Scholarlink

<p>The grain-size-dependent strengthening mechanisms during rolling deformation of a Ni–Fe–Cr-based superalloy at the nanoscale remain unclear. In this study, the micro-strengthening behavior under rolling was systematically investigated using molecular dynamics&#xa0;(MD) simulations. Five polycrystalline models with different grain sizes and one single-crystal model were constructed using atomsk, and a micro-scale rolling simulation framework was established. The influences of grain size on rolling force response, friction behavior, dislocation evolution, and grain-boundary–dislocation interactions were analyzed. The results show that increasing grain boundary fraction with grain refinement leads to a notable reduction in average normal rolling force, indicating weakened resistance to normal deformation. The average tangential rolling force exhibits only minor variation but remains lower than that of the single-crystal model. Although grain refinement increases the total length of subsurface dislocations, grain boundaries restrict dislocation motion, resulting in increasingly localized dislocation distributions that are unfavorable for rolling-induced strengthening.When the grain size decreases, grain boundary softening becomes dominant, accompanied by weakened grain-boundary–dislocation interactions. These findings provide atomic-scale insights into the grain-size-controlled deformation and strengthening mechanisms of a rolled Ni–Fe–Cr-based superalloy.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Molecular dynamics study of grain size effects on rolling-induced deformation and strengthening in a Ni–Fe–Cr model superalloy

  • 期刊论文

  • 发表日期：

    2026年6月23日

查看全文
  • Fang Yu,
  • Jiachun Li

摘要

The grain-size-dependent strengthening mechanisms during rolling deformation of a Ni–Fe–Cr-based superalloy at the nanoscale remain unclear. In this study, the micro-strengthening behavior under rolling was systematically investigated using molecular dynamics (MD) simulations. Five polycrystalline models with different grain sizes and one single-crystal model were constructed using atomsk, and a micro-scale rolling simulation framework was established. The influences of grain size on rolling force response, friction behavior, dislocation evolution, and grain-boundary–dislocation interactions were analyzed. The results show that increasing grain boundary fraction with grain refinement leads to a notable reduction in average normal rolling force, indicating weakened resistance to normal deformation. The average tangential rolling force exhibits only minor variation but remains lower than that of the single-crystal model. Although grain refinement increases the total length of subsurface dislocations, grain boundaries restrict dislocation motion, resulting in increasingly localized dislocation distributions that are unfavorable for rolling-induced strengthening.When the grain size decreases, grain boundary softening becomes dominant, accompanied by weakened grain-boundary–dislocation interactions. These findings provide atomic-scale insights into the grain-size-controlled deformation and strengthening mechanisms of a rolled Ni–Fe–Cr-based superalloy.