A metallic alloy that is tough and ductile at cryogenic temperatures

A new concept in metallic alloy design – called "high-entropy alloys" - has yielded a multiple-element material that not only tests out as one of the toughest on record, but, unlike most materials, the toughness as well as the strength and ductility of this alloy actually improves at cryogenic temperatures. This multi-element alloy was synthesized and tested through a collaboration of researchers at the U.S. Department of Energy (DOE)'s Lawrence Berkeley and Oak Ridge National Laboratories.

"We examined CrMnFeCoNi, a high-entropy alloy that contains five major elements rather than one dominant one," says Robert Ritchie, a materials scientist with Berkeley Lab's Materials Sciences Division. "Our tests showed that despite containing multiple elements with different crystal structures, this alloy crystalizes as a single phase, face‐centered cubic solid with exceptional damage tolerance, tensile strength above one gigapascal, and fracture toughness values that are off the charts, exceeding that of virtually all other metallic alloys."