In a world-first breakthrough for the materials and advanced manufacturing fields, Monash University engineers have developed a new and improved way to manufacture aluminium alloys, overturning 100 years of established practice and opening up new options for industry to test and develop new alloy manufacturing processes.
Developed by Professor Christopher Hutchinson, the ‘cyclic plasticity’ method creates aluminium alloys with better combinations of properties than existing alloys, at room temperature, within a matter of minutes. The new fine-scale homogenous nanostructure contains none of the defects introduced during traditional aluminium alloy processing, that usually compromise the fatigue and corrosion performance.
The results of ‘Precipitation strengthening of aluminium alloys by room-temperature cyclic plasticity’, published today in Science, offer a radically different manufacturing method to industry. Since the last innovation in 1906, metallurgists have ‘baked’ aluminium alloys at high temperatures over 10-12-hour periods, a costly and environmentally unfriendly method that introduces defects into the material that engineers then must design around to compensate.
During the new process, the aluminium alloy is rearranged at an atomic level in a controlled process using a back and forth dislocation movement. The repetitive, cyclic deformation of the material creates aggregations of atoms that dramatically strengthen the material without compromising other properties.
Manufacturing industries such as transportation, aerospace and defence have the option to upscale their production process to deliver faster, more energy-efficient and failure-resistant aluminium alloys. Also, researchers may now apply the cyclic plasticity method to investigate strengthening and improving other alloy systems, such as magnesium, opening up new opportunities in materials innovation.
Professor Christopher Hutchinson said, “Our new approach is exciting because it allows us to create new types of alloy nanostructures that lead to improved combinations of properties. It’s a bonus that we can do this at room temperature instead of the long and costly elevated temperature heat treatments. When a manufacturing process becomes ingrained after 100 years of practice, it’s easy to forget to look for alternatives. Our work shows that not only is there another way, there’s a much better way.”