Interatomic potentials for Ti-Al with and without angular forces
Interatomic potentials for Ti-Al with and without angular forces
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DOI：
10.1088/0965-0393/2/5/003
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发表时间：
1994-09
影响因子：
1.8
通讯作者：
D. Farkas
中科院分区：
文献类型：
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作者：
D. Farkas
通过对L10 TiAl四元相性质的经验拟合，导出了Ti-Al系中嵌入原子和嵌入缺陷类型的原子间相互作用势。还考虑了DO 19 Ti 3Al和DO 22 TiAl 3相的性能。嵌入原子势再现了所需的大部分性质，除了L1 o TiAl呈现一个负的Cauchy压力，这意味着使用嵌入原子方法无法精确拟合弹性常数。为了正确拟合弹性常数，采用了角向力的嵌入缺陷技术。在保持嵌入原子势的有效对相互作用不变的情况下，利用嵌入缺陷技术研究了角向力的影响。角向力的最强影响体现在弹性常数的值上。平面断层能量变化约5%。的潜力进行了测试的晶格性质的其他稳定和亚稳相的二元系统中的利益。结果表明，角向力的加入对四角晶系和六角晶系的相稳定性和c/a比值影响不大。本电位适合于模拟Ti-Al系各相的缺陷。
Interatomic potentials of the embedded atom and embedded defect types were derived for the Ti-Al system by empirical fitting to the properties of the L1o TiAl tetragonal phase. Consideration was also given to properties of the DO19 Ti3Al and the DO22 TiAl3 phases. The embedded atom potentials reproduce most of the properties needed, except that L1o TiAl presents one negative Cauchy pressure, meaning that the elastic constants cannot be fit exactly using the embedded atom method. The embedded defect technique for angular forces was used in order to fit the elastic constants correctly. Keeping the same effective pair interaction of the embedded atom potential, the effects of angular forces were studied using the embedded defect technique. The strongest effects of the angular forces are seen in the values of the elastic constants. Planar fault energies change by about 5%. The potentials were tested for the lattice properties of other stable and metastable phases of interest in the binary system. It was found that the addition of angular forces has little effect on phase stability, and c/a ratios of the tetragonal and hexagonal structures. The present potentials are adequate for simulation of defects in various phases of the Ti-Al system.