Alcoa’s aluminium lithium plate used in friction-stir welded development

ALCOA says its aluminium lithium plate is featured in NASA’s friction-stir welded, spun-form dome which was unveiled on 30 March 2010.

Alcoa engineers, along with Lockheed Martin and MT Aerospace, formed the consulting team providing materials expertise to develop the first full-scale friction-stir welded and spun-formed tank dome designed for use in large liquid propellant tanks.

According to Alcoa, the tank dome proves the viability of using friction-stir welding to reliably and cost-effectively join large aluminium-lithium plates for high-strength applications.

Friction-stir welding is a process specifically designed for working with aluminium, while spin-firming was used to form the round symmetric parts for the dome.

NASA hopes to use the new technology to reduce the weight of future large liquid propellant tanks by 25%, and cut production costs.

Alcoa says two of its aluminium-lithium plates were joined into one plate using the friction-stir weld process.