Y alloy

Y alloy is a nickel-containing aluminium alloy. It was developed by the National Physical Laboratory during World War I, in an attempt to find an aluminium alloy that would retain its strength at high temperatures.

Duralumin, an aluminium alloy containing 4% copper was already known at this time. Its strength, and its previously unknown age hardening behaviour had made it a popular choice for zeppelins. Aircraft of the period were largely constructed of wood, but there was a need for an aluminium alloy suitable for making engines, particularly pistons, that would have the strength of duralumin but could retain this when in service at high temperatures for long periods.