Computer Simulation of the Thermodynamics of Coherent Interfaces

相干界面热力学的计算机模拟

• 批准号: 10650645
• 负责人: MARCEL Sluiter
• 金额: $ 1.41万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650645/
• 关键词: Interfaces; Alloys; AntiPhase Boundaries; Impurities; Ni-Al-Ti alloys; Interphase Boundaries; Segregation; Cluster Variation Method; クラスター変分法; 第一原理クラスター変分法(CVM); 状態図; 整合界面; 界面エネルギー; Ni_3Al

The classification of impurity behavior at coherent interfaces based on the ternary phase diagram, was studied. Cluster variation method (CVM) calculations were applied to the fcc - L1ィイD22ィエD2 interphase boundary, and the interphase boundary (IPB) energy, concentration profile and segregation, site preference and fcc/ L1ィイD22ィエD2 partitioning were computed. A strong correlation between site preference and partitioning and its temperature dependence was discovered. Moreover, impurities which have repulsive interactions with both A and B segregate away from an IPB and increase its energy. Other types of impurities segregated towards the IPB but lowered its energy only slightly.The (111) and (100) antiphase boundary (APB) energies in NIィイD23ィエD2Al alloyed with Ti were calculated from first principles. Effective interatomic interactions were computed from electronic total energy calculations and very large scale CVM calculations (using 10s of thousands of correlation functions) were carried out. Ti strongly segregated away from the (111) and (100) APBs and raises the APB energy by as much as 50 mJ/mィイD12ィエD1 per a/o Ti. This result agrees with the (scarce) experimental data.Sofar the effect of the long-ranged elastic strain was neglected. Therefore, a new way to compute this contribution to the solution energy of impurities was derived and applied to Mg, Sr, Li and vacancies in an fcc Al matrix and applied to antisite defects in GaAs. Somewhat surprisingly, the accurate solution energies were shown to be useful for obtaining enthalpies of mixing as well.

研究了基于三元相图的共格界面上杂质行为的分类。采用团簇变分法（CVM）计算了fcc/L1/D22/D22相间边界，计算了相间边界能量、浓度分布和分凝、位置偏好和fcc/ L1/D22/D22分配。一个很强的相关性之间的网站偏好和分区和它的温度依赖性被发现。此外，与A和B都具有排斥相互作用的杂质从IP B分离并增加其能量。用第一性原理计算了Ni_（111）Al_（23）Al_（22）Al_（23）Al_有效的原子间相互作用从电子总能量计算和非常大规模的CVM计算（使用成千上万的相关函数）进行了计算。Ti强烈地从（111）和（100）APB中分离出来，并且每a/o Ti使APB能量增加多达50 mJ/m Ω D12 Ω D1。这一结果与实验数据相符，但忽略了长程弹性应变的影响。因此，一种新的方法来计算这种贡献的溶解能的杂质推导和应用到镁，锶，锂和空位在fcc铝矩阵和应用到反位缺陷GaAs。有些令人惊讶的是，精确的解决方案的能量被证明是有用的，以及获得混合。

项目成果

M.Sluiter,Y.Kawazoe: "Prediction of Solution Enthalpies of Substitutional Impurities in Aluminum"Mat. Sci. Eng.. 8. (2000)

M.Sluiter，Y.Kawazoe：“铝中取代杂质的溶解焓的预测”Mat。

M.Sluiter,H.-P.Wang,and Y.Kawazoe: "A Classification of the Role of Impurities at Inter-Phase Boundaries" Proceedings of the Special Symposium on Advanced Materials 4.(Nagoya University,Nagoya). 369-372 (1998)

M.Sluiter、H.-P.Wang、Y.Kawazoe：“A Classification of the Role of Impurities at Inter-Phase Boundaries”先进材料特别研讨会论文集 4.（名古屋大学，名古屋）。

M. Sluiter and Y. Kawazoe: "Prediction of Solution Enthalpies of Substitutional Impurities in Aluminum"Modelling and Simulation in Mat. Sci. Eng.. May(accepted). (2000)

M. Sluiter 和 Y. Kawazoe：“铝中取代杂质的溶解焓的预测”Mat 中的建模和仿真。

H.P.Wang: "Segregation Effects of Substitutional Impurities of Coherent Interfaces"M. Sc Thesis, Tohoku Univ. (1999)

H.P.Wang：“相干界面取代杂质的偏析效应”M。

M.Sluiter and Y.Kawazoe: "A Study of the Thermodynamics of Segregation and Partial Order at (111) Anti-Phase Boundaries in Ni_3Al"Phil. Mag. A. 78. 1353-1364 (1998)

M.Sluiter 和 Y.Kawazoe：“Ni_3Al (111) 反相边界处的偏析和偏序热力学研究”Phil。