Smart Manufacturing Engineering Magazine May 2019
By Ray Huff and Terry Wohlers
The world of additive manufacturing (AM), commonly referred to as 3D printing, is quickly changing. The technology allows companies to manufacture products faster, with greater variation, and often with entirely new forms and functions. In the past, AM has been plagued by overpromising headlines that often led to unrealistic expectations. AM is undoubtedly changing the manufacturing scene, but in a more organic and strategic way than some may have expected.
One thing is sure: the overall growth in producers of industrial AM systems is not slowing. This year, Wohlers Associates has tracked the development of 177 producers of industrial AM systems, which are those that sell for $5,000 or more. This is 31 percent more than the 135 reported last year. Notably however, the growth of desktop 3D printers (AM machines priced at less than $5,000) slowed considerably in 2018. Market hype may have contributed to the rapid growth of desktop systems from 2013 to 2016, yet they too are now finding their place in many industrial sectors.
Investors, business executives, and others the world over are catching the scent of profitability in the AM industry. Growth can be seen in the production of systems and materials, the making of parts as a service, and the development of special software for designing in an AM environment. All of these areas present ripe opportunities for an attractive return on investment.
Investments are being made in many ways. Companies of all sizes are being purchased outright. LPW, a producer of metal AM powders, was purchased by Carpenter Technology Corp. for $81 million in October 2018. The following month, PTC purchased Colorado-based Frustum for $70 million, adding topology optimization software to its suite of products.
A wide range of startup companies continue to secure venture capital. AM system manufacturer Velo3D, for example, has secured $90 million over the past four years for the development of its metal AM technology. In January 2019, Desktop Metal closed a Series E investment round of $160 million, bringing the total investment in the company to $438 million since its founding in 2015. In March 2019, AM machine manufacturer Markforged announced an investment of $82 million.
Growth in manufacturing generally requires more floor space, and AM is no different. In January 2019, Tekna announced that it would invest EUR 5 million in a new metal powder production facility in Mâcon, France. The new facility will produce up to 500 tons of metal AM powders annually, nearly doubling the company’s material output for AM. Weeks earlier, Materials Solutions cut the ribbon on a new EUR 30 million facility in the United Kingdom. Siemens acquired the company in 2016.
AM materials have also seen significant investment and growth. Many AM applications require specialty materials, and third-party materials producers are jumping in to claim a piece of the expanding market. In February 2019, Equispheres of Canada raised $8 million for its metal AM powder production. In January, AM polymer-producer Essentium of California received an investment of $22 million from BASF Ventures. Investment in startups, facilities, and new technology is expected to increase over the coming years.
Adoption in Aerospace
AM offers great benefits for complex, high-value parts that must be lightweight. They are a perfect match for the needs of the aerospace industry. Often made of aluminum, titanium, or a superalloy, every ounce shaved off an aerospace part is money saved in material and fuel. Airbus has shown dozens of new designs for its aircraft over the past several years. Several of the parts have made it onto test flights as part of the certification process. The company’s first metal AM part, a fuel pipe elbow for the A400 transport aircraft, went into serial production in 2016.
Boeing has also made strides in producing end-use AM parts. The company has made strategic investments to improve print consistency, part reproducibility, and certification for flight. Boeing has shown several metal AM parts designed to reduce material and weight. As of February 2019, the Federal Aviation Administration (FAA) had certified more than a half-dozen metal parts for flight. Currently, tens of thousands of AM parts, mostly polymer, are flying on aircraft around the world.
Design for Additive Manufacturing
AM has been called a disruptive technology by many. AM’s main disruption is not in its displacement of other manufacturing processes, but rather how it impacts new designs, both in form and function. Using AM to produce 100,000 aluminum parts that could otherwise be stamped, for example, is simply not prudent or economical. To take advantage of the many powerful benefits of AM and to make it cost effective, it is necessary to apply methods of design for additive manufacturing (DfAM).
Consolidating many parts into one, digitally, and then printing the consolidation as one piece is something that cannot be done with conventional manufacturing. This is one way in which companies can make AM cost effective by dramatically reducing manufacturing operations, inventory, labor, and certification costs. A reduction of material waste and weight can further increase the value of AM parts, sometimes significantly.
DfAM training is not one-size-fits-all. Becoming an expert in designing production-quality parts for material extrusion (a.k.a. fused deposition modeling, or FDM) is quite different than designing for polymer powder bed fusion (PBF), for example. Training and experience is expensive in both time and money, and DfAM experts in the field are hard to come by. The need for DfAM has slowed the adoption of AM at many companies because of an underestimation of what it requires. Many are entirely unaware of the need. Over time, the problem will be addressed, but it could take years.
Improvements to the DfAM process come not only in education, training, and a lot of practice, but also in the tools used in the process. CAD, topology optimization, and generative design software improvements create new design possibilities. These tools enable designers to push the limits of product concepts and innovative solutions. For example, Bugatti used DfAM tools to produce a titanium brake caliper via AM. The caliper, completely redesigned for AM, reduces weight by 40 percent compared to the conventionally produced aluminum version. The company claims that the brake caliper is the largest of its kind in the industry.
Meanwhile, Gillette has put DfAM to work in a unique consumer product application: custom shaver handles. Customers select from a set of designs and materials and input custom text using Gillette’s Razor Maker website. Handles are printed on machines from Formlabs and delivered to the customer in three to four weeks. Custom products, such as these razors, differentiate themselves in markets flooded with competition.
