Aluminium and steel - If you can’t join them, beat them

The Economist magazine has published an interesting story about a laboratory in Korea that has created a new alloy of aluminium and steel.

Steel is by far the most used metal in the world, but aluminium is second. Each metal has its own unique properties - steel is strong, but heavy. Aluminium is light but doesn’t have the strength. And we all know that these two metals don’t mix well. You don’t want steel/iron in your aluminium drink can, because when the steel rusts and falls out, you end up with your drink in your lap. Welding steel and aluminium is a tricky process usually involving a third metal. And on a grander scale, the two industries are locked in a war to win/defend the automobile industry. Aluminium panels are now being introduced into SUVs in the USA, in response to legislation calling for better fuel economy.

Scientists have long played with different alloy combinations to try to bring the best of the two metals together, and according to the Economist, Dr Hansoo Kim at the Pohang University of Science and Technology has had a breakthrough. They have created an alloy of iron, aluminium, carbon, manganese and nickel, where the nickel bonds with some of the aluminium to form a shield between the iron molecules. The resulting metal has the strength that Dr Kim was looking for, but the lightness of aluminium.

As the Economist points out, it is still a long way from the laboratory to the production floor of GM or Ford, but the tests so far have been successful enough for the Korean steel giant POSCO to step in and arrange for an industrial scale test to be done later this year.

The Economist’s story is based on an article in Nature magazine.