A two-day conference sponsored by the American Welding Society in mid-August proved that welding continues to be a dynamic process, and that its reach into new areas will continue to grow.

The AWS conference, “The Explosion of New Welding Processes,” addressed applications for which welding will be used in the future. It had 14 speakers who talked about advancing welding technology beyond the standard processes, and developing new processes to take metal joining into new areas.

Stir welding – both friction stir welding and laser stir welding for aluminum alloys – could roughly be considered the star of the conference, with four talks delivered on those processes.

It should be no surprise, but friction stir welding – a process that combines a hybrid type of machine tool with welding technology – is being used extensively in aerospace applications. It is a primary joining process that the Boeing Company is using for its new 787 Dreamliner, the mid-sized, wide-bodied jet aircraft that is to go into service in May 2008. Friction stir welding is one of the processes that Boeing is using to reduce the weight of the 787, and to make it a stronger aircraft with improved fuel efficiency.

Friction stir welding also is being used by Boeing to reduce the manufacturing time for the Delta IV booster rocket that is designed to carry a payload to Mars. With friction stir welding powered by machines provided by ESAB, Boeing has been able to reduce the manufacturing time for the boosters from 23 days to 4 days, according to Tim Zappia of MTS Systems Corp.

The applications for friction stir welding are increasing, as engineers become more comfortable with and more knowledgeable about the process. Another talk at the conference addressed the uses of friction stir welding for stainless steels, steel with high nickel content and other high temperature alloys. Speakers also talked about:

• Magnetic pulse welding, a process that has been considered costly. However, the speaker said that advances into the technology to develop the coils used to generate the magnetic pulse have reduced the cost of this process from $1 per weld to 4-cents per weld, making it an attractive alternative for the right applications.
• Two new approaches to gas-metal arc welding (GMAW), both of which used dual electrodes in part to supply additional melt metal. The first, developed at the University of Kentucky, reduces the heat in-put to the base metal via the double electrode, and increases productivity. The system operates with a standard power supply and a standard laptop computer. The second approach feeds two wires through one torch to increase productivity. David Yapp, a professor at Cranfield University, where this approach is being developed, said it can weld a 48-in pipe, such as that used in the Alaska pipeline, in 1 min., rather than the standard 4 min. time it now takes.
• Fiber laser welding that can use a single laser source to make multiple welds at distances to 656 ft. (200 meters). The process relies on fiber optics to split and carry laser light to the place at which the weld is to be completed.

As if those developments were not amazing enough, Dr. Timothy Weihs, chief technical officer for Reactive NanoTechnologies (www.mtfoil.com), demonstrated his company’s recent development – brazing metals at room temperature.

The process uses nano technology to produce a chemically reactive foil that, when activated, produces a chemical reaction similar to a thermite reaction. The foil flashes and reaches temperatures of 1,500 deg. F. to 2,000 deg. F. and, because it is so thin, its temperature affects only the thinnest layer of the metal that it is in contact with.

In what could’ve been a part of a magic act, Weihs stood at the front of the room, flourished two pieces of metal, then held them in his hands while he brazed them. Admittedly, the pieces of metal were small, but he passed them around the room so that everyone could see they were very well joined together.

Each of these technologies deserves to be watched, and should engender thinking about how they can be put into profitable use.