SAN ANTONIO Aluminum has great growth opportunities in the automotive sector, but the light metal faces stiff competition from new high-strength steels and composites, according to one industry expert.
Aluminum demand will grow with an increase in vehicle sales as automakers look to make cars and trucks lighter and more fuel efficient, said Alan Taub, professor of materials science and engineering at the University of Michigan and chief technology officer at the American Lightweight Materials Manufacturing Innovation Institute.
The light metal has reached an "inflection point" where companies will start making big capital investments, Taub said at the Aluminum Associations spring meeting in San Antonio. But despite the increasing penetration of aluminum and magnesium, advanced high-strength steels have made bigger gains in vehicles than any other material in the past 20 years, he noted. "The question is: Which material is going to win?"
Taub, who retired from Detroit-based General Motors Co. in 2012 and also worked at Dearborn, Mich.-based Ford Motor Co., said cost concerns have favored steel in the past, but that may be changing as fuel economy grows more important and higher-strength steels become trickier to work with. "Within a decade (aluminum) could become the dominant material," he said.
Most of aluminums penetration to date has been in casting applications, but cast parts increasingly will call for mixed materials and overcasting of different metals, he said.
"The days of single-material-intensive vehicles are over," Taub said. "But the real question is how far ... is aluminum going to become dominant in the body structure?"
Aluminums advance in that arena is clear in vehicles such as the new Ford F-150 pickup but is not guaranteed, Taub said. Automakers are now working with advanced high-strength steels, which they did not have the expertise to weld or form 10 years ago. "If we can get higher-strength steels and learn how to handle them, we can continue to shrink the gauge and lighten the vehicle," he said.
New high-strength steels require hot pressing, "an extremely large capital investment" that original equipment makers may be reluctant to make, Taub said, but there are "hints on the horizon" of advanced high-strength steels that could be cold-stamped. "Thats something the aluminum industry should keep its eyes on."
Carbon fiber also has made gains in manufacturing efficiency, Taub said, noting that automakers, including GM, Ford and Munich-based BMW AG, are working at making new vehicles with the material even as its cost concerns persist. "You have a competitor on the horizon. Id say its a pretty hard technical challenge, but it might happen," Taub said. That leaves the aluminum industry, automakers and their suppliers wrestling with whether to make capital investments in aluminum when an alternate material could win.
Automakers also run the risk of running into corrosion issues as they ramp up the use of ferrous and nonferrous metals in mixed-material vehicles, Taub said. "I believe the automotive industry, unfortunately, is about to discover corrosion again," he said, noting that corrosion could be most pronounced at places where mixed materials are joined.
"Whenever you are taking mixed materials and putting them on a product thats abused for 15 years, water will enter the gaps and we will have corrosion problems unless weve done good galvanic isolation," Taub said.