EAGER: Manufacturing Interface Dominated Microstructures in Bulk Metal-Metal Composites for Ultra-High Strength and Formability

纳米结构多层膜-由厚度仅为几纳米的金属交替层组成的材料-是一类具有独特性能的工程材料。以块体形式制造这些多层具有显著的加工挑战。传统上，多层金属多层膜已经使用可以将总膜厚度限制在亚毫米水平的技术来合成，但是最近的研究表明，大量的纳米结构金属多层膜可以通过称为累积辊压接合的替代工艺来制造。EARLY概念探索性研究赠款（EAGER）奖支持通过辊压粘合工艺以块状形式合成镁基纳米结构多层所需的基础研究。这些材料作为轻质结构材料具有许多应用。由于镁合金比铝合金轻35%，比钢轻78%，因此这项研究的潜在社会影响和回报可能是巨大的。运输行业燃油效率的提高意味着更低的工作温度、更耐用的部件和更少的温室气体排放。在消费电子行业环保计划的推动下，镁满足了消费电子产品变得更轻、更薄和更移动的的设计挑战。这种结合建模和实验研究的具体目标是：a）制造新的纳米晶粒和富相界面的金属-金属（六方密排镁-体心立方铌或钒）复合材料，B）建立对界面驱动的微观结构发展和微观结构-性能关系的基本理解，以及c）制定和验证一组基于物理学的模型，其能够实现基本理解并且能够预测这种材料的行为。成功完成这项研究后，将证明加工镁合金纳米层状复合材料的概念验证能力，并确定将复合材料细化到纳米级以及相关强度和可成形性增强的基础科学。

Nanostructured multilayers - materials comprised of alternating layers of metal with thicknesses of just a few nanometers - are a class of engineering materials with unique properties. Fabricating these multilayers in bulk form has significant processing challenges. Traditionally multilayer metallic multilayers have been synthesized using techniques which can limit the total film thickness to sub-millimeter levels, but recent research has demonstrated that bulk quantities of nanostructured metallic multilayers can be manufactured by an alternate process known as accumulative roll bonding. This EArly-concept Grants for Exploratory Research (EAGER) award supports the fundamental research needed for synthesis of magnesium-based nanostructured multilayers in bulk form through the roll bonding process. These materials have many applications as lightweight structural materials. Because magnesium alloys are 35 percent lighter than aluminum alloys and 78 percent lighter than steel, the potential societal impact and pay-offs of this research can be tremendous. Improvements in fuel efficiency for transportation industry means lower operating temperatures, longer-lasting components, and reduced greenhouse gas emissions. Driven by environmental programs across the consumer electronics industry, magnesium meets the design challenges that are instrumental to consumer electronics becoming lighter, thinner, and more mobile. The specific objectives of this combined modeling and experimental research are to: a) fabricate new nano-grained and phase interfaces-rich metal-metal (hexagonal close-packed magnesium - body-centered cubic niobium or vanadium) composites in bulk form, b) establish a fundamental understanding of the interface driven microstructure development and microstructure-property relationships, and c) formulate and validate a set of physics based models that enable fundamental understanding and can predict behavior of such materials. Upon successful completion of this research, proof of concept ability to process magnesium alloy nano-lamellar composite will be demonstrated and the fundamental science behind refining the composite to nano-scale and associated strength and formability enhancements will be determined.