Alcoa announced that its aluminum lithium plate is featured in NASA’s friction-stir welded, spun-form dome that made its debut March 30 at the Marshall Space Flight Center in Huntsville, Ala. Along with Lockheed Martin and MT Aerospace, Alcoa engineers were part of the consulting team providing materials expertise that helped to develop this groundbreaking technology – the first full-scale friction-stir welded and spun-formed tank dome designed for use in large liquid propellant tanks.
“We want to congratulate NASA on this important achievement,” said Harry Kiskaddon, global commercial director, Alcoa Rolled Products. “The tank dome proves the viability of using friction-stir welding to reliably and cost-effectively join large aluminum-lithium plates for high-strength applications. It is a great first step in testing the fundamentals of this technology – and a terrific example of how next-generation aluminum alloys continue to push the boundaries of innovation. It illustrates how Alcoa delivers both products and technology innovations to designers to enable more efficient and high-performance structures.”
The 18-foot dome was developed with friction-stir welding, a welding process specifically designed for working with aluminum, and spin forming, a metal-working process used to form round, symmetric parts. Through this new technology, NASA hopes to reduce the weight of future large liquid propellant tanks by 25 percent. Additionally, the cost of producing the tanks is reduced because friction-stir welding and the concave net shape spin forming process eliminate manufacturing steps, such as machining.
“We were able to supply the aluminum-lithium plates needed for the dome because our Davenport, Iowa, facility is the widest hot rolling mill in the world,” said Kiskaddon. “Two of our wide plates were joined into one plate using the friction-stir weld process.”
Since its inception, the space program has used Alcoa aluminum. Alcoa’s Davenport Works is the only supplier certified by NASA to provide the light-gauge, high-quality, aluminum-lithium plate for crew launch vehicles.
NASA awarded Alcoa contracts now totaling $18.7 million since 2007 to develop manufacturing capabilities and to supply the initial requirements for aluminum-lithium alloy products. A year later, NASA certified Alcoa as the sole supplier of the high performance aluminum-lithium alloy thin plate. In supplying plate products to NASA since 2008, Alcoa’s Technical Center and Davenport Works facilities have demonstrated the product capability, manufacturing flexibility and technological innovation needed for NASA to meet its program goals.
Alcoa is a leader in the development of aluminum-lithium alloys, which are lightweight, low density and strong. Aluminum-lithium alloy 2099 won the R&D 100 Award, considered the Oscars of Invention, in 2007.