Steel, Aluminum, and Plastics Look Ahead

Automobile Material Choices

Will steel retain its dominance in the automotive material market or could aluminum and plastics unseat the incumbent?

By Robert J. Garino and Si Wakesberg

Robert J. Garino is director of commodities for the Institute of Scrap Recycling Industries (Washington, D.C.). Si Wakesberg is New York bureau chief for Scrap Processing and Recycling.

What material will automakers favor in future car designs?The answer depends on whom you ask-responses differ among automotive design engineers, industry consultants, trade association reps, and executives of major raw materials producers.  But basic material choices for major automobile components, especially structural parts, seem to come down to a three-way contest pitting aluminum against steel, and plastics against both metals.

Since each of these materials will likely hold an important share of the automotive market in coming years, it's mighty hard to pick which-if any-will be the ultimate winner of the coveted material-of-choice designation by the auto industry.  After all, long-term material choices made by the automakers involve complicated strategic planning, based on tangibles such as weight characteristics, costs, machine tooling factors, recyclability, and so forth, as well as numerous intangibles like fashion/style and future fuel-economy and air-emissions standards.

To be sure, there is much at stake in such decisions because of the enormous quantities of raw materials that go into making the world's automobiles.  In the United States alone, for instance, automakers are believed to have consumed more than 11.5 million tons of iron and steel plus more than a million metric tons (mt) of nonferrous metals and untold tons--in the hundreds of thousands--of plastics.  For a more global perspective, consider this finding from the recent study, "Metals Use in the International Car Industry" by metals consulting firm Brook Hunt and Associates (London): More than 30 million passenger cars were produced in North America, Japan, and Western Europe in 1993, with production of this vast fleet accounting for 12 percent of the Western World's demand for aluminum last year, 8 percent of its copper, 32 percent of its lead, 10 percent of its nickel, and 13 percent of its zinc.

Aluminum Consumption in Cars Just Keeps Growing

Those percentages could soon change.  According to the Brook Hunt study, more aluminum, lead, and nickel will be consumed by the automobile industry at the turn of the century than is used now, but less copper and zinc.  Among these metals, aluminum shows the greatest potential for future demand growth in the automobile market, thanks to promising physical and mechanical properties, the study reports.  Thus, the firm estimates, by 2005, annual world consumption of aluminum for passenger cars will rise by 83 percent to 3.95 million mt.  Automobile copper consumption, in contrast, is expected to fall by nearly 12 percent to 480,000 mt.

Other industry observers generally concur with this aluminum forecast, pointing to the significant inroads the metal has made into the automobile picture in the past decade, replacing steel and copper in various uses.  And most analysts agree that aluminum use will broaden substantially further by 2000.  Still, two key factors will determine the extent of that growth--future developments in fuel consumption standards and aluminum’s price volatility, which could hinder the metal's competitive position.

Ford Motor Co. (Dearborn, Mich.), which reportedly leads the U.S. auto industry in the use of aluminum in its current steel-bodied cars with an average of 219 pounds per vehicle, appears to be betting on a positive outcome for aluminum in these determinants.  Signs of aluminum's gains at Ford can be seen in the metal's growing use in engine blocks, suspension components, and body exterior panels, notes Bill Stuef, the company's manager of vehicle systems.  In these areas, aluminum's gains have principally been steel's losses, he notes.

And Ford continues to study aluminum's automobile potential.  The company's prototype Synthesis 2010 concept car prominently features aluminum, and the automaker is already testing a number of Taurus sedan designs that use aluminum panels in place of steel body components.  Ford has also signed an agreement with Alcan International Ltd. (Montreal) to participate in a $32 million joint program designed to develop a high-volume, all-aluminum vehicle.

The other domestic carmakers are also focusing new attention on aluminum. Chrysler Corp. (Farmington Hills, Mich.), for instance, recently introduced a lightweight passenger car, the Neon Lite, which boasts an aluminum body, hood, deck lid, and door.  The aluminum-intensive vehicle tips the scales at 600 pounds less than the regular-production Neon.

And at General Motors Corp. (Detroit), which follows Ford's lead with a per-passenger car aluminum lode of 197 pounds, a spokesman notes that two factors have encouraged the company to increase its aluminum use: the metal's durability and its life cycle cost.  One of the biggest wins for aluminum at GM is the radiator. "Aluminum has effectively replaced copper and brass radiators," says the spokesman.  He notes that while some copper and brass will still find their way into replacements, "the primary product, as far as radiators are concerned, is aluminum."

Automakers outside the United States are investigating their aluminum options as well, and in some cases are far beyond the concept stage.  Audi, for one, introduced its A8 luxury sedan, an aluminum-intensive vehicle, in March and began selling it this summer in Europe.  In contrast to the typical family vehicle, which contains about 180 pounds of aluminum, Audi's A8 sports a whopping 880 pounds, nearly 25 percent of its total weight.  Most of the aluminum can be found in the body and its rigid spaceframe--relatively new uses for the metal--as opposed to die castings. Thanks to this aluminum-laden design, the A8 weighs 439 pounds less than comparable steel-bodied cars, a weight reduction that allows use of a smaller, V-6 engine in place of a V-8, reportedly improving fuel efficiency by 2.6 miles per gallon without suffering a loss in performance.

