GOALI: Fundamentals of High Temperature Deformation in Polycrystalline Ni-Al-Nb Eutectic Alloys

技术概述：基于Ni-Al-Nb体系的新型多晶伪三元共晶γ - γ′- δ合金，最近被证明具有一套很有前途的高温性能，这可能会彻底改变现代燃气涡轮发动机的设计，并导致性能和效率的革命性改进。这项研究计划的目的是建立对控制这些合金高温强度的机制的基本理解。这将通过选择一系列近共晶Ni-Al-Nb基合金来完成，目的是量化合金添加量和δ相平衡体积分数对强度和抗蠕变性能的影响。体积和新颖的小规模机械测试方法将用于系统地分离高温下化学和微观结构强化的贡献。详细的透射电镜研究将用于阐明控制合金系统力学性能的潜在变形机制。变形力学的计算模型将用于补充实验测量，并协助制定基于物理的本构模型，该模型能够准确预测这种新型合金系统在高温下的变形特性。该计划的结果有望为革命性新材料的开发提供新的方向，这些新材料有可能取代高温结构应用中的传统镍基高温合金。非技术总结：高温结构材料的进步已经成为开发超低油耗、最大限度减少二氧化碳和氮氧化物排放的超高效燃气轮机的关键技术。除了经济和环境效益外，由于先进的燃气轮机技术在发电、太空探索、航空航天/海洋推进和各种其他国防相关应用中的重要性，美国在这一领域保持技术领先地位也存在战略需要。该提案的目的是通过结合实验测量和基于物理的本构模型来研究一类新型高温结构材料的基本变形行为。罗尔斯·罗伊斯北美技术公司的联合项目负责人直接参与，研究生和本科生将有机会在快节奏的工业研究环境中为技术进步做出重大贡献，并为工业相关问题开发创新解决方案。结合拟议的研究，PI和研究生都将积极参与促进针对芝加哥地区当地中学科学教师的教育外展活动，以加强初中/高中课程并提高学生的水平。具有材料科学和工程知识。这将包括为面向高中生的ASM材料营和面向高中科学教师的ASM教师营提供资源和支持。

TECHNICAL SUMMARY: Novel polycrystalline pseudo-ternary eutectic gamma-gamma'-delta alloys, based on the Ni-Al-Nb system, have been recently demonstrated to possess a promising set of high temperature properties that may permit radical changes in the design of modern gas turbine engines and lead to revolutionary improvements in performance and efficiency. This aim of this research program will be to establish a fundamental understanding of the mechanisms governing the high temperature strength of these alloys. This will be accomplished by selecting a series of near eutectic Ni-Al-Nb based alloys with the objectives of quantifying how alloying additions and the equilibrium volume fraction of delta phase affect the strength and creep resistance. Both bulk and novel small-scale mechanical testing methods will be used to systematically isolate contributions from chemical and microstructural strengthening at elevated temperatures. Detailed transmission electron microscopy studies will be used to elucidate the underlying deformation mechanisms governing the mechanical properties of the alloy system. Computational modeling of the deformation mechanics will be used to complement the experimental measurements and assist in the formulation of a physics-based constitutive model capable of accurately predicting the deformation characteristics of this novel alloy system at elevated temperatures. Results from the proposed program are expected to suggest new directions for the development of revolutionary new materials that have the potential to replace conventional Ni-base superalloys in high temperature structural applications.NON-TECHNICAL SUMMARY: Advances in high temperature structural materials have served as key enabling technologies that have been critical to the development of ultra-efficient gas turbines with reduced fuel consumption, and minimization of CO2 and NOX emissions. In addition to the economic and environmental benefits, there exists a strategic need for the U.S. to maintain technological leadership in this field due to the importance of advanced gas turbine technologies for power generation, space exploration, aerospace/marine propulsion and various other defense related applications. The aim of the proposal is to investigate the fundamental deformation behavior of a novel new class of high temperature structural materials by combining experimental measurements with physics-based constitutive models. With direct involvement of the Co-PI from Rolls-Royce North American Technologies, graduate and undergraduate students will have the opportunity to contribute significantly to technological advancements within a fast-paced industrial research setting and develop innovative solutions for industrially relevant problems. In conjunction with the proposed research, both the PI and the graduate students will be actively involved with promoting educational outreach activities aimed at local Chicago-area secondary school science teachers to enhance the middle/high school curricula and raise the students? awareness of materials science and engineering. This will include the provision of resources and support for both the ASM Materials Camp for high school students and the ASM Teacher's Camp for high school science teachers.