Herrmann, M.M.HerrmannSchubert, C.C.SchubertKlemm, H.H.KlemmTangermann, K.K.Tangermann2022-03-082022-03-081998https://publica.fraunhofer.de/handle/publica/304060Production of a silicon-containing non-oxide ceramic body, having surface silicate glaze-forming components of thermal expansion coefficient matching that of the ceramic base material, involves forming the glaze at 600-1770 deg. C and taking into account the quantity of reactive silicon dioxide formed in the glaze. Also claimed is a silicon-containing non-oxide ceramic body produced by the above process and having a silicate-based glaze on its surface. Preferably, the body is a sintered silicon nitride or carbide body which is glazed by applying an alkali or alkaline earth metal compound or a rare earth metal compound and chemically reacting the compound with the silicon nitride or carbide in an oxidising atmosphere at 600-1400 deg. C (for an alkali or alkaline earth metal compound) or at 1100-1500 deg. C (for a rare earth metal compound). USE - For producing glazed heavy duty non-oxide ceramic bodies, including entire pots and chemical equipment fittings. ADVANTAGE - The process forms a corrosion protective, surface levelling and optionally coloured coating thus reducing the costs of post-machining for surface smoothing and polishing.de608666620patent1997-19712918