Thoughest ever shape memory alloy

August 15, 2015

Film

Professors Manfred Wuttig and Eckhard Quandt at the Universities of Maryland, USA and Kiel, Germany, have produced a new shape memory alloy so tough it returns to its original shape even after being bent and heated over ten million times. This makes the new alloy, a mixture of titanium, nickel and copper, a candidate for “high cycle” applications such as artificial heart valves and solid state air conditioners. In contrast the previous highest-performing shape memory alloy could be deformed approximately 16,000 times before it succumbed to fatigue.

All shape memory alloys are phase-changing materials, meaning they can shift into different molecular configuration—such as water into ice. The new alloy’s transition can be “activated” by heat in one of its forms, and by a release of tension in another. Wuttig and Quandt discovered that the key to the alloy’s durability was the presence of a small impurity, a precipitate of titanium and copper (Ti2Cu). These particles were compatible with both of the alloy’s phases, allowing it to mediate millions of complete and reproducible transformations thereby reducing fatigue.

Current Issue

Improving lives

Nickel in healthcare

December 19, 2017

cover

Feature Story:
Nickel alloys helping hearts beat stronger
With an aging population, demand is stronger than ever for pacemakers and defibrillators. With increased usage of Magnetic Resonance Imaging (MRI), it is important that permanent implants are made from non-magnetic materials, such as UNS R 30035.