A new method to track the evolution of rock microstructures in shear deformation (torsion) experiments.

一种在剪切变形（扭转）实验中跟踪岩石微观结构演化的新方法。

• 批准号: NE/G01034X/1
• 负责人: Elisabetta Mariani
• 金额: $ 3.75万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FG01034X%2F1
• 关键词: new; method; track; evolution; rock

Rock microstructures evolve during creep deformation and have a fundamental control on creep mechanisms and rheology. Understanding of creep deformation would improve significantly if we could track the evolution of individual grains and grain boundaries during experiments. No creep deformation experiments of polycrystalline materials relevant to the crust or upper mantle have succeeded in tracking the microstructural evolution of individual grains. This proposal aims to develop and test a new, relatively easy and inexpensive method to track the evolution of specific rock microstructures (e.g. individual grains) during laboratory creep experiments to high shear-strain at elevated pressure (P) and temperature (T); a method applicable to a wide range of rock types. In the case for support we demonstrate that a single cylindrical sample can be twisted incrementally in torsion and the microstructures on the outer surface of the cylinder imaged between each strain increment. The proposal requests funding for a stage for a scanning electron microscope (SEM) that will enable 1) microstructural mapping of the outer surface of cylindrical samples without distortions and 2) accurate registration of data from different strain increments. A pilot study, shearing Carrara marble, will track the orientation and internal structure of individual grains, migration of grain boundaries, and the orientation and evolution of recrystallized grains and should give new insights into polycrystal deformation and recrystallization.

岩石微观结构在蠕变变形过程中演化，对蠕变机制和流变学具有根本控制作用。如果我们能够在实验过程中跟踪单个晶粒和晶界的演变，那么对蠕变变形的理解将会显着提高。与地壳或上地幔相关的多晶材料的蠕变变形实验还没有成功地跟踪单个颗粒的微观结构演化。该提案旨在开发和测试一种新的、相对简单且廉价的方法，以在高压（P）和温度（T）下进行高剪切应变的实验室蠕变实验期间跟踪特定岩石微观结构（例如单个晶粒）的演变；一种适用于多种岩石类型的方法。在支撑的情况下，我们证明单个圆柱形样品可以在扭转中增量扭转，并且在每个应变增量之间成像圆柱形外表面上的微观结构。该提案要求为扫描电子显微镜 (SEM) 的平台提供资金，该平台将能够 1) 不变形地绘制圆柱形样品外表面的微观结构图，2) 准确记录不同应变增量的数据。剪切卡拉拉大理石的试点研究将跟踪单个晶粒的取向和内部结构、晶界的迁移以及再结晶晶粒的取向和演化，并应为多晶变形和再结晶提供新的见解。

项目成果

Insight into the phase transformations between ice Ih and ice II from electron backscatter diffraction data

从电子背散射衍射数据洞察冰 Ih 和冰 II 之间的相变

• DOI: http://dx.10.1016/j.scriptamat.2011.09.044
• 发表时间: 2012
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Prior D

Time-lapse misorientation maps for the analysis of electron backscatter diffraction data from evolving microstructures

用于分析演化微结构的电子背散射衍射数据的延时定向误差图

• DOI: http://dx.10.1016/j.scriptamat.2011.06.035
• 发表时间: 2011
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Wheeler J