相关实验视频
Updated: Jun 25, 2025

05:04
Determining the Mechanical Strength of Ultra-Fine-Grained Metals
Published on: November 22, 2021
2.2K
在高合金中的弹性应变诱导的无形化
Yeqiang Bu1,2, Yuan Wu3,4, Zhifeng Lei5
1Center for X-mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, 310027, China.
Nature communications
|May 30, 2024
概括
高合金 (HEAs) 呈现出一种新的弹性不稳定性,在高弹性应变时经历无形化. 这种由局部原子不均质驱动的现象与晶体固体中的传统可塑性机制形成鲜明对比.
科学领域:
- 材料科学 材料科学 材料科学
- 固体力学 固体力学是什么
- 晶体学 晶体学是指结晶学.
背景情况:
- 弹性稳定性控制了材料的反应,如结晶固体中的融化,可塑性和断裂.
- 之前的研究主要集中在脱位介导或缺陷积累介导的无形化.
- 高合金 (HEAs) 由于其复杂的原子结构,具有独特的材料特性.
研究的目的:
- 研究高合金 (HEAs) 的弹性稳定性.
- 描述高压电机在拉力负荷下变形的机制.
- 阐明局部原子环境与弹性应变诱导的无形化之间的关系.
主要方法:
- 在拉伸负荷下进行现场机械测试.
- 使用传输电子显微镜 (TEM) 进行原子分辨率表征.
- 第一原则计算和原子分辨率化学映射.
主要成果:
- 在大约10%的弹性应变下,在HEAs中观察到晶格秩序的突然丧失 (模态化).
- 确定了一种新的弹性应变诱导的无形化机制,它与脱位或缺陷介导的过程不同.
- 与压抑的失位核化相关的无形化,归因于高的局部原子环境不均性.
结论:
- 弹性应变诱导的无形化代表了HEAs中的弹性不稳定性的新形式.
- 这些发现突出了当地的原子环境在HEA机械行为中的同质性的关键作用.
- 提供了对先进材料的弹性不稳定性和初始可塑性的基本见解.
相关概念视频
Strain-Energy Density
390
Understanding the strain energy density in materials under axial load is crucial for evaluating their mechanical behavior and durability. When a rod is subjected to such a load, it elongates and stores energy, known as strain energy, as potential energy within the material. This energy is measured in terms of energy per unit volume.
In the elastic region of a material, the relationship between the stress and the strain is linear and follows Hooke's Law. The strain energy density in this...
In the elastic region of a material, the relationship between the stress and the strain is linear and follows Hooke's Law. The strain energy density in this...
390
Plastic Behavior
196
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and...
196
Stress-Strain Diagram - Ductile Materials
702
The stress-strain relationship in ductile materials such as structural steel or aluminium is intricate and progresses through several stages. When a specimen is loaded, it initially exhibits a linear length increase, depicted by a steep straight line on the stress-strain diagram. It indicates the material is elastically deforming and will return to its original shape once unloaded. However, when a critical stress value is reached, plastic deformation begins. This stage sees substantial...
702
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
264
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
264
Hooke's Law
378
Hooke's law, a pivotal principle in material science, establishes that the strain a material undergoes is directly proportional to the applied stress, defined by a factor called the modulus of elasticity or Young's modulus.
378
Elastic Strain Energy for Normal Stresses
155
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...
155

