Surface etched aluminum bar
Using a technique that creates a new nanoscale architecture, researchers have created an aluminum alloy just as strong as steel but with reasonable plasticity to stretch and not break under stress. Importantly, the technique of creating these nanostructures can be used on many different types of metals and the team plans to work on strengthening magnesium, a metal that is even lighter than aluminum that could be used to make strong, lightweight body armor for soldiers.
Dr. Yuntian Zhu, a professor of materials science at North Carolina State University worked on the project to create the super strong aluminum alloy along with colleagues from the University of Sydney in Australia; the University of California, Davis; and Ufa State Aviation Technical University in Russia. He says the aluminum alloys have unique structural elements that, when combined to form a hierarchical structure at several nanoscale levels, make them super-strong and ductile.
The aluminum alloys have small building blocks, called “grains,” that are thousands of times smaller than the width of a human hair. Each grain is a tiny crystal less than 100 nanometers in size. Bigger is not better in materials, Zhu says, as smaller grains result in stronger materials. Zhu also says the aluminum alloys have a number of different types of crystal “defects.” Nanocrystals with defects are stronger than perfect crystals.
Aside from Zhu’s plans to collaborate with the Department of Defense on a project to make magnesium alloy to be used in body armor, the ability to create lighter – yet stronger – materials is crucial to devising everything from more fuel-efficient cars to safer airplanes.
The paper detailing the team’s findings appears in the journal Nature .