Page 20 - 3D Metal Printing Winter 2018

3D Everything Under One Roof
Sintavia primarily supplies the aerospace market—75 percent of its business—via runs typically ranging from 10 to 100 parts.
lower costs, shorter manufacturing times and dramatic design improvements,” Neff stated in announcing the approval.
Though incorporated in 2012 by Neff, Sintavia really got its start in late-2014, and now boasts 24 employees in 10,000 sq. ft. of space, filled with production, fin- ishing and testing equipment. Neff brought Hedges over from CTS Engines, a Fort Lauderdale-based company specializing in maintenance and repair of jet engines, and both have a wealth of experience in aerospace. Intimately familiar with the industry, Neff and Hedges knew that AM success in aerospace depended upon process and material validation, and made that Sintavia’s cornerstone.
“We look at AM as the core process, but you need to have other disciplines to do it well,” explains Hedges. “You need to be good at design, post-processing, heat- treatment, machining, finishing and more. All of that is pivotal to the AM process.”
Proof Is in the Powder
“Metallurgy differentiates us,” Hedges says, touting Sintavia’s full metallurgical laboratory. “This is the first area that we focused on—the characterization process
of metal AM—and we were setting up the met lab while still planning on what pri- mary AM equipment to buy. We investi- gated tensile and fatigue frames, heat- treatment machines, HIP setups and more. Now, with our capabilities, we can prove our parameters from our machines in the metallurgical lab. It is a step-wise approach to learning how to make good parts.”
Sintavia relies on its own testing to make sure that arriving powder—core materials include nickel-based alloys as well as titanium and aluminum—is exactly what it is claimed to be.
“We perform full powder characteri- zation as the powder arrives from vendors, even if it comes with certification,” offers Hedges. “That includes a number of tests to assess particle size, distribution, flowa- bility and much more. We do all of this ourselves. We want to be responsible for the parts right from the beginning.”
Formidable Printing Lineup
With powder internally certified, Sin- tavia’s shop floor is poised to produce. The roster includes three SLM Solutions 280 selective-laser-melting machines, one sin- gle-laser and two twin-laser; one EOS M 290 direct-metal laser-sintering machine; a Concept Laser M2 direct-metal laser-melt- ing unit; and an Arcam Q20plus electron- beam machine. Add to that a newly installed EOS M400-1, and in March, Sintavia will bring online a Trumpf TruPrint 3000.
Most of the machines are locked down to run a single material, notes Hedges, as many of Sintavia’s customers do not want machines sharing powders in order to eliminate the possibility of contamination. Though Sintavia quotes part runs into the thousands, most production, especially for aerospace, ranges from 10 to 100 parts per run.
Even after a build, powder is top of mind.
“We perform powder sampling and reconditioning after every build,” Hedges says. “We take the powder out of the machine and sample it. We characterize that powder in our met lab to determine its ongoing life. Can it last five, 10 or 20 more runs? The industry doesn’t really
know, so we have developed intellectual property to help us determine that.”
Heattreat, HIP and More Inhouse
For an all-inhouse operations, espe- cially one like Sintavia that validates every step of the way, after the build is no time to relax. The company brings vast resources to bear in meeting unique post- build challenges. For example, for critical aerospace applications, HIP and vacuum heattreatment are required to remove porosity from the part, increase ductility and reduce fatigue damage. Sintavia has invested in both technologies.
That includes a Quintus Technologies QIH 15L HIP press, featuring a 7.3 by 19.7- in. hot zone, capable of pressure to 30,000 psi and able to handle temperatures to 2550 F. Its Uniform Rapid Cooling tech- nology, which incorporates densification and heattreatment capability, reportedly allows for shortened cycle times, thus higher productivity. The furnace, a Super Series X model from T-M Vacuum Systems, Inc., offers a 2-cu.-ft. work zone and can hold as much as 200 lb. of material. It can be used for brazing, sintering, tempering, austenitizing, hardening, stress relieving, bonding, annealing and more.
“Vacuum heattreating and HIP set us apart,” Hedges says. “We have a high-vac- uum furnace for stress relief, which pro- duces brighter parts due to a lack of oxy- gen in the chamber.”
The furnace, capable of rapid quench- ing, provides needed stress relief. After wire-EDM work to remove supports and the base, HIP may be the next destination, to address internal imperfections such as voids. Parts of nickel-alloy material, for example, then return to the vacuum fur- nace. These procedures help guarantee the needed mechanical properties.
“We may be alone among businesses of our type in being able to offer these processes inhouse,” says Hedges, noting advantages related to costs, lead time and most importantly, quality control. “We know that AM parts are not ready for use without the right post-processing. We have a lot of intellectual property related to these steps that assist greatly in producing
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