Structure and Failure of fcc/bcc Heterophase Boundaries in Metals

金属中 fcc/bcc 异相边界的结构和失效

• 批准号: 5428651
• 负责人: Professor Dr. Peter Gumbsch
• 金额: --
• 依托单位: Institut für Angewandte Materialien - Zuverlässigkeit und Mikrostruktur (IAM-ZM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5428651?language=en
• 关键词: Structure; Failure; fcc; bcc; Heterophase

Heterophase Interface between fcc and bcc metals exist in many microelectronic devices and in composite materials. Compared to other interphase boundaries, for example metal/ceramic interfaces, the failure processes at fcc/bcc heterophase boundaries are poorly understood. The purpose of the proposed project is to study the structure, the mechanical properties and the resistance to damage formnation of different fcc/bcc interfaces in the Cu-Ta model system. The interfacial structure will be studied in close collaboration with the group of Prof. Yuri Mishin at George Mason University, Fairfax, USA, who is also developing the angularly dependent interatomic Potentials used to model the atomic interaction in the Cu-Ta system. The group of Prof. Mishin will then focus on the study of diffusion at the fcc/bcc interface, whereas we will focus on the determination of the initial failure modes as a function of loading mode and orientation of the interface and of the two adjacent crystals. Particular emphasis will be put on defects at the fcc/bcc interfaces and on pore formation. The transition of vacancy clusters to a macroscopic pore, as well as the actual decohesion process will both be studied. The dynamics of crack propagation and energy dissipation mechanisms at high temperatures shall also be investigated. The correlation between structure, mechanical properties, defect formation, diffusion coefficients and fracture at these heterophase boundaries will significantly advance our understanding of the behavior of heterophase boundaries in such material systems. It will also lay the foundations for further studies towards electromigration failure and reliability of fcc/bcc composites.

面心立方和体心立方金属间的异相界面存在于许多微电子器件和复合材料中。与其他界面(如金属/陶瓷界面)相比，面心立方/体心立方异相界面的失效过程鲜为人知。本项目的目的是研究铜-钽模型体系中不同fcc/bcc界面的结构、力学性能和抗损伤形成能力。界面结构将与美国费尔法克斯乔治梅森大学的Yuri Mishin教授密切合作研究，他还在开发角度相关的原子间相互作用势，用于模拟Cu-Ta系统中的原子相互作用。然后，Mishin教授小组将重点研究面心立方/体心立方界面的扩散，而我们将重点研究作为加载模式和界面和两个相邻晶体取向的函数的初始失效模式。将特别强调fcc/bcc界面的缺陷和气孔形成。空位团簇向宏观孔的转变，以及实际的解聚过程都将被研究。还应研究高温下裂纹扩展的动力学和能量耗散机制。这些异相界的结构、力学性能、缺陷形成、扩散系数和断裂之间的关系将极大地促进我们对这类材料体系中异相界行为的理解。为进一步研究FCC/BCC复合材料的电迁移失效和可靠性奠定了基础。