3D printing: manufacturing’s changing landscape

Additive manufacturing, a rapidly advancing technology, is growing in acceptance with plenty of support from industry and public initiatives.

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The term does not matter – additive manufacturing (AM) and 3D printing (3D) are interchangeable. Understanding the market, where it’s going, how it’s used, what it means to manufacturers, and who to turn to for more knowledge and support does matter.

AM/3D printing is growing. According to the 19th edition of the Wohlers Report, published by Wohlers Associates Inc., companies are pushing the limits of AM/3D printing and applying the technology in new ways. The research projects the AM/3D printing industry to reach $12.8 billion by 2018, estimating it grew $3.07 billion in 2013. By 2020, forecasted revenue should exceed $21 billion.

“The industry is experiencing change that has not been seen in 20-plus years,” states Tim Caffrey, senior consultant at Wohlers Associates, and one of two principal authors on the report. “What’s most exciting is that we have barely scratched the surface of what’s possible.”

Terry Wohlers, president and the other principal author, says revenues from the production of parts for final products represents 34.7% of the entire market for AM and 3D printing. In 2013, the AM market segment of parts for final products topped the $1 billion mark, and aerospace, medical, dental, and other industries “are finding ways to use AM to produce quality parts.”

Metal parts production is increasing in popularity as the number of AM/3D machines that produce metal parts has skyrocketed, jumping to 348 units in 2013 from 198 a year earlier, a 75.8% increase. Companies such as Airbus and General Electric are using this technology to produce complex metal parts, says Wohlers, who has followed the market for metal AM machines for 14 years.

But, what if you are new to the market, where do you turn to learn more?

Throughout this special report, materials, machines, processes, and the players offer new and experienced AM/3D users a look at what’s to come.


 

A terminology primer

The term additive manufacturing (AM) represents many technological subsets also known as:

  • Direct digital manufacturing (DDM)
  • Additive fabrication
  • 3D printing
  • Rapid prototyping (RP)
  • Layered manufacturing

AM builds 3D objects, layer-by-layer, using a range of materials. Designs are created in CAD using a 3D modeling program or via a 3D scanner that makes a digital copy of an existing object, which is then uploaded into the CAD 3D modeling program.

Then, the software slices the final CAD model into hundreds to thousands of horizontal layers so when the file is uploaded to the AM machine, the design can be read, layer-by-layer as a 2D image, which once built, results in the three-dimensional finished product.

The processes used to create 3D products also varies. The most common are:

  • Selective laser sintering (SLS) – Powdered material is deposited on the machine bed, and then high-power lasers fuse the material by scanning the layers generated by the software. After the first layer is complete, the bed lowers by one layer of thickness, new powder is applied, and the process repeats.
  • Stereolithography (SLA) – Ultraviolet curable photopolymer resin and an ultraviolet laser work together as the laser is aimed at a pool of resin, traces the pattern of the model, and cures it. Each layer is repeated, with the laser curing and joining the new layer to the one below it.
  • Fused deposition modeling (FDM) – Invented and patented by Scott Crump, the founder of Stratasys. In FDM, solid material is delivered to an extrusion nozzle where it is heated to melting. The nozzle, moving horizontally and vertically via numerical control from the computer-aided manufacturing (CAM) software, traces the cross-section pattern on a machine bed and extrudes the melted material in a layer that hardens immediately so the process can repeat for each consecutive layer.
  • 3DP – A powder of starch- or plaster-based material fills a container where the model will be built. An inkjet-type head applies a small amount of binder to the container to form a layer. After the binder is applied, a new layer of powder sweeps over the build and more binder is added. This is repeated until the object is complete.
  • Multi-jet modeling (MJM) – Thermopolymer material is applied via a nozzle – comprised of hundreds of small jets – that moves back and forth in the X, Y, and Z dimensions.


 

Domestic, industry use

According to Sharon L.N. Ford, author of the most recent report from the U.S. International Trade Commission (USITC), “Additive Manufacturing Technology: Potential Implications for U.S. Manufacturing Competitiveness,” AM/3D printing offers industry a range of unique possibilities. The technology can produce three-dimensional objects of virtually any geometry without significantly increasing costs. It also has the potential to reduce – or even eliminate – the constraints of molds and dies. Due to AM/3D printing’s speed and efficiency in producing prototypes and parts, the technology will have the greatest impact on products requiring customization, having complex designs, and being made in small quantities.

