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.
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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.