particle. The energy absorbed by materials is the work that the charged particles do to overcome the ambient damp force. The damp coefficient seriously affects the absorption ability of materials. In metal, the damp force to free electrons is very small, so metals hardly absorb microwave and reflect almost all of them. In nonmetallic materials, the damp force to charged particles is very large, so this kind of materials hardly absorbs microwave, in contrast with metal it allows almost all microwave penetrate it. With the temperature increasing, the damp force decreases, the absorption abilities of those materials increase greatly.