Verfahren zur Herstellung eines Werkstoffes, Formkoerpern aus diesem Werkstoff und deren Verwendung

Producing a silicon-containing non-oxide ceramic material comprises subjecting a green body or layer, formed from a homogeneous powder of a non-oxidic silicon compound or pure silicon, to heat treatment at at least 800 deg. C in an oxidising atmosphere and/or to heat input from a deflected laser beam. Also claimed is the production of an article by layer-wise selective laser sintering of the above material. USE - The material is used as a filter material, as an electrostatic filter or as a protective layer on metallic substrates (claimed). ADVANTAGE - The presence of an oxidising atmosphere causes in-situ formation of small amounts of a temporary binder phase of silicon and/or Si-O-N compounds to provide high strength with almost no undesired by-products. The material has low production cost, can be formed to a wide variety of shapes (including large or complicated shaped bodies), can be produced without the use of a sintering aid, exhibits almost no shrinkage during production and has a relatively high porosity allowing use as a filter material or subsequent metal (e.g. aluminium) or silicon infiltration.