Amazing discovery: Healing Metals themselves. A microscopic chip breaks out in an experiment, revealing the possibility of a self-healing machine.
Scientists have seen for the first time pieces of metal that split apart and fuse together without human intervention, overturning basic scientific theories. If the newly discovered material can be used, it can lead to a technological revolution – in which engineering, bridges and aircraft can reduce the damage of wear and tear, making them safer and more durable.
A research team from Sandia National Laboratories and Texas A&M University described their findings today in the journal Nature.
“It’s exciting to see first-hand,” said Brad Boyce, a materials scientist at Sandia.
“What we’ve confirmed is that metal has an inherent and natural ability to heal itself, at least in the case of nanoscale fatigue damage,” Boyce said.
Fatigue stress is one of the ways in which a machine breaks and eventually breaks. Pressure or repetitive motion causes visible cracks to form. Over time, these cracks grow and spread until – snap! The whole device breaks, or in scientific terms, it fails.
The crack that Boyce and his team saw disappearing was one of those tiny but big cracks — measured in nanometers.
“From our solder joints and electronic devices to the engines in our cars to the bridges we travel on, these structures often fail due to cyclic loading that leads to crack initiation and eventual rupture,” Boyce said. “When they fail, we will be responsible for replacement costs, lost time and, in some cases, injury or loss of life. The economic impact of these failures is estimated at hundreds of billions of dollars per year for the United States.
Although scientists have developed self-healing materials, most of which are plastics, the idea of a self-healing metal is part of science fiction.
“There is no crack in metals never intended to be bigger, not smaller. Even some of the basic equations we use to describe crack development are governed by the possibility of such treatment methods,” Boyce said.
Unexpected discoveries showed
In 2013, Michael Demwawicz – Then professor and Massachusetts Institute of Deputy Science and Engineer I – Started from the program. He published a new story, depending on computer system results, which, below some conditions, metal needs to be closed cracks closed.
The discovery and realization of his theory came unexpectedly at the Center for Integrated Nanotechnologies, a joint venture between Sandia and Los Alamos National Laboratories.
“Really, we don’t want it,” Boyce said.
Khalid Hattar, now an associate professor at the University of Tennessee at Knoxville, and Chris Barr, who now works for the Department of Energy’s Office of Nuclear Energy, were leading the experiment at Sandia when the discovery was made. They just wanted to assess how cracks formed and propagated through a nanoscale piece of platinum using a specialized electron microscope technique they had developed to repeatedly shoot the ends of the metal 200 times per second.
Amazingly, about 40 minutes into the experiment, the damage returned. One side of the crack closed as if retracing its steps, leaving no trace of the old wound. As time went on, the explosion took a different turn.
Hattar called it “unprecedented insight”.
Boyce, who was familiar with the idea, reported his findings to Demkowicz.
“I’m very happy to hear it, of course,” Demkowicz said. The professor repeated the experiment on a computer model, showing that what was observed at Sandia was the same thing he had imagined years before.
Their work was supported by the Department of Energy’s Office of Basic Energy Sciences; National Nuclear Security Administration and National Science Foundation.
Much is still unknown about self-healing, including whether it will be a useful tool in a manufacturing environment.
“The degree to which these findings can be interpreted will be the subject of further research,” Boyce said. “We show that this happens in nanocrystalline metals under vacuum.
But we don’t know if it can be relied on the jewelry. “”
However, for all who do not know, the detection still is continuing the science territory.
“I hope that the example will encourage those who explore the encouraging and material cases, in good conditions that can do what we expect!
Source: Sandia National Laboratories
