Interactions of Multiple Phase Transformations and Dislocations: Modeling and Simulation from Atomistic to Microscale

多相变和位错的相互作用：从原子到微观尺度的建模和仿真

基本信息

批准号：
1536925
负责人：
Liming Xiong
金额：
$ 40.5万
依托单位：
Iowa State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-01 至 2020-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536925&HistoricalAwards=false
关键词：
Interactions Multiple Phase Transformations Dislocations

项目摘要

This award supports fundamental research to provide knowledge toward understanding phase transformations, plasticity, and their interactions. The research under this award will focus on phase transformation and plasticity in silicon and germanium. Predicting the deformation response in these materials is important for semiconductor engineering. This research will lead to a multifaceted computational tool for quantitative predictions of properties of these materials. The computer simulations enabled by the computational tool would reveal the main mechanisms during the interaction between phase transformation and plasticity from the atomic to the macroscopic level. As an extension, the computational tool can also find applications to other material processes and technologies, including the thermomechanical treatment of steel, the behavior of shape memory alloys, and the synthesis of superhard ceramics. The software developed under this award will be shared with the research community on the team's webpages and high performance computing clusters. The research team will also participate the Freshman Honor Program that connects undergraduates with research activities at Iowa State University. Two new graduate courses on phase transformations and plasticity, and atomistic-continuum modeling will be developed. This research will also promote active participation from under-represented groups through the Program for Women and Science in Engineering in the College of Engineering at Iowa State University. The objective of this research is to establish a predictive multiscale modeling framework by linking a reactive concurrent atomistic-continuum method and a continuum phase field approach. The reactive concurrent atomistic-continuum method will be based on a finite element implementation of an atomistic field formalism. Simultaneous phase transformations and dislocation-mediated plasticity as a consequence of chemical bond breaking and reforming, changes of the crystal structures and slip will be simulated for micron-sized domains of silicon and germanium. The phase field approach will be based on a new multiphase thermodynamic potential for large strains and will enable large-scale simulations of coupled phase transformation and plasticity in materials. Formations of multiple phases and evolutions of dislocation microstructures in silicon and germanium will be simulated at the macroscale. The research team will validate the predictive capability of the multiscale computational tool through fully atomistic simulations and also experimental measurements. Lastly, the team will apply the multiscale simulation tools to find methods for promoting or suppressing dislocation activities and phase transformations through tailoring the microstructures of materials and controlling applied loading conditions.

该奖项支持基本研究，以提供了解相变，可塑性及其相互作用的知识。根据该奖项的研究将重点介绍硅和锗的相变和可塑性。预测这些材料中的变形响应对于半导体工程非常重要。这项研究将导致一个多方面的计算工具，用于定量这些材料性质的预测。计算工具启用的计算机模拟将揭示从原子到宏观水平的相互作用与可塑性之间的相互作用期间的主要机制。作为扩展，计算工具还可以在其他材料过程和技术中找到应用，包括钢的热机械处理，形状记忆合金的行为以及超级陶瓷的合成。根据该奖项开发的软件将在团队的网页和高性能计算集群上与研究社区共享。研究团队还将参加新生荣誉计划，该计划将大学生与爱荷华州立大学的研究活动联系起来。将开发两个有关相变和可塑性的新研究生课程，以及原子 - 胞源建模。这项研究还将通过爱荷华州立大学工程学院的妇女和工程学计划促进代表性不足的群体的积极参与。这项研究的目的是通过连接反应性的原子 - 胞本方法和连续相位场方法来建立预测性的多尺度建模框架。反应性的原子 - 原子化方法将基于原子形式主义的有限元实现。由于化学键断裂和改革，晶体结构和滑移的变化将模拟硅和锗的微小结构域，同时进行相变和脱位介导的可塑性。相场方法将基于新的多相热力学潜力，以实现大型菌株，并能够大规模模拟材料中耦合相变和可塑性的大规模模拟。在宏观上，将模拟多个阶段和位错微结构的发展。研究团队将通过完全原子模拟和实验测量来验证多尺度计算工具的预测能力。最后，团队将应用多尺度仿真工具来查找通过调整材料的微观结构和控制所应用的加载条件来促进或抑制错位活动和相变的方法。