Researchers at the University of Vermont have announced that they have developed a stronger silver alloy, paving the way for a new class of materials that are stronger and equally electrically conductive as their weaker counterparts.
“We’ve discovered a new mechanism at work at the nanoscale that allows us to make metals that are much stronger than anything ever made before—while not losing any electrical conductivity,” says Frederic Sansoz, a materials scientist and mechanical engineering professor at the University of Vermont.
To perform this feat of modern alchemy, Sansoz and his team precisely mixed trace amounts of copper into their silver supply. This copper doping transformed the once-pure silver into a “micro-alloy” with controllable and uniform impurities that facilitate electrical conduction.
Using advanced computer simulations, engineers were able to build a virtual model of their silver alloy at the nano-scale level, and better understand the relationship of material strength versus material granularity (as the crystalline building blocks of a material get smaller, the material gets stronger), allowing for their breakthrough.
For some time, scientists have known about this strength vs. granularity ratio—–known as the Hall-Petch relation—but it was Sansoz and his team that pushed beyond the theoretical limit allowed by the Hall-Petch relation.
“We’ve broken the world record, and the Hall-Petch limit too, not just once but several times in the course of this study, with very controlled experiments,” says Sansoz.
While Sansoz’s breakthrough is a boon for material science, he also sees the discovery as being crucial to extending the supply of the world’s materials.
“This is a new class of materials and we’re just beginning to understand how they work. When you can make material stronger, you can use less of it, and it lasts longer,” said Sanoz.