Weld method creates strong bonds in high-tech alloys

Technique consumes 80% less energy than a common welding method to create bonds that are up to 50% stronger

US researchers have developed a technique that welds light-weight, high-tech alloys once considered unweldable. 

The technique is claimed to consume 80% less energy than a common welding method to create bonds that are up to 50% stronger. The research comes at a time when the automotive industry is increasingly developing cars that combine traditional heavy steel parts with lighter, alternative metals to reduce vehicle weight.

The Vaporised Foil Actuator technique developed at Ohio State University uses a high-voltage capacitor bank to create a very short electrical pulse inside a thin piece of aluminium foil. The foil vaporises, creating a burst of hot gas that pushes the two pieces of metal together at speeds approaching thousands of miles per hour.

The impact seamlessly bonds the metals at the atomic level without melting them. So far, the engineers have bonded different combinations of copper, aluminium, magnesium, iron, nickel and titanium and created strong bonds between commercial steel and aluminium alloys – traditionally one of the most problematic welds. The high-strength steel and aluminium join together with weld regions that are stronger than the base metals.

Glenn Daehn, professor of materials science and engineering at the university, said: “With our method, materials are shaped and bonded together at the same time, and they actually get stronger.”