Most frequently associated with medical and aerospace applications, the largest consumer of AM/3D technology, as of 2011, was the automotive industry – making up 19.5% of all purchases, according to the USITC report. Medical use followed at 15.1% and aerospace makes up 12.1% of the market.

AM/3D printing techniques make up barely 0.01% of all automotive manufacturing, but are more common in medical (0.04% of total industry output) and aerospace (0.02% of industry output).

Ford notes that AM/3D printing is not yet suitable for mass production due to limitations such as lengthy build time, limited object sizes, machine costs, and sizes, and materials used. For example, while the process is capable of creating a 1.5" cube per hour, on average, an injection-molding machine can produce several similar parts in less than a minute.

However, technology is changing – rapidly – and the functionality is gaining support from innovation hubs to even machine tool builders.


 

AM extends part life, reduces costs

Challenge: Extending the life of rotor and stators for Ulterra’s downhole drilling applications
Solution: ExOne 3D metal printing technology to produce components in an S4 stainless/bronze matrix
Advantage: AM produced more wear-resistant parts at a lower cost

Costs by method
ExOne 3D:
$75 to $100/each
Conventional machining: $400 to $500/each

Specifications
Customer:
Ulterra, manufacturer of PDC drill bits and downhole tools for the oil & gas industry
Part: Stator
Batch: 10 parts
Part size: 3" to 5"

ExOne’s M-Flex prints in stainless steel, bronze, or tungsten. Its flexible job box can print one prototype or short runs of multiple and/or custom parts.

ExOne
www.exone.com


 

Making it in the USA

Youngstown, Ohio-based America Makes is an extensive network of more than 100 companies, non-profit organizations, academic institutions, and government agencies from across the United States.

Founded in August 2012 as the flagship institute in the National Network for Manufacturing Innovation (NNMI), it leverages technical minds from government, industry, and academia to accelerate the adoption of AM/3D printing technologies in the U.S. manufacturing sector.

According to Rob Gorham, director of operations, the goal is to create manufacturing competitiveness through a truly collaborative environment, bringing technical advancements from the lab to the factory floor, creating jobs, and producing products that are more competitive on a global scale.

However, not all industries have adopted AM/3D printing in their operations, and some are not sure where to start. Clearing the haze is one area of assistance the institute offers.

Gorham says his group is working in early stage problems such as standards, design methodologies, tools, materials, process control, equipment, non-destructive evaluation, qualification, certification, and supply chain integration.

Another initiative of the institute is validating materials and techniques. “America Makes is leading an effort to qualify materials and the mid-tier supply chain partner to the multiple aerospace OEM specifications.”

Another project addresses the metal casting industry and its need to understand the opportunity AM/3D printing brings to the bottom line. A result of the metal-casting project is a collaboration among several top-tier metal castings suppliers to build demonstrations, use cases, and validate the benefits of AM/3D printing in their industries.

“It’s a truly collaborative environment that brings technical advancements from the lab to the factory floor, creates jobs, produces more competitive products, and ultimately reaffirms our place in the global market,” Gorham states.


 

Setting standards

As additive manufacturing continues to advance, materials and product qualification testing becomes crucial.

By David Podrug


Few advances have had such impact in manufacturing in recent years or attracted as much attention as additive manufacturing (AM). As possibilities become reality through this technology, industry leaders continue to race ahead to innovate, producing parts and components with complex geometries impossible through traditional subtractive manufacturing techniques.

The opportunities for innovation are endless, given the increasingly diverse challenges that organizations attempt to address through AM. In the aerospace sector, primes and their suppliers are constantly seeking to reduce the weight of aircraft to deliver improved efficiencies in fuelling. Energy companies are looking to increase mass customization and energy efficiency. Industries with high-volume manufacture, such as transportation and medical devices, are demanding significant cost reductions through shorter development times and new component production methods.

However, the reality of industry-wide adoption is less plausible if the risks of producing parts and components by AM are not fully understood. At Element Materials Technology, engineers are developing international testing methods and standards needed to adopt AM. Industry collaboration on certification and qualification of materials and components is crucial.

