BYU, Toyota develop new welding technique for minivan sliding doors

PROVO — An unlikely partnership is developing the future of minivans: engineers at Brigham Young University and the Japanese vehicle-manufacturing giant Toyota.

BYU partnered with Toyota to develop a more efficient welding method for the sliding doors on the Toyota Sienna.

The current welding technique — resistance spot welding — is designed for steel. The new process, refill friction stir spot welding, is based on the same fundamental principles but tweaked and specialized for aluminum’s unique chemical properties.

The new technique is more relevant than ever as car manufacturers focus on utilizing lighter aluminum parts rather than steel. It uses 40 times less energy, emits fewer emissions and produces welds that are 10 times stronger, a release from BYU said.

BYU manufacturing engineering professor Yuri Hovanski showcased the welding innovation at a conference where the Toyota team saw him and suggested a partnership. Hovanski and graduate student Damon Gale visited Toyota’s manufacturing plant in Indiana to evaluate current production and analyze how to use the new process in aluminum sliding doors.

“Toyota has been using the cleanest technologies they have available to them, but what BYU research is bringing to them is a technology that is a game changer,” Hovanski said. “They partnered with us to be able to essentially do a side-by-side comparison of the same model of car with new welding technology.”

Refill friction stir spot welding joins metal together without melting it, resulting in the metal remaining in a solid state. Pressure is applied, then a pin is inserted into the metal where it is softened by friction.

The two sheets of aluminum are then stirred together with a tool and when the pressure is released, the hole fills in. This creates a strong-quality joint that requires fewer spot welds than typical joints in a vehicle.

“Ultimately, we are looking for ways to do things more efficiently, greener and cleaner,” Hovanski said.

The process cuts down on consumables because no filler material is required and less equipment is used.

“It is super exciting to demonstrate that what we’re working on is helping the environment. Ultimately, as engineers, we believe in trying to be good stewards of the planet,” Hovanski said.

Hovanski and his students published papers with their findings in the SAE International and Journal of Manufacturing and Materials Processing

“Our research concludes that refill friction stir spot welding is a preferable method for joining aluminum body panels and is positioned to become the new standard in automotive manufacturing,” said Gale, who was the first author of the SAE International paper.