By Geoff Giordano
Record attendance and spirited discussion from beginning to end marked the most successful Laser Additive Manufacturing (LAM®) Workshop to date. LIA’s sixth-annual LAM spotlighted a multitude of promising developments in AM research, materials and processes, and previewed progress on the horizon.
Organized into two educational tracks, showcasing powder-bed processes March 12 and powder-fed technology March 13, LAM 2014 brimmed with case studies and highlights from around the world. More than 200 attendees traveled to Houston from more than a dozen countries, drawn not only by a wide-ranging slate of presentations but also the opportunity to talk directly with suppliers of AM solutions.
Attendees got a nuts-and-bolts look at all angles of additive manufacturing performed with machines by Concept Laser, EOS, Phenix, ReaLizer, Renishaw and SLM Solutions with materials like Inconel 625 and 718, titanium TiAl6V4, aluminum AlSi10Mg, stainless steel 316, maraging steel, cobalt chrome and more. A 90 minute panel discussion on powder-bed processes at the end of day one provided an opportunity to quiz 10 experts, who were then available to resume those discussions during the 90-minute exhibitor reception that followed.
“It’s a broad industry, and you can see that everybody in the world is getting into it,” said first-time attendee Nick Vassiliou of Lockheed Martin Aeronautics. “We’re going to start getting into it with our repair business. We’re exploring possibilities and trying to add our knowledge to the industry when we get up and running.”
Among the recurring themes of LAM 2014 were that:
- Key players worldwide are not shy about investing significant time and money toward expanding AM capabilities in the automotive, aerospace, energy, medical and even consumer-goods sectors. A primary quest is for machines with larger build chambers to produce larger parts.
- There remains no “cookbook” for how to engage in additive manufacturing. But novel practices like crowdsourcing design ideas for AM parts, or “printing” parts from customers’ CAD data and shipping the results, demonstrate the evolving business practices AM is fostering.
- Process monitoring and control are vital to ensure that hours of production time aren’t for naught because an error early in the layer-by-layer manufacturing process went undetected.
- Data — either too much or too little — remains a core challenge. On the one hand, generating gigabytes of AM process data can impede the ability to zero in on vital manufacturing parameters. On the other hand, AM users struggle without relevant databases — for instance, those that define the properties of metal powders or ensure repeatable parts and products.
Chaired by Jim Sears of GE’s Global Research Center in Niskayuna, NY, the program for LAM 2014 featured about two dozen speakers who offered a wealth of AM success stories and spurred intense Q&A sessions. International perspectives ranged from repair and manufacturing initiatives in the US and Europe to South America and Australia. Notable global developments included:
Day one keynote speaker Todd Rockstroh noted 1,000 pound weight reductions in external engine components at GE Aviation, but cautioned that in some cases post-production inspection can account for 25 percent of AM costs. He also updated his audience on GE’s Leap engine fuel-nozzle project, which combines 20 parts into one additively manufactured component with five times the working life and 25 percent less weight. GE expects to produce more than 40,000 per year by 2018.
Frederick Claus of California-based Solid Concepts showed how the company additively manufactured a 1911-model handgun in 36 hours, cutting hand-finishing time from 500 hours on the first attempt to 50 with subsequent efforts. Built out of stainless steel 17-4PH with CAD data obtained from the Internet, the weapon has since been used to fire more than 3,500 rounds. However, Claus noted the weapon costs $11,900: “We didn’t do this to make it lighter or cheaper or faster but to prove the technology.
South Africa’s Aerosud, which makes parts for Boeing, Airbus and others, envisions that its Aeroswift project will grow titanium aerospace parts measuring 2 meters by .6 meters by .6 meters, about 6.5 feet by 2 feet by 2 feet.
Australia’s RMIT University opened a $25 million AM precinct in 2011, said the school’s Milan Brandt. The research and teaching facility is geared to supporting local companies transitioning to new manufacturing technologies. “For Australia, we have to look at niche markets; we can’t compete globally with the US or Europe,” Brandt said. Among RMIT’s projects are efforts to repair Australia’s aging US-made aircraft, as well as assessing the laser direct manufacture of small-scale, high-value components for a joint-strike fighter plane. While working on aircraft parts like landing wheels, engine mounts and rudder anti-rotation brackets, RMIT has also partnered with an orthopedic surgeon who performs surgery on cancerous bones and provides just-in-time bone-specific implants.
France’s IREPA LASER, a technical center for industrial laser applications, demonstrated how it spurred technology transfer to a spinoff business after building its CLAD five-axis AM machine with two clad heads (1 mm and 2.2 mm). The CLAD machine, which features Precitec process monitoring with four photodiodes, can achieve deposition rates up to five meters per minute and has been used for repairing knife edges on sealing rings for a Pratt & Whitney turbofan engine. After validating the two-hour-per-part process with metallurgical examination and fluorescent penetration inspection, the technology was transferred to a company called BeAM, and more than 600 parts have repaired with the process.
“The biggest challenge is getting our designers and engineers to think away from conventional, classical machining,” Rockstroh urged. Ingomar Kelbassa of RWTH Aachen University echoed the theme: “We need a new generation of engineers who can think additively.” Kelbassa and others also called attention to a pressing need for AM-specific powders tailored to the demands of contemporary 3D printing.
When asked what the next big application might be besides aerospace, Rockstroh pointed to medicine: “I think they are going to stay ahead as the FDA starts certifying use of those implants in the States. That’s the nice thing about cobalt chrome: it works in our fuel nozzle, and the medical industry keeps the (powder) price relatively low. I don’t see, at least on the metals side, anybody taking over the volume of the medical industry; that’s going to be the next mushroom.”
