采用计算相图构建的Ge-Pd体系热力学模型

发布时间：2018-07-29 13:08

【摘要】：针对Ge-Pd体系实验测定的相图难以外推到多元体系的问题,提出采用计算相图(Calphad)技术构建Ge-Pd体系的热力学模型。Ge-Pd体系中不同类别的相采用不同的热力学模型描述,其中纯组元Ge对Pd几乎不存在固溶度,可直接采用欧洲热力学研究组发布的热力学模型;液相和端际固溶体(Pd)采用溶体模型描述;化学计量比化合物GePd、GePd_2和Ge_8Pd_(21)采用线性化合物模型描述;非化学计量比化合物Ge_9Pd_(25)、GePd_3、α-GePd_5和β-GePd_5采用亚点阵模型描述其成分区间。对于各相的热力学模型参数,利用已有的液相混合焓、液相混合熵、不变反应的温度和成分等实验数据进行优化,获得了Ge-Pd体系中一套自洽的热力学模型。采用该热力学模型的计算结果与大部分实验数据相吻合,可外推至多元体系,从而可为Ge基多元体系的热力学数据库构建、材料成分设计和制备工艺优化提供依据。
[Abstract]:In view of the difficulty of extrapolating the phase diagrams measured in the Ge-Pd system to the multicomponent system, a thermodynamic model of the Ge-Pd system using the computational phase diagram (Calphad) technique is proposed. Different thermodynamic models are used to describe the different types of phases in the Ge-Pd system. The pure component GE has almost no solid solubility to PD and can be directly used as the thermodynamic model published by the European study Group of Thermodynamics, and the liquid phase and interterminal solid solution (Pd) is described by the solution model. The stoichiometric compounds GePd2 and Ge8Pd21 are described by linear compound models, and the non-stoichiometric compounds Ge9Pd25 / GePd3, 伪 -GePdStack5 and 尾 -GePdst5 are described by sublattice models. For the thermodynamic model parameters of each phase, a set of self-consistent thermodynamic model in Ge-Pd system was obtained by using the existing experimental data of liquid phase mixing enthalpy, liquid phase mixing entropy, temperature and composition of invariant reaction. The calculated results of the thermodynamic model are consistent with most of the experimental data and can be extrapolated to the multicomponent system, thus providing a basis for the thermodynamic database construction, material composition design and preparation process optimization of the GE based multicomponent system.
【作者单位】：长安大学材料科学与工程学院;北京百慕航材高科技股份有限公司;
【基金】：国家自然科学基金资助项目(51401032,51401033) 中央高校基本科研业务费专项资金资助项目(0009-2014G1311089,310831163401)
【分类号】：O642.4

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