CAREER: On the Engineering of Light Metals for Enhanced Dynamic Properties and Fatigue Performance

Worcester Polytechnic Institute, Worcester MA

Investigators

Abstract

TECHNICAL SUMMARY: The goal of this CAREER award to Worcester Polytechnic Institute is to build and integrate fundamental knowledge of materials science and fracture mechanics to aid in the optimization of existing light metal alloys and the development of new and lighter alloys designed for improved fatigue and fatigue crack growth resistance in structural applications. This research will also lead to the creation of original experimental, analytical, and computational tools and strategies for accurate fatigue life predictions and design of fatigue-critical and high-integrity structural components. The proposed work will provide a fundamental understanding of the fatigue crack growth mechanisms at the micro-/nano-structural scale of light metals, as well as methods for improved design. In addition to their contributions to the scientific community, the results of this work will also impact the industry -- both the materials and processing and design communities. On a larger scale, complementary to the improvements in materials design and fatigue performance, these developments will contribute to important reductions in fuel consumption and carbon emissions. NON-TECHNICAL SUMMARY: Our nation's ambitious energy goals and reduced carbon pollution can only be achieved if the transition to renewable and clean energy will be complemented by effective venues to reduce vehicle weight. Weight reductions will translate into reductions in fuel consumption, and consequently, reductions in the carbon footprint. One way to reduce vehicle weight is to replace ferrous materials in structural components with well-engineered lighter metals. In structural components, the dynamic properties and fatigue performance of the materials are critical as more than 90% of all mechanical failures are fatigue related. Therefore, a transition to lighter metals in such applications needs to be based on a fundamental understanding and optimization of the fatigue behavior of the materials. Another means to reduce weight is to use accurate life prediction tools to design structural components with a higher degree of confidence, which requires appropriate fatigue data generation, interpretation, and use. This will allow applying sufficient yet not excessive safety factors, which will result in further weight and cost reductions. The CAREER award to Worcester Polytechnic Institute will support both fronts by providing a mechanistic understanding of fatigue in light metals, as well as methods for improved design. The ultimate goal of the work is to facilitate the design of better, lighter, and more reliable structural components for the transportation sector. Through direct collaborations with the industry, the knowledge, data, and techniques emerging from this work will be effectively validated and implemented. In the broader impact of this award, a wide spectrum of activities will be used to stimulate the interest and engagement in fundamental and applied science and materials science of a range of students from undergraduate and graduate to middle- and high-school to professionals.