Multiscale Crystal Plasticity Analysis for Production of Ultrafine-Grained Metals Based on Self-Organization of Subgrain

基于亚晶自组织的超细晶金属生产的多尺度晶体塑性分析

• 批准号: 16560078
• 负责人: SHIZAWA Kazuyuki
• 金额: $ 2.37万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560078/
• 关键词: Dislocation cell structure; Subgrain; Self-organization; Polycrystal; Ultrafine-grained metal; Multiscale modeling; Reaction-diffusion equations; Crystal plasticity analysis; セル再分割

Ultrafine-grained metals (UFGM) have attracted interest as high-strength materials. It is expected in the field of material textures control that a microscopic mechanism of production process for the UFGM is numerically predicted. However, such a study has never been reported. In this study, aiming at a prediction of production process of UFGM, reaction-diffusion equations are rigorously derived, that describe the self-organization of dislocation cell structure and subgrain. A stress effect model for rate coefficients of the reaction-diffusion equations is proposed so as to reflect the information of resolved shear stress of a crystal on dislocation patterning. In order to extend this self-organization model to a model for polycrystal, a dislocation reaction term is improved so that it can express an accumulation of geometrically necessary (GN) dislocation on grain boundary and a decrease of dislocation annihilation ratio near the boundary. A difference of stage transition timing for t … More hree-stage hardening of a crystal due to difference between the initial orientations of grain is introduced into the stress effect coefficient model and a dislocation mean free path model. Furthermore, substituting the immobile dislocation density calculated from the reaction-diffusion equations into a hardening modulus of a crystal, a multiscale crystal plasticity model is developed, that couples the dislocation patterning and polycrystal deformation.A multiscale crystal plasticity simulation using a FDM for dislocation patterning and a FEM for crystal deformation is carried out applying this model to a compression problem of an FCC polycrystal plate under severe strain condition. It is numerically predicted that the cell structure in the micrometer size is formed in a grain and the GN dislocations are accumulated around grain boundary in stage II. It is also reproduced that a lot of micro shear bands generate and subgrain walls with accumulated GN dislocations are formed along the shear bands in stage III. The timing of transition from cell to subgrain is different depending on the resolved shear stress condition of each grain. Moreover, the generation process of ultrafine grain is appropriately visualized and it is clarified that GN boundaries are induced in a grain by applying severe strain locally over 2 and a grain is separated along the GN boundaries into plural fine grains in the sub-micron order with large angle boundary. This study lays a foundation of multiscale simulation that enables computationally to predict the production process of UFGM on the basis of dislocation behaviors. Less

超铁粒金属（UFGM）吸引了作为高强度材料的兴趣。在材料纹理领域控制的是，在数值上预测了UFGM生产过程的微观机制。但是，这项研究从未得到报道。在这项研究中，针对UFGM生产过程的预测，反应扩散方程是严格得出的，这些方程描述了位错细胞结构和亚晶粒的自组织。提出了反应扩散方程的速率兼容性的应力效应模型，以反映位错图案上晶体的分辨剪切应力的信息。为了将这种自组织模型扩展到多晶模型，改进了位错反应项，以便它可以表达在晶界对几何必需（GN）脱位的积累，并在边界附近表达了降低的歼灭比的降低。 t的阶段过渡时机的差异……由于晶粒初始方向之间的差异，将晶体的更高阶段硬化引入压力效应核心模型和脱位平均自由路径模型中。 Furthermore, substituting the immobile dislocation density calculated from the reaction-diffusion equations into a hardening modulus of a crystal, a multiscale crystal plasticity model is developed, that couples the dislocation patterning and polycrystal deformation.A multiscale crystal plasticity simulation using a FDM for dislocation patterning and a FEM for crystal deformation is carried out applying this model to a compression problem of an FCC在严重应变条件下的多晶板。基本上预测，千分尺尺寸中的细胞结构是在晶粒中形成的，并且GN位错在II期晶界周围积累。还重现了许多微剪切带产生和亚晶墙，并沿着III期的剪切带形成了累积的GN位错。从细胞到亚晶粒的过渡时间不同，具体取决于每种晶粒的分辨剪切应力条件。此外，对超细晶粒的生成过程进行了适当的可视化，并澄清说，通过在2上局部施加严重的菌株，在晶粒中诱导了GN边界，并将晶粒沿GN边界分离为以较大角度边界的次级微米晶粒分离为复数细晶粒。这项研究奠定了多尺度模拟的基础，该基础能够根据位错行为在计算上预测UFGM的生产过程。较少的

