Polymer-Derived In-Situ Metal-Matrix Nanocomposites: A New Paradigm in Processing, Structure, and Properties of Dispersion Strengthened (copper) Alloys

聚合物衍生的原位金属基纳米复合材料：弥散强化（铜）合金加工、结构和性能的新范例

• 批准号: 1105347
• 负责人: Rishi Raj
• 金额: $ 46万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1105347&HistoricalAwards=false
• 关键词: Polymer; Derived; Situ; Metal; Matrix

TECHNICAL SUMMARY: A nanoscale dispersion of stable, non-coarsening ceramic particles into a metal matrix is a precondition for metallic composites that resist creep at high homologous temperatures. The goal of this program is to develop the scientific underpinnings for a new method for dispersing fine particles of a ceramic phase into a metal, and understanding how they influence the mechanical properties. In this method the ceramic is introduced into the metal as a polymer, which is then pyrolyzed in-situ to create the nanodispersed ceramic phase. This research program will explore the basic mechanisms for the in-situ conversion of the polymer into the ceramic. Copper, dispersed with nanoparticles of a polymer-derived ceramic phase constituted from Si-C-N-O, will be employed as the "model" material system for this investigation. The microstructural stability and the creep and creep fracture behavior of the alloy at temperatures approaching 950 °C (about 0.9 of the melting temperature) will be investigated. Fundamental mechanisms that include how the size and spacing, and the structure and bonding at the particle-matrix interface control the climb of dislocations and the nucleation of voids under mechanical loading at high temperatures, will be studied. A key issue is to elucidate how the interfacial bonding influences the threshold stress, the ultimate goal being to achieve a threshold stress that approaches the Orowan upper bound for the escape of dislocations pinned by hard particles. Atomistic modeling isexpected to inform the experimental results.NON-TECHNICAL SUMMARY: New nanomaterials with unusual properties are often highly complex, both in the way they are made and how they perform. For them to be successfully implemented into next-generation systems, their performance must be underpinned by scientific understanding and models. This research program is dedicated to the science and development of novel high temperature metallic alloys that are potentially important for future engineering systems. Their novelty lies in a polymer route to the creation of a highly stable, nanoscale dispersion of ceramic particles in a metal matrix. The research plan includes intimate international collaborations in Austria and Germany that provide important expertise in atomic scale characterization and modeling. The program has an aggressive plan for dissemination of the scientific outcomes of this research, primarily through International Meetings that are held every two years in Boulder, Colorado.

技术概要：稳定的、非粗化的陶瓷颗粒在金属基体中的纳米级分散是金属复合材料在高同源温度下抵抗蠕变的先决条件。该计划的目标是为将陶瓷相的细颗粒分散到金属中的新方法开发科学基础，并了解它们如何影响机械性能。在这种方法中，陶瓷作为聚合物被引入到金属中，然后原位热解以产生纳米分散的陶瓷相。该研究计划将探索聚合物原位转化为陶瓷的基本机制。 铜，分散与纳米粒子的聚合物衍生的陶瓷相构成的Si-C-N-O，将被用作“模型”材料系统进行这项调查。将研究合金在接近950 °C（约为熔化温度的0.9）的温度下的微观结构稳定性以及蠕变和蠕变断裂行为。将研究基本机制，包括尺寸和间距，以及颗粒-基体界面的结构和键合如何控制高温机械载荷下位错的爬升和空洞的成核。一个关键的问题是阐明界面结合如何影响阈值应力，最终目标是实现阈值应力，接近奥罗万上限的逃逸的位错钉扎硬颗粒。原子模型有望为实验结果提供信息。非技术总结：具有不寻常特性的新纳米材料通常非常复杂，无论是在制造方式还是在性能方面。要使它们成功地应用到下一代系统中，它们的性能必须得到科学理解和模型的支持。该研究计划致力于对未来工程系统具有潜在重要性的新型高温金属合金的科学和开发。他们的新奇在于一种聚合物路线，以创造一个高度稳定的，纳米级分散的陶瓷颗粒在金属基体。该研究计划包括在奥地利和德国的密切国际合作，提供原子尺度表征和建模方面的重要专业知识。该计划有一个积极的计划，主要通过每两年在科罗拉多博尔德举行的国际会议传播这项研究的科学成果。