New alloy can shift shape thousands of times
OCT 04, 2013
DOI: 10.1063/PT.5.027398
BBC : Richard James of the University of Minnesota and his colleagues have created a new metallic alloy, Zn 45Au 30Cu 25, whose crystalline microstructure and bulk structure change in response to a change of temperature. Known as shape memory metals, such materials can be bent into a new shape above the transition temperature, yet will regain their original shape below it. They are already in use in eyeglass frames, brassiere wires, and medical stents. But the current shape memory metals, made from alloys of titanium and nickle, have a significant drawback. After repeated transitions, the transition temperature drifts, sometimes by as much as 20°C. By contrast, the transition temperature of James’s new alloy stays 0.5° within its initial value even after 16 000 shape shifts.
© 2013 American Institute of Physics