Pushing AM to its limits
As manufacturers innovate, it becomes increasingly difficult to predict the properties of materials and components created through these techniques and how they will operate in the real world. While the technology changes, the rigorous requirements to ensure quality and safety – and satisfy regulatory bodies such as the Federal Aviation Authority (FAA) – correspondingly become more complex.

Traditional subtractive manufacturing processes – such as pouring steel into ingots – deliver predictable properties. Changes to the manufacturing process can bring complexities not encountered previously. For example, in AM, issues may develop that cause unpredictability between layers.

The complex range of existing standards require deep knowledge of testing to ensure that innovation in AM is not stalled by failure to anticipate properties and performance. Element has the capabilities to qualify and inspect materials across a range of industries. For example, within the aerospace sector, engineers conduct non-destructive testing (NDT) for applications in space hardware; mechanical, physical, and chemical testing on metallic materials for space applications; fatigue testing of metals for jet engines; and allowables testing on non-metallic materials for commercial and military aircraft. NDT enables clients to make the most of new processes without compromising on their commitments to quality and safety.

Collaboration and qualification
Within the testing, inspection, and certification market, collaboration with clients promotes advances in AM quality. Industry bodies such as the FAA might prescribe specific instructions regarding data requirements (multiple batches, iterations at different temperatures, and factors of safety up to 99%). Working with clients to run these datasets ensures that materials and components deliver the quality required.

Element offers expert opinion on testing methodologies used by manufacturers and engineers, enabling them to improve their internal processes beyond their existing capabilities.

The future of AM
The global AM industry is currently worth around $3.2 billion, but this will grow to an estimated $12 billion to $25 billion by the year 2020. With this projected growth, it is necessary for materials testing companies to stay at the forefront of technological advances in AM to ensure that its application is fully understood and qualified.

One initiative to ensure this is Committee F42, an international body led by ASTM and ISO to create and publish the test methods needed to validate additively manufactured components and parts. Element is represented on the committee and is driving the development of international testing standards from its AM Center of Technical Excellence in Cleveland, Ohio. Overcoming the challenges that AM poses will allow us to determine the level of testing required to ensure consistent production, the properties at risk, and detection of critical flaw sizes more accurately than before.
 

Element Materials Technology
www.element.com


About the author:
David Podrug is the advanced materials business manager at Element Materials Technology and is a member of ASTM Committee F42 on additive manufacturing technologies.

 
 

Additive, subtractive, hybrid

When considering a new process, designers must determine which parts are candidates. AM/3D printing is generally better for complex parts with difficult-to-machine geometries, but the tradeoff is reduced speed compared to CNC machining. The choices have grown now that machine tool builders are offering hybrid technologies for start-to-finish processes.

Greg Langenhorst, technical marketing manager, MC Machinery Systems, offers one example of where AM fits nicely – mold-and-die production where effectively cooling parts is vital so they do not warp and can be ejected quickly.

“A big advantage of AM powder-metal sintering is the ability to build conforming cooling channels within a mold. Precisely located channels made this way allow 20% to 30% faster part cooling and better part accuracy with less warping and shrinkage,” Langenhorst states. “The problem is that laser-sintering alone cannot produce finished surfaces in these channels – that requires a separate milling step. But, AM produces complex geometries that do not always allow machining after the build. The solution is to incorporate milling while the AM part is created, layer by layer.”

One machine, the LUMEX Avance-25, combines laser sintering and CNC-milling in one platform. The 400W fiber-laser sinters at 5,000mm/sec, adding layers 50µm (0.002") thick. Once 10 layers are put down, a mill as small as 0.6mm (0.024") in diameter can finish the surface, eliminating ridge lines. Rib shapes as small as 0.02" can be finished in a core as it is being built. Applications have included molds for plastic electric drill casings and automotive connector plugs.

“Because you no longer have to design to your manufacturing capability, you can design for the optimization of whatever the part needs to be,” Lagenhorst says. “You can put cooling channels where you want, without worrying about twists and turns.”

