At the Pohang University of Science and Technology in South Korea, materials-science researcher Hansoo Kim and his team have come up with a new variant of steel that is as light and as strong as titanium alloys, but when produced at scale, costs just a tenth of what the latter would have. This invention could have sweeping ramifications once adopted; for one, as The Economist notes, it could be used to create lighter vehicles which, in turn, would mean better fuel efficiency. In fact, the new material has Posco, one of largest steel companies in the world, interested enough to plan trials at an industrial scale.
Steel has been valued for strength, but the iron-carbon alloy has been dragged down by its weight. Adding aluminium, a cheaper, lighter metal to the mix does cause it to become lighter but the resulting alloy is very brittle. Mixing in managanese helped remedy the brittleness but not to an extent where the alloy would be useful for heavy-duty functions. Kim and his team added in a fifth element, nickel, and it reacted with the aluminium in the alloy to create B2 inter-metallic (which have equal number of atoms of the two elements in the molecule) crystals, spanning just a few nanometres, that are resistant to shearing, and therefore, increase the strength of the alloy.