LOS ANGELES—Engineers at the University of California, Los Angeles (UCLA) have developed a way to weld an aluminum alloy that was difficult to join in the past. Super-strong but lightweight, AA 7075 may now be more widely used in automobiles and other products.
The material originally developed in the 1940s has long held promise for use in manufacturing, except for one key obstacle. Although it’s nearly as strong as steel and just one-third the weight, it is almost impossible to weld. That’s because when the alloy is heated during welding, its molecular structure creates an uneven flow of its constituent elements—aluminum, zinc, magnesium and copper—which results in cracks along the weld.