Titanium is often regarded in the manufacturing industry for its strength and weight. However, cost is always an issue when it comes to titanium, so material scientists looked to aluminum for a comparable alternative. Their solution? An iron-aluminum alloy capable of performing just as well as titanium. The only difference is that this new alloy comes at just 10% of titanium’s cost. From Gizmodo:
A team from Pohang University of Science and Technology, in South Korea have manipulated the structure of an iron-aluminum alloy to create a new kind of material that could find application in everything from bicycles to airplanes.
Steel is renowned for its strength and low price, but is very heavy. To make use of it in scenarios that demand light weight—without resorting to buying titanium—material scientists often alloy it with aluminum, which is light and also mercifully cheap. The mixture of aluminum and steel also usually includes a sprinkling of manganese to make it less brittle, but even then, the material is still usually too brittle for use in vehicles.
Now, the team from South Korea has added nickel to the mixture. The addition of this metal brings about a reaction with some of the contained aluminum, forming what are known as B2 crystals. Sitting both within the grains of steel in the alloy and at their boundaries too, the crystals—just a few nanometres in size—resist shear forces in the material. Because, ultimately, all materials fail by shear, where one layer of atoms slides across the other, taking microscopic cracks with it, increasing the resistance to shear forces increases the strength and stops the material failing by cracking.
Enough, in fact, to provide the new alloy with the same strength as titanium. The mix of steel and aluminium also provides a density similarly to that of the more expensive metal, too. The raw materials and (proposed) processing techniques also mean that the material could, when made at scale, cost just a tenth of what titanium does, too.
This new material is beginning to see mass production. If its early tests hold up, it could be one of the biggest manufacturing revolutions the metal industry has seen. Stay tuned on this one…