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Scientists Watch a Metal Repair Itself In a Vacuum! Confirm Metals' Self

Jul 23, 2023

We are all too familiar with that feeling of our hearts skipping a beat every time our phone slips from our hands and crashes to the ground. Praying fervently for its safety, we gingerly pick it up, wishing a simple ‘Reparo!’ spell could undo the damage even in the muggle world.

But what if we told you that it is possible for metals to repair themselves terminator-style, sealing fractures and cracks in the blink of an eye?

A team of scientists from Sandia National Laboratories and Texas A and M University, while conducting intense metal testing to determine its toughness, stumbled across this never-before-seen phenomenon.

Using a specialised electron microscope, they pulled the metal’s ends some 200 times every second. Typically, this kind of extreme stress creates tiny fractures or cracks in the metal, scientifically known as ‘fatigue damage’. Over time, such microscopic cracks and damages can bring down a powerful machine or even a mighty building.

But in this case, something extraordinary began to unfurl in the lab!

You see, after the intense metal workout, scientists suspended this overstretched and fatigued 40-nanometer-thick piece of platinum metal in a vacuum. And after about 40 minutes of observation, those tiny cracks in the platinum started to heal themselves — just like magic!

"What we have confirmed is that metals have their own intrinsic, natural ability to heal themselves, at least in the case of fatigue damage at the nanoscale," says materials scientist Brad Boyce from Sandia National Laboratories.

These unprecedented observations prove previous theories of metals possessing the superpower to carry out nano crack healing. This occurs thanks to tiny crystalline grains inside the metal that move around when stressed, similar to how a stress ball changes shape when it is squished.

Moreover, all of this was surprisingly happening at room temperature. Usually, broken metal objects need some hot welding to change their shape.

Scientists say this magical mending could be attributed to a phenomenon called ‘cold welding’. Herein, under optimal temperatures, as the metal’s surface comes in close contact with another metal piece, the atoms dancing around in these metals begin to tangle and glue together.

But, here’s the twist: this self-healing magic can happen only in a vacuum, where a lack of air contaminants can bring pure metals close enough to bond and stick together. In our everyday environment, however, air and other contaminants may get in the way and derail the metal’s healing properties.

It remains to be seen how this same process would play out with conventional metals in the regular world. But if we crack the code, it would herald a whole new era of engineering, where repairing massive bridges, engines and even phones would become super-efficient when powered by self-healing metals.

This study was published last month in the reputed journal Nature and can be accessed here.


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