Wednesday , May 12 2021

Small particles at high speed could push a hole into the space station, study shows

We know that even a grain of dust or a small drop can damage the heavy metal surface if the particle is collected at high speed when it breaks into it.

But, until now, there is a problem to find out how or why that damage is happening. This is because the speed must be really incredibly high, and the stairs are really incredibly small.

Now researchers from MIT have developed cameras that are fast enough and have enough magnification to comprehensively grasp that moment of impact – and they learned that these gears are so intense, and the impact is actually partial it's melting surface.

This was "unforeseen," based on a previous erosion study, scientists say.

High speed microscopic particles can actually be quite useful, and the way they erode the surfaces is not bad. Sandy study is one such application, or application of coatings.

But they can be dangerous, too – as micrometeorites that bombard the IBS, for example, or particles carried by strong winds blowing wind turbines.

"We want to understand the mechanisms and precise conditions when these erosion processes can happen," engineer Mostafa Hasani-Gangaraj of MIT explained.

So he and his team came up with a series of experiments to find out, using a test micro-particle test developed at MIT. With a frequency of up to 100 million FPS, the test can record at incredibly high speeds.

Then they set up a sheet of metal and used a laser to heat one more tin. This evaporates the surface of the substrate and expels and accelerates the microscopic particles of the tin in the process. This resulted in tin small particles of diameter about 10 micrometers – about 0.01 millimeters – hitting the surface of the tin at a speed of kilometer per second (2.237 miles per second).

They also used lasers to illuminate these effects for a clear view of what was happening.

This allowed them to see for the first time the mechanism that causes the damage, rather than relying on the surface examination after the impact.

And there, in the video, you can clearly see the unfolding material sprayed by the blow.

impact erosion semScanning an electronic micrograph on one of the 10 μm impacts at 1kps. (Hasani-Gangaray and others)

This information is actually incredibly valuable. This can help to improve, for example, those industrial processes using high-speed microscopes, where the accepted wisdom, according to researchers, is that higher speeds achieve better results.

These results show that this is not always the case – you bend it too high and you can melt things without the intention of doing so.

This can also help us understand how microparticles can damage turbines, spacecraft, and pipelines. And what about the poor robots on Mars, which overcome this crazy storm of dust. Equipped with this new knowledge, engineers could develop more materials resistant to erosion, both for spatial and terrestrial applications.

Obviously there is still a bit of research to be done. The team used only tin and with a direct impact angle. There will probably be slightly different effects for different materials – with varying levels of hardness or hardness, and different melting points (the tin is fairly low), as well as different angles of influence.

But this first step, in demonstrating that the test and experimental setup can be used to capture and analyze that moment of impact, is very impressive.

"We can extend it to any situation where erosion is important," said MIT engineer David Weisset.

The team's research is published in the journal Natural communications.

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