Deformation Response of Oriented Crystalline Aggregates: Experiment and Theory

定向晶体聚集体的变形响应：实验与理论

• 批准号: 250393-2013
• 负责人: Diak, Bradley
• 金额: $ 1.6万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=547621
• 关键词: Deformation; Response; Oriented; Crystalline; Aggregates

This work explores how the microstructure in oriented crystalline materials mediates the atomistic physics of slip to the larger macroscopic responses of strength and ductility. Strength and ductility are essential properties in the processing and service of most structural materials used by modern society, and so they are essential to understand and control. The orientations of crystalline grains in aggregates develop naturally during materials processing, with certain ideal orientations becoming more common than others. Often these ideal orientations are surrounded by different levels of orientation noise, which are weak minor or random components that have not been well studied. The primary suppliers of structural materials for transportation, packaging, and energy sectors usually produce materials with tailored ideal orientations obtained through their patented processing cycles to exploit desirable materials properties. Currently, multi-scale models can predict average orientation development during processing, but are unable to capture the statistical deviations observed in the crystalline matter developed as "microstructure" during processing. These variations can be attributed to limitations in understanding of the atomistic processes of deformation, the role of point defects such as alloying elements on collective deformation behaviour, and the effect of internal interfaces, or grain boundaries on communicating the slip activities between neighbouring crystals. As a way forward, the objective of this work is to (i) explore novel methods to fabricate ideally oriented polycrystalline materials so to investigate (ii) the effect of specimen size and time scales on the thermally activated process of deformation, (iii) the connection between orientation and microstructure stability under deformation or heating, and (iv) the role of solute atom impurities on the stability of nano-voids in different aluminum alloy systems and their effect on general plasticity. These studies identify key length scale features in different materials from which collective macroscopic phenomena such as ultra-strength or surface roughening might be exploited in new functional materials by existing and future Canadian metals suppliers and fabricators.

这项工作探讨了定向结晶材料中的微观结构如何介导滑动的原子理物理学，从而介导了强度和延展性的较大宏观响应。 力量和延展性是现代社会使用的大多数结构材料的加工和服务的重要特性，因此它们对于理解和控制至关重要。 聚集体中晶粒的方向在材料加工过程中自然发展，而某些理想的方向比其他理想取向变得更加普遍。 通常，这些理想的方向被不同级别的定向噪声所包围，这些噪声是较弱的次要或随机组件，尚未得到充分研究。 用于运输，包装和能量部门的结构材料的主要供应商通常会通过其专利的加工周期获得的理想方向生产材料，以利用理想的材料特性。 当前，多尺度模型可以预测处理过程中的平均方向发展，但无法捕获在处理过程中开发为“微结构”的晶体物质中观察到的统计偏差。 这些变化可以归因于理解变形原子过程的局限性，诸如合金元素在集体变形行为上的点缺陷的作用以及内部接口的影响或晶界对邻近晶体之间的滑移活动的影响。 作为前进的道路，这项工作的目的是（i）探索新的方法以制造理想的定向多晶材料，以研究（ii）样品大小和时间尺度对热激活的变形过程的影响，（iii）在变形或加热下的方向和微结构稳定性之间的联系，（iv）溶质原子杂质在不同铝合金系统中纳米粒稳定性及其对一般可塑性的影响。 这些研究确定了不同材料中的关键长度尺度特征，这些材料的集体宏观现象（例如超强度或表面粗糙）可能会被现有和未来的加拿大金属供应商和制造商在新功能材料中利用。