The auto industry’s been one of the biggest topics of this blog over the past few months, but we haven’t gone too much into the specifics — it’s just known that the auto industry has seen aluminum as part of its path to lighter, more fuel-efficient vehicles.

GM, however, offered more details about how it’s enabling greater use of aluminum in its manufacturing process. In particular, it has to do with the way the material is welded, as traditionally aluminum is difficult to weld. From GM’s press release:

“GM’s new resistance spot welding process uses a patented multi-ring domed electrode that does what smooth electrodes are unreliable at doing – welding aluminum to aluminum. By using this process GM expects to eliminate nearly two pounds of rivets from aluminum body parts such as hoods, liftgates and doors.

Spot welding uses two opposing electrode pincers to compress and fuse pieces of metal together, using an electrical current to create intense heat to form a weld. The process is inexpensive, fast and reliable, but until now, not robust for use on aluminum in today’s manufacturing environment. GM’s new welding technique works on sheet, extruded and cast aluminum because GM’s proprietary multi-ring domed electrode head disrupts the oxide on aluminum’s surface to enable a stronger weld.”

This process has already been used on the hood of the Cadillac CTS-V and the liftgate of the Chevy Tahoe and GMC Yukon (hybrid editions). We’ll see more of this in 2013, thus promoting greater fuel efficiency and moving towards a better experience from manufacturers to motorists.