Boeing’s announcement that its cutting-edge 787 Dreamliner would be fabricated mainly of carbon fiber composites set off cries of ‘May Day’ across the aluminum heat-treat plate sector. Today, some seven years later, a combination of new alloys and a better understanding of the benefits and shortfalls of composites have kept aluminum from losing altitude.
Widespread fear of aluminum losing market share to carbon fiber composites in the aerospace sector has proven to be largely unfounded, due in no small part to survival responses by aluminum producers unwilling to pass the torch without a fight.
Aluminum heat-treat plate had been widely expected to lose its place as a dominant aerospace material following the 2003 announcement that the light metal would make up just 20 percent of Boeing Co.’s 787 Dreamliner. But to the relief of players in the aluminum sector, that has not been the case.
“We’re not seeing the big shift that was initially talked about when the 787 first came out,” Harry Kiskaddon, commercial director of Alcoa Aerospace, told AMM. “There was talk that everything would go composite right down to the business jets, the regional jets, and it’s far from that.”
Instead, aluminum has held its ground as a key material in the aerospace sector, as evidenced by the fact that the next generation of aircraft has kept aluminum brightly on the radar. China’s first jumbo jet, for example, Commercial Aircraft Corp. of China Ltd.’s C919, as well as the redesigned Boeing 747-8 and Mitsubishi Aircraft Corp.’s reconfigured Mitsubishi Regional Jet commercial plane are primarily metal, Kiskaddon said, quelling misconceptions that composites are the only way to fly into the future.
“Whereas there was a thought probably a few years back that, ‘Oops, the 787 is composite—that must be the way to go for everything,’ it’s not turning out to be a solution for every application,” Kiskaddon said. “Composites are still a competitive material, but we absolutely feel there’s a much more level playing field now.”
According to players in the industry, some of aluminum’s staying power can be attributed to the underperformance of composites, which while very successful in the sector may not have met all the soaring expectations set for them.
Touted as lightweight and durable solutions for the aerospace sector, composites in fact bring challenges of their own, sources said, giving aluminum a fair chance to compete after all. Take, for example, composites’ promise of light-weighting, a tempting attribute in a world of increasing fuel-efficiency demands. Composite materials continue to help aircraft shed pounds, but Christophe Villemin, president of Rio Tinto Alcan’s global aerospace division, said the savings are less pronounced than had been pledged.
“Composites require extra reinforcements, thus not fully delivering on their light-weighting promises,” Villemin said, noting that extra material, like meshing, is required to secure the so-called lighter composite material. “The best material is not necessarily the lighter, but the one that allows the aircraft to be lighter,” he said.
Composites’ resilience against corrosion also has come up short. “The fact that they don’t corrode or fatigue does not mean they do not age. There is simply not much history and knowledge to describe their behavior when projected over the duration of the life cycle of an airplane,” Villemin said.
Kiskaddon agreed that composites have failed to impress in some performance areas, noting that some aluminum alloys appear to offer equal or better corrosion resistance than composites. “I think there are just some solutions where the composite may not be as cost-competitive nor as weight-competitive as originally thought, so it’s not the gap they thought it would originally be on all applications,” he said.
While the less-than-perfect performance of composites has no doubt played a supporting role in helping aluminum to retain market share, it was not defense but the offense mounted by aluminum players that has really secured the light metal’s place.
“We as an industry are working very hard to retain aluminum’s position as the most widely used raw material in aerospace manufacturing,” said Keith Harvey, vice president of sales and marketing at Kaiser Aluminum Corp.
One way producers have worked to keep aluminum flying high is through the development of new alloys and product lines that are better able to compete with composites than their vintage counterparts. Aluminum-lithium alloys, for example, which are produced by both Pittsburgh-based Alcoa Inc. and Rio Tinto Alcan, Montreal, are a lighter-weight and more corrosion-resistant alternative to traditional aerospace alloys, allowing aluminum to regain some footing against carbon fiber composites.
“The development of these alloys in recent years has provided a step-change in the strength and lightness of the materials we have been supplying to the industry, but also demonstrates the multi-functional nature of aluminum,” Villemin said.
Foothill Ranch, Calif.-based Kaiser also has developed a new product line to respond to a changing marketplace, Harvey said, noting that its Kaiser Select brand of plate products requires far less reworking and as a result can save customers hundreds of dollars per part—an attractive feature in today’s cost-cutting environment.
In addition to the development of new alloys and products, aluminum companies also are staying ahead of the curve through capital investment.
Since 2006, most players in the heat-treat aluminum plate sector have expanded capacity, according to research by Davenport & Co. LLC, with total capacity swelling 40 percent to 805 million pounds by the end of 2009 from 574 million pounds three years earlier. As much as 52 percent of global capacity sat idle last year, Davenport said, but the extra capacity may still come in handy, with plate demand expected to rebound 6 percent to 408 million pounds in 2010 and another 21 percent in 2011 and 8 percent in 2012.
Kaiser, for instance, which announced a three-part, $139-million expansion at its Trentwood, Wash., facility in 2005, said that the capacity growth will help the sector maintain market share going forward. “This capacity expansion was extremely important to Kaiser’s customers as these products are very difficult to produce and there are only a handful of producers in the world that can supply these products,” Harvey said. “We must continue to invest in our operations to meet the growing demand for our products by our global customer base as the aerospace sector grows through 2030 and beyond.”
In addition to new alloys and facility expansions, arguably the most important offensive move by producers of aluminum heat-treat plate unwilling to lose market share to composites is the active push to work side by side with original equipment manufacturers (OEMs), sources told AMM.
It’s really a matter of continuing to stay very close with OEM design teams, which we do. We’re right there from the beginning of folks talking about planes,” Kiskaddon said. “They’re talking to us now about aircraft that won’t enter service until maybe 2020, so it really gives us encouraging feedback to know we’re certainly in the hunt for applications that far out. That’s not a ‘fold up and go away’ strategy at all on our part.”
“If the aluminum players continue to innovate,” Villemin said, “the future of aluminum is positive.”
