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

University Of New Hampshire, Durham NH

Investigators

Abstract

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.