Recent studies on thermophysical properties of metallic alloys with PROSPECT: Excess properties to construct a solution model
Recent studies on thermophysical properties of metallic alloys with PROSPECT: Excess properties to construct a solution model
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DOI：
10.32908/hthp.v49.851
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发表时间：
2020-01-01
影响因子：
1.1
通讯作者：
Adachi, M.
中科院分区：
文献类型：
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作者：
Fukuyama, H.;Watanabe, M.;Adachi, M.
展望了高温下热物性测量的系统前景。精确的热物理测量提供了精确的过剩函数，这代表了溶液的非理想性。我们在电子结构和热力学的基础上，利用过剩函数讨论了溶液模型。Pd-Fe体系表现出正的过剩体积V-E和负的过剩吉布斯能G(E)。这些系统的相图与其他Pd-X和Pt-X系统(其中X是Fe、Ni、Co或Cu)的相图有共同的特征，这意味着它们都有有序-无序转变。从合金的电子结构出发，讨论了V-E和G(E)之间的关系，并提出了一个能图来解释这种关系。在整个成分范围和较宽的温度范围内，Fe-Ni熔体的超额热容C-p(E)均为正值。我们估算了从C-P(E)到Fe-Ni熔体的超额热H-E和超额熵S-E与温度的关系。对于具有正C-p(E)的H-E和S-E，满足Lupis-Elliott规则。
We have developed the system PROSPECT for measuring thermophysical properties at high temperature. Precise thermophysical measurements provide accurate excess functions, which represent non-ideality of solutions. We use excess functions to discuss solution models on the basis of electronic structure and thermodynamics. Pd-Fe systems show positive excess volume V-E with negative excess Gibbs energy G(E). The phase diagrams of these systems have common features with those of other Pd-X and Pt-X systems (where X is Fe, Ni, Co, or Cu), which means they all have order-disorder transitions. The correlation between V-E and G(E) is discussed in terms of the electronic structure of the alloys, and an energy diagram is proposed to understand this correlation. The excess heat capacity C-p(E) of Fe-Ni melts is positive over a whole composition range and a wide temperature range. We estimate the temperature dependences of the excess enthalpy H-E and excess entropy S-E of Fe-Ni melts from C-p(E). The Lupis-Elliott rule is satisfied for H-E and S-E with positive C-p(E).