At left, a deformed sample of pure metal; at right, the strong new metal made of magnesium with silicon carbide nanoparticles. Each central micropillar is about 4 micrometers across. Credit: UCLA Scifacturing Laboratory
Mg infused with dense ceramic Silicon Carbide nanoparticles could be used for airplanes, cars, mobile electronics, spacecraft, and cars, helping to improve fuel efficiency, as well as in mobile electronics and biomedical devices. It has extremely high specific strength and modulus, or stiffness-to-weight ratio. To create the super-strong but lightweight metal, the team found a new way to disperse and stabilize nanoparticles in molten metals. They also developed a scalable manufacturing method that could pave the way for more high-performance lightweight metals.
“It’s been proposed that nanoparticles could really enhance the strength of metals without damaging their plasticity, especially light metals like magnesium, but no groups have been able to disperse ceramic nanoparticles in molten metals until now,” said Xiaochun Li, UCLA.
Structural metals are load-bearing metals; they are used in buildings and vehicles. Mg, at just 2/3 density of Al, is the lightest structural metal. Silicon carbide is an ultra-hard ceramic commonly used in industrial cutting blades. The researchers’ technique of infusing a large number of silicon carbide particles <100nm into magnesium added significant strength, stiffness, plasticity and durability under high temperatures.
They dispersed the particles into a molten magnesium zinc alloy. This new nanoparticle dispersion relies on the kinetic energy in the particles’ movement which stabilizes the particles’ dispersion and prevents clumping. To further enhance the new metal’s strength, they used high-pressure torsion to compress it.
The new metal nanocomposite is about 14% silicon carbide nanoparticles and 86% magnesium. The researchers noted that magnesium is an abundant resource and that scaling up its use would not cause environmental damage.
http://newsroom.ucla.edu/releases/ucla-researchers-create-exceptionally-strong-and-lightweight-new-metal
Recent Comments