Iron-Aluminum Alloy
As light and strong as titanium at 1/10 the cost:
https://gizmodo.com/new-iron-aluminum-alloy-is-strong-and-light-as-titanium-1683920338
As light and strong as titanium at 1/10 the cost:
https://gizmodo.com/new-iron-aluminum-alloy-is-strong-and-light-as-titanium-1683920338