Design and Development of Body-Centered Cubic Alloys with Increased Strength and Toughness for Infrastructural and Structural Applications

用于基础设施和结构应用的强度和韧性增强的体心立方合金的设计和开发

• 批准号: 0826535
• 负责人: Semyon Vaynman
• 金额: $ 39.99万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0826535&HistoricalAwards=false
• 关键词: Design; Development; Body; Centered; Cubic

Design and Development of Body-Centered Cubic Alloys with Increased Strength and Toughness for Infrastructural and Structural ApplicationsAbstractA theoretical and experimental program to ductilize alloys with body-centered cubic (bcc) structure and specifically steel will be performed. The guiding principle is that nanoscale precipitates that are coherent with the matrix not only significantly increase the strength of the material but also reduce the ductile to brittle transformation temperature by locally lowering the Peierls stress for screw dislocations. The ferritic matrix of the steel will be strengthened and ductilized with nano-scale precipitates containing Cu, Ni, Mn and Al. The relationship between the precipitate composition, structure, size and mechanical properties will be established. The composition of the steel and heat-treatment conditions will be selected to give the optimal strength, ductility and fracture toughness at low temperatures. Theory of ductilization of bcc metals by nano-size slightly misfitting precipitates will be generalized using the methods of micromechanics and will be applied to other metals where high Peierls stress limits the ductility. The results of the experimental work will guide and test the theoretical work.The proposed concept will have far-reaching implications in materials design, such as improving the toughness of Cr and Ti-based alloys, intermetallics, and possibly ceramics. This will open up new opportunities for research and development of new materials for infrastructure and structural applications. Also this project will be very effective in training of graduate and undergraduate students since it combines the use of advanced scientific tools with theoretical work.

设计和开发具有增强的强度和韧性的体心立方合金，用于航空结构和结构应用摘要将进行体心立方（bcc）结构合金和特别是钢的塑性化的理论和实验计划。其指导原则是，与基体一致的纳米级沉淀物不仅显著增加了材料的强度，而且通过局部降低螺旋位错的Peierls应力来降低韧脆转变温度。研究了Cu、Ni、Mn、Al等纳米级析出相对钢的铁素体基体的强化和韧化作用，并建立了析出相成分、结构、尺寸与力学性能的关系。钢的成分和热处理条件将被选择为在低温下提供最佳的强度、延展性和断裂韧性。 体心立方金属的塑性化的纳米尺寸轻微失配的沉淀物的理论将被推广使用的方法的微观力学，并将被应用到其他金属的高Peierls应力限制的延展性。实验工作的结果将指导和检验理论工作。所提出的概念将对材料设计产生深远的影响，例如提高铬基和钛基合金、金属间化合物以及可能的陶瓷的韧性。 这将为基础设施和结构应用的新材料的研究和开发开辟新的机会。此外，这个项目将是非常有效的研究生和本科生的培训，因为它结合了先进的科学工具与理论工作的使用。