相关实验视频
Updated: Feb 16, 2026

06:05
Additive Manufacturing-Enabled Low-Cost Particle Detector
Published on: March 24, 2023
2.5K
在单晶的增材制造中,变形诱导的流浪粒的形成
Dongsheng Zhang1, Zixu Guo2, Yuxiao Li1
1Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China.
Advanced science (Weinheim, Baden-Wurttemberg, Germany)
|February 15, 2026
概括
单晶的增材制造 (AM) 中的流浪粒 (SGs) 是由于脱位活动引起的亚粒旋转引起的,而不仅仅是热. 特定的基质取向可以通过控制位移分布来抑制SG.
科学领域:
- 材料科学 材料科学 材料科学
- 制造业 工程 制造工程
- 固化科学 固化科学
背景情况:
- 流浪颗粒 (SGs) 是用于高温航空航天部件的单晶增材制造 (AM) 的重要障碍.
- 现有的理解主要将SG形成归因于固化过程中的热效应.
研究的目的:
- 阐明在Ni基单晶合金的增材制造过程中流浪粒形成的潜在机制.
- 确定影响流浪粒形成的可控制因素,并提出一个预测指标.
主要方法:
- 在现场同步子成像和衍射的整合.
- 现场材料表征技术.
- 多物理计算建模.
主要成果:
- 流浪颗粒的形成是由子颗粒的旋转驱动的,源于异质的脱位活动,而不是仅仅是热效应.
- 基质的方向极大地影响了因脱位引起的流浪粒形成.
- 提议将基尼位移分布系数作为一种基于物理学的指标,用于预测流浪谷物的易感性.
结论:
- 这项研究揭示了在增材制造中产生流浪粒的新机制.
- 控制基质的方向和脱位分布可以抑制流浪粒.
- 这些发现指导了对高质量的增材制造单晶元件的制造,用于苛刻的应用.
相关概念视频
Radical Formation: Addition
2.3K
Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
2.3K
Plastic Deformations of Members with a Single Plane of Symmetry
384
When a structural member undergoes plastic deformation due to bending, it is crucial to understand the position of the neutral axis and the stress distribution. This member, characterized by a single plane of symmetry, exhibits a uniform stress distribution, with negative stress above the neutral axis and positive stress below. Notably, the neutral axis does not align with the centroid of the cross-section. This misalignment is typical in cases where the cross-section is not rectangular or...
384
Conjugate Addition (1,4-Addition) vs Direct Addition (1,2-Addition)
4.4K
α,β-Unsaturated carbonyl compounds with two electrophilic sites, the carbonyl carbon, and the β carbon, are susceptible to nucleophilic attack via two modes: conjugate or 1,4-addition and direct or 1,2-addition.
Conjugate addition results in a thermodynamically stable product. The reaction retains the stronger C=O bond at the expense of the weaker C=C π bond. The process is slow as the β carbon is less electrophilic than the carbonyl carbon.
Direct addition products are...
Conjugate addition results in a thermodynamically stable product. The reaction retains the stronger C=O bond at the expense of the weaker C=C π bond. The process is slow as the β carbon is less electrophilic than the carbonyl carbon.
Direct addition products are...
4.4K
Plastic Deformations
480
Plastic deformation represents a fundamental concept in materials science, which explains the irreversible change in the shape of a material when it experiences stress beyond its elastic capability. This phenomenon is important in structural engineering, especially in designing and analyzing cantilever beams—structures that are securely fixed at one end and bear loads at the opposite end. When these beams are subjected to loads within their elastic range, they will return to their...
480
Plastic Deformations
487
It is essential to understand how structural members behave under plastic deformation when the bending stress exceeds the material's yield strength. This state of deformation permanently alters the shape of the member, in contrast to the linear elastic behavior observed before yielding. The strain at any point in the member is expressed in terms of maximum strain. Notably, the neutral axis, which coincides with the centroid during elastic bending, shifts away from the centroid under plastic...
487
Ionic Crystal Structures
18.1K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
18.1K

