尽量减少多主元素合金中空隙和间隙之间的扩散率差异.
Bozhao Zhang1, Zhen Zhang1,2, Kaihui Xun1
1Center for Alloy Innovation and Design, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
概括
研究人员发现了一种方法,使金属中的间隙原子和空隙以类似的速度移动. 这一发现有助于消除缺陷,减少胀和空洞形成,从而提高了对辐射的耐受性.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 计算材料科学科学 计算材料科学
背景情况:
- 间歇性原子通常比金属中的空隙更快地扩散,阻碍了在辐射下点缺陷重组.
- 这种扩散失衡是无效的缺陷消灭的主要原因,导致材料降解.
研究的目的:
- 研究一种合金设计策略,以平衡NiCoCrFe (Pd) 合金中的间隙和空隙扩散.
- 了解控制多元件合金中缺陷扩散的原子尺度机制.
主要方法:
- 使用ab initio建模来模拟单缺陷扩散行为.
- 分析原子大小差异对扩散激活能量障碍的影响.
主要成果:
- 用 (Pd) 替换 NiCoCrFe 显著减少了间隙原子和空隙之间的扩散率差异.
- 的较大原子尺寸缩小了间歇物质的扩散通道,增加了它们的激活能量 (E).
- 同时,Palladium通过更轻松地适应债券长度变化,减少了空缺职位的E.
结论:
- 可以利用原子尺寸差异来操纵点缺陷动态.
- 这一策略有助于缺陷消灭,抑制空隙形成和胀.
- 这些发现为提高金属材料的辐射耐受性提供了一条途径.
相关概念视频
Metallic Solids
18.4K
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....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.4K
Bonding in Metals
47.4K
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”.
47.4K
Metal-Semiconductor Junctions
352
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
352
Saint-Venant's Principle
601
The principle of Saint-Venant postulates that the stress distribution within a structural member does not rely on the precise method of load application except in the vicinity of the load application points. Consider a scenario where loads are centrally applied on two plates. In this case, the plates move toward each other without any rotation. This movement causes the member to contract in length and expand in width and thickness. Uniform deformation across all elements and maintaining...
601
Properties of Transition Metals
25.9K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
25.9K
Theory of Metallic Conduction
1.3K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.3K


