the.com/duralumin
the alloy that learned to harden itself, just by sitting around being aluminum.
self-strengtheningGains strength for days at room temperature after quenching
zeppelin frameBuilt the rigid skeletons of doomed airships
named for townCoined from Düren, Germany, where it was made
corrosion problemCopper content makes it rust-prone without coatings
accidental discoveryAlfred Wilm found the hardening trick by surprise