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No Mass Appeal—Yet Additive manufacturing slowly gains acceptance as mass-production option 30 | MAY/JUNE 2012 | MICROmanufacturing Things look good for additive manufacturing. AM technologies have never offered better performance, and demand for them has never been greater. Large companies and the U.S. government are interested. So is the mainstream media, which has been covering AM a lot lately. One notable example is the inclusion of AM in a special report in The Economist entitled “The third industrial revolution.” Unlike subtractive techniques, which remove material from a workpiece, additivemanufacturing processes join materials to make objects. Guided by 3-D CAD data, AM systems usually stack thin layers of plastic, metal or composites, making the processes suitable for producing almost any shape or feature, including those difficult, or impossible, to make via conventional manufacturing processes. In many cases, AM can fabricate complex and precise features without secondary operations, which saves time and money, noted Bill Booth, vice president of market development for Microfabrica Inc., an AM firm in Van Nuys, Calif. By William Leventon, Contributing Editor FineLine Prototyping made these 316L stainless steel jaws via selective laser melting. FineLine Prototyping AM processing also consumes less material than subtractive methods, which proves especially advantageous when producing parts from high-cost materials. And, AM can fabricate monolithic parts that incorporate moving components. In 2011, the compound annual growth rate for additive manufacturing was nearly 30 percent, according to a recent report by Wohlers Associates, a Fort Collins, Colo., consulting firm that follows AM trends. The firm sees the industry’s strong growth continuing during the next several years, with global sales of AM products and services surpassing $6.5 billion by 2019. Despite the rosy picture, a longstanding question remains: Is AM ready to move beyond its rapid-prototyping (RP) roots and take a place beside traditional mass-production technologies? Holding AM back At present, AM is still widely considered to be more of a one-off, rapid-prototyping process than a mass-manufacturing option. One reason
is the relatively high cost of making AM parts. “Even to make small parts, you’re talking about a sizable investment for the machine and the know-how,” said Terry Wohlers, president of Wohlers Associates. In almost every case, high-volume AM production is more expensive than the alternatives because it requires more time on more-expensive equipment, according to Rob Connelly, president of FineLine Prototyping Inc., Raleigh, N.C., which uses AM processes to make both prototypes and end-use parts. “An item on the ‘to-do’ list of all manufacturers of [AM] technologies is to create pathways to get their processes to work on a more cost-effective basis,” he said. Another AM disadvantage is manufacturing speed. With most AM systems, a beam—laser or electron—defines a 2-D layer of the part’s perimeter and features in a liquid or powder. Defining one thin layer at a time, a 3-D object is built from the bottom up. That can be a timeconsuming process. AM is a “whole lot faster than making a mold and then making 50 parts,” said Wohlers. “But if you’re making 500,000 parts, molding can be faster, even if you include the time it takes to make the mold.” On the other hand, he added, the smaller the part, the faster it can be In many cases, AM can fabricate complex and precise features without secondary operations, which saves time and money. built using AM. That makes AM more competitive in the micro realm. On the downside, surface finish can be problematic at the microscale. Selective laser sintering, for example, has made major strides in recent years, but Connelly pointed out that parts made using the process have a rough texture. “And when you scale down to a size of 8mm or less, that texture can really take over, preventing you from getting the tiny features and tight tolerances that are required.” Sometimes, though, microscopic surface roughness is an advantage, noted Arthur Chait, president of EoPlex Technologies Inc., an AM firm in Redwood City, Calif. It can, for example, facilitate bonding. “Think of the instructions on a bottle of glue, where it says to rough up the surface before you glue it,” Chait said. For that reason, some microroughness is advantageous for the semiconductor packaging products made using EoPlex’s AM process. Still, any product that requires a very smooth surface is probably not a good candidate for AM, unless it’s only the top and bottom layers that need to be very smooth. AM is capable of making these layers smoother, but they still are not likely to be as smooth as machined or molded parts, Chait said, adding that sintering processes like that employed by EoPlex can bring surface roughness down to 0.5µin. to 2µin. Ra. As for the other sides of objects produced using AM, the problem is the micromanufacturing.com | 31
Page 2 and 3: Someone challenged us to a little g
Page 4 and 5: Features May/June 2012 • Volume 5
Page 6 and 7: FRONTpage Don Nelson Publisher Hybr
Page 8 and 9: TECHnews Applications abound for na
Page 10 and 11: SubScribe now! Don’t miss an issu
Page 12 and 13: TECHnews these technologies creates
Page 14 and 15: TECHnews UM is suitable for workpie
Page 16 and 17: Micro End Mills l .002" to .125" Cu
Page 18 and 19: MEASUREMENT matters Video measureme
Page 20 and 21: DOWNsizing Silicon that goes pitter
Page 22 and 23: SWISSmachining By Kip Hanson, Contr
Page 24 and 25: SWISSmachining high-polish finishes
Page 26 and 27: More than Meets the Eye Eyewear tha
Page 28 and 29: More than Meets the Eye continued m
Page 30 and 31: More than Meets the Eye continued a
Page 34 and 35: End Mill Solutions Miniature Millin
Page 36 and 37: Power Scavengers The market for ene
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Page 40 and 41: Prickly Situation Makers of microne
Page 42 and 43: Prickly Situation continued in-vivo
Page 44 and 45: PRODUCTS/services CARBIDE DEBURRING
Page 46 and 47: PRODUCTS/services INDUCTION COILS.
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Page 50 and 51: LASTword One of the challenges of m
Page 52: Miniature end mills that have mater

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