Fabrication of High Strength Lightweight Metals for Armor and Structural Applications: Large Scale Equal Channel Angular Extrusion Processing of Aluminum 5083 Alloy

This report entails the summary of work done under a Phase II Small Business Innovation Research project, W911NF-12-C-0113, awarded to Engineered Performance Materials, Inc., Whitmore Lake, Michigan. In the report, we show for the first time the successful implementation of large-scale equal channel angular extrusion ECAE processing in a manufacturing environment. We describe the key features of the large-scale tooling, the pertinent steps in the ECAE process sequence, and identify the necessary operational protocols as they have been applied to 24- x 24- x 4-inch AA5083 billets. While the technology transition and feasibility of the upscaled process were demonstrated, several key issues were identified that prevented the successful demonstration of the multi-pass nature of the ECAE process. These issues include the need to maintain the tooling at isothermal conditions, reducing the time delay between successive passes, and improving the dexterity in handling the hot billet between removal and reinsertion from the tool. We conclude the report by offering potential solutions and a path forward towards the implementation of the process.