Building up standards in metal additive manufacturing
Dr Dieter Schwarze and Bodo Haack, of SLM Solutions, discuss the importance and progression of standardisation in laser metal additive manufacturing
Additive manufacturing (AM) is a relatively new and very complex technology. Barriers to entry can be quite high, as implementing the technology is not unproblematic and made more difficult without specialised knowledge to understand the intricacies of the process.
Guidelines and standards offer a summary of expertise, because they usually combine the knowledge of many specialists with AM experience. They also create a framework of rules and regulations from a variety of qualified and, above all, verified information on how to successfully implement the technology. This information provides answers to questions ranging from the operation of AM equipment to defining the criteria for fabricating additive parts and the quality criteria on which they are evaluated. Standards also help further spread adoption of the technology. Especially for equipment manufacturers like SLM Solutions, it is essential to provide as much process-specific information as possible to the operators of the AM systems, making it easier to get started with this interesting technology, while accelerating its dissemination, whether for prototyping or serial production.
At the early stages in developing a new technology, large efforts in creating standards may be premature and useless, or lead to setbacks. Early development requires maximum flexibility. Once a technology is widely adopted, standardisation can be a booster for its usage. An example is the need for unified formats, so that files and data keep pace with digitisation. But, it is important to implement a clever, open format to not restrict the future.
The key of standardisation is the knowledge of those participating in the steering committees. This knowledge generates the quality of the emerging standard or guideline. As with any new technology, it is difficult for manufacturers to keep an eye on the large number of applicable standards in the field of AM. Only with qualified information can we help potential users get started.
The groundwork to this success has already been displayed by the recently completed directive Additive Manufacturing Processes from the VDI (Association of German Engineers) and the DIN EN ISO/ASTM 52900 regulating the terminology for AM, establishing, among others, the term PBF-LB/M for laser beam powder bed fusion with metals (SLM). DIN EN ISO/ASTM means that four independent standardisation bodies collaborated strongly, indicating what is necessary to help boost AM: a common international understanding with respect to many aspects of AM to become a tool for series production of end-use products in a variety of industrial sectors worldwide. Often this is referred to as one world – one standard.
Significant weight reduction and functional integration have been reached by redesigning this gooseneck bracket for additive manufacturing. (Image: SLM Solutions)
Despite this progress, there is a gap in knowledge of AM and information on the pros and cons is still missing. A limited number of AM studies exist to rely on for reference, and more long-term studies are needed. The development of AM is happening at speeds so fast that standards struggle to keep up. Creation of standards needs the participation of enough supporting industrial stakeholders, as well as those resisting such framework rules. Realistic targets in the one world – one standard approach are required to prevent risk-taking that could otherwise jeopardise the work. One way that may help in thinking about standardisation is to try and answer the question of what it doesn’t mean. No protectionism, no lobbying, IP protection or market isolation…
Integrators and users of metal AM need standardisation to innovate and be more productive by avoiding, or at least reducing, trial and error in their implementation of the technology. This helps secure their investment. Personnel, metal powder and machine costs, to name only a few, call for first-time-right manufacturing, and to work toward this goal emphasis is needed on all steps of the metal AM process and their standardisation.
Without doubt, the industrial laser market has experienced growing sales into the AM space in recent years. The usage of AM for series production with PBF-LB is a driver for the laser market, especially with the growing number of multi-laser machines in use. New laser sources will be required in the future, such as infrared laser arrays, visible or ultraviolet wavelength lasers and combinations thereof. Pulsed or modulated lasers, or those with tuneable beam intensity profile, are used less often today. Further standardisation will boost the LBF-LB market, providing an advantage to the laser market as well.
The history of humankind wouldn’t have been successful without standardisation; for more than 35,000 years standards have helped us survive. Creating them when and where they are needed and helpful – that’s the art to go with the science.
SLM Solutions contributes to the development of metal additive manufacturing standards by sharing its expertise and best practices with the standardisation community. Dr Schwarze is the deputy head of the Advisory Board for Additive Manufacturing in the DIN Standards Committee Technology of Materials. He is also head of science and technology research at SLM Solutions. Bodo Haack is head of technology coordination and system security at the firm