The Relationship Between Grain Structure and Deformation Behavior to the Fracture Mechanism in High Strength-High Ductility Combination Nanostructured Materials

非技术摘要关于下一代高强度材料的拟议研究旨在扩大高强度-高塑性合金加工的最新水平，使其具有更好的成形性。揭示高强高塑性组合的断裂机制，将是指导强韧金属材料发展的重大突破。最终目标是确定指导方针，以开拓高强度-高延性材料的新前沿，用于轻型和涉及能量吸收和成型性的高效解决方案。此外，将开发新的技术来了解材料的行为，这将适用于其他金属系统。纳米颗粒材料的高强度-高塑性组合将允许更薄的截面或部件，这将导致运输部门的燃料经济性。技术摘要该奖项的研究目标是确定在纳米范围内获得高强度-高塑性组合的基本标准。这些标准将通过进行受控机械变形实验以及通过显微镜工具对变形区域的研究来阐明。实验将涉及随着颗粒尺寸的减小而增加主成分的稳定性。该标准将确定金属材料主要成分的稳定性是否对高强度金属材料的延展性和延迟断裂负责。变形行为的变化将作为从纳米晶区到常规微米区的晶粒度的函数来研究。将根据晶粒度、变形过程和断裂机制之间的相互关系，开发具有广泛材料系统预测能力的物理模型。

Non-technical Abstract The proposed research concerning the next generation of high strength materials is envisaged to extend the state-of-art of processing of high strength-high ductility alloys with superior formability. The unlocking of fracture mechanisms underlying high strength-high ductility combination will be a major breakthrough in guiding the development of strong and ductile metallic materials. The ultimate objective is to determine guidelines to pioneer a new frontier of high strength-high ductility materials for light and efficient solutions involving energy absorption and formability. Furthermore, new techniques will be developed to understand material behavior that will be applicable to other metallic systems. The high strength-high ductility combination of nanograined materials will allow for thinner sections or components, which will lead to fuel economy in the transportation sector.Technical AbstractThe research objective of the award is to determine the fundamental criteria in obtaining high strength - high ductility combination in metals with grain size in the nanometer range. The criteria will be elucidated by conducting controlled mechanical deformation experiments in conjunction with the study of deformed region via microscopy tools. Experiments will involve increasing the stability of the principal constituent with decrease in grain size. The criteria will define if the stability of the principal constituent of the metallic material is responsible in governing the ductility and delayed fracture of high strength metallic materials. The changes in deformation behavior will be studied as a function of grain size from nanograin regime to conventional micrometer regime. Physical models with predictive capabilities for a wide range of material systems based on the inter-relationship between grain size, deformation process and fracture mechanisms will be developed.