Lately, material scientists have created ever-stronger metals by involving intricate microstructures, but the welding technique every so often ruin their properties and microstructure.
Vaporized Foil Actuator (VFA) welding
Ohio-Engineers at The Ohio State University have developed new technique to weld the materials which were previously un-weldable. This technically advanced method consumes 80 percent less energy than a typical welding technique, yet generates bonds that are 50 percent stronger.
A common technique used to weld metals, by passing a high electrical current through pieces of metal so that the natural electrical resistance generates heat that melts them together and forms a weld- is known as resistance spot welding. But the downsides of this technique is that it generates high currents and consumes huge amount of energy and it also weakens the melted portion around the weld.
To deal with these problems, Glenn Daehn and his team have been collecting more than half a dozen patents on a method called Vaporized Foil Actuator(VFA) welding. In this technique a high-voltage capacitor bank generates a short electrical pulse, which is passed through a piece of thin aluminum foil. The foil vaporizes within microseconds, and a burst of hot gas pushes both the pieces of metal together at speed of thousands of miles per hour.
The metals don’t melt, so there’s no weakening of metal; instead the impact directly makes a bond of atoms of one metal to atoms of the other metal. At a microscopic level- the bond is visible as delicate curlicues in spots with hints of both material outspread and wrap around each other.
The technique uses a lesser amount of energy because the electrical pulse is so short, and because the energy essential to vaporize the foil is less than what would be used to melt the metal parts. Thus far, the team have used this method to join different combinations of copper, magnesium, aluminum, nickel, iron, and titanium.
The technique is sufficiently powerful to shape metal parts as well as it welds them together, saving a step for manufacturers. Daehn and his team now want to accompany manufacturers to further develop the technology, which will be licensed through Ohio State’s Technology Commercialization Office.
This method can bring a revolution in the industry by providing solutions to various problems.The method will gain interest of engineers, who are very keen to use the up-to-the-minute high-strength materials – which will let them to cut off weight from automobiles or whatever else they’re designing.
