Microwave heating of ceramic composites

The microwave heating of a ceramic composite is modelled and analysed. The composite consists of many small ceramic particles embedded in a ceramic ce ment. The composite is assumed to be well insulated, and each particle is a ssumed to be in imperfect thermal contact with the surrounding cement. Base d on these two assumptions an asymptotic theory exploiting the small Blot n umber and small non-dimensional contact conductance is developed. Our asymp totic theory yields a set of nonlinear partial differential equations which govern the temperature in the composite. These are reduced to a set of cou pled nonlinear ordinary differential equations in which the surface area of each particle enters as a parameter. Recent experiments with such composit es have shown that the steady-state temperature of the composite is strongl y dependent upon the radii of the embedded particles. Our model captures th is effect. In fact, our analysis shows that the assumption of imperfect the rmal contact between the particles and the ceramic cement is essential for this trend to be established.