Influence of different methods of controlling microwave sintering

The ceramic industry uses enormous amounts of energy to produce products at high temperatures. Energy-saving measures based on sintering process improvements are examined. Oxide ceramics were irradiated by two different methods during microwave sintering: intermittent use of the same high power levels (time-control method) and continuous use of lower, increasing levels of power (power-control method). We found that: 1) the power consumption and efficiency of the time-control method were lower than those of the power-control method; 2) the power-control method gave more precise control of temperature under our experimental conditions; 3) sample densification did not differ greatly between the two methods; and 4) grain growth did not differ greatly between the two methods.