An article published in the journal “Nature” describes a research conducted at UCLA that led to develop an extremely strong and lightweight material. It’s magnesium infused with nanoparticles of silicon carbide. The material obtained may be useful in various industries ranging from aerospace to produce vehicle parts to electronics to produce various types of components.
A team at UCLA Henry Samueli School of Engineering created this material finding a new way to disperse and stabilize nanoparticles in molten metals. This was a necessary step to verify a concept proposed in the past, that nanoparticle could increase the strength of metals without damaging their plasticity.
Magnesium is a metal much lighter than aluminum and titanium but also less rigid and robust than many other metals. Another problem is that in its pure form it’s highly flammable. For these reasons, despite being common and also biocompatible, generally it’s used in the production of alloys with other metals such as aluminum.
Silicon carbide, also known as carborundum, is a ceramic material formed by silicon and carbon. It’s extremely hard and exists in a lot of crystalline forms. For its properties, it’s used in many different fields in which very hard ceramics are required.
So far, no one had managed to obtain a dispersion of nanoparticles in molten metals. Attempts to improve a metal using ceramic microparticles failed because the infusion caused a loss of plasticity. The problem with nanoparticles, meaning particles less than 100 nanometers long, was due to their tendency to clump together rather than to disperse homogeneously.
The solution was found by dispersing the nanoparticles in an alloy formed by magnesium and zinc relying on the kinetic energy in the nanoparticles movement. This allowed to stabilize their dispersion avoiding their clumping. The new metal obtained was further reinforced using a technique that allows to exert a high compression on it.
These conditions allowed to simultaneously achieve strength, rigidity, flexibility and stability at high temperatures. The material obtained is 14% nanoparticles of silicon carbide and 86% magnesium. The researchers believe that it can replace metals such as titanium and aluminum in various fields.
According to Xiaochun Li, the principal investigator in this research, this result is just the beginning of the discovery of a hidden treasure, that is a new class of metals with revolutionary properties and functionalities. It’s a bold statements but if the materials produced with these techniques can really replace some currently used it’s really a great discovery.
