Additive manufacturing (AM), often erroneously called 3D printing in mainstream media, is a fast-expanding market. If proof were needed, in 2014 it registered a compound annual growth rate of 34.9 %, the highest in 17 years. According to the Wohlers Report 2014 – the reference on the AM industry’s progress – the industrial and business machines sector makes the most use of the technology with an 18.5 % market share, followed by electronic goods, motor vehicles and medical devices. Aerospace is another one to watch and companies such as Airbus are using AM processes to produce complex metal parts for next-generation aircraft.
Although often casually referred to as 3D printing, an AM machine is poles apart from your ordinary 2D printer. In a nutshell, it is a machine that enables the layering of materials to make parts or objects from 3D model data under computer control. AM itself is an inherent part of the product development process used to manufacture prototypes, tools and industrial parts. Instead of milling a workpiece from a solid block, it builds up 3D structures from fine powders and liquids. There are actually many different process categories and AM is a principle that can be applied to the creation of widely differing technologies.
Groundbreaking it is, yet creating objects by successive addition of material is as old as the world itself. Think of ceramic before the pottery wheel or the additive building of a swallow’s nest. In fact, it is the most natural way of manufacturing complex geometries. Moreover, the processes for making three-dimensional photographs and maps have been patented since the 1800s.
Old hat then? Not quite, as it was not until the development of computer technology that the three-dimensional solid modelling inherent in the definition of AM could be developed. The impulse was given by the American automotive industry, which met serious competition from Japanese auto makers during the 1980s. The main problems it faced were time and cost: it simply took too long and was too expensive to develop new models. Hence several processes for “rapid prototyping” were developed – a group of techniques used to quickly fabricate a scale model of a physical part using CAD software – which are at the origin of today’s additive manufacturing industry.
Getting parts fast
The strengths of additive manufacturing lie in those areas where conventional manufacturing reaches its limitations. If there is one thing engineers can count on, it is that there will be modifications and redesigns during production. With additive manufacturing, they now have the freedom to redesign and innovate “on the fly”, a freedom without time or cost penalties. This yields significant rewards: compressed production schedules, better quality products, more diversified designs and, in the end, more revenue.
This streamlining of traditional manufacturing (compressed processes) also means a smaller environmental footprint. Additive machines can read CAD files to know how long it will take to build a part and how much material is needed before it’s even on the machine, resulting in very little waste and much time saved. The upshot: a more fluid product development and design process that produces parts on demand. This is an attractive proposition for making lightweight parts for vehicles and aircraft, tailored dental implants or that made-to-measure replacement hip-joint. Which brings us back full circle to the freedom to redesign without penalties.
The argument for standards
Despite the obvious benefits, there are issues. One of the stumbling blocks to the technology’s wider application is the lack of a supporting framework and industrial standards. It is difficult for AM to compete with traditional techniques; for companies looking for a rejection rate of just a few parts per million, there is no way AM can come close to that. This is where a set of standards can help guarantee a level of reproducibility, and give business and manufacturers the much needed assurance that AM processes, materials and technologies are safe and reliable.
But where do you start? For Jörg Lenz, Chair of technical committee ISO/TC 261 on additive manufacturing, one of the challenges is “understanding which applications and parts are suited to AM standardization, and choosing them accordingly”. The traditional application areas for AM include fit-and-assembly, patterns for prototype tooling and metal casting, presentation models, visual aids, and education and research, which result in improved communication, faster product development and fewer defective parts. But these are well-established fields, which do not necessarily require industrial standards.
According to Klas Boivie, Convenor of ISO/TC 261’s working group WG 1 for AM terminology, the market for functional parts has reached an impressive 29 %, while tooling components are at 5.6 %. With functional parts pervading everything from aerospace to dentistry and medicine, since these products often have a critical function, there is a growing need for standards to accommodate the requirements for all these areas.
As in any field where standards are present, the standardization process must follow market needs. There has been a lot of hype surrounding AM, which has attracted interest on almost all fronts. But the science is young; it will develop and mature over time as knowledge of the technology grows, and any standards developed now must leave room for innovation. As Lenz sees it, “International Standards are really needed to provide clarity and dispel concerns, to provide reliability, acceptance and safety, and to further the technology in the market.”
Together we grow
The standardization process must follow market needs.
The appetite for AM standards is relatively recent. “The initiative came from the AM community,” explains Boivie. “It was very clear that this technology had the capability for much wider industrial application, but the industry was slow and skeptical about using it, unless for very special or non-critical applications.” This motivated a group of key actors within the international AM community to initiate a discussion for the creation of technical standards for AM. However, since this group could not be certain to gather a wide enough international support, the initiative was brought to ASTM International (formerly the American Society for Testing and Materials), which led to the creation of ASTM committee F42 for additive manufacturing technologies in 2009. While this debate was going on, the Association of German Engineers (VDI) was hard at work on a series of guidelines for what was then called “rapid technologies”. These guidelines eventually led to the creation of ISO/TC 261, in 2011, whose secretariat is held by DIN, the ISO member for Germany.
With the international AM community being so small, many of the experts invited to review the VDI standard proposal were already involved with ASTM F42. The creation of ISO/TC 261 raised serious concerns about work duplication, or worse, the development of competing standards. Happily, what might have been a source of discord led to fruitful collaboration between the two organizations and the development of an ASTM/ISO partnership agreement.
Opportunities and constraints
Despite the urgent need for standards to shape the industry, AM standardization is hampered by time constraints and underfunding. Boivie has experienced these first-hand: “Since all standardization work is based on voluntary participation, and has no funding attached with it, this means we have to do our regular work alongside the development of AM standards.”
To ensure that additive manufacturing delivers on promise, it is important to build a foundation that guarantees the reproducibility of AM components. Their strength is that they can be redesigned and could then very well reach superior quality and performance. Besides, Lenz adds, “We also need quality assurance procedures in cases where standards for AM parts do not exist or where existing standards do not apply completely.”
Meanwhile, more and more organizations are keen to get their foot in the door and develop their own AM standards, which could leave the sector with competing standards after all. As Boivie explains, the community of experts currently involved in the ASTM and ISO collaboration clearly have the broadest expertise in AM technology anywhere in the world. There is a real risk that standards developed outside this collaboration will not have the same level of insight, which would only stifle the steady development of the technology.
On the horizon
Despite the apparent confusion, though, there is a plan. Priority has been given to terminology and general principles, which will provide the bedrock for the development of any future standards. When asked where all this is going, Boivie muses, “The use of the AM terminology standard in an open-information database will do a lot to spread the operative ‘word’ and give the industry a common voice.”
What was once considered science fiction – the ability to produce objects on demand – is in the process of becoming a reality. AM is an enabling technology that makes it possible to produce parts that may not have been feasible or realistic in the past, creating endless possibilities for innovation. So although it is hardly possible to foresee where this technology is taking us, we know our three-dimensional future is looking bright. And with standards in the offing, let’s wager that AM will soon become an industrial strength, improving the way we live our lives.
3 questions about additive manufacturing
Additive manufacturing (AM) is the life passion of Jörg Lenz, Collaborative Projects Coordinator at EOS GmbH, the technology and market leader for design-driven, integrated e-manufacturing solutions for additive manufacturing. With over 20 years’ experience in the field, the Chair of ISO/TC 261 tells us why standards development for the sector is essential.
Tell us a little about additive manufacturing at EOS.
For EOS, AM is mostly about developing the right solutions for our customers although we also use laser-sintered components in our own products (machines, peripheral devices, etc.). These are designed by our engineers and manufactured both internally and by external suppliers so that we can make informed decision about how to design, produce, purchase and use AM parts, all based on experience.
What is EOS’ standardization strategy with regard to additive manufacturing? How important are ISO standards for a company like EOS with global operations?
Our strategy is to actively encourage and support the creation of standards in areas that are relevant to the use of our products. It’s a two-way collaboration. On the one hand, standards must increase industry acceptance of AM parts, and benefit our customers accordingly; on the other hand, it is easier for us to fulfil our customers’ needs and expectations if they have common requirements, based on standards. Standards with a global reach,such as ISO’s, support these goals better than a host of individual standards (e.g. national, industry- or company- specific) relating to the same topic.
How does EOS’ participation in ISO/TC 161, and in standardization in general, assist the company in its own work?
Essentially, it helps us to understand our customers’ likes and dislikes, and to achieve our long-term goals.