Metal Manipulation: Technique yields hard but stretchy materials
Metalworking is an ancient craft, with time-tested practices that go back thousands of years. But now, working within the modern context of nanotechnology, researchers have found a way to make strong yet stretchy metals. Metallurgists might eventually incorporate such improved materials into countless applications, from micromechanical machines to biomedical implants.
In the Oct. 31 Nature, En (Evan) Ma and his colleagues at Johns Hopkins University in Baltimore report that they’ve combined a standard metalworking technology–rolling–with a programmed sequence of cooling and heating steps to process copper into a form that contains both nanoscale and microscale crystal grains. The resulting material has six times the strength of unprocessed copper yet retains most of the metal’s characteristic ductility, or stretchiness.