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arXiv 1706.09282cond-mat.mtrl-sci
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高熵合金稳定性的第一性原理预测

First-principles prediction of high-entropy-alloy stability

Rui Feng, Peter K. Liaw, Michael C. Gao, Michael Widom

摘要:

高熵合金(HEAs)是多组分化合物,其高构型熵允许它们凝固成具有简单晶格结构的单相。一些HEA表现出理想的性能,如高比强度,延展性和耐腐蚀性,同时挑战科学家在面对多个竞争阶段时做出自信的预测。我们证明了多元合金系Cr-Mo-Nb-V的相稳定性,其中一些二元子系统发生相分离和复杂的金属间相形成。我们的自由能的第一性原理计算预测,从T = 1,700 K到熔化,构型熵稳定单个体心立方(BCC)相,而在较低温度下有利于复杂金属间化合物的沉淀。我们形成的化合物实验和确认,它作为一个单一的BCC相从熔体形成,但它在较低的温度下可逆地转变。

英文摘要:

High entropy alloys (HEAs) are multicomponent compounds whose high configurational entropy allows them to solidify into a single phase, with a simple crystal lattice structure. Some HEA's exhibit desirable properties, such as high specific strength, ductility, and corrosion resistance, while challenging the scientist to make confident predictions in the face of multiple competing phases. We demonstrate phase stability in the multicomponent alloy system of Cr-Mo-Nb-V, for which some of its binary subsystems are subject to phase separation and complex intermetallic-phase formation. Our first-principles calculation of free energy predicts that the configurational entropy stabilizes a single body-centered cubic (BCC) phase from T = 1,700K up to melting, while precipitation of a complex intermetallic is favored at lower temperatures. We form the compound experimentally and confirm that it forms as a single BCC phase from the melt, but that it transforms reversibly at lower temperatures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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