Dense silicon nitride composite material and process for its production

: Klemm, H.; Herrmann, M.; Tangermann, K.; Schubert, C.

Abstract
The invention relates to a dense silicon nitride composite material which can be utilized as a high-temperture component in the construction of fittings and engines. The invention is based on the technical problem of producing a dense silicon nitride composite material which has a long life and reliability at high temperatures. The problem is solved by the invention by means of a dense silicon nitride composite material which contains a proportion of 3% to 50% by mass of a strengthening component, whereby the strengthening component contains 10% to 90% by mass of Me<-5 Si<-3 and the remaining proportion of MeSi<-2 or MeSi<-2 and silicides of other stoichiometries, where Me is a metal or a mixture of metals. The problem is also solved according to the invention by a process whereby the material is produced by sintering and/or sintering under pressure and/or high-termperature isostatic pressing, and the strengthening component used is Me<-5 Si<-3 - and MeSi<-2 powder or is used as a prec ursor, whereby a nitrogen/temperature ratio must be adjusted until closed porosity is reached, said ratio leading to the formation and stabilization of Me<-5 Si<-3.