METHOD FOR PRODUCIN SINGLE-PHASE INCONGRUENTLY MELTING INTERMETALLIC PHASES

摘要

A method for producing single-phase intermetallic phases, which melt incongruently within a temperature range of 900.degree. to 2,000.degree.K, with a homogeneity range of ? 10 atom% at room temperature by co-reduction is described. The exothermic reaction of the calciothermal reduction is adjusted by altering the oxide content of the reaction mixture, the composition of which corresponds to the desired single-phase alloy, in such a way that the temperature condition Tm > TR ? 0.9 Tm (in .degree.K) is fulfilled, Tm being the melting temperature of the intermetallic phase and TR the reaction temperature. The components of the reaction mixture, with the exception of calcium, have an average particle size of ? 75 .mu.m. The reaction product at the end of the exothermic reaction is tempered at a temperature which is at least 0.7 times the melting temperature Tm of the desired, single-phase alloy, measured in .degree.K, but is less than the meltingtemperature Tm, during a period sufficient for the diffusion of the components.