Looking Deep Into Aluminum Alloy Development

Manufacturers are increasingly attuned to the rapid pace of research, and attracted to the possibilities of adopting novel or emerging developments at the industrial scale. It’s drawing businesses into focused partnerships with research centers - like the new Center for Recycling, Extrusion and Aluminum Technology (CREATe) at the University of Michigan College of Engineering. Hydro, the global aluminum producer and the largest domestic producer of extruded aluminum, has committed $2.5 million over five years to advance nonferrous metallurgy along specific process tracks.

“Hydro was founded 120 years ago at the intersection of a commercial visionary and a brilliant researcher,” according president and CEO Eivind Kallevik. “Industrial progress happens when industry and science work together to solve problems and develop new solutions. I look forward to following this collaboration between Hydro and the University of Michigan, and to seeing it drive new advances in aluminum recycling and alloy innovation,” says Eivind Kallevik, President and CEO of Hydro.

CREATe’s focus will be on developing alloys that retain strength and performance through multiple recycling cycles, addressing particular challenges like ferrous impurities. Three research teams will be assigned to study and advance:

•  Electric current-assisted intermetallic refinement - a technique that applies high-density electric current (often in pulses) to control, break down, and refine intermetallic compounds and grain structures during solidification. (It’s also used for welding and solid-state processing.)

Through a combination of localized heat, electromigration (directed movement of atoms), and induced electromagnetic stirring in liquid metal, the method is principally used to increase ductility and tensile strength (or improvements of materials’ mechanical properties) by reducing the size of intermetallic particles and promoting a more homogeneous microstructure.

The practical applications of electric current-assisted intermetallic refinement may be significant for metalcasting (more uniform solidification) and heat treatment.

•  Composition-enhanced solidification, which is a metallurgical process by which an alloy's chemical composition is designed or modified to improve the solidification microstructure, refine grains, or enhance the mechanical properties for the solid state. For example, by adding specific alloying elements (e.g., Ti, B, or Sr), an alloy’s nucleation rate will increase, leading to a more refined dendrite structure and smaller, more uniformly distributed second-phase particles.

The process may be impactful for developing low-silicon aluminum alloys and high-entropy alloys, as well as high-pressure diecasting and additive manufacturing.

•  Computational alloy design uses computer algorithms, artificial intelligence, and thermodynamic models to identify or predict, and optimize metal combinations that supply particular properties like high-strength or heat resistance, or corrosion resistance.

It has particular application for aerospace, automotive, biomedical, electronic, and industrial machinery design, and also additive manufacturing, because of the potential for faster research and testing, meaning a quicker route to production.

The new research will augment things Hydro already has underway at two research centers in Michigan, where the focus is on automotive structures and crash management.

"This partnership brings together top minds in materials science and manufacturing to expand what's possible in recycling aluminum, a metal that packs incredible strength into a lightweight form and has become one of the world's most widely used engineering materials,” stated Karen A. Thole, the Robert J. Vlasic Dean of Engineering at the University of Michigan.