VERFAHREN UND VORRICHTUNG ZUR HERSTELLUNG VON HOCHREINEM SILICIUMCARBIDPULVER UND SEINE VERWENDUNG

摘要

Very high purity powder of silicon carbide in the submicronic field, which can be used as sintering material for producing shaped articles. The preparation of this silicon carbide powder can be done by passage of alkylsilanes in gaseous phase and chemical scission of the alkylsilane at high temperature. Such a process is carried out in particular by passage of the alkylsilanes through a flow reactor; during this passage the gasified alkylsilane is heated up to a temperature range comprised between 450`C and the temperature produced in a plasma burner, so as to obtain the thermal scission, the pulverulent product thus obtained is then collected in a precipitation chamber. An apparatus allowing to obtain the silicon carbide powder comprises: a graphite conduit (1) with conical inlet surrounded by a thermal insulator, a cooling system (5) arranged at the end of the graphite conduit, a water-cooled device allowing to introduce the gas current through a central injector and a circular injector (6) and a device for precipitation of the power (7).