改进的M-MIVM在镍基固态合金中的应用

合金的热力学性质在材料科学和工程中起着重要的作用。因此，对于复杂体系，利用灵活可靠的热力学模型进行理论计算具有重要价值和科学意义。改进的M-MIVM能够同时表达分子构型的微观状态数（熵）和分子相互作用（焓）对过量吉布斯自由能的贡献，具有坚实的物理基础，可预测实际固溶体的热力学性质。该模型的一个显著优点在于仅利用二元无限稀释活度系数或二元活度数据就可以描述和预测多元固溶体的热力学性质。利用改进的M-MIVM对Au-Ni、Co-Ni、Cr-Ni、Cu-Ni、Fe-Ni、Ni-Pd、Ni-Pt、Ni-V、Co-Fe、Cr-Fe、Co-Fe-Ni、Cr-Fe-Ni、C-Co-Fe-Ni系等镍基固溶体合金的活度进行了预测。研究结果表明：除Cr-Ni、Ni-V两个二元非连续固溶体外，其余体系的活度模型预测值与实验数据吻合较好，13个体系总的相对平均偏差仅为4.75%，且预测效果优于MIVM，能够满足工程计算要求。改进的M-MIVM在镍基固态合金应用中具有一定的准确性、稳定性和适用性，可为镍基合金设计提供较为可靠的热力学数据。

Application of Modified M-MIVM in Ni-based Solid Alloys

Thermodynamic properties for an alloy system play an important role in the materials science and engineering. Therefore, theoretical calculations by using thermodynamic model having the flexibility and reliability to deal with complexity are very useful and have scientific meaning. The modified M-MIVM was deduced from physical principles, and it can reflect the contributions from both the molecular configuration micro-state number (entropy) and molecular interactions (enthalpy) towards excessive Gibbs free energy. The proposed equations are more consistent with the practical solid solutions. A significant advantage of this model lies in its can use either the relevant binary infinite dilution activity coefficients or binary activity to describe and predict the thermodynamic properties of the binary or multi-component solid solutions. The thermodynamic properties of Ni-based solid solution alloys such as Au-Ni, Co-Ni, Cr-Ni, Cu-Ni, Fe-Ni, Ni-Pd, Ni-Pt, Ni-V, Co-Fe, Cr-Fe, Co-Fe-Ni, Cr-Fe-Ni and C-Co-Fe-Ni systems were predicted by using the proposed model. The results show that the activity values predicted by the modified M-MIVM are in good agreement with the experimental data except for Cr-Ni and Ni-V binary discontinuous solid solutions, and the total average relative error of the 13 systems is 4.75%, and the prediction effect of the new model is better than that of MIVM, which can meet the requirement of engineering calculation. The modified M-MIVM has certain accuracy, stability and applicability in the application of Ni-based solid alloy, and can provide more reliable thermodynamic data for Ni-based alloy design.