| Реферат: | eng: This paper presents a theoretical analysis of quasi-equilibrium directional solidification of a quaternary melt. We consider the variation in the composition of phases in each portion of the sample and changes in phase composition for various types of phase reactions. The results indicate that the melt trajectory during directional solidification may belong only to those phase diagram elements corresponding to the crystallization of binary, ternary, or quaternary eutectics or single-phase crystallization regions. Using the directional solidification of a melt with the composition (at %) Cu 29.37, Ni 17.72, Fe 5.91, and S 47.00, we obtained a sample consisting of zones with different phase compositions: [Ni z (Fe,Cu) 1 - z ]S 1 ± δ single-phase zone, [Ni z (Fe,Cu) 1 - z ]S 1 ± δ + Cu 5 ± x Fe 1 ± x S 4 binary eutectic mixture, and [Ni z (Fe,Cu) 1 - z ]S 1 ± δ + Cu 5 ± x Fe 1 ± x S 4 + (Ni z Fe 1 - z )S 2 ternary eutectic mixture. In going from one zone to another, new phases appear and the average composition of the sample changes sharply, whereas the compositions of the melt and solid solution present in neighboring zones vary continuously. These results are consistent with theoretical concepts. © 2011 Pleiades Publishing, Ltd.
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