Hybrid method for firing of ceramics

Abstract

A method of firing ceramic materials involving placing the ceramic material in a microwave heating apparatus having a microwave cavity and subjecting the ceramic material to combination of microwave radiation and conventional heat energy according to predetermined time-temperature profile. The time-temperature profile, ranging from room temperature the sintering soak temperature, comprises a series of target heating rate temperature setpoints and a series of corresponding core and surface temperature setpoints with each of the core and surface temperature setpoints being offset from the target heating rate setpoints a predetermined offset temperature. In a preferred embodiment, the method involves continuously measuring the ceramic body core temperature, T , and the surface temperature T and independently controlling the microwave power and the conventional heat in response to the core temperature value and the surface temperature value, respectively. Preferably, controlling of the microwave power involves adjusting the microwave power in response to a difference between core temperature setpoint and a biased core measured temperature, and controlling of the conventional heat involves adjusting the conventional heat in response to the difference between the surface temperature setpoint and a biased surface temperature.