By Geoff Giordano
If additive manufacturing is becoming the next big thing as some experts and companies believe, the Laser Institute of America’s fifth-annual Laser Additive Manufacturing (LAM®) Workshop helped pave the way by providing more information on the road map leading to an AM revolution.
Situated in its largest venue yet, LAM 2013 featured more than 20 presentations covering everything from nuts-and-bolts cladding and repair to sky’s-the-limit projections of the growing impact of additive processes. While US government initiatives trumpet innovation in photonics and manufacturing, LIA continues to lead the charge in advocating greater profitability through advanced laser-based AM applications.
More than a third of LAM 2013’s nearly 200 attendees came from outside the US; most were primarily focused on metals, a few on plastics. Sessions remained packed throughout the two days of the workshop as the program ran the gamut from the latest AM methods in the energy, aerospace and defense industries, to more esoteric usages in health care and customizable personal products.
As President Barack Obama praised the nation’s first manufacturing innovation institute in his State of the Union address on Feb. 12, LAM 2013 opened with a keynote by renowned AM consultant Terry Wohlers of Fort Collins, CO. Speaking at his second consecutive LAM, Wohlers noted the significant uptick in corporate inquiries into AM technologies. Large companies like Wal-Mart, Staples and Germany’s SAP are among the firms that have approached Wohlers seeking advice on how to get into the 3D printing/AM game.
By the time LAM General Chair Paul Denney of Lincoln Electric wrapped up the proceedings with a highly detailed assessment of the bottom-line repair-or-replace decisions confronting various industries, attendees had been treated to a workshop rich in detail, organized in eight segments.
LAM 2013 showcased new methods, new workflows, new facilities and new possibilities in sessions spotlighting process chains, digital manufacturing, surface tailoring, powders and an overview of the National Additive Manufacturing Innovation Institute (NAMII) — the pilot facility under the National Network for Manufacturing Innovation.
In addition to NAMII in Youngstown, OH, LAM educated attendees about Penn State’s Center for Innovative Materials Processing via Direct Digital Deposition. CIMP-3D, a major metals lab for NAMII, serves as an “honest broker” of additive-enabling technologies, explained Richard Martukanitz. It now features a new 8,000 square foot Additive Manufacturing Demonstration Facility that aggregates the university’s AM and prototyping technology under one roof.
Similarly, Ryan Dehoff of the Oak Ridge National Laboratory explained ORNL efforts to facilitate AM research by allowing partners to use its resources. In the past 14 months, ORNL’s manufacturing demonstration facility has entertained more than 1,000 visitors, Dehoff said. In partnership with Carpenter Powder Products, ORNL has produced iron-based nanocomposite powders in industrial quantities — more than 12 tons to date — to clad ship decks for skid resistance and the inside of nuclear fuel containers.
ORNL is “helping industry understand additive manufacturing a little bit better,” Dehoff explained. “With all the emphasis and hype out there, it’s a little confusing. If you just get the sales pitch with additive manufacturing, you don’t get a true picture of additive manufacturing. We try and help companies work through those challenges and give them direction and work with them to solve their problems.”
Meanwhile, Christian Hinke, managing director of Fraunhofer ILT’s just-launched photonic production research campus in Aachen, Germany says the new facility will explore femto and nano photonic production during its 15-year funding window.
“We have a seen a huge increase in process efficiency for laser-based manufacturing technologies,” asserted Hinke. This enables innovative business models and extraordinary levels of customization, such as with the printing of consumer-uploaded designs for iPhone covers. In a first, Nokia has released a 3D development kit to its customers so they can print custom covers for their Lumia 820 phones. EOS has even released a jewelry-specific laser-sintering machine, he said.
These are just a few of the many indicators of an active year for AM. “There has never been so much excitement in this industry,” Wohlers enthused. “It is absolutely off the charts, through the roof. Interest is at an all-time high.”
A vital part of any use of AM is a well-designed process chain. Workshop Co-Chair Ingomar Kelbassa presided over a three-presentation segment emphasizing the all-important computer-assisted framework that helps realize the “complexity for free and individualization for free” at the core of the most futuristic AM.
