The influence of reaction paths on powder metallurgical reactions, illustrated at the preparation of some sulphide carbides

The choice of the reaction path can be of importance in the case where chemical equilibrium is not readily reached, as it is the case in powder metallurgical solid state reactions. An example is the synthesis of the sulphide carbides Ti2SC, Nb21SC1−x and Ta2S2C. Some aspects of the ternary phase diagrams TaSC, TaSeC and NbSC are discussed. In special cases there is also the possibility to prepare compounds that are not part of the equilibrium phase diagram, like Nb2S2C, by more complex reaction paths.