Ion implantation plays a nontrivial role in improving the mechanical properties of materials. Unfortunately, the atomic-scale understanding and awareness of the improvement mechanisms remain insufficiently clear and accurate. This paper investigates the nanostructural evolution of carbon ion implanted ferrite and the mechanical response under uniaxial tension leveraging molecular dynamics (MD) simulation, providing direct atomic-scale evidence of alloy strengthening. Regarding nanostructural evolution, grain boundary migration induced by carbon ion implantation becomes significant with increasing doses. However, point defects and amorphous structures caused by collision cascades tend to saturate gradually with increasing implantation doses. Uniaxial tensile test results indicate that the strength of all ion-implanted samples is appreciably enhanced compared to non-implanted samples, especially with an implantation dose of 6.23 × 1013 ions/cm2, where the strength increases by 39%. The underlying strengthening mechanism is that defects, amorphous structures, and lattice distortions induced by ion implantation collectively act as formidable barriers to dislocation motion during plastic deformation, strongly governing dislocation propagation and multiplication. More importantly, the interaction between carbon atoms from ion implantation and dislocations renders the formation of Cottrell atmospheres, which further enhances solid solution strengthening by pinning dislocations. These results advancing the fundamental understanding of nanostructural evolution and strengthening mechanism under ion implantation suggest a mechanistic strategy for augmenting alloy strength.

中文翻译：

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碳离子注入铁氧体的原子模拟机械响应


离子注入在改善材料的机械性能方面起着重要作用。不幸的是，对改进机制的原子尺度理解和认识仍然不够清晰和准确。本文利用分子动力学 （MD） 模拟研究了碳离子注入铁氧体的纳米结构演变和单轴拉伸下的机械响应，提供了合金强化的直接原子尺度证据。关于纳米结构进化，碳离子注入诱导的晶界迁移随着剂量的增加而变得显着。然而，由碰撞级联引起的点缺陷和非晶结构往往随着植入剂量的增加而逐渐饱和。单轴拉伸测试结果表明，与未注入的样品相比，所有离子注入样品的强度都明显增强，尤其是在 6.23 × 1013 个离子/cm2 的注入剂量下，强度提高了 39%。潜在的强化机制是离子注入引起的缺陷、非晶结构和晶格畸变共同成为塑性变形过程中位错运动的巨大障碍，强烈控制位错的传播和倍增。更重要的是，离子注入和位错产生的碳原子之间的相互作用导致了 Cottrell 大气的形成，这进一步增强了通过钉扎位错强化固溶体的强化。这些结果促进了对离子注入下纳米结构演变和强化机制的基本理解，提出了一种增强合金强度的机械策略。