PLANT

Automakers are lightening up


May 27, 2010
by Noelle Stapinsky, Features Editor

Steel makers are focused on developing a third generation of advanced high-strength steel.

Photo: iStockphoto

As automakers focus more on light-weighting vehicles, there has been some debate over which is better: alloys such as aluminum and magnesium or advanced high-strength steels. Some firms are even dabbling in composite plastic materials in anticipation of the electric car.

Aluminum and magnesium are used for component parts, but automotive manufacturers argue the cost of these materials is high and unpredictable. Making the switch from conventional steel products is far too pricey.

“Aluminum is becoming an important component part for engine blocks and body parts,” says Steve Treiber, engineering professor at McMaster University in Hamilton. “And the only time you’re going to find magnesium is in wheels and engine components. But both are strictly for high-end applications. You’re not going to see them in a Honda Civic unless some kid decided to tune his car.”

Indeed, aluminum, magnesium and titanium are used mainly in the high-performance racecars that reach 12,000 rpm, or in luxury niche vehicles. And some automakers such as Aston Martin are going even more high-end. It unveiled its One-77 two-door sports coupe featuring a complete carbon fibre chassis at the 2009 Geneva Motor show. Layers of the carbon fibre are applied by hand and put into an autoclave multiple times for heating and forming. Sleek exterior body panels are made of handcrafted aluminum.

“It’s a $2-million car,” laughs Treiber, “so it’s a little out of most people’s price range.”

Although the tensile strength and crashability of these alternatives are comparable to steel, they probably won’t make it into mainstream production unless the cost comes down.

Eugene Ng, a mechanical engineer at McMaster University, partnered with Treiber to create the Manufacturing Technology Network to promote innovation in manufacturing. He says there’s not a lot of magnesium and aluminum development being done in Canada because GM, Ford and Chrysler dictate which materials parts manufacturers must use, and next-generation high-strength steel will continue to have a firm grip on the market.

Gunter Riegel, one of the owners of Markham, Ont.-based Woodbine Tool and Die Manufacturing Ltd., a tier two tool and die manufacturer that produces stampings and welded assemblies for the automotive industry, admits he looked into working with magnesium but passed on it, partly because of cost fluctuation.