Imagine a material that could make jet planes, road trains, even the family car lighter – saving fuel, money and importantly, emissions.
It’s called a ‘nano-cermet’, a nanocomposite of aluminium and silicon carbide, and the first few precious fibres of it have been grown at La Trobe University’s Bendigo Campus.
Engineering Professor James Maxwell has created what he believes is the world’s first Al-SiC cermet fibres, grown from gases using cutting-edge laser technology housed in the new Bendigo Campus Engineering building.
“You may wonder why that’s important,” Professor Maxwell said.
“It’s because aluminium doesn’t want to be in silicon. To our knowledge, this is the first time anyone has been able to trick small amounts of aluminium into mixing with silicon, which is pretty big news in the science community.
“We’re trying to get metals to mix with ceramics, to get the best properties of both.”
Professor Maxwell said ceramics, such as silica or silicon carbide, are strong, stiff, lightweight, and don’t conduct electricity.
“But they are also traditionally brittle, which means they can shatter when impacted,” he said.
“Aluminium, on the other hand, is a very lightweight, ductile metal, which means that it can be impacted and not fracture. It is not brittle, but it is not as strong as silicon carbide.
“By combining both, we are hoping to create a nano-cermet that doesn’t fracture easily upon impact.”
Professor Maxwell evaporated two chemicals, one for the aluminium, and one for the silicon carbide, and grew both materials within a single fibre.
“The process is called HP-LCVD, or hyperbaric pressure laser chemical vapor deposition,” he said.
For planes, trains, automobiles and more
Professor Maxwell said if these fibres were produced on an industrial scale they would create a material suitable for “important applications where the temperatures are very high, such as jet engines”.
“A material like this allows us to make things that are stronger than traditional metals, but that don’t break as easily as traditional ceramics,” he said.
“It makes for strong, lightweight materials that can be used to build aircraft, spacecraft, turbines, wind mills blades, and eventually, automobiles. Less weight means you use less energy to move it—which means saving energy.
“Airlines would give a lot to have lower fuel costs to transport the same number of people along a route, as fuel is their primary cost, and car owners would be happy to pay less at the petrol station to move the same size car around.
“This is an exciting area for future research, where we can create entirely new materials for the future of mankind.
“La Trobe University has provided the necessary environment for new discoveries to be made, and is a place where students and researchers can be creative and try fundamentally new ideas.”
Professor Maxwell recently joined La Trobe University’s engineering department. He received his PhD from Rensselaer Polytechnic Institute in New York, USA and has over 20 years’ experience carrying out government projects.
He teaches manufacturing engineering subjects at both Bundoora and Bendigo campuses, and his research interests include the effects of extreme conditions during materials processing.
Among his goals are to create a global nanomaterials library, and the world’s first self-replicating machines.
Photograph by Leon Schoots, courtesy of Bendigo Magazine.