Scientists from several different universities have developed a new method for creating super-strong and lightweight aluminium.
We have highlighted a number of innovations in construction technology, including a method for creating an ultra-thin, curved concrete roof and paint that can cool buildings. Up to now, however, there have not been many options for replacing steel as the metal of choice in construction. Steel is strong, but it is also heavy. Aluminium alloys are much lighter, but they are also softer and have lower mechanical strength. This limits their usefulness in industries such as construction, and automobile and aerospace manufacturing. Now, researchers at several universities, including Purdue University and Rice University, have worked together to succeed in creating a super-strong, lightweight aluminium alloy.
The atoms in aluminium form a crystal lattice, made up of repeating sequences of atoms, layered on top of each other. Creating the new high-strength aluminium involves introducing distortions, called ‘stacking faults’, in the crystal structure. They are difficult to create in aluminium because doing so requires a great deal of energy. The researchers at Rice overcame this by bombarding ultra-thin aluminium films with tiny micro-projectiles of silicon dioxide. This produced a type of stacking fault leading to an increase in strength, ductility and thermal stability in the aluminium. At Purdue, however, researchers used a different method. Their method introduced iron atoms into aluminium’s crystal structure using a procedure called magnetron sputtering. They reported that the resulting aluminium-iron alloy coatings proved to be comparable to high-strength steels. Additionally, the material could potentially be scaled up for industrial applications.
The research received funding mostly from the U.S. Department of Energy’s Office of Basic Energy Sciences, Materials Science and Engineering Division and was reported in the Advanced Materials journal. The researchers note that potential applications could include wear and corrosion resistant aluminium alloy coatings for the electronics and automobile industries. What other uses might there be for super-strong and lightweight aluminium?