Czinger 21C on Pacific Coast Highway.
In part one of our double cover feature from TCT Europe 28.3, SLM Solutions' Global Head of Business Development Ralf Frohwerk discussed how the metal AM pioneers are roadmapping a route to additive manufacturing (AM) success. In part two of the interview, we’ll see how the company is pushing towards industrialisation.
Can you talk to us a little about repeatability and how companies ensure that in series production every part is the same? What are the factors to consider?
SLM Solutions provides in-line process quality control systems that ensure monitoring & controlling of quality relevant process parