A team from Sandia National Laboratory and Texas A&M University tested the metal’s toughness using a special transmission electron microscope to pull the ends of the metal out 200 times per second. Next, they observed self-healing at ultra-small scales on a 40-nanometer-thick piece of platinum suspended in vacuum.

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Cracks resulting from the type of deformation described above are known as metal fatigue: repetitive pressures and movements cause microscopic cracks that eventually lead to the failure of machines or structures.. Surprisingly, after about 40 minutes of observation, the crack in the platinum began to grow and repair itself before moving in the other direction.

It was absolutely fascinating to witness it with my own eyes. We certainly weren’t looking for that. We confirmed that metals have their own inherent, natural ability to self-heal, at least in the case of fatigue damage at the nanoscale.
– says materials scientist Brad Boyce of Sandia National Laboratory.

These are the exact conditions, and we do not yet know exactly how this happens and how we can use it. However, when you consider the cost and effort required to repair everything from bridges to motors to telephones, it’s hard to imagine how much of a difference self-healing metals can make.

And while this observation is unprecedented, it’s not entirely unexpected. In 2013, Texas A&M University materials scientist Michael Demkovich worked on a study in which he predicted that such nanocrack healing could occur because small crystal grains in metals essentially change their boundaries in response to stress.

Demkovic was among the participants of this new study. He used updated computer models to show that his decades-old theories about the self-healing of metals at the nanoscale correspond to what’s going on here.

• HE auto-recovery took place at room temperatureand is another promising aspect of research. Metal usually needs a lot of heat to change its shape.
• The downside is that the experiment is done in a vacuum, so scientists have yet to find out if the same process would occur with ordinary metals in the air.