在纳米结构金属中具有高拉伸柔性
Yinmin Wang1, Mingwei Chen, Fenghua Zhou
1Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Nature
|November 1, 2002
概括
研究人员开发了一种新的热力学处理铜,创建双模粒结构. 这种方法显著提高了纳米晶体金属的拉伸柔性,改善了它们的实际应用.
科学领域:
- 材料科学 材料科学 材料科学
- 金工业是金工业的一个方面.
- 纳米技术纳米技术
背景情况:
- 纳米晶体金属 (粒径小于100纳米) 与粗粒或合金金属相比,具有更高的强度.
- 然而,它们的实际应用受到在室温下低拉伸柔性限制.
- 纯纳米晶体铜具有很高的强度 (>400 MPa),但延伸到故障是有限的.
研究的目的:
- 开发一种热力学处理铜,以提高拉伸柔性,同时保持高强度.
- 为了研究二模态粒度分布对机械性能的影响.
- 为了使纳米结构金属的实际应用.
主要方法:
- 对铜进行了一种新的热力学处理.
- 这种处理诱导了双模颗粒大小分布:微米大小的颗粒在纳米晶体/超细 (<300 nm) 矩阵内.
- 评估了机械性能,包括拉力强度和柔性.
主要成果:
- 经过处理的铜呈现出双模粒状的粒状结构.
- 高强度归因于纳米晶体矩阵,与霍尔-佩奇关系一致.
- 不均的微观结构促进了应变硬化,从而显著提高了拉伸柔性 (65%的延伸到故障,30%的均延伸).
结论:
- 热力学处理可以创建坚固的纳米结构金属,具有高强度和高可塑性.
- 双模态微结构是实现纳米晶体材料拉伸性能改善的关键.
- 这一进步对微电子机械和生物医学系统中的成型操作和高性能结构应用具有前景.
相关概念视频
Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Stress-Strain Diagram - Ductile Materials
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...
Hooke's Law
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.
Yield Criteria for Ductile Materials under Plane Stress
In designing structural elements and machine parts using ductile materials, it is crucial to ensure that these components withstand applied stresses without yielding. Yielding is initially determined through a tensile test, which evaluates the material's response to uniaxial stress. However, tensile stress is insufficient when components face biaxial or plane stress conditions This condition requires advanced criteria to predict failure.
The Maximum Shearing Stress Criterion, also known as the...
The Maximum Shearing Stress Criterion, also known as the...
Mechanical Characteristics of Steel
The mechanical characteristics of steel are assessed through various tests that evaluate its strength, toughness, and flexibility. These tests include tension, torsion, impact, bending, and hardness assessments, each providing crucial information about steel's suitability for specific applications.
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used to...
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used to...


