MD simulations of strengthening by graphene in iron crystals

铁晶体中石墨烯强化的 MD 模拟

• 批准号: 427509047
• 负责人: Professor Dr. Johannes Roth, since 4/2023
• 金额: --
• 依托单位: Institut für Funktionelle Materie und Quantentechnologien
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/427509047?language=en
• 关键词: MD; simulations; strengthening; graphene; iron

In iron alloys, the increase in strength caused by solid solution, precipitate and grainboundary strengthening, plays an outstanding role in the technical application of the materials. In this project, the influence of nanoscale graphene discs embedded into the iron matrix and of carbon in solid solution on the mechanical properties, respectively, is investigated by means of ab initio and molecular dynamics (MD) simulations. The addition of graphene disks is expected to improve several mechanical properties. In particular, the thermal stability of the graphene discs and the properties of elasticity, strength and plasticity of the iron/graphene composite material are of importance. To estimate the thermal stability of the graphene discs, ab initio simulations are performed, which are also used to improve the interatomic potentials for the MD simulations. Molecular dynamics simulations using single- and polycrystals will be performed for different temperatures, carbon and graphene concentrations, as well as for different sizes, distances and orientations of the graphene discs.The objectives of the simulations are fundamental findings concerning dislocation/precipitate interactions, stress fields and residual stresses in the crystal lattice caused by the graphene discs or alloyed carbon atoms, and the associated changes in the mechanical properties of these materials.For the first time, MD simulations are used to investigate whether and to which extent the properties of iron can be improved by the addition of graphene discs in the desired direction of maximum strength with maximum elasticity and best possible plastic deformability (ductility and fracture strain) respectively.

在铁合金中，由固体溶液，沉淀和晶粒增强引起的强度增加，在材料的技术应用中起着出色的作用。在该项目中，通过AB IST和Molecular Dynamics（MD）模拟研究了嵌入在机械性能上的固体溶液中的纳米级石墨烯盘和固体溶液中的碳的影响。石墨烯磁盘的添加有望改善几种机械性能。特别是，石墨烯盘的热稳定性以及铁/石墨烯复合材料的弹性，强度和可塑性的性能非常重要。为了估计石墨烯盘的热稳定性，进行了从头算模拟，这些模拟也用于改善MD模拟的原子间潜力。使用单晶和多晶的分子动力学模拟将针对不同的温度，碳和石墨烯浓度以及石墨烯二聚体的不同尺寸，距离，距离，距离和方向进行。模拟的目标是基本发现是关于脱位的基本发现，这些发现是涉及脱位/沉淀的既定型，以及在晶体上与晶体相关的界限，或者在晶体上相关的，既定的，或者在晶体上相关的习惯，既定的习惯，则是晶体的依从性依赖的习惯。这些材料的特性。首次使用MD模拟来研究是否和何种程度可以通过在最大强度的最大强度方向上添加石墨烯盘，并分别具有最大弹性和最佳的塑性可变形性（延性和裂缝菌株）。