Development of anisotropic microstructures by dynamic recrystallization in the crust and mantle

地壳和地幔动态再结晶形成各向异性微观结构

• 批准号: 12640438
• 负责人: SHIMIZU Ichiko
• 金额: $ 2.37万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640438/
• 关键词: dynamic recrystalization; rock deformation; stress; rheology; anisotropy; texture; grain size distribution; 動的再結晶組織; 結晶粒径分布; 核形成-成長モデル; 石英; オリビン; 結晶方位定向配列; 高温高圧実験; 核形成-成長理論; カンラン石; 核形成; 粒界移動; 漸移クリープ; 数値シミュレーション

Dynamic recrystallization (DRX) is characterized by cyclic events nucleation and grain growth during plastic deformation. The evolution of grain size distribution in dynamic recrystallization was investigated by a stochastic model of nucleation-and-growth. Scaling relations representing characteristic grain size and recrystallization cycle were derived from nucleation rate and growth rate. The grain size evolve from an initial distribution to a steady-state one that is approximated by a lognormal distribution. A universal relation between deformation conditions (i.e., stress and temperature) and the steady-state grain size were formulated for recovery creep of minerals. The influence of DRX on texture (or lattice preferred orientation, LPO) development is an important issue in considering seismic anisotropy in the Earth mantle. Since a grain with 'favorable' orientation (soft grain) has larger dislocation energy than that with 'unfavorable' orientation (hard grain), soft grains are replaced with hard grains by grain boundary migration. Therefore, the LPO produced by crystalline slip becomes weak or diminished by grain growth. On the contrary, strain-free nuclei have nearly the same orientation as their host grains, hence nucleation would enhance the LPO dominated by soft grains. Textures between the above two end-members are possible for DRX

动态再结晶 (DRX) 的特点是塑性变形期间的循环事件成核和晶粒生长。通过成核和生长的随机模型研究了动态再结晶中晶粒尺寸分布的演变。代表特征晶粒尺寸和再结晶周期的比例关系是从成核速率和生长速率导出的。晶粒尺寸从初始分布演变为近似于对数正态分布的稳态分布。为矿物的恢复蠕变制定了变形条件（即应力和温度）与稳态晶粒尺寸之间的普遍关系。 DRX 对纹理（或晶格择优取向，LPO）发育的影响是考虑地幔地震各向异性的一个重要问题。由于具有“有利”取向的晶粒（软晶粒）比具有“不利”取向的晶粒（硬晶粒）具有更大的位错能，因此软晶粒通过晶界迁移被硬晶粒取代。因此，由晶滑产生的LPO会因晶粒生长而变弱或减弱。相反，无应变核具有与其主体晶粒几乎相同的取向，因此成核会增强由软晶粒主导的LPO。上述两个终端成员之间的纹理对于 DRX 是可能的

项目成果

Shimizu, I: "Grain size evolution in dynamic recrystallization , Mater. Sci. Forum"Trans Tech Publ. (in press). (2003)

Shimizu，I：“动态再结晶中的晶粒尺寸演变，材料科学论坛”Trans Tech Publ。

Ikeda, S., Toriumi, M., Yoshida, H., Shimizu, I: "Experimental study of the textural development of igneous rocks in the late stage of crystalliation : the importance of interfacial energies under non-equilibrium conditions"Mineral, Petrol.. 142. 397-415

Ikeda, S.、Toriumi, M.、Yoshida, H.、Shimizu, I：“结晶后期火成岩结构发育的实验研究：非平衡条件下界面能的重要性”矿物、石油

Shimizu, I.: "Grain size evolution in dynamic recrystallization"Mater.Sci.Forum, Trans Tech Publ., Switzerland. (in press). (2003)

Shimizu, I.：“动态再结晶中的晶粒尺寸演变”Mater.Sci.Forum，Trans Tech Publ.，瑞士。

Shimizu, I., J.H. ter Hege, J.H.P. de Bresser, C.J.Spiers: "Grain size evolution in dynamic recrystallization : A Theoretical model"Deformation Mechanisms, Rheology, Microstructures. 146. (2001)

清水，I.，J.H.

澤口 隆, 清水 以知子: "走査型レーザー顕微鏡による岩石組織の可視化:反射像と透過像"地質雑. 108. XI-XII (2002)

Takashi Sawaguchi、Ichiko Shimizu：“使用扫描激光显微镜可视化岩石结构：反射和透射图像”地质学杂项 108。XI-XII (2002)