There’s a reason why blacksmiths fire metals before hammering them. Heat always softens metal, making it more malleable and easier to reshape. Or does it? In a surprising new study, Northwestern University engineers discovered that, in extreme conditions, heat doesn’t soften pure metals—it strengthens them.
Not only does this new finding challenge long-held assumptions of how metals behave, it also could provide new insights for designing metals for futuristic applications in extreme conditions, such as hypersonic flight, extraterrestrial construction and advanced manufacturing.
The study will be published Tuesday (Feb. 17) in Physical Review Letters.








