Aluminum Illuminated for Vehicle Manufacturers
Award-winning friction stir welding process creates lighter car parts at faster rates
Durability and fuel-efficiency rank high on the desired-features list for the auto industry. Aluminum is a strong, lightweight alternative to heavy steel. But joining aluminum, especially sheets of dissimilar thicknesses, at factory speeds has eluded manufacturers for years.
By modifying a technique known as friction stir welding (FSW), PNNL, General Motors, Alcoa, TWB Company LLC, and DOE achieved a tenfold increase in the manufacturing rate. FSW works by using a spinning pin to create friction between two pieces of aluminum to heat, mix, and link the sheets (see video). The key to the improved process, which was funded by the DOE Office Energy Efficiency and Renewable Energy, is the rate at which the pin spins between the aluminum parts. The faster it spins, the stronger the bond. And, consequently, the less time it takes to weld.
The process allows a thicker gauge of aluminum where additional strength is needed, such as near the hinges of a door panel, to be joined to a thinner piece of aluminum. By leveraging PNNL’s method, manufacturers can produce car doors that are 62 percent lighter.
The technique recently received a Federal Laboratory Consortium Far West Regional Award for Outstanding Partnership. By enabling greater use of aluminum in manufacturing, FSW paves the way for more fuel efficient automobiles.
For more information, read the PNNL press release.
PNNL Research Team: Yuri Hovanski and Dave Greenslade