The weight factor, of course, is a prime consideration among material purchasing executives at all the automakers and is the principal reason for aluminum's growing usage at Ford, GM, and Chrysler, as well as European and Japanese carmakers.  In some components, however, aluminum has in turn been replaced by even lighter materials such as magnesium.  GM, for instance, has reportedly approved the use of magnesium in steering column supports in some of its car lines.  And Ford has also selected magnesium for some uses, including steering column components, but magnesium replacement of aluminum parts is not widespread, according to Stuef.

Steel Responds to Pressure

Aluminum's forecasted gains are expected to come largely at the expense of steel, which currently accounts for about 70 percent by weight of the typical U.S. passenger car. Thus, steel companies, deeply concerned about maintaining market share in this vital segment, are likely to push for every advantage they can find over this challenger. The aluminum/steel battle is "going to be a dogfight," predicts Walter Bargeron, vice president of technology for Bethlehem Steel Corp. (Bethlehem, Pa.).

Steel producers can probably rely on steel's obvious cost advantages and its inherent strength and machine-formability compared with either aluminum or plastics to help ensure its continued dominance in the automobile market.  In fact, GM's president and chief executive officer, Jack F. Smith Jr., offered a vote of confidence in steel at the American Iron and Steel Institute's (AISI) (Washington, D.C.) annual meeting in May, telling the steel executives gathered, "Steel remains the material of choice for the auto industry because of the progress you've made in making the material more versatile and cost-competitive with all the alternatives."

Steel has another undeniably strong advantage over any vehicle market competitors: Automakers have billions of dollars invested in equipment specifically designed to bend, stamp, and weld steel.  Much of this machinery would have to be replaced to switch to other materials, a massive expenditure that would have to be passed along to car buyers, probably wiping out for the foreseeable future any possible consumer benefits in fuel efficiency that would be presented by lighter cars.

Data support this: A Massachusetts Institute of Technology (Cambridge, Mass.) study, for example, reckons that for every pound shaved from a car by substituting aluminum for steel, the automakers would have to spend $1.50 in additional raw materials and manufacturing costs.  A similar conclusion was recently reached by AISI's automotive application committee, which warned of "severe penalties" in using aluminum to reduce weight.  AISI reported that the per-ton price of steel in an "optimized lightweight car" would be around $550 compared with $1,650 to $1,925 for a ton of aluminum.

Nevertheless, to preserve and enhance their share of world automotive demand, 25 major steel companies in Asia, Europe, and the United States are working to jointly develop a lightweight steel that will be able to compete for automotive structural applications against the new products presented by aluminum and synthetic resin manufacturers, according to the International Iron and Steel Institute (Belgium).

The project, directed by Porsche Engineering Services Inc., the U.S. affiliate of Germany's Porsche AG, aims to develop steels 20 to 30 percent lighter than those currently used by auto manufacturers, according to a Japanese news report.  Japanese steel officials confirmed the report, noting that the development effort will soon lead to assembly and evaluation of a prototype vehicle.  No timetable has been announced yet, however.

And Taking Both On--Plastics

In the other comer, plastics continue to make inroads in the auto market, displacing ferrous and nonferrous metals in more and more of the approximately 10,000 parts found in the average vehicle today.  According to the American Plastics Council's (Washington, D.C.) automotive committee, plastics currently account for slightly more than 8 percent of an average vehicle's weight, and this figure, plastic proponents contend, will continue to grow.

The plastic industry is, of course, aggressively looking to exploit what many in that industry see as steel's "weight penalty" and aluminum's "cost penalty." Indeed, plastic's design versatility, low weight, and low cost virtually assure it an increasingly important role in automobiles.

But the plastic industry must contend with a negative image related to recycling, which is an increasingly important long-term concern of automotive purchasing executives. Every year, scrap recyclers in the United States process about 10 million cars, which represents an impressive 94-percent recycling rate.  This process yields 11 million tons of recoverable steel and 800,000 tons of reusable nonferrous metals, especially aluminum, copper, lead, and zinc.

The plastics from automobiles, in contrast, mostly end up as waste, accounting for about a third of the 2.5 to 3 million tons of automobile shredder residue, or fluff, generated annually. (The balance is mainly rubber, glass, and dirt.) Although numerous studies are trying to figure out how to economically separate and reclaim the plastic fraction from the shredder residue, for now virtually all fluff is landfilled.

Declaring a Winner?

Clearly, major factors determining which materials ultimately gain and which lose market share in tomorrow's automobiles have yet to be decided. Certainly the stakes are high.

At first glance, aluminum appears well-positioned, as do plastics, since both are key ingredients in producing lightweight, fuel-efficient transportation.  At the same time, no one is counting out the steel industry's ability to meet the exacting demands of design engineers.  Steel's inertia in the auto market, its comparative cost advantage, and its dependable physical properties--including recyclability--will likely ensure its continued, though certainly not complete, dominance among the competing materials for the foreseeable future. •