用TEM对塑性变形材料进行弹性应变映射
Arthur Després1, Salomé Parent2, Muriel Véron1
1Univ. Grenoble Alpes, CNRS, Grenoble INP, SIMaP, F-38000 Grenoble, France.
Ultramicroscopy
|July 12, 2024
概括
这项研究引入了一种新的方法,用于利用传输电子显微镜 (TEM) 在变形材料中绘制弹性菌株的映射. 该技术准确地测量了脱位周围的应变场,揭示了塑性变形机制的洞察力.
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
- 电子显微镜电子显微镜
背景情况:
- 标准的应变测量方法在塑性变形材料中的方向梯度方面存在困难.
- 精确地绘制弹性应变场对于理解材料变形行为至关重要.
- 传输电子显微镜 (TEM) 提供高分辨率成像,但需要专门的方法进行定量应变分析.
研究的目的:
- 开发和介绍一种使用TEM的新方法,用于绘制塑性变形材料中的弹性菌株.
- 为了应对应变分析中的方向梯度的挑战.
- 为了能够详细描述微观结构特征 (如位移) 周围的应变场.
主要方法:
- 来自扫描前置电子衍射 (SPED) 数据集的合方向和应变图.
- 通过旋转坐标系以测量失方向为基础,计算方向梯度.
- 计算旋转坐标系中的弹性应变,目前处理的是亚齐木斯旋转.
- 应用于塑性变形的Cr2AlC单晶,经过纳米机械测试.
主要成果:
- 开发的方法成功地映射了塑性变形的Cr2AlC样本中的弹性应变场.
- 包括堆积和墙壁在内的脱位周围的应变场与理论预测一致.
- 在脱位堆积和墙壁之间的应变场中观察到明显的差异.
- 菌株地图有助于识别Burgers向量方向,并估计失位源的位置.
结论:
- 提出的方法为具有方向梯度的材料中的弹性应变映射提供了一个强大的方法.
- 这种技术增强了对脱位行为和塑性变形机制的理解.
- 未来的应用包括对复杂的变形微观结构和材料的详细研究.
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