Improving Steel with a Twist
Though perhaps not always recognized as such, steel is one of the most important materials to humanity, and the processes to manufacture it are equally vital. A major reason for this is the metals great strength and ductility, but sadly improving one of those properties tends to reduce the other. Researchers at Brown University and universities in China though have found a way around this with one kind of steel.
Twinning-induced plasticity (TWIP) steel is a kind of steel that forms special nanoscale structures called deformation twins, which increase its strength, or resistance to failure. Like other kinds of steel, hardening TWIP steel will cause it to lose ductility, or the ability to bend and deform without breaking. The Brown researchers however have found a way around this by deforming cylinders of TWIP steel a specific way. Typically one would bending, flattening, or hammering it on a forge, but instead the researchers twisted the steel, causing the outside of the cylinders to deform more than the inside. The result was a still ductile core with a doubly strong outside.
While the research was done using cylinders just centimeters long, there were no indications from the process that it cannot be applied to larger pieces of TWIP steel. Potentially we may see this strengthened steel used in drive shafts or axles in cars and trains, where cylindrical pieces of steel are already used.
Source: Brown University