Effect of Alloying and Thermo-Mechanical Processing on the Deformation of Hexagonal Close-Packed Alloys

合金化和热机械加工对六方密排合金变形的影响

• 批准号: 1727237
• 负责人: K. Linga Murty
• 金额: $ 47.43万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-15 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1727237&HistoricalAwards=false
• 关键词: Effect; Alloying; Thermo; Mechanical; Processing

Hexagonal close-packed (HCP) metals such as titanium, magnesium and zirconium alloys are commonly used for structural applications in energy, transportation and biomedical technologies, and a thorough understanding of their mechanical integrity is central for their in-service sustainability. Correlating fine-scale structure of the alloys with their resistance to deformation at service temperatures will allow for new understanding of the mechanisms that control alloy performance, and can provide guidance for design of high-strength, durable components. This award supports fundamental scientific research to understand the role of alloy composition and structure on mechanical properties in zirconium-based alloys. The research brings experimental testing together with computational modeling to predict the behavior of these alloys based on the new knowledge of their composition, structure, and how these relate to properties and performance in service. The work will lead to new scientific understanding that can be applied to a number of important alloy systems, and will provide excellent educational opportunities for students participating in the research. Particular emphasis is placed on broadening participation in scientific research through engagement in K-12 outreach programs which will allow high school students the opportunity to participate in the research, along with undergraduate and graduate students.This research addresses the influence of thermo-mechanical treatment and alloying on creep anisotropy of zirconium alloys with emphasis on niobium addition and heat treatment. The addition of niobium as an alloying element has been shown to lend better performance and durability, and this research aims to understand the phenomena controlling this behavior. Creep anisotropies in these alloys will be investigated in the different regimes such as power-law and viscous creep, as well as at high stresses in the power-law breakdown region. Corresponding deformation microstructures will be characterized for a thorough understanding of the underlying creep mechanisms and the biaxial creep anisotropy. The knowledge derived from this research can be applied to understand the plastic deformation mechanisms of other HCP alloys at high temperatures, and can provide robust tools to predict dimensional changes in service. This research involves both experimental and modeling approaches, and the findings will be integrated into classroom teaching for training the next generation of Engineers.

钛、镁和锆合金等半导体密堆积（HCP）金属通常用于能源、交通和生物医学技术中的结构应用，对其机械完整性的透彻理解对其在役可持续性至关重要。将合金的精细结构与其在使用温度下的抗变形性相关联，将使人们对控制合金性能的机制有新的理解，并可为高强度、耐用部件的设计提供指导。该奖项支持基础科学研究，以了解合金成分和结构对锆基合金机械性能的作用。该研究将实验测试与计算建模结合起来，根据合金成分、结构的新知识以及这些与性能和使用性能的关系来预测这些合金的行为。这项工作将带来新的科学认识，可应用于许多重要的合金系统，并将为参与研究的学生提供良好的教育机会。特别强调的是通过参与K-12推广计划，这将使高中学生有机会参与研究，沿着与本科生和研究生。这项研究解决了热机械处理和合金化对蠕变各向异性的锆合金，重点是铌添加和热处理的影响。添加铌作为合金元素已被证明可以提供更好的性能和耐久性，本研究旨在了解控制这种行为的现象。这些合金的蠕变各向异性将在不同的制度，如幂律和粘性蠕变，以及在高应力的幂律击穿区进行研究。相应的变形微观结构的特点是一个彻底的理解潜在的蠕变机制和双轴蠕变各向异性。从这项研究中获得的知识可以应用于了解其他HCP合金在高温下的塑性变形机制，并可以提供强大的工具来预测使用中的尺寸变化。这项研究涉及实验和建模方法，研究结果将被整合到课堂教学中，以培养下一代工程师。