Meeting tougher emissions rules often means reducing vehicle weight. Lighter vehicles burn less fuel. So makers are using more aluminum in bodies and in stamped blanks for body closures such as doors, hoods and trunks.
Shiloh Industries Inc. is working with carmakers to validate a process to quickly and consistently make tailored laser-welded aluminum blanks. This process is set for a 2021 vehicle model.
A tailored laser-welded aluminum blank is an aluminum sheet composed of two or three pieces of different gauges, welded edge to edge. Heavier-gauge aluminum is used only in the area requiring added strength, such as a stressed aperture hinge point. By using thinner gauge elsewhere, the cost, count and mass of parts are reduced, compared with using a single sheet of aluminum.
"Tailored laser-welded steel blanks have been used for 20 years or more," says Jim Evangelista, director, R&D at Shiloh. "With a welded blank, it is the only time you're going to ask a weld to be formable. The weld must bend and go through a stamping die. It will go into compression, tension and a certain amount of elongation. With steel, it's not much of a problem. Steel and its welds are not as brittle as aluminum."