Apparatus for processing ceramics using microwave oven with resistance heating unit

An apparatus for processing ceramic materials, comprising

• an insulated housing providing a heating chamber defining a workspace and a secondary chamber disposed adjacent to the heating chamber,
• the heating chamber having an interior microwave-impermeable lining enclosing the workspace and access means permitting the materials to be placed in and removed from the workspace,
• convectional heating means in said secondary chamber,
• a microwave energy source,
• waveguide means coupled to the heating chamber for propagating microwave energy into the heating chamber,
• a perforated wall separating the heating chamber and the secondary chamber to permit convectional and radiative heat transfer from the secondary chamber to the heating chamber, and
• temperature measuring means for measuring the temperature of the workspace and control means for selectively activating said convectional heating means for preheating the workspace to approximately 500.degree.-600.degree. C. and means for selectively activating the microwave energy source when the ambient temperature in the workspace has reached a selected temperature approximately corresponding to threshold temperature at which microwave absorption of a ceramic material being processed increases significantly.