NEW YORK New alloys have to "buy their way" onto aircraft, and aluminum-lithium has proven too expensive for Boeing Co., according to a senior executive.
"So far it has been cost-prohibitive," Jeff Carpenter, senior manager of raw material procurement, supplier management, for the parent companys Boeing Commercial Airplanes unit, said at AMMs Aluminum Summit in New York.
The aluminum industry claims aluminum-lithium has superior strength-to-weight performance vs. more conventional alloys as well as improved stiffness, damage tolerance and corrosion resistance.
Carpenter acknowledged that aluminum-lithium is "interestingits great." But "its really expensive." He did not reveal just how excessively costly Boeing believes it to be.
Carpenter also stressed Boeings reluctance to adopt a material whose developer is determined to keep production in-house. "Our preference is for dual sourcing on commodity-type materials," he said, adding later that this is just a starting point.
This attitude to sourcing is not limited to Boeing or aerospace, Carpenter indicated. He noted that an automotive executive told Aluminum Summit delegates earlier that it is become increasingly difficult to choose "proprietary boutique alloys" for his companys vehicles.
Carpenter urged aluminum producers to ensure there are multiple production sources for any widely used material. "Were looking for the industry to come together," he said.
Carpenter did not mention any aluminum producers in particular. Constellium, formerly Alcan Engineered Products, is considered a major global factor in aluminum-lithium, and has been working to develop the alloys for decades. Alcoa Inc., which has completed expansion of its Kitts Green facility in England, said last week it expects its aluminum-lithium annual revenues to quadruple to $200 million within six years (amm.com, June 18).
Bombardier Inc.s C-Series airliner, due to enter service next year, and Airbus SAS A350 XWB, entering service in 2015, are among the aircraft that are believed to be using aluminum-lithium alloys.
Carpenter noted that one of the claimed advantages for aluminum-lithium is that "in theory" it could serve as a "drop-in replacement everywhere" for other aluminum alloys without the need for redesigning a planes major parts or components, as could occur when a brand-new material is substituted.
He also said that high-speed machining has allowed Boeing to take products like castings out of its planes and instead produce certain parts by "hogging out plate." He noted that Boeing has more than 500 "key machine shops buying aluminum for us," primarily through its exclusive service provider, Kent, Wash.-based service center TMX Aerospace Inc., a division of ThyssenKrupp Materials NA Inc.