Researchers at the University of California, Los Angeles (UCLA) have discovered a material so lightweight and strong that it could revolutionize the production of airplanes, automobiles, and spacecraft. A group of scientists led by Xiaochun Li of the UCLA Henry Samueli School of Engineering and Applied Science found a new way to disperse and stabilize nanoparticles in molten metal.
Researchers also develop a scalable manufacturing method
Findings of the study were described in the latest issue of the journal Nature. The structural metal that is composed of magnesium and ceramic silicon carbide nanoparticles has extremely high specific strength and stiffness-to-weight ratio. Li said the material could be used to make spacecraft, lighter airplanes, cars, mobile electronics, and biomedical devices. Li and his colleagues also developed a scalable manufacturing process, paving the way for more high-performance, lightweight metals.
The new metal nanocomposite consists of 86% magnesium and 14% silicon carbide nanoparticles. Magnesium is an abundant resource. So, producing the new metal in large quantities would not cause environmental damage. Structural metals are load-bearing materials that are used in buildings, vehicles, and aircraft. Magnesium is the lightest structural metal with a density just two-thirds of aluminum.
UCLA researchers’ new technique increases the metal’s durability
The UCLA’s technique of infusing a large number of silicon carbide particles smaller than 100 nanometers into magnesium significantly increased its durability, plasticity, stiffness, and strength under high temperatures. Ceramic nanoparticles such as silicon carbide could be used to enhance the strength of metals. But they tend to clump together instead of dispersing evenly because small particles attract one another. That’s why, until now, no one had succeeded in dispersing ceramic nanoparticles evenly in molten metals, said Xiaochun Li.
To avoid clumping of particles, Li dispersed the particles into a molten magnesium zinc alloy. And then they used a technique called high-pressure torsion to compress the metal and enhance its strength. “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,” said Li.
