A team of University of California, Los Angeles researchers have created a structurally lightweight metal that is exceptionally strong and possesses very high specific strength and modulus, also known as a stiffness-to-weight ratio. Composed of magnesium that is infused with ceramic silicon carbide nanoparticles, the material was created using a new method of dispersing and stabilizing nanoparticles in molten metal. The material has the potential to be used in the creation of lighter airplanes, spacecrafts and cars, which could improve fuel efficiency, as well as for use in electronic and biomedical devices.
"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," Xiaochun Li, the principal investigator on the research, said in a press release.
"With an infusion of physics and materials processing, our method paves a new way to enhance the performance of many different kinds of metals by evenly infusing dense nanoparticles to enhance the performance of metals to meet energy and sustainability challenges in today's society," he said.
The use of nanoscale particles allowed the researchers to enhance the strength of the material while at the same time maintaining and sometimes even improving the metal's plasticity, something not possible with ceramic particles at a microscale level due to a loss of plasticity. The only problem with nanoscale ceramic particles is their tendency to clump together due to the tendency of their particles to attract each other.
To solve this issue, the researchers dispersed the nanoscale ceramic particles into a molten magnesium zinc alloy, which dispersed the nanoparticles by taking advantage of the kinetic energy in each particle's movement, thus stabilizing their dispersion and preventing clumping. Furthermore, the researchers also used the high-pressure torsion technique to compress the metal and increase its strength.
"The results we obtained so far are just scratching the surface of the hidden treasure for a new class of metals with revolutionary properties and functionalities," Li said.
The findings were published in the Dec. 24 issue of Nature.