A vital part of any use of AM is a well-designed process chain. Kristian Arntz of Fraunhofer IPT urged a holistic approach to creating specialized CAM modules that facilitate everything from repair of turbine components to laser machining of complex geometries to improving part life up to 80 percent. Considerations like tool-path planning and collision avoidance during processing are critical. “Laser alloying and wire deposition welding are examples where complex process conditions have to be brought on free-formed parts,” he explained.
In a more academic approach, Gerald Bruck of Siemens Power Generation shared results of a study of the effect of angle of beam incidence on ytterbium fiber laser cladding of alloy 625. By using a six-space “shish kebob” allowing assessment of beam-substrate interaction at 15, 30, 45, 60, 75 and 90 degrees, he and his fellow researchers simulated instances, particularly in the energy industry, where components are generally flat or horizontal but with a bevel introduced in the same feature. They found that, with decreasing angle of beam incidence and constant power density, about 80 percent of melt width can be maintained without powder feeding. About 25 percent of the powder is scattered, and dilution rapidly increases, while capture efficiency decreases from about 60 percent to 35 percent. Furthermore, with angle of beam incidence, the bead profile leans and slumps downhill until gravitational effects are overcome by reduced deposit and surface tension.
Ted Reutzel of the Applied Research Lab at Penn State University updated attendees on successes and lessons learned during the in-situ laser cladding repair of Naval vertical launch system tubes. Using a portable laser-safe enclosure to enable restoration of the nickel-based substrate, the system is an alternative to less-durable brush electroplating.
Another Penn State effort involves repair of seawater valves in various parts of ships at multiple orientations and made from different materials. The laser-driven system must be deployable within the ship. Researchers developed a wire-based laser head that clads at 45 degrees and tested it against gas tungsten arc welding. As a result, the design of that head has been transferred royalty-free to five small US businesses, Reutzel said.
In an even bolder project, Ryan Bucurel of Westinghouse detailed a dry underwater laser beam welding process that uses constantly flowing inert gas to remove water from the weld area. In single-pass and multiple-pass tests, negligible amounts of crack-producing hydrogen entered the weld. The process is intended for repairing spent-fuel pool liners or cracked Stellite 6 radial guide clevises in nuclear reactor vessels.
Speaking of processing hard-to-reach places, Aravind Jonnalagadda of Fraunhofer CCL announced the imminent release of the third version of its interior cladding device, which will deliver up to 3 kilowatts of laser power out to 39.4 inches of reach in a minimum tube diameter of 3 inches.
THE FUTURE OF AM
Low-cost systems like personal 3D printers and high-end parts production will continue to drive the adoption of AM, Wohlers asserted. He and Professor Bill O’Neill of the University of Cambridge stressed that relatively inexpensive digital systems can foster children’s creativity and could become a fixture in many homes.
On the high-value end, aviation and aerospace are poised to continue making great strides in AM. Boeing is creating structural parts on a satellite using Ti-6Al-4V on a powder-bed fusion system. Airbus parent EADS has 40 employees studying, among other things, how to consolidate many parts into one and how to reduce part weight with lattice structures and topology optimization. Honeywell Aerospace has been flying an Inconel 718 part for certification for almost three years, and GE Aviation “has been very vocal with their interest in this area,” particularly during development of the LEAP engine. GE has converted a 20-part fuel-injection system produced with brazing into a single CAD-driven component printed layer by layer that is slated to gradually reach full production by 2016.
In terms of national developments, the US is investing $70 million in NAMII, the first of 15 manufacturing innovation institutes to cost about $1 billion. Martukanitz noted that within a year of its inception, NAMII is set to award about $8 million in project funds for research at Technology Readiness Levels 4 to 7 and will issue a call for a second project in June.
Meanwhile, China has announced an RMB 1.5 billion multiyear investment in AM, Wohlers said, and Australia has completed three projects focused on AM. In late November, Germany’s, SLM Solutions unveiled a 1 million euro, 2.8 kilowatt metal system using multiple lasers. At the same time, another German firm, Concept Laser, showed a 1 kilowatt variable-focus laser costing 1.4 million euros developed in a partnership with Fraunhofer ILT. Daimler, the partnership’s initial customer, will use it to build automobile parts, including full-scale engine blocks, he said.
