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交替金属层组成的材料-是一类具有独特性能的工程材料。以块状形式制造这些多层膜具有重大的工艺挑战。传统上，多层金属多层膜的合成技术可以将薄膜的总厚度限制在亚毫米级，但最近的研究表明，大量的纳米结构金属多层膜可以通过一种称为累积滚压连接的替代工艺来制造。这一早期概念探索性研究补助金(AGER)奖支持通过滚压粘合工艺合成块状镁基纳米结构多层膜所需的基础研究。这些材料作为轻质结构材料有很多应用。因为镁合金比铝合金轻35%，比钢轻78%，所以这项研究的潜在社会影响和回报可能是巨大的。运输行业燃料效率的提高意味着更低的运行温度、更持久的部件和更少的温室气体排放。在整个消费电子行业环境计划的推动下，镁迎接了设计挑战，这些挑战有助于消费电子产品变得更轻、更薄、更灵活。这种建模和实验研究相结合的具体目标是：a)以块状形式制造新的纳米晶和富相界面的金属-金属(六方密堆积镁体心立方Nb或钒)复合材料，b)建立对界面驱动的微结构发展和微结构-性能关系的基本理解，以及c)制定和验证一套基于物理的模型，使能够对此类材料的基本了解和行为进行预测。在这项研究成功完成后，将展示加工镁合金纳米片层复合材料的概念验证能力，并将确定将复合材料细化到纳米级以及相关强度和成形性增强背后的基础科学。

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.