In a breakthrough for the materials and advanced manufacturing fields, engineers from Monash University have developed an improved way to manufacture aluminium alloys, overturning 100 years of established practice and opening up new options for industry to develop and test 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 and within minutes. The new fine-scale homogenous nanostructure contains none of the defects introduced during traditional aluminium alloy processing, which usually compromise fatigue and corrosion performance.
Since the last major 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, which engineers then must design around.
In the new method, 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 its other properties.
Advanced 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 can apply the method to investigate strengthening and improving other alloys, such as magnesium, opening up new opportunities in materials innovation.
“Our new approach is exciting because it allows us to create new types of alloy nanostructures that lead to improved combinations of properties,” Professor Hutchinson says. “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.”