相关实验视频
Updated: May 23, 2025
05:04
Determining the Mechanical Strength of Ultra-Fine-Grained Metals
Published on: November 22, 2021
2.1K
梯度纳米化高合金的张力压缩不对称性
Xingguo Yang1,2,3,4, Fei Yin1,3,4
1Hubei Longzhong Laboratory Xiangyang 441000 Hubei China.
RSC advances
|March 11, 2025
概括
这项研究揭示了CoCrFeMnNi高合金 (HEAs) 中的粒径梯度如何影响机械反应. 谷物边界活动的差异导致应力和应变不对称,为材料设计提供了洞察力.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 计算材料科学科学 计算材料科学
背景情况:
- 高合金 (HEAs) 由于其多元素组成,具有独特的特性.
- 了解纳米结构HEAs的变形机制对于先进的应用至关重要.
- 梯度纳米结构引入了复杂的机械行为,需要详细的研究.
研究的目的:
- 研究CoCrFeMnNi HEA在不同粒度梯度下的机械反应和变形机制.
- 在不同的负载条件下探索梯度纳米化HEA (G-HEA) 中的张力-压缩不对称性.
- 阐明梯度纳米结构在调节应力和应变分布中的作用.
主要方法:
- 用分子动力学 (MD) 模拟来研究机械反应.
- 在不同的工程应变下分析应力和应变分布.
- 识别和描述初级谷物边界 (GB) 活动和变形机制.
主要成果:
- 正常应力和剪切应力的梯度分布随着应力增加而减少.
- 谷物边界迁移和融合是GB的关键活动;细粒显示出更高的活力.
- 多种变形机制 (位移滑动,结合,HCP转换) 在协同作用下相互作用.
- 在GB活动和失位核化位点的差异导致机械性质的不对称.
结论:
- 谷物边界活动是G-HEAs中应力和应变不对称的主要驱动因素.
- 梯度纳米结构显著影响机械性能和变形行为.
- 这些发现为设计针对特定应用的G-HEA提供了理论基础.
相关概念视频
01:20Elastic Strain Energy for Shearing Stresses
151
As discussed in previous lessons, strain energy in a material is the energy stored when it is elastically deformed, a concept crucial in materials science and mechanical engineering. This energy results from the internal work done against the cohesive forces within the material. When a material undergoes shearing stress and corresponding shearing strain, the strain energy density, which is the energy stored per unit volume, is calculated. Within the elastic limit, where the stress is...
151
01:22Elastic Strain Energy for Normal Stresses
131
Strain energy quantifies the energy stored within a material due to deformation under loading conditions, a fundamental concept in materials science and engineering. The strain energy can be modeled when a material is subjected to axial loading with uniformly distributed stress. In this scenario, the stress experienced by the material is the internal force divided by the cross-sectional area, and the strain induced is directly proportional to this stress through the modulus of elasticity.
If...
If...
131
01:20Normal Strain under Axial Loading
425
Normal strain under axial loading is an important concept in the field of mechanics of materials. Axial loading implies the application of a force along the axis of a material, like a column or bar. This force can either compress or stretch the material. In the context of axial loading, normal strain is the deformation experienced by the material in the direction of the loading force. It's calculated as the change in length divided by the original length of the material. This unitless ratio...
425
01:16Eccentric Axial Loading in a Plane of Symmetry
155
Eccentric axial loading occurs when an axial load is applied away from the centroidal axis of a structural member. This scenario is common in engineering, where structural elements may not be directly aligned due to various design or functional requirements.
155
01:15Strain and Elastic Modulus
3.5K
The quantity that describes the deformation of a body under stress is known as strain. Strain is given as a fractional change in either length, volume, or geometry under tensile, volume (also known as bulk), or shear stress, respectively, and is a dimensionless quantity. The strain experienced by a body under tensile or compressive stress is called tensile or compressive strain, respectively. In contrast, the strain experienced under bulk stress and shear stress is known as volume and shear...
3.5K
01:29Three-Dimensional Analysis of Strain
190
Three-dimensional strain analysis is crucial for understanding how materials deform under stress, particularly in elastic, homogeneous materials. This method employs principal stress axes to simplify complex stress states into more understandable forms. Subjected to stress, a small cubic element within a material either expands or contracts along these axes, transforming into a rectangular parallelepiped. This transformation effectively illustrates the material's deformation. The principal...
190