Nanoscaled deformation and fracture processes in nanolayers

纳米层中的纳米级变形和断裂过程

• 批准号: 0140317
• 负责人: Scott Mao
• 金额: --
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140317&HistoricalAwards=false
• 关键词: Nanoscaled; deformation; fracture; processes; nanolayers

0140317MaoNanoscale multilayers, composed of sub-micrometer thick layers of two or more species of materials are of significant interest for high-technology applications and devices in many fields of industry, including microelectronics, magnetic recording, optics, and micro-electro-mechanical systems. The physical performance and reliability of these devices depend on the structural integrity of the multilayers. Hence, there is considerable worldwide research interest in the mechanical response of multilayers, including the deformation and fracture behavior. The development of viable novel devices based on these advanced multilayer systems and their further improvement requires a basic understanding of the fundamental processes that are the agents of the macroscopic deformation and fracture performance. The main goal of the proposed project is the investigation of the processes of micro-plasticity involved in the fracture of carefully selected model nanoscale multilayer systems by dynamic in-situ straining TEM experiments as well as static post-mortem TEM. This research will produce new insights regarding dislocation mobilities and interactions with interfaces and their relationship to crack growth in multilayers. Hence, the fundamental relationships between processes of plasticity, local flow and fracture in Cu/Ni, Cu/Cr and Cu/TiN multilayers with selected interfacial structure and layer thickness will be elucidated. The project objectives are:to investigate the deformation and fracture process of metal/metal (Cu/Ni, Cu/Cr) and metal/ceramic (Cu/TiN) multilayers by in-situ straining transmission electron microscopy. to predict the fracture resistance and the effect of interfaces on crack tip stresses in the nanolayers as a function of layer thickness, and crystal orientation using a dislocation-interface interaction model.Both in-situ TEM fracture experiments and dislocation based modeling of the deformation and fracture processes in the nanolayers will be performed. Two graduate students (one in materials science and one in mechanical engineering) will be trained during the project as the follows: Student 1: in-situ TEM experiment on microplasticity and fracture in nanolayers (Dr. Wizorek)Student 2: dislocation based modelling on the deformation and fracture process (Dr. Mao).Dr. Mao will be responsible for the design of the in-situ straining experiments and dislocation-based modeling. Dr. Wiezorek will be responsible for the performance of TEM characterization and in-situ TEM testing. Because of the comprehensive and interdisciplinary nature of the proposed research, the involvement of students in the project will provide effective means for training of the new generation of materials scientists for the new century.

0140317Maonanoscale多层层由两种或多种材料种类的亚微米厚层组成，这对于许多行业领域的高技术应用和设备引起了重大关注，包括微电源，磁性记录，光学，光学器件和微电力机械系统。这些设备的身体性能和可靠性取决于多层的结构完整性。因此，全世界对多层机械反应的研究兴趣，包括变形和断裂行为。基于这些先进的多层系统及其进一步改进的可行新颖设备的开发需要对宏观变形和断裂性能的基本过程有基本的理解。拟议项目的主要目标是研究通过动态内部的固定性TEM实验以及静态验尸后TEM的精心选择模型纳米级多层系统破裂所涉及的微塑性的过程。这项研究将产生有关错位迁移率和与界面的相互作用及其与多层破解增长的关系的新见解。因此，将阐明可塑性，局部流动和断裂过程之间的基本关系，Cu/cr/cr和Cu/Tin多层与所选界面结构以及层厚度之间的基本关系。 项目目标是：通过原地释放透射电子显微镜研究金属/金属（Cu/Ni，Cu/Cr）和金属/陶瓷（CU/TIN）多层的变形和断裂过程。 为了预测纳米层中裂纹的断裂抗性和界面对层厚度的函数的裂纹尖端应力，并使用脱位界面相互作用模型进行晶体方向。将执行纳米层中的断裂过程。在项目期间，将对两名研究生（一名在材料科学领域，一名在机械工程中）进行培训：学生1：Nanolayers（Wizorek博士）的微塑性和骨折实验（Wizorek博士）学生2：基于基于脱位的模型变形和断裂过程（Mao博士）.dr。 MAO将负责基于原位的拉克实验和基于脱位的建模的设计。 Wiezorek博士将负责TEM表征和原位TEM测试的性能。由于拟议研究的全面和跨学科的性质，学生参与项目将为培训新世纪的新一代材料科学家提供有效的手段。