A heat-resistant alloy created for space missions
Stiffness of most metals decreases when temperature increases due to thermal expansion. However, the alloy discovered by Professor Yang and his team retains its stiffness over a wide range of temperature changes.
“When this alloy is heated to 700 °C, or even above, it is as stiff as, or even slightly stiffer than it is at room temperature. It expands without any notable phase transition,” said Professor Yang.
“We discovered this phenomenon in 2017 and spent several years trying to understand the underlying mechanism,” he added. No known metals have been found to behave this way before.
In the paper published in Nature, the team found that the alloy has a special highly distorted lattice structure and a complex atomic-scale chemical composition. This unique structure gives the alloy a very high energy barrier against dislocation movements with an impressive elastic limit and high energy storage capacity.
With its ability to store energy, Professor Yang suggested that the alloy could be useful in high-precision devices such as watches and chronometers, especially those used in space missions where extreme temperature changes can occur.