Scientists have discovered an amazing property of metal to self-heal at the nano level

A recent experiment conducted by scientists from Sandia National Laboratories and the University of Texas at Austin shocked the scientific community with its unexpected result: a piece of metal damaged during testing began to self-heal.

The study reportedly focused on the elastic properties of a thin layer of platinum, just 40 nanometers thick, which was kept in a vacuum. The scientists used an advanced transmission electron microscope, which allows them to observe the process at the nanoscale. During the experiment, the metal sample was subjected to cyclic stretching: its ends were pulled at a frequency of about 200 times per second.

For about 40 minutes, the scientists observed the development of microscopic damage - fatigue cracks that occur under repeated loads. And suddenly, to the researchers' surprise, the crack began to heal on its own, growing together and healing the damaged areas without external intervention. Moreover, the process took place in conditions as close as possible to the normal ambient temperature, which makes it especially promising for practical application.

The observation was a sensation because metals were previously thought to have no ability to repair themselves after damage, especially at the nanoscale. Researcher Brad Boyce said: “This was truly amazing. We confirmed that metals have an intrinsic ability to repair themselves, at least under certain conditions and at very small scales.”

Interestingly, in 2013, materials scientist Michael Demkovich of the University of Texas predicted that nanocracks inside metals could self-heal. He used computer modeling to show that tiny crystal grains inside metals could shift their boundaries in response to stress, helping to heal the damage.

Demkovich and his colleagues suggested that under certain conditions, especially in a vacuum and at room temperature, these processes might occur naturally. Experimental results support these theories, making them particularly important for future technologies.

One possible explanation for the observed phenomenon is a process known as cold welding. It occurs when metal surfaces in very close contact are joined at the atomic level without heat. In a vacuum and in the absence of contaminants, the metal atoms can literally “stick together,” forming a strong bond.

This means that damaged areas of metal, even if they appear to be destroyed, can, under certain conditions, “heal” and restore their integrity. However, scientists do not yet fully understand all the mechanisms of this process and continue research to learn how to control it.

Although the experiment was conducted under controlled conditions, its results open up new possibilities for the development of self-healing materials. If scientists manage to scale up and control this effect, it could become the basis for new types of materials — self-healing metals and alloys. This is especially relevant for the aerospace, automotive, construction, and electronics industries, where microcracks and damage are a constant problem.

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