• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >First-principles investigations of iron-based alloys and their properties.
【24h】

First-principles investigations of iron-based alloys and their properties.

机译：铁基合金及其性能的第一性原理研究。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Fundamental understanding of the complex interactions governing structure-property relationships in iron-based alloys is necessary to advance ferrous metallurgy. Two key components of alloy design are carbide formation and stabilization and controlling the active deformation mechanism. Following a first-principles methodology, understanding on the electronic level of these components has been gained for predictive modeling of alloys.;Transition metal carbides have long played an important role in alloy design, though the complexity of their interactions with the ferrous matrix is not well understood. Bulk, surface, and interface properties of vanadium carbide, VCx, were calculated to provide insight for the carbide formation and stability. Carbon vacancy defects are shown to stabilize the bulk carbide due to increased V-V bonding in addition to localized increased V-C bond strength. The VCx (100) surface energy is minimized when carbon vacancies are at least two layers from the surface. Further, the Fe/VC interface is stabilized through maintaining stoichiometry at the Fe/VC interface.;Intrinsic and unstable stacking fault energy, gammaisf and gamma usf respectively, were explicitly calculated in nonmagnetic fcc Fe-X systems for X = Al, Si, P, S, and the 3d and 4d transition elements. A parabolic relationship is observed in gamma isf across the transition metals with minimums observed for Mn and Tc in the 3d and 4d periods, respectively. Mn is the only alloying addition that was shown to decrease gamma isf in fcc Fe at the given concentration. The effect of alloying on gammausf also has a parabolic relationship, with all additions decreasing gammaisf yielding maximums for Fe and Rh.
机译：从根本上理解铁基合金中支配结构-特性关系的复杂相互作用是推进黑色冶金发展的必要条件。合金设计的两个关键要素是碳化物的形成和稳定以及控制主动变形机制。遵循第一原理方法，已经获得了对这些成分的电子水平的理解，可以用于合金的预测建模。；过渡金属碳化物在合金设计中长期发挥着重要作用，尽管它们与铁基体相互作用的复杂性并不高非常明白。计算了碳化钒VCx的体积，表面和界面特性，以提供碳化物形成和稳定性的信息。除局部增加的V-C结合强度外，由于增加的V-V结合，显示出碳空位缺陷还可以稳定整体碳化物。当碳空位距离表面至少两层时，VCx（100）的表面能会降到最低。此外，通过保持Fe / VC界面的化学计量比来稳定Fe / VC界面。;在非磁性fcc Fe-X系统中显式计算X = Al，Si，Fe时固有和不稳定的堆垛层错能分别为gammaisf和gamma usf。 P，S以及3d和4d过渡元素。在过渡金属中的γisf中观察到抛物线关系，分别在3d和4d期间观察到Mn和Tc的最小值。在给定的浓度下，Mn是唯一能降低fcc Fe中γisf的合金添加物。合金化对gammausf的影响也具有抛物线关系，所有添加物的减少都会使gammaisf降低，从而使Fe和Rh达到最大值。

著录项

  • 作者

    Limmer, Krista Renee.;

  • 作者单位

    Missouri University of Science and Technology.;

  • 授予单位 Missouri University of Science and Technology.;
  • 学科 Materials science.;Condensed matter physics.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 112 p.
  • 总页数 112
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号