The new metal is formed from magnesium infused with ceramic silicon carbide nanoparticles. The combination has led to something very strong, very light and with a high rating “modulus,” which means stiffness-to-weight ratio. Magnesium is a shiny gray solid, and classed as a lightweight metal. Silicon carbide is sometimes referred to as carborundum, and it is a compound of silicon and carbon. Silicon carbide is a semiconductor and it is also used in industrial cutting blades.
Key to creating the new metal was in finding a way to disperse and stabilize nanoparticles in molten metals. Nanoparticles can theoretically boost the strength of any material they bind with, but they have proven hard to evenly disperse and to keep the material flexible — until now. Expanding on this, Xiaochun Li, the lead researcher, told Phys.Org: “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.”
The new metal is regarded as both the lightest and strongest based on two measures, as described in the research note:
Specific strength, that is how much weight a material can withstand before breaking;
Specific modulus, which is the material’s stiffness-to-weight ratio. It also showed superior stability at high temperatures.
The potential applications for the new material are with the manufacturer of lighter airplanes, spacecraft, and cars. These vehicles would have a much better fuel efficiency than any other comparable metal.
The research group was based at UCLA Henry Samueli School of Engineering and Applied Science. The research is published in the journal Nature, in a paper titled “Processing and properties of magnesium containing a dense uniform dispersion of nanoparticles.”
