Shape-memory metal will spring back after 10 million uses

A new shape memory alloy retains its properties even after ten millions of transformations, compared with the previous records that number in thousands.

The low fatigue of the thin films of titanium-nickel make bring closer to reality the myriad of potential uses of the metal from surgical stents and heart valves, to refrigeration and aircraft parts.

Manfred Wuttig, a material scientist at the University of Maryland who helped lead the team, said they had stumbled on the alloy, which is detailed in a new paper in the journal Science

“This really is a huge breakthrough, and could make shape-memory alloys much more widely used in everyday technology” Richard James, a leading shape-memory materials scientist at the University of Minnesota, told Popular Mechanics.

“I’ve personally made many, many [shape-memory] alloys that have various super interesting properties, but no one would be able to use them as they last only a few cycles.”

The scientists are not 100% sure why the alloy behaves the way it does but they believe  the presence of a precipitate, known as Ti2Cu, helps to facilitate the phase transitions underlying the materials’ shape memory.

This precipitate acts as a sentinel, they say, smoothing out the alloys’ physical transformations and ensuring complete and reproducible memory cycles each time.

Bill Condie

Bill Condie

Bill Condie is a science journalist based in Adelaide, Australia.

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