The Study Of Terminal Solubility For Binary Alloys With The Embedded Atom Method

The terminal solubilities of alloys are important for the phasediagram. At present, the phase diagram datas are generally obtained byexperiment, thermodynamics method and the first principle. Theembedded-atom method has been used to compulate the alloy's muchcharacter, such as the formation enthalpy, the suface gather, vacantposition enthalpy, and so on, which proves that the method is successfulfor the study of alloy's performance. Considering this advantage of theembedded-atom method, we combine it and thermodynamics method tostudy the terminal solubilities of binary alloys. The terminal solubilitiesof Mo-Pd and Cr-Ni bcc-fcc binary alloys at different temperature arecalculated, and some significative results are achieved.With the MAEAM model, the curves of Mo-Pd binary alloy'freeenergy-component at 1473K and 2028K are calculated according the bccand fcc structure respectively. The configuration free energy is consideredduring computation. With the method of common tangent, we concludethe following conclusions. At 1473K, the terminal solubilities are foundto be 0.6at% Pd for bcc Mo (Pd) and 26.8at% Mo for fcc Pd (Mo). At theperitectic temperature (2028K) neighbor, which are 1.1at% and 29.5at%,respectively. The phase stability is also analysed according the curve offree energy-component. At the same time, the possible reasons of errorare analysed.With the MAEAM model, considering the configuration free energyand libration free energy, the curves of Cr-Ni binary alloy'freeenergy-component at 1550K are calculated according the bcc and fccstructure respectively. The terminal solubilities at 1550K are obtained.That is, the terminal solubilities are 6at% Ni for bcc Cr(Ni) and 51at% Crfor fcc Ni (Cr). The phase stability and the possible reasons of error arealso analysed.The terminal solubilities of bcc-fcc binary alloys are studied by theembedded-atom method for the first time. During computation, the configuration entropy and libration entropy are considered. Thecalculation results are in agreement with other theoretical andexperimental results. Which illustrate that it is feasible to study theterminal solubilities of bcc-fcc binary alloys with the MAEAM modeland the study of this paper is successful.