More stringent fuel economy and emissions standards are driving automotive suppliers to build parts that are thinner, lighter, stronger, and—if they want to stay competitive—at the lowest price possible. One automotive parts supplier, Dana Canada Corporation, is prepared to meet the challenge with a technology that transforms aluminum alloy sheet into complex-shaped parts that are otherwise too difficult and costly to manufacture using traditional stamping processes.

"Aluminum alloys are attractive engineering materials because of their light weight and corrosion resistance, but they do have limitations for producing thin-gauged complex shapes," says Dr. Sooky Winkler, Manager, Materials and Joining Technology at Dana Canada's Advanced Engineering and R&D Centre in Oakville.

The Natural Sciences and Engineering Research Council of Canada (NSERC) has been supporting warm forming research between Dana and the University of Waterloo since 2007 to address this challenge. Now, Automotive Partnership Canada is contributing $1.9 million towards the $3.2 million project to help Dana and the University of Waterloo to move the process from the lab to the plant floor.

"At the end of three years we will have the computer modelling and process worked out to implement this technology in full production. I'm not aware of any university in North America doing such work at this scale," says Dr. Michael Worswick, the lead researcher on the project at the University of Waterloo.

Warm forming has already been demonstrated to work on at a laboratory bench scale. In this phase, a pilot manufacturing line will be installed at the University of Waterloo to demonstrate its feasibility under production-simulated conditions. Additional mechanical testing and residual stress analysis will be done at the CANMET Materials lab in Hamilton, which is also home to a unique pilot-scale metal forming laboratory.

"We're developing the warm forming process for improved material formability and higher production yields at low cost," says Winkler. "It also expands our product design flexibility, enabling us to manufacture new, high performance products that are cost effective, to further grow our business in the global automotive market."

Dana's core business is developing and manufacturing thermal management systems for vehicles, including heat exchangers to cool the engine and powertrain, as well as battery cooling systems for electric and hybrid electric vehicles. Until now, however, it was not technically feasible or cost effective to use warm forming to make the geometrically complex and thin walled parts found in thermal management systems for high efficiency combustion and battery powered vehicles.

Take the core plates that comprise the fluid channels and manifolds in a typical heat exchanger, for example. There are up to 30 of these plates on every heat exchanger and each one needs to be shaped and brazed as an assembly with other components and onto one another. Heating the material increases its formability and reduces spring back, improving the dimensional control and shape of the final part.

But heating the aluminum sheets to the desired temperatures takes time, which slows production. Worswick's group is developing techniques to rapidly heat the aluminum so that non-isothermal warm forming be done at mass production speeds. Refining and proving out these methods will be a key element of this research project.

"Imaging pushing a shape into a die with a punch," explains Worswick. "What we've shown is if you heat the die but keep the punch cold you get an even bigger formability gain. A key goal in this project is to work with Dana's Advanced Engineering people to accelerate the development of this manufacturing process so Dana can commercialize this technology. Success will also open up a lot of opportunities beyond heat exchangers."

Those additional opportunities include automotive body panels with more complex geometrical shapes and new materials with higher strength and lighter weight.

"This project is directly linked to the development and manufacture of advanced battery cooling systems for electric vehicles," adds Winkler, one of Worswick's former post-doctoral students. "If we're successful, it will have broad product application and wide impact on Dana's competitive advantage in today's world economy."