Abstract
A ternary σ-phase (Cr0.39–0.57Mo0.47–0.29Si0.14) has been detected in the chromium—molybdenum—silicon system at 1500 °C. The novel σ-phase, which displays only a small degree of ordering, undergoes eutectoid decomposition at ca. 1200 °C, into (Cr, Mo)+(Cr,Mo)3Si. The relative stability bility of the ternary σ-phase and the non-existing binary σ-phases (Cr−Si, Mo−Si) were estimated from the observed equilibria. With respect to the coexistent phases there is an amount of 2500 cal/g atom metal necessary for stabilizing of the ternary σ-phases at 1500 °C. The slight deviation from completely random distribution reflects on the entropy change and there is fair agreement with the entropy change calculated from the temperature dependency of ΔG z, σ.
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Rudy, E., Nowotny, H. Eine σ-Phase im System Chrom—Molybdän—Silicium. Monatshefte für Chemie 105, 156–168 (1974). https://doi.org/10.1007/BF00911301
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DOI: https://doi.org/10.1007/BF00911301