项目成果

超微細サブグレインの自己組織化に関する転位-結晶塑性シミュレーション

超细亚晶自组织的位错晶体塑性模拟

• 发表时间: 2004
• 期刊: 日本材料学会第53期学術講演会講演論文集
• 作者: Iwamoto;M.;Tanaka;E.;Miki;K.;岩本正実;伝田耕平;岩本正実;永原斉;Shingo Oishi;Naoshi Yamaki;青柳 吉輝;青柳 吉輝;Shingo Oishi;Naoshi Yamaki;Yoshiteru Aoyagi;Yoshiteru Aoyagi;Naoshi Yamaki;Naoshi Yamaki;青柳 吉輝;Shingo Oishi;Naoshi Yamaki;海宝 寿実雄;堀部 尚裕;Naoshi Yamaki;Kazuyuki Shizawa;山本 直;Yoshiteru Aoyagi;志澤 一之
• 通讯作者: 志澤 一之

Modeling and Simulation of Crystal Plasticity Based on GN Crystal Defects for Ultrafine0Grained Metals Induced by Severe Plastic Deformation

基于强塑性变形引起的超细晶金属 GN 晶体缺陷的晶体塑性建模与仿真

• 发表时间: 2006
• 期刊: Namomaterials by Severe Plastic Deformation, Materials Science Forum 503-504
• 作者: Iwamoto;M.;Tanaka;E.;Miki;K.;岩本正実;伝田耕平;岩本正実;永原斉;Shingo Oishi
• 通讯作者: Shingo Oishi

Modeling and Simulation of Crystal Plasticity Based on GN Crystal Defects for Ultrafine-Grained Metals Induced by Severe Plastic Deformation

基于强塑性变形引起的超细晶金属 GN 晶体缺陷的晶体塑性建模与仿真

• 发表时间: 2006
• 期刊: Nanomaterials by Severe Plastic Deformation, Materials Science Forum Vol.503-504
• 作者: Iwamoto;M.;Tanaka;E.;Miki;K.;岩本正実;伝田耕平;岩本正実;永原斉;Shingo Oishi;Naoshi Yamaki;青柳 吉輝;青柳 吉輝;Shingo Oishi
• 通讯作者: Shingo Oishi

Dislocation-Crystal Plasticity Simulation Based on Self Organization for Repartition of Dislocation Cell Structures and Subgrains

基于自组织的位错晶体塑性模拟用于位错单元结构和亚晶的重新分配

• 发表时间: 2006
• 期刊: Nanomaterials by Severe Plastic Deformation, Materials Science Forum Vol.503-504
• 作者: Iwamoto;M.;Tanaka;E.;Miki;K.;岩本正実;伝田耕平;岩本正実;永原斉;Shingo Oishi;Naoshi Yamaki;青柳 吉輝;青柳 吉輝;Shingo Oishi;Naoshi Yamaki
• 通讯作者: Naoshi Yamaki

強ひずみ付与による結晶粒微細化に関するGN転位-結晶塑性シミュレーション

强应变晶粒细化的 GN 位错-晶体塑性模拟

• 发表时间: 2005
• 期刊: 日本材料学会第54期学術講演会講演論文集
• 作者: Iwamoto;M.;Tanaka;E.;Miki;K.;岩本正実;伝田耕平;岩本正実;永原斉;Shingo Oishi;Naoshi Yamaki;青柳 吉輝;青柳 吉輝;Shingo Oishi;Naoshi Yamaki;Yoshiteru Aoyagi;Yoshiteru Aoyagi;Naoshi Yamaki;Naoshi Yamaki;青柳 吉輝
• 通讯作者: 青柳 吉輝