When it comes to radiators, the battle lines have been drawn between copper and aluminum as metal suppliers in opposing camps tout the advantages of their product and further potential for improvements.
Aluminum has clearly taken the dominant role, controlling 95 percent of the global light-vehicle radiator market in 2008 in North America, Japan, South Korea, all of Europe (excluding Russia) and Ukraine, according to Richard Schultz, project consultant for Ducker Worldwide LLC, Troy, Mich.
The consensus was mixed, though, on which metal currently holds the majority of the world's heavy-vehicle radiator market.
The trend in China is even more pronounced, with aluminum forecast to hold a whopping 99 percent of the car radiator market this year and 100 percent by 2010, according to data from Fourin China Auto Weekly, a unit of Aichi, Japan-based Fourin Inc. The trend isn't limited to just cars aluminum radiators are expected to hold 90 percent of the market for buses and mini-, light-, medium- and heavy-duty trucks by 2010, up from an estimated 50 percent this year.
But that doesn't mean copper should be eliminated as a contender. Copper suppliers remain adamant that the red metal stands as a valid alternative to aluminum.
Copper-based products haven't yet reached their full potential, according to product experts at Luvata Sweden AB, a Vasteras, Sweden-based supplier of fabricated copper to the auto radiator market.
Luvata, in cooperation with the New York-based International Copper Association (ICA), has been working to improve its traditional copper-brass radiators through the emerging CuproBraze technology. The technology makes use of brazing—similar, but not identical to, aluminum brazing—instead of traditional soldering to join copper and brass radiator components, with the result purportedly being a stronger, lighter and more corrosion-resistant product.
Development of the technology by the ICA came in response to the shift to aluminum, which began more than two decades ago—a trend that spread from Europe to the United States before heading to Asia as the industry sought a lighter, cheaper and lead-free metal for use in radiators.
Proponents of the technology argue that while copper does indeed still have significant room for improvement, aluminum faces a virtual standstill as key advancements with the metal have already been made.
"CuproBraze technology has a really huge development potential for at least the next 30 years," according to Ulf Anvin, market segment manager of Luvata's Engine Cooling North America division, and Markku Ainali, Luvata's general manager of customer product development. "On the other hand, aluminum brazing has been in the market for 30 years and has started to be old, and we don't see so many new advantages coming out of it."
Since the first CuproBraze plant debuted some eight years ago, there has been growing awareness and interest in the technology, the Luvata managers said. Luvata believes that CuproBraze will become more relevant amid stricter regulation of diesel engine emissions as engine manufacturers drive for cleaner emissions in the next few years by increasing the pressure and heat in radiators—areas in which copper should hold a clear advantage, Anvin and Ainali said.
As currently designed, aluminum radiators likely would have to use pre-coolers made of stainless steel as a primary means for absorbing heat. However, this would be unnecessary with the CuproBraze technology, they said, adding that technical advantages such as these outweigh the relatively higher cost of using copper.
Luvata estimates that there will be at least 1.5 million CuproBraze heat exchangers in operation by yearend 2008, with the market growing at an annual rate of 15 percent. Most sales will be to original equipment manufacturers (OEMs) for heavy-vehicle applications in Russia, the United States and China. Notable users of the CuproBraze technology include the Kohler Power Systems unit of Kohler Co. in Kohler, Wis.; Siemens Transportation Systems Group, Erlangen, Germany; and Nanning Baling Technology Inc., based in Nanning in China's Guangxi province.
Aluminum companies disagree, arguing that the development of aluminum-brazing technology is far from over and the trend continues to favor aluminum.
Two years ago, Novelis Inc., an Atlanta-based company specializing in aluminum rolling and recycling, launched its Novelis Fusion casting technology, which allows the simultaneous solidification of multiple alloy layers into a single aluminum rolling ingot for aluminum brazing sheet (AMM, July, 2007). This leads to faster production time, cladding uniformity and clean and oxide-free clad, the company said. Like most of its competitors, Novelis previously relied heavily on the cladding of aluminum.
"We have not yet fully realized all the potential benefits this new technology can bring to aluminum brazing sheet, but we will be working with our customers to look at the new capabilities and opportunities it provides to make aluminum brazing sheet even better in the future," a Novelis spokesman said.
An Alcoa Inc. spokesman agreed, noting that the Pittsburgh-based company, which has an aluminum brazing business, doesn't believe the CuproBraze technology will be as popular as aluminum in light or heavy vehicles, given the cost differential between the red metal and aluminum. "What is the cost of aluminum vs copper? That's the first step," he said. "The use of aluminum in those applications is growing just as the overall use of aluminum is expanding. Aluminum is now the second most widely used material in the automotive industry. And people are not big proponents of moving from one material back to another."
Aluminum manufacturers are armed with plenty of evidence to back-up their claims. They're expanding production of aluminum radiators with new investments and roll-outs globally.
The Novelis Fusion technology first entered production in March 2006 at the company's Oswego, N.Y., plant. Earlier this year, the company began production at a 130,000-tonne-per-year Novelis Fusion casthouse at its Sierre, Switzerland, facility and completed the installation of the technology in South Korea in June (AMM, July 1). It also plans to install Novelis Fusion facilities in South America.
In February, Alcoa completed an $83-million, 26-month modernization project at its Alcoa-Kofem operations in Szekesfehervar, Hungary, to expand sheet product offerings and add airfoil castings and Dura-Bright wheel manufacturing at the plant. The core of the investment was the modernization of Alcoa European Mill Products, which involved expanding brazing sheet capability to offer a full range of gauges for markets, including the automotive and heat-exchanger sectors (AMM, Feb. 22).
Whatever these technologies bring to bear, the aluminum vs. copper battle in the heat-transfer segment of the vehicle market appears poised to run red hot on for some time.