Silicon carbide (SiC) is a ceramic compound made of silicon and carbon, used by industrial microwave furnaces as a susceptor material to speed radiant heating in the ramp-up stages of sintering, and to moderate the cooling stages.  The microSinterWave dental ovens use a high temperature formulation of silicon carbide which remains effective and stable at temperatures of 1600°C, manufactured by combining silica sand and carbon in a high temperature graphite electric resistance furnace..

A susceptor is a material which easily absorbs microwave radiation and converts it to heat.  Susceptors are used in industrial heating processes and occasionally even in home cooking. In home microwaves, the grey paper susceptor material in the sleeve around a Hot Pocket frozen entree gets to high termperatures very quickly and radiates heat on the food effectively browning the outside with infrared energy while the microwaves more deeply penetrate and cook the inside.  The same principles apply to microwave sintering of dental ceramics, where copings are placed on a susceptor plate made of silicon carbide inside a crucible that contains silicon carbide flakes, both designed to radiate infrared heat onto the samples.  The susceptors quickly get the dental ceramics up to a temperature where they can directly couple with the microwave energy to complete the sintering process (Zirconia couples with microwaves at about 1000ºC).