A paper just published in Nature by Hansoo Kim from the University of Science and Technology in South Korea demonstrates that by manipulating the structure of steel on a nano-meter scale, you can create a new steel alloy that is stronger and lighter than titanium but at a tenth the cost.
It has been a dream to alloy steel with aluminum and have the best properties of each but that has not been the case in recent decades. The alloys have been too brittle to be useful. Adding manganese helps a bit but just not enough. The addition of nickel and some special processing seems to be the key to this new material.
The addition of nickel reacts with some of the aluminum to create small crystals just a few nano-meters across. The crystals form both between and within the steel’s grains when it is annealed. These crystals are resistant to searing so when a force is applied the to the materials they do not break. The tiny crystals stop cracks from propagating through the material which gives it great strength. The addition of aluminum brings the lightness.
This is an exciting new breakthrough in material science. POSCO, one of the largest steel companies in the world is planning the first industrial scale run of the material later this year.