Video: Aluminium started as one of the world's most expensive materials because it was difficult to refine — even though it made up eight per cent of the world's crust. But eventually aluminium became one of the cheapest materials after methods of mass producing it were invented in the 1880s. It went from $US1200 ($1576) per kilogram down to a dollar in 50 years. The aluminium used back then was still weak and malleable, though. It wasn't until Alfred Wilm accidentally discovered age-hardening which transformed aluminium to duralumin, an alloy with a much stronger crystalline structure, that things began to change. Duralumin was used to create the first all-metal aeroplane, and its strength eventually led to new plane structures being built that changed air travel forever.
Real Engineering goes through the history of aluminium and makes the case that it's one of those materials in history that completely changed the world. The video cites other examples for aluminium's importance, like how its lightness is favoured in power lines (even though copper is a better conductor) and how its used in construction. There's a damn fun history for such an interesting material.