Breakthrough Discovery: Tension Can Fuse Metal

MIT researchers have discovered that under certain conditions, putting a cracked piece of metal under tension - exerting a force that would be expected to pull it apart - actually has the reverse effect, causing the crack to close and its edges to fuse together. By creating a computer model of the crystalline microstructure of nickel and studying its response to various conditions, the researchers found that there is a mechanism that can, in principle, close cracks under any applied stress. This computer simulation shows the boundaries between microcystalline grains (white lines forming hexagons) and a small crack (dark horizontal bar at the bottom) that heals itself as the metal is put under stress.