Aluminum-lithium alloys may be used for Boeing 777X
May 3, 2013, 2:44pm PD
Staff Writer-
Puget Sound Business Journal
As Boeing officially enters the fray against
in the large twin-jet category with Boeing's planned 777X, a secondary theme is that Boeing is continuing to bet on aluminum.
But not your parents’ aluminum.
The stretched 777-9, the biggest twin-engine model Boeing Co. (NYSE: BA) is planning to build, may be partly fabricated from a new breed of aluminum-lithium alloys, lighter and stronger than the aerospace-grade aluminum now used. Boeing
Yes, these new alloys do include lithium, the highly reactive metal that caused Boeing such problems with the 787’s lithium-ion batteries. (Boeing’s 787 Dreamliner has been grounded for more than three months due to charring of two lithium-ion batteries, and only recently was cleared to return to service by the Federal Aviation Administration, after an expensive battery fix.)
But don’t worry, when lithium and aluminum are mixed together, the resulting alloy has no propensity to combust.
The promise of aluminum lithium alloys is so interesting to the aerospace industry that an entire panel was devoted to the subject at the Pacific Northwest Aerospace Alliance annual conference in Lynnwood, in February.
Executives from Dutch aluminum company Constellium and from
Aerospace updated the audience, mostly made up of aerospace suppliers.
“As aircraft design requirements change, aluminum is still innovating, and we expect to be here for a long time,”
, an Alcoa engineer, told the crowd. “New aluminum lithium alloys can offer 1 to 2 percent improvements for long-range aircraft.”
Alcoa is
to produce aluminum lithium alloys, expecting it to be incorporated in new aircraft including Boeing’s planned 777 and perhaps the 737 Max. Boeing hasn't said whether or not it will use aluminum-lithium alloys in either plane.
Alcoa is now building a $90 million aluminum-lithium ion production plant in Lafayette, Ind. When completed next year, the new factory will be able to produce 200,000 metric tons of the alloy a year.
“Our primary role as aerospace solution providers is to help the OEMs (original equipment manufacturers) reduce fuel consumption per seat mile,” said
, president of Alcoa Forgings and Extrusions, in a statement at the factory groundbreaking last year. “Our aluminum-lithium supply chain will be the premier operation in the world, and this specialty alloy will be flying on the next generation of aircraft.”
Alcoa also is expanding another aluminum lithium facility, located in Upper Burrell, Penn.
Currently Boeing’s popular 777 300-ER weighs 370,000 pounds when empty, and carries 386 passengers in a standard configuration. The new stretched 777-9 is intended to carry 21 more passengers. What if the combination of a aluminum-lithium fuselage and a new composites wing made its weight the same or less?
That might be a key to competing against the formidable Airbus A350-1000, which features a light composites fuselage and wings. Airbus engineers are claiming their plane, which also uses aluminum lithium alloys, will be 25 percent more fuel efficient, on a per-seat mile basis, than the current 777. And a big piece of that gain is about less weight.
Alcoa claims that using its aluminum-lithium alloys can lower an aircraft’s weight by 10 percent, and manufacturing and repair costs by 30 percent.
These are big numbers. It’s very likely you’ll hear word lithium used a lot around the 777-9, and the word won’t be referring to batteries.
