Material and Vehicle design for High‐Value Recycling of Aluminum and Steel Automotive Sheet

Start Date: 
Jan 1, 2022
End Date: 
Dec 31, 2023
University of Michigan - College of Engineering

Problem Statement: The embodied energy of vehicles is growing as energy-intensive materials such as aluminum auto body sheet (ABS) are used to deliver improved performance. This presents an opportunity for recyclers to shift towards high-value recycling into wrought alloys and for car makers to increase the end-of-life (EOL) recycled content of their sheet (on average, currently ≈0% and ≈14% for U.S. aluminum and steel auto body sheets respectively), reducing their material costs and energy burden. However, the current system cannot effectively recycle the aluminum and steel sheets. Shredded and contaminated EOL metal (e.g., mixed aluminum alloys with steel rivets and mixed steel alloys with embedded copper wiring) is often exported, downcycled to castings, or recycled as rebar. Aluminum is classed as a critical material because the U.S. is 100% import reliant on bauxite [10]; yet, ≈90% of U.S. aluminum auto shred is exported due to its residual content. Furthermore, a shift to electric vehicles (EVs) will see greater high-quality sheet demand (e.g., aluminum ABS and Advanced High Strength Steels (AHSS) for light weighting), a doubling of vehicle copper wiring that acts as an EOL contaminant, and the potential loss of traditional residual sinks (vehicle castings). Combined with trade tensions, we could be facing lower future (down-)recycling rates.

Goal and Objectives: The goal is to increase automotive sheet metal EOL (post-consumer) recycled contents; thus, reducing vehicle embodied energy and primary feedstock consumption. The objectives are to produce a new analytical design for recycling tool tailored for automotive metal sheet, and to generate new knowledge on how EOL sheet recycling is affected by vehicle design (e.g., alloy specification), recycling system infrastructure (e.g., deployment of emerging separation processes), and sheet manufacturing process decisions (e.g., temperature profiles informed by new Integrated Computational Materials Engineering (ICME) tools).

United States Department of Energy (DOE)