Applications and Materials
Examples of strides toward a new paradigm in manufacturing for the 21st century were exhibited by, among others, Germany’s Fruth Innovative Technology (FIT), Michigan’s Linear Mold and Engineering and the Quad City Manufacturing Laboratory on the Rock Island Arsenal in Rock Island, IL.
FIT, which is reducing data file sizes by focusing on 2.5D imaging vs. 3D, can deliver custom implants to patients in Europe in three days — for example, for a motorcyclist with a fractured jaw. Presenter David Schafer said targeted handling of production information has helped the company tailor data points to specific AM technologies, cutting file sizes up to 80 percent for its 20 AM machines (13 for plastics and seven for metals).
Meanwhile, Linear, founded in 2003, claims to own the most AM machines of any service provider in North America and runs 11 materials on those machines, according to Bruce Colter, director of new business development. “We just recently cracked the code on how to do production in the metals business,” Colter noted, turning out 20 to 50 parts a month. “That’s kind of the holy grail everybody’s looking to get to. A lot of people make parts; our focus in 2014 and going forward is that we are going to try to take this from being cool technology … and we are going to try to start making money for our clients.”
Using additively produced conformal cooling and heating inserts, Linear improves profitability by reducing cycle times and sometimes eliminating a machine or two for a given process. “We use SLM machines to grow inserts that chase hot spots in mold and tooling applications,” Colter explained. “It’s one of our most requested pieces of business.” The company, with three facilities in Livonia, has been fielding 15 to 20 calls per month about the technology, Colter said. A major success for Linear was using its conformal inserts to improve the molding of a customer’s speaker grills — significantly reducing scrap and dramatically extending production time. With a goal of 350,000 parts per year, the manufacturer had only been able to run 12 shots at a time before parts started warping; Linear extended production time to 11 hours. Meanwhile, Linear has also grown, welded and shipped a Cadillac ELR sun-roof surround in seven days and produced a carbon fiber and titanium drive shaft for Formula-student race cars that was 73 percent lighter than a steel drive shaft.
For those interested in more traditional cladding for repair, case studies were abundant. Kenneth Meinert, of Penn State’s Applied Research Lab and facilities manager at the Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3D), detailed several AM successes: repairing torpedo systems used in repeated training exercises; tripling the life of aircraft carrier trough covers from 10 years to 30; restoring high-value machinery shafts; and cladding steel struts for earth-moving equipment. CIMP-3D Director Richard Martukanitz discussed the facility’s success with repairing high-value Department of Defense components featuring carburized or chromium-plated surfaces.
Nick Wald, general manager of RPM Innovations in Rapid City, SD, detailed how the business — spun off Jan. 1, 2013, to fully separate laser-based operations from mining-focused RPM & Associates — does about 70 percent of its work in aerospace and defense. RPM is pursuing certification for more aerospace production and has built parts about 4 feet tall and 60 to 80 inches long on custom-made equipment running lasers of 1 to 4 kilowatts. However, Wald noted that RPM equipment has travel capability of 5 feet (X axis) by 5 feet (Y) by 7 feet (Z). Meanwhile, of the variety of shafts RPM repairs, Wald noted a power plant atomizer shaft that spins at 8,800 rpm. RPM’s customer was repairing the shafts — which reside in large housings and require days to extract and fix — every seven or eight months. RPM began repairing the shafts about seven years ago with 420 stainless steel; the shafts now last five to six years.
And Jelmer Brugman of Hornet Laser Cladding in the Netherlands said steam turbine casings it fixed onsite for Stork showed no sign of wear two years after repair of severe erosion.
Be it powder-bed or powder-fed processing, residual stress reduction remains a key hurdle, said David Keicher of Sandia National Laboratories in his day two keynote address. Keicher, who invented Laser Engineered Net Shaping (LENS) technology and commercialized it at Optomec, emphasized that powder-fed processes allow a more unique mix of materials and alloys with properties approaching forged/wrought.
LAM 2014 concluded with a trio of presentations on powders, two of which detailed efforts to compile comprehensive performance data for Inconel 625 and 718. Ben Ferrar of LPW Technology in the UK closed the proceedings with an eye-opening look at one supplier’s broad array of available powders — 15 to 20 versions of stainless steel 316L alone, tweaked for different machines and processes.
The Final Word
For first-time and repeat attendees alike, LAM 2014 delivered high-quality content and excellent opportunities to connect with customers.
It was the second time at LAM for Kegan Luick of Caterpillar. “I do remanufacturing applications, and I’m looking to learn what other people are doing in that space,” he said. “We see everything from Inconel to cast iron to titanium. Everything (LAM presenters) talked about so far has been quite good.”
Another returning participant, Kyle Taylor of Wolf Robotics in Fort Collins, CO, saw “a lot more industry here this time. Some of our key customers were coming, so it’s a good idea to come out and make sure we get the same information (and) we’re able to share with them.”
Martin Konkel, head of production for optical components for TRUMPF in Cranbury, NJ, ventured to LAM for the first time “as a potential customer. I’m looking into the options of SLM for manufacturing parts in-house — potentially for heat-sink components. But (my work) is in an early stage; for me it’s something new, technology-wise. My colleague said I should definitely be going to see what’s out there and what the market is doing.”
To view some of the presentations given at LAM 2014, visit www.lia.org/lam.