Industrial waste converted into a coating for aircraft turbines

Industrial waste converted in coating for aircraft turbines

A group of specialists from the Center for Research in Advanced Materials (Cimav), have developed nanostructured coatings capable of withstanding temperatures exceeding 1000 degrees Celsius, which are used in aviation turbine components.

Dr. Ana Maria Arizmendi Morquecho, leader of the project, explained that through the development of coatings the team is looking to solve one of the most common problems in the aviation industry, which is the microstructural degradation of superalloys that integrate turbines due to the high temperatures reached by the devices.

"The components of the blade and nozzle in the hot zone of the turbines, which are made of Nickel-based superalloys, are exposed to temperatures above one thousand degrees Celsius, which causes very strong microstructural degradation of the substrates and impact on the thermal and mechanical properties of the structure by decreasing the energy efficiency of the turbines," explained the researcher.

The project consist in the development of advanced thermal barriers based nanocomposites that would protect the structures from the superalloys some components of the turbine are manufactured with.

For this, the group of Arizmendi Morquecho uses flying ash as a ceramic matrix incorporating various nanoparticles to create new materials developed by researchers.

"We found that taking advantage of the large amount of mullite, which is a chemically and thermally stable compound found in the flying ash, we can use this material as a ceramic matrix, which by the addition of different particles have obtained novel nanocomposites that greatly diminish the thermal conductivity and are used in developing coatings for superalloys," said Arizmendi Morquecho.

Industrial waste converted in coating for aircraft turbines

Besides the application for the aviation industry, this technology seeks to impact in an environmental level with the use of a material that until now was considered polluting industrial waste, such as flying ash, which is mainly obtained from coal plants installed in northern Mexico.

According to Arizmendi Morquecho, after five years of analysing the different materials that could be used as advanced thermal barrier systems, the team is expecting to make the final tests to validate the materials obtained at the laboratory , to continue with the process of scaling up the technology to be transferred to an interested company.

While this technology is considered basic research, its guidance hopes to solve industrial problems.

"This is part of the focus of Cimav at the Park of Research and Technological Innovation located in the Moneterrey, north of Mexico."

"Therefore, we combine a multidisciplinary group of researchers to conduct basic and applied science, as well as having liaisons with industry, academy and research centers globally," explained Morquecho.

Trillions of tiny bits of plastic pollutant materials trapped in Arctic ice

A team of researchers with Dartmouth College in the U.S. and the University of Plymouth in the U.K. has found that a massive amount of tiny bits of rayon, plastics and other man-made materials are embedded in Arctic sea ice.

In their paper published in the journal Earth's Future, the team describes how they found evidence of the materials in core samples taken in 2005 and 2010 and note that as Arctic sea ice melts, the embedded material will be released into the ocean, likely causing problems for marine life.

We all use plastics and other materials every day, but few of us give much thought to what happens to it after we toss it in the trash after it's no longer useful to us.

A lot of it winds up in landfills, of course, but a lot goes missing and now it appears that the researchers studying core samples, may have found where it's gone: it's been captured in Arctic sea ice, torn apart into tiny pieces during the journey there.

The rayon and plastic bits aren't noticeable to a person walking around in the Arctic because the pieces are so small, typically less than 5 millimeters in length. It's in the form of beads, fibers or irregular fragments.

Scientists have observed such material in the ocean before, particularly around garbage islands such as the Great Pacific Garbage Patch, but never before have scientists noticed them in ice cores taken from the top of the world.

The researchers don't see any imminent threat from the embedded materials, the problem is that global warming is causing Arctic sea ice to melt, and as it does so, it will release the captured material into the sea, and no one knows what sort of impact that will have.

Most of the materials aren't expected to be toxic, but many are known to soak up chemicals, like a sponge. If the chemicals are toxic and an animal eats them, it likely would get sick or die.

In counting the number of bits of material in the ice cores and estimating the amount of ice they are in, the researchers have concluded that there might be in the neighborhood of a trillion pieces of the stuff in position ready to be released into the world's northern oceans.

A little over half of the bits were rayon, the researchers report, others were polypropylene, acrylic, nylon, polyester, polyethylene and polystyrene.

More information: Global warming releases microplastic legacy frozen in Arctic Sea ice, Earth's Future, DOI: 10.1002/2014EF000240