CAREER: Study of the Mechanical Properties of Thin Metal Films and Shape Memory Alloy Coatings

职业：金属薄膜和形状记忆合金涂层的机械性能研究

• 批准号: 0133559
• 负责人: Joost Vlassak
• 金额: $ 39.76万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0133559&HistoricalAwards=false
• 关键词: CAREER; Study; Mechanical; Properties; Thin

This project aims at greater understanding of deformation and fracture mechanisms of thin films. It has been known that these mechanisms interact with microstructural features such as grain size, grain orientation, interfaces and surfaces, and dislocation substructure albeit the nature of these interactions is not well established. The project investigates the stress-strain behavior of freestanding films using bulge test technique while films on substrates will be studied using the substrate curvature method. Another goal of the project is to investigate the precipitation hardening and the shape memory effects in Ni-Ti thin films. Third objective of the project is to develop micromechanical techniques for measuring thin film fracture toughness. These techniques are used to investigate sub-critical crack growth under cyclical loading conditions and to determine how factors like film thickness, chemical environment, and process conditions affect the fracture toughness of thin metal and alloy films. A new undergraduate Introductory Materials Science course along with a special topics course will serve as the main vehicles for some of the educational activities.%%%This research develops new and improved understanding of the deformation mechanisms that operate in thin films, resulting in better models for thin film mechanical behavior that will have an impact on many engineering applications where thin films are used, such as integrated circuits, MEMS devices, and wear resistant coatings. The fracture toughness and fatigue resistance of thin films are applicable from reliability concerns for MEMS devices in non-hermetic packaging that is more cost-effective than traditional hermetic packaging.

该项目旨在更好地理解薄膜的变形和断裂机制。人们已经知道，这些机制相互作用的微观结构特征，如晶粒尺寸，晶粒取向，界面和表面，和位错亚结构，尽管这些相互作用的性质还没有很好地建立。该项目使用凸起测试技术研究独立薄膜的应力-应变行为，而基板上的薄膜将使用基板曲率方法进行研究。本计画的另一个目的是研究Ni-Ti薄膜的沉淀硬化与形状记忆效应。该项目的第三个目标是开发测量薄膜断裂韧性的微机械技术。这些技术用于研究循环载荷条件下的亚临界裂纹扩展，并确定薄膜厚度、化学环境和工艺条件等因素如何影响薄金属和合金薄膜的断裂韧性。一门新的本科材料科学入门课程沿着一门专题课程将作为一些教育活动的主要工具。%%%这项研究开发了新的和更好的理解在薄膜中工作的变形机制，从而产生更好的薄膜机械行为模型，这将对使用薄膜的许多工程应用产生影响，例如集成电路，MEMS器件和耐磨涂层。薄膜的断裂韧性和抗疲劳性适用于非气密封装中的MEMS器件的可靠性问题，非气密封装比传统的气密封装更具成本效益。