“Aerospace and medical will drive additive manufacturing over the next three to five years,” Wohlers concluded. “Whenever the volumes are relatively low and the part value is high, and the parts are relatively small, you can begin to make a business case to at least consider using this technology for manufacturing.” He is seeing “waves of certifications” that promise a bright future for AM.
“We have a heavy push from aerospace,” agreed ORNL’s Dehoff. “We also see a lot of defense agencies. Most people we interact with have a pretty good business case for additive somewhere in their product line. It may not be making product — it may be making a tool or die for their product line. But they say, ‘Oh, I didn’t know I could do that.’ That’s one of the things we’re really trying to do: Get people to understand what you can and can’t do — what are the limitations of the different technologies.”
But while enthusiasm builds for 3D printing, selective laser melting, laser metal deposition and sintering, attendees were encouraged to continue embracing bread-and-butter approaches.
“Before we believe this technology is a panacea, we always have to keep in mind that there is a direct inverse relationship between the deposition rates that can be achieved vs. the feature qualities,” Martukanitz said. “I believe the ability to alter these curves either through build rates, end definition or feature quality is the next generation of emphasis.” In fact, “when you look at what we’re accomplishing (at CIMP-3D), it’s joining technology, and we believe that we can learn a lot from the welding and joining community.”
Workshop Co-Chair Jim Sears of GE Global Research Center concurred, noting that “as you find where (AM) fits, it’s not a replacement technology; it’s an additional technology that takes you to a new place. That’s where design innovation will be a necessary asset. (AM is) just another thing in the box; you still have to post-process (a part), you have to be able to inspect it, you’ve got to be able to finish it. (AM) does give you some enabling capabilities, but you can’t leave everything else behind.”
ECONOMICS OF CLADDING
While opportunities in advanced AM continue to bubble up, business in the 2D realm continues to be a benefit for the laser industry. “There are about as many different types of wear as there are different types of cancer,” said Denney, who noted that Lincoln Electric took on laser technology within about the past two years and purchased two laser systems integrators within the past year.
As Denney explained, the annual cost of friction and wear is 6 percent of global Gross Domestic Product: $4.14 trillion out of $69 trillion. Meanwhile, corrosion costs about 3.1 percent of the GDP for the US — about $1 trillion in 2012. Earlier, ORNL’s Dehoff noted that the cost of steel wear to the US economy is estimated at $65 billion a year.
In addition to the costs of wear and tear are costs in labor, he stresses: a $5,000 part in a ship, for instance, might cost $50,000 to remove and repair.
Efforts continue to get laser processes closer to arc cladding deposition rates. For instance, Denney noted, Fraunhofer IWS has achieved rates up to 30 pounds an hour by pairing an 8 kilowatt laser with 12 kilowatts of induction heating in the area of the process. Lincoln Electric has been able to use resistance heating of the wire to decrease the laser power required to deposit clad material, he said. That means for the same laser power, the deposition rate is greater than what is possible with powder alone.
The ability to maximize the heating of the wire without causing an arc is possible by using a solid-state power supply that monitors and stops an arc before it starts. “This allows us to double or triple deposition rates,” Denney explained. For nickel alloys, “we can put down one layer for about $70 a square foot vs. $280 for arc.” Even if the hot wire process needed to deposit two layers to equal the performance of the arc clads, the hot wire laser process should still be about half the operating cost. At 5,000 square feet a year, that equates to $700,000 to $1 million in savings, including labor and utility costs. That is about the cost of a laser hot wire cladding system, he noted.
THE FINAL WORD
All in all, “I thought the workshop and content were good,” said Wayne Penn, president of platinum sponsor Alabama Laser. Sears concurred. “I was happy with the presentations,” he concluded. While LAM 2013 devoted ample time to US AM initiatives, Sears emphasized that “what’s happened in industry is probably more interesting, with acquisitions and forward movement of technology.”
Dehoff, a first-time LAM attendee who fielded many inquiries after his presentation, said: “I’m impressed with the international presence. I like the cladding aspect and the other aspects of lasers that aren’t necessarily there in the additive community.”
To stay in touch with the latest trends and cutting-edge applications in AM, plan to attend LAM 2014; visit www.lia.org/lam for updates on the location, dates and program. In the meantime, select presentations from LAM 2013 will be available online at www.lia.org/laseru.