DfAM is driven by the AM processes themselves as much as by design requirements. If thinner fins on a heat exchanger are needed but cannot be readily produced using current AM machine technology, one might give up on the idea. United Technologies Corp. faced this very problem when conducting a research project focused on improvements in metal PBF processes for heat exchanger design and production. Over roughly five years, the team determined that not only are specific design principles key to the production of heat exchangers, but often custom AM machine build parameters are necessary to achieve the desired internal channels and surfaces.
Improvements in AM processes and software can have an effect on design. An example is the need for support structures, also referred to as anchors, in metal PBF processes. Support material is usually required for overhanging features of less than 45° from horizontal. Support material adds build time, material cost, and post-processing steps that can be expensive. Internal features, such as holes and channels, can be entirely restricted, making it impossible to remove the support material from such areas.
Velo3D claims that its special software and hardware enable overhangs of less than 10°. If its system proves reliable and cost-competitive, it could change the rules of DfAM and broaden the spectrum of possibilities.
As in recent years, the entrepreneurial spirit among AM system manufacturers is strong. Companies are popping up around the world and offering many types of AM products. Companies offering entirely new approaches to AM are developing, but in fewer numbers as the industry matures. Most companies are offering variations of what is already available, but at a lower cost, and sometimes with new and interesting features.
Also, many systems use an open architecture, meaning that customers can use competitively priced third-party materials in the machines. Materials for AM are being offered by more suppliers, with new metal alloys, polymers, and composites being released regularly. This is a welcome change from just a few years ago, when only a handful of options were available.
Producers of new metal AM systems are using expired patents and building upon them to create potentially better solutions. SPEE3D and Titomic, both of Australia, are applying cold spray processes previously used for metal coatings to develop AM systems. Cold spray technology is fast at creating near-net-shaped parts with good material properties.
Markforged has made headway in the realm of composite materials with its two-headed material extrusion systems. The machines produce composite parts, such as carbon-fiber-filled nylon, with good strength and stiffness. The systems have become popular among product development groups for functional prototypes, end-use parts, and tooling.
A notable trend among new system developers is the introduction of metal binder-jetting (BJ) systems. Desktop Metal has shipped its Production System and HP is developing its Metal Jet system. Both are based on BJ technology. Stratasys announced a process called layered powder metallurgy, which is akin to BJ but with an added powder-compacting step. These machines are in development, but the fundamental BJ process has been in use for a long time. ExOne, Voxeljet, and Digital Metal and their customers have produced metal parts using BJ systems for years.
An advantage to these systems is the option to use standard metal powders, such as those used in metal injection molding. BJ systems are also generally faster than PBF systems in the printing step. The materials and speed open the opportunity to produce a wider range of parts at a lower cost. With BJ, “green” parts are produced, then debound and sintered similar to traditional metallurgical processes. Metal BJ will not take over the entire metal AM market anytime soon, but it does offer cost advantages for certain types of parts, such as relatively small ones produced in large batches. BJ systems are expected to penetrate the automotive market, which has been slow to adopt metal PBF due to cost.
Many innovative products have been made possible by AM. Among them are custom orthotic inserts created by Wiivv and Dr. Scholl’s. The companies partnered to combine a simple scanning phone app with polymer PBF technology to deliver custom shoe inserts and sandals to customers in weeks. This kind of accessible custom product fits well with AM’s flexible production capability.
Riddell announced that it had partnered with Carbon to produce custom football helmet liners for the NFL. Using thousands of impact tests and simulation, Riddell modeled liners made up of more than 140,000 polymer trusses that absorb impact. This represents a new opportunity for a reduction of head injuries through AM technology. After the end of the most recent NFL season, it was disclosed that select professional players used one of these innovative designs.
In motorsports, Formula One racing is famous for the amount of R&D invested in each racecar. In the sport, aerodynamics and lightweighting are key to staying competitive, and this is where AM can help. Employing DfAM techniques, the Sauber Alpha Romeo team partnered with Additive Industries to deploy metal AM parts in its cars. The motorsports industry has used AM for 20 years, but mostly for prototyping and wind tunnel testing. The Sauber team is now showing the competitive advantage of using DfAM and metal AM for parts that reduce weight in the car’s frame.
3D printing in the construction industry has gotten a lot of media attention. Some of the efforts show promise for niche applications, but most are believed to be much too costly. For it to have merit, architects will need to apply methods of DfAM, similar to the way some engineers are applying them to parts for aircraft and other products.
One barrier to entry for these applications is the regulation of the construction industry, which requires materials and processes to be thoroughly tested and certified for safety. The U.S. Marine Corps and the U.S. Army teamed up to test concrete AM machines for building bridges and other structures in a combat environment. This application shows promise due to the conditions the military faces when needing a structure quickly, with cost being less of an issue.
Path to Growth and Adoption
When applied correctly, AM is a remarkable technology, as proven by countless examples of applications and business opportunities. Each example is the product of many hours and dollars invested by those who see AM as a factor in shaping the future of design and manufacturing. A number of the examples involved many lessons learned “the hard way.” Mistaken attempts are often fueled by a promise of quick success by a “magic” technology.
The truth is that AM is one tool among many, and as with most tools, skill and experience are key to its effective use. Those entering the field are becoming increasingly aware of the capabilities and limitations of AM processes, DfAM principles, and how to spot perfect-fit product ideas. With proper grounding in the past and present, proponents of AM are certainly in the best position to build our future, one layer at a time.
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