Alcoa Goes for Light Alloys in a Big Way

Alcoa inaugurated its new aluminum-lithium alloys casting complex in Lafayette, IN, in October 2014, the result of a two-year, $90-million development that now takes its place as the largest such operation in the producer’s global portfolio. The others are at the Alcoa Technical Center near Pittsburgh and at a fabricated products campus at Kitts Green, England. While each of those operations have been updated in recent years, too, Alcoa noted the Indiana operation is producing “advanced, third-generation aluminum-lithium alloys” for aerospace customers, including applications for the Airbus A380 and A350 and Boeing 787 commercial jets, and the Gulfstream G650 business jet.

“The future of aviation is being built with aluminum-lithium, and Alcoa is making big moves to capture that demand,” stated chairman and CEO Klaus Kleinfeld. “This state-of-the-art facility positions Alcoa as the world’s premier aluminum-lithium supplier, offering the broadest portfolio of aluminum-lithium components for next generation aircraft.”

The Lafayette cast house is designed to pour over 20,000 metric tons (44 million pounds) of aluminum-lithium annually—making it the largest facility of its kind in the world.

Aluminum-lithium alloys are used in increasing volumes by airframe manufacturers because alloying aluminum with lithium reduces the structural mass of the material. According to Alcoa, it has contracted $100 million in aluminum-lithium revenues for 2017.

Specifically, because lithium is the least dense elemental metal the newer materials are significantly less dense than standard aluminum alloys — though commercial-grade Al-Li alloys contain no more than 2.45% of lithium by weight.

While lithium reduces the alloyed materials’ mass by displacing denser elements, it also increases the specific stiffness, enhances the strain hardening qualities (thus resulting in a stronger material), and with proper treatment can improve the materials’ corrosion-resistance versus other aluminum alloys.

Alcoa researchers developed most of the alloys cast at the new plant — which have applications in rolled products, extrusions, and forgings — as well as the casting and processing technology. Compared with some competing aircraft composite materials, Alcoa claims its aluminum-lithium alloys will reduce the weight of single-aisle aircraft fuselage applications by up to 10%; reduce the cost to manufacture, operate, and maintain planes by up to 30% (with fewer production risks); and contribute to 20% greater fuel efficiency.

In addition to aerospace markets, Alcoa supplies aluminum-lithium materials to spacecraft programs (including the ULA rocket, and in development for SpaceX); automotive, commercial trucks, and high-performance car applications; and defense programs.

At Lafayette, Alcoa will be producing the world’s largest aluminum-lithium ingots — approximately 50% percent larger than the nearest competitor, it stated, and large enough to produce any unitary aircraft part now in commercial production. Minimizing the number of joints or seams is important in aircraft design, enhancing structural reliability and reducing production costs.

Among the aluminum-lithium products to be produced from the ingots cast there will be a forged front fan blade for Pratt & Whitney’s PurePower turboshaft engines — a product in development by Alcoa and the jet-engine manufacturer as part of a 10-year, $1.1-billion supply agreement they announced earlier this year.

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