Furnace for sintering ceramics, carbon heater used therefor and process for sintering ceramics.

摘要

In a furnace for sintering non-oxidic ceramics, particularly Si3N4, which comprises a space for accommodating a ceramic shaped body (12), carbon heaters (8) arranged around the ceramic shaped body in said space and heat insulating layers (13) of carbon fiber mat that cover the inner walls of the furnace, sheetings (18) of laminated graphite leaves having an ash content of not more than 0.3% by weight are provided between said heat insulating layers (13) and said ceramic shaped body (12). The carbon heaters are of high purity graphite having a carbon content of at least 99.9980%, a silicon content of not more than 5 ppm and an iron content of not more than 9 ppm by weight. These measures protect the shaped body from harmful influence of carbon fiber dusts liberated from the insulating layers during sintering.