Zr-Ti合金相稳定性与弹性性质的第一性原理研究

First-principles study on phase stability and elastic properties of Zr-Ti alloy

摘要:

利用SQS超晶胞模型及第一性原理计算研究了Zr1-xTix合金中Ti含量及相结构（hcp与bcc结构，α相与β相）对合金相稳定性及弹性性质的影响。研究表明：从弹性性质上看， Ti含量增加会使Zr-Ti合金的结构更加稳定， Zr-Ti合金α相的结构稳定性普遍高于β相；Zr-Ti合金普遍具有延展性， Zr-Ti合金的α相具有更高的硬度并且其硬度和韧性都与Ti元素浓度成正比，Zr-Ti合金的β相具有更高的韧性；从电子结构上看， Ti不会显着改变hcp结构和bcc结构Zr-Ti合金系统的DOS，Zr-Ti合金系统的DOS分布中的费米能级与纯Zr系统的相似， Ti含量对Zr-Ti合金的相稳定性影响不大。

Abstract:

In this paper, the super-cell model based on SQS methed and first-principles calculation is performed on investigating the influences of Ti concentration and phase structure(hcp and bcc structure )( α and β phase) on phase stability and elastic properties in Zr1-xTix systems.The results show that from the perspective of elastic properties, the structure of Zr-Ti alloy is more stable with the increase of Ti content. The α phase of Zr-Ti alloy generally has higher structural stability than β phase; Zr- Ti alloys generally have ductility. The α phase of Zr-Ti alloy has higher hardness and its hardness and toughness are proportional to the concentration of Ti. From the perspective of electronic structure, the concentration of Ti does not significantly change the DOS of hcp structure and the bcc structure of the Zr-Ti alloy systems.The Fermi level in the DOS distribution of the Zr-Ti alloy system is similar to that of the pure Zr system. Therefore, the content of Ti in the Zr-Ti alloy has little effect on the phase stability of the Zr-Ti alloy.