在冷却过程中,液体Al-Zn合金中原子间距离异常扩大
Zhouqing Xu1, Feihu He1, Tao Hu1
1School of Materials Science and Engineering, State Key Laboratory of Advanced Special Steel, Shanghai University, 200444 Shanghai, People's Republic of China.
The Journal of chemical physics
|August 4, 2025
概括
合金化物在火过程中表现出异常膨胀,偏离了典型的负热膨胀. 这种与原子扩散相关的现象受度和集群大小的影响.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 计算材料科学科学 计算材料科学
背景情况:
- 金属材料的特性与其化状态结构密切相关.
- 了解液体金属的行为对于材料开发至关重要.
研究的目的:
- 研究火过程中Al-Zn合金中的局部结构演变.
- 描述化Al-Zn合金中的异常膨胀现象.
主要方法:
- 利用飞机机器学习力场 (MLFF) 模拟.
- 在高精度模拟中使用ab initio分子动力学.
- 分析了协调数和结合角分布函数.
主要成果:
- 在Al-Zn融的第一个协调中观察到异常膨胀,与纯金属的线性负膨胀不同.
- 异常扩张范围随着的度增加而缩小.
- 在较大的系统 (>10^4原子) 中证实了这种现象,并将其与原子扩散和热激发联系起来.
- 鉴定了由于集群中的界面能量导致的压力下降,导致原子排列更松散.
结论:
- 该研究揭示了Al-Zn合金中独特的异常膨胀,由扩散和热效应驱动.
- 洞察原子结构的演变和合金中的潜在的液体-液体过渡.
- MLFF模拟提供了对复杂的化金属行为准确的见解.
相关概念视频
Metallic Solids
18.7K
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....
18.7K
Thermal Strain
2.3K
Thermal strain is a concept that arises when we consider how temperature changes affect structures. Unlike the conventional assumption that structures remain constant under load, real-world scenarios often involve temperature fluctuations that can significantly impact these structures. Consider a homogeneous rod with a uniform cross-section resting freely on a flat horizontal surface. If the rod's temperature increases, the rod elongates. This elongation is proportional to the temperature...
2.3K
Thermal expansion and Thermal stress: Problem Solving
1.3K
San Francisco's Golden Gate Bridge is exposed to temperatures ranging from -15 °C to 40 °C. At its coldest, the main span of the bridge is 1275 m long. Assuming that the bridge is made entirely of steel, what is the change in its length between these temperatures?
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
1.3K
Temperature Dependent Deformation
193
In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added...
193
Thermal Expansion
4.6K
The expansion of alcohol in a thermometer is one of many commonly encountered examples of thermal expansion, which is the change in size or volume of a given system as its temperature changes. The most visible example is the expansion of hot air. When air is heated, it expands and becomes less dense than the surrounding air, which then exerts an upward force on the hot air to, for example, make steam and smoke rise, and hot air balloons float. The same behavior happens in all liquids and gases,...
4.6K
Residual Stresses
279
Residual stresses reside in a structure even after removing the original stress inducer. This phenomenon often arises from varied plastic deformations across different parts of a structure. Consider a rod stretched beyond its yield point. It will not regain its original length due to permanent deformation. Even after load removal, the rod does not entirely lose stress because of uneven plastic deformations, resulting in residual stresses. The computation of these stresses in structures is...
279