Another hybrid machine is DMG MORI’s Lasertec 65 3D, a laser deposition welding and milling machine. Combining additive manufacturing and traditional cutting methods enables new applications and geometries. The changeover from laser allows direct milling of sections not reachable at the finished part. DMG MORI engineers designed the machine to completely melt the powder metal alloy as it is sprayed into the focal point of the laser. The laser melts both the powder and the substrate, producing full bonding between the two mediums.

Renishaw, a global engineering technologies company focused on machining, metrology, and process control is also actively participating in the AM/3D printing field. Offering a laser melting process, Renishaw’s AM250 additive manufacturing machine benefits injection mold producers. Using a high-powered fiber laser, Renishaw’s system melts and fuses metal powder grains (steel, aluminum, and other materials). The machine can build up complex parts, layer-upon-layer of fused metal. Layer thicknesses range from 20µm to 100µm. Low-volume parts for medical companies, aerospace contractors, or motorsports competitors can go directly from the laser machine to the user.


 

GKN Aerospace’s additive focus

The company’s AM program extends across the value chain, taking in new materials, applications, processes, and part qualification.

By Rob Sharman

GKN Aerospace is researching and developing programs to advance a variety of additive manufacturing (AM) techniques. Because AM creates the material as it makes parts, these processes open up new possibilities for component and system design. Eventually, we will develop totally new materials and functionally graded structures.

To obtain aerospace qualification for AM-produced components, GKN Aerospace is investing heavily in testing – and standardizing – processes and materials to generate quality procedures. AM-manufactured parts are flying today, and the company expects the number of additive parts to increase significantly during the next 2 to 5 years.

In parallel, the company is developing a thorough understanding of the design freedom afforded by AM, the processes and materials involved, and what will be required to produce the entirely novel parts needed for the next generation of aircraft.

Activity focuses on several AM technologies, including:

  • Large scale deposition – producing larger scale, near-net forms that require less machining than traditional forgings. Future structures may be components too large for powder bed, or large bulkheads, wing ribs, or spars.
  • Small-scale deposition – smaller net shapes with greater detail that can be directly deposited onto larger structures. Modification and repair of high-value engine and airframe components are also possible.
  • Laser powder bed – producing small, intricate, highly complex, high-value components.
  • Electron beam powder bed – to produce near-net shape and structurally optimized, small- to medium-sized engine and airframe prismatics.

AM processes promise to revolutionize aerospace component manufacturing by enabling the creation of new, efficient, lightweight designs, made by tailored, higher performing materials. Simultaneously, these developments will lower material waste associated with subtractive processes, reduce time and energy required in manufacture, and lower carbon emissions. AM will allow material optimization throughout the component and, most significantly, flip the established cost/complexity equation familiar to manufacturing, enabling design optimization and a level of structural complexity that is not cost effective – or simply not achievable – to manufacture today.
 

GKN Aerospace
www.gknaerospace.com

About the author: Rob Sharman is head of Additive Manufacture, GKN Aerospace, and can be reached at info@gknaerospace.com.


 

Materials and more

Beyond the machines are the materials used. Poly-ether-ketone-ketone (PEKK) is used widely in injection-molded parts, but Oxford Performance Materials (OPM) of South Windsor, Connecticut, wanted to use the high-performance plastic in laser sintering to replace aluminum and magnesium in parts.

OPM has three divisions: biomedical raw materials that uses PEKK-polymer-based OXPEKK material; a biomedical devices section that produces molded and selective-laser-sintered (SLS) OsteoFab medical parts and implants from OXPEKK polymers; and an industrial parts group that focuses on aerospace parts production.

OPM is a full-service provider, not a service bureau, notes Larry Varholak, vice president of programs, OPM Aerospace & Industrial. A proprietary design algorithm determines a proposed part’s structural form to maximize strength, flexibility, and weight. The design is then 3D-printed directly from the digital file using SLS. The company can create complex parts otherwise too expensive to produce conventionally, in a build volume up to 16" x 20" x 22", using an EOS P800 machine.

If PEKK is to replace metals, it is essential to qualify its performance characteristics. One of OPM’s first goals was to set up design allowables for PEKK to take advantage of additive manufacturing, according to Paul Martin, president of OPM Aerospace & Industrial.

