运动晶界与调幅分解相互作用过程的相场法研究  

A phase-field study on interaction process of moving grain boundary and spinodal decomposition

作　　者：郭灿 赵玉平 邓英远 张忠明[1] 徐春杰[1] Guo Can;Zhao Yu-Ping;Deng Ying-Yuan;Zhang Zhong-Ming;Xu Chun-Jie(School of Materials Science and Engineering,Xi'an University of Technology,Xi’an 710048,China)

机构地区：[1]西安理工大学材料科学与工程学院,西安710048

出　　处：《物理学报》2022年第7期323-329,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51801154);陕西省高等学校学科创新引智基地项目(批准号:S2021-ZC-GXYZ-0011);西安市高校重大科技创新平台及科技成果就地转化项目(批准号:20GXSF0003)资助的课题。

摘　　要：晶界控制的调幅分解对材料微观组织及性能有着十分重要的影响,然而,限于研究手段,我们对晶界与调幅分解间相互作用过程及机制的认识仍存在不足.本文采用相场法模拟了实际多晶体系的调幅分解过程,研究了晶界曲率及晶界处原子扩散速率对调幅组织形貌的影响,并讨论了调幅分解与晶界迁移的相互作用关系.结果表明,晶界能够促进并调制调幅组织形貌,晶界附近为各向异性调幅组织,晶粒内部为各向同性双连通调幅组织;随着晶界曲率增大,调幅组织由垂直晶界转变为平行晶界;调幅分解速度随着晶界原子扩散系数的增大而增大,而调幅分解过程中的晶界迁移速度则随着晶界原子扩散系数的增大表现为先减小后增大;三维模拟结果与二维模拟结果相一致.The grain boundary-directed spinodal decomposition has a substantial effect on the microstructure and properties of poly crystalline materials.However,due to the fact that the spinodal decomposition is usually too fast to be captured in experiments,our understanding of the grain boundary-directed spinodal decomposition process is still very limited.In this work,we simulate the spinodal decomposition process of a poly crystalline system by the phase-field model,check the influences of the curvature and the atom diffusion constant inside the grain boundary(M;)on the phase decomposition patterns,and discuss the interaction between the moving grain boundaries and spinodal decomposition.The simulation results indicate that the velocity of spinodal decomposition near the grain boundary is faster,and the spinodal morphology at the grain boundary presents the anisotropic bicontinuous microstructures different from the isotropic continuous microstructures in the bulk phase.Further,we find that the spinodal pattern is parallel to the grain boundaries with larger curvatures,and it will perpendicular to the grain boundaries with smaller curvatures.We also find that the spinodal decomposition velocity increases with the augment of M;,while the grain boundary migration velocity will first decrease and then increase with the augment of M;under the effect of spinodal decomposition.Finally,we simulate the spinodal decomposition process of two-grain system in three dimensions,and we obtain the results consistent with the two-dimensional simulations.

关 键 词：调幅分解 晶界 曲率 晶界迁移 

分 类 号：TB30[一般工业技术—材料科学与工程]