Abstract: A process for preparing a ceramic composite material containing alpha silicon carbide whiskers is disclosed.In the process, a slurry containing non-aqueous liquid and aluminum material, amorphous carbon, and silica is provided. This slurry is thereafter pelletized, the pellets are dried, the dried pellets are preheated, and the preheated pellets are then ignited. The ignited pellets undergo an exothermic reaction, forming the composite containing alpha silicon carbide whiskers.The composite material is heat-treated by first heating it to a temperature of 900-1100 degrees centigrade at a rate of 8-15 degrees per minute, and then heating it to a temperature of 1,250-1,350 degrees centigrade at a rate of 2-5 degrees per minute.

Abstract: A process for the preparation of a mixture comprising a solid phase and a liquid phase of a metal alloy, in which the concentration of the said solid phase has a pre-established value, is described; it comprises at least a first stage for bringing the said alloy into a completely fluid state, a second stage for creating a constant range flow of the mixture between an inlet section and an outlet section, a third stage for subdividing in a longitudinal direction the said flow into a plurality of flow sections, each of which has a predetermined length and in each of which the flow is subdivided into at least two independent streams, and a fourth stage for making each of the said streams flow along such a trajectory as to obtain in each of the said streams of each flow section a confluence of parts of both streams of the immediately preceding section.