“OPM has developed a database of strength characteristics of the material to know its limits from more than 3,400 test components,” Martin states. “We view ourselves as halfway between metal and nylon. Compared to aluminum fabrication, we can produce complex and expensive parts at a fraction of the cost.”


 

Cutting through AM clutter

Searching for the right additive manufacturing (AM) machines, material, or both used to be a monumental task, but the Senvol Database changes all that.

Senvol, a consulting firm offering quantitatively focused AM analytics, built a database of available machines and materials clients could use to cross-reference machines and materials that went together.

Launched in January 2015, the free, online Senvol Database currently contains detailed specs on more than 350 industrial AM machines and 450 materials.

When searching for machines, users choose from drop-down menus for manufacturers, model, process, and materials, and then have the option to input the minimum size of the build envelope required. Results display all available machines that fit the criteria. Users can then click on the details button for additional machine information. Searching for material offers input criteria for hardness, physical, thermal, and mechanical properties.

Results are not linked to the actual company, but the Senvol Database winnows the results to a manageable list for further research. Once the user has the cross-reference results, visiting that manufacturer’s website will garner the specifics to start the in-depth comparison process.
 

Senvol Database
www.senvol.com

 


 

Prostheses control

Device
Coapt’s Complete Control system enhances the control of upper-extremity prostheses with pattern recognition technology to non-invasively acquire information from muscle signals. The device’s electronic components needed to be in an attractive and durable casing. Custom, hard tooling for injection molding was prohibitively costly.

Solution
ProtoCAM, a service bureau with PolyJet 3D printing capabilities, produced cases with the attractive finish of stereolithography and the durability of selective laser sintering. The Objet500 Connex3 3D system’s 16µm build resolution delivered the required precision with faster turnaround and more attractive pricing than injection molding.

Results
With ProtoCAM-produced casings housing a powerful micro-controller, the Complete Control system has moved into full production.
 

ProtoCAM
www.protocam.com


 

CNC to FDM

Advanced Composite Structures (ACS) repairs helicopter rotor blades and other composite structures for fixed-wing and rotary-wing aircraft, and produces low-volume production composite parts for the aerospace industry. Both offerings require tooling while many jobs also require fixtures to locate secondary operations, such as drilling.

Old
In the past, ACS typically produced layup tools, drill fixtures, and consumable core patterns on CNC machines. Another option was producing a model using a CNC machine or power tools and using it to mold a composite layup mandrel. It typically cost around $2,000 to hire a machine shop to produce a metal composite mold.

Producing a model and molding a composite layup tool cost about the same. In both cases, lead times were 8 to 10 weeks.

New
Today, ACS produces nearly all of its tools using additive manufacturing (AM) on a Fortus fused deposition modeling (FDM) machine. A typical FDM layup tool costs about $400 and takes about 24 hours to produce. The method means ACS can easily remake tools found to have problems on the manufacturing floor.

For example, ACS recently produced a camera fairing for a forward-looking infrared camera on a military aircraft. The Fortus machine built the layup tool directly from a CAD drawing. In another example, the geometry of a vertical fin assembly for a helicopter is so simple that a layup mandrel was not needed. However, the Fortus machine produced a drill fixture to accurately locate a series of holes.

“Tools produced with FDM cost only about 20% as much as CNC-produced tooling,” says Bruce Anning, owner of ACS. “Moving from traditional methods to producing composite tooling with FDM has helped us substantially improve our competitive position.”
 

Stratasys
www.stratasys.com

Advanced Composite Structures
www.acs-composites.com


 

The future

There is so much more to tell, but one thing comes through: this disruptive technology is entering mainstream acceptance, with many players joining the market. From machines to materials to processes, AM/3D printing has changed the way certain parts are manufactured, and it is opening new areas of part production.
 

America Makes
www.americamakes.us

DMG MORI
www.us.dmgmori.com

EOS
www.eos.info

MC Machinery Systems Inc.
www.mcmachinery.com

Oxford Performance Materials
www.oxfordpm.com

Renishaw Inc.
www.renishaw.com

Wohlers Associates
www.wohlersassociates.com


About the author: Elizabeth Engler Modic is the editor of Aerospace Manufacturing and Design and can be reached at emodic@gie.net or 216.393.0264.