UNIQUE APPLICATION OF MICROWAVE-ENERGY TO THE PROCESSING OF CERAMIC MATERIALS

Microwave energy has been used to internally ignite combustible materials, resulting in a relatively uniform combustion wavefront propagating radially outward. Since microwave heating and combustion synthesis assist each other, samples of Ti + C reactants having compact density greater than 80 percent of theoretical values have been ignited successfully. Internal heating by microwave radiation has also been utilized to control propagation of the combustion wavefront in high density compacts of TiO2 + Al + C reactants. Microwave ignition and controlled combustion of dense compacts followed by sintering has allowed fabrication of Al2O3/TiC composites without significant expansion usually observed with conventional self-propagating high-temperature synthesis (SHS).