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Additive manufacturing increases its presence at IMTS

This replica of a Willys Jeep was printed on a large additive manufacturing bed. It was on display at the Oak Ridge National Laboratory booth at IMTS.

Ten years ago a metal fabricator could visit the biannual International Manufacturing Technology Show (IMTS) in Chicago and have the opportunity to view some of the latest press brake and laser cutting technologies. It wasn’t FABTECH®, but the tradeshow still had a decent collection of machine tool vendors that served the fabricating market.

A metal fabricator attending the 2016 IMTS, held Sept. 12-17, at Chicago’s McCormick Place, might wonder why he was there. Only one traditional CNC press brake could be found in the Fabricating & Lasers section of the facility’s North Hall, when at least three or four could have been found in past shows. IMTS has traditionally been a machining technology show, and that was more evident than ever this year.

IMTS isn’t just about chipping, however. Show organizers have done well to embrace segments such as industrial automation and surface finishing, which has helped to boost interest in the event. More than 110,000 attendees were expected to walk the aisles and visit with the more than 2,000 exhibitors.

While fabricating technology may not be as plentiful as it once was on the IMTS show floor, additive manufacturing (AM) technology is emerging to take its place. In fact, two familiar names to fabricators—TRUMPF and Lincoln Electric—shared some their own technological advancements with show-goers.

TRUMPF has actually been involved with AM for more than 13 years. Frank Geyer, product manager, additive manufacturing and laser systems, said TRUMPF actually had an additive machine called the TrumaForm in the early 2000s, but the company decided against further commercialization because there appeared to be no market for it. Geyer said he has recently been to conferences and plant visits where he witnessed both a large shop with more than 15 AM machines and a small shop with just two AM machines producing parts 24 hours per day, and he’s convinced the market has finally arrived for additive manufacturing.

“They are doing production parts, not just prototypes,” he said of the manufacturing shops he has visited. “They have a business case. That means that there is a market.”

TRUMPF’s newest AM machine is very different from the TrumaForm. The TruPrint 1000 has a 200-W fiber laser, not a CO2 laser, and it works much more quickly than the older technology thanks to a patented coating system that optimizes the metal powder application and subsequent laser exposure that leads to solidification. With the ability to take CAD drawings and translate them into machine code, a manufacturer can turn out metal parts with complex geometric shapes. Because the metal powder is layered and solidified from the ground up, part features can be created that could never be replicated in a machining center. These parts can be made of stainless steel, mild steel, aluminum, titanium, and even precious metals.

Because of the compactness of the 3-D printer, it processes small parts, but that doesn’t mean that AM has to be limited to small confines. Lincoln Electric, in cooperation with Wolf Robotics, which it acquired in early 2015, unveiled its entry into the AM arena with a robotic metal additive system.

This Robotic Big Area Additive Manufacturing equipment is not too unlike traditional cladding efforts, said Jason Flamm, Wolf Robotics’ product manager. Instead of simply adding material from a melted wire, however, this new system relies on a laser powder and a laser hot-wire process to create the layers of steel and titanium that turn into aerospace parts. Company officials think this is a perfect alternative to traditional steel castings used to create complex parts.

Flamm said this robotic approach is much more cost-effective because it uses technology that most metal fabricators are familiar with. It’s a simple matter of “CAD to toolpath,” he said, referring to the automated programming of the robot.

“This has the advantage of well-established and tried-and-true GMAW equipment and robotic equipment being powered with easy-to-use software. This is what makes this cell attractive,” Flamm said.

Familiar technology is also present in an ultrasonic additive manufacturing process from Fabrisonic, a for-profit affiliate of EWI, formerly the Edison Welding Institute. In this case, the AM equipment is basically a milling center that has been retrofitted with welding technology.

This approach to additive manufacturing doesn’t involve powder, however. It uses metal tape.

Here’s how it works: High-frequency, typically 20,000 hertz, ultrasonic vibrations are applied to metal foil materials, which are held together under pressure. As the vibrations are locally applied to the tape, the metal material is joined to the base material under it. Successive layers are welded together to build up the part.

Mark Norfolk, Fabrisonic’s president, said this approach to AM has proved to be particularly useful for joining dissimilar metals, such as copper and aluminum. If excessive heat were applied to these materials in an attempt to join them, a brittle substrate would be the result. The ultrasonic welding method of joining avoids the extreme heat and allows a strong bond to be created between the two materials.

The lack of heat also allows for sensors to be embedded into solid metal parts, Norfolk added. This is especially attractive to aerospace manufacturers that build parts that are constantly inspected over their lifespan.

Additive manufacturing isn’t exactly metal fabricating, but perhaps it’s not as foreign to metal fabricators as many might believe.