Word of the Day
16 April 2026
duralumin
nounMetallurgy
An alloy of over 90% aluminium, 4% copper and traces of manganese, magnesium, iron and silicon, widely used in the aircraft industry.
Why this one
Its trick is age hardening: the alloy keeps gaining strength for days after quenching, which was found by accident and only later understood. The copper that buys that strength also costs it corrosion resistance, so sheet gets a pure aluminium skin.
In use
That skin's duralumin, so don't go at it with a steel brush; you'll scrub straight through the cladding and it'll pit inside a month.
Written by our editors to show how the term is used, not a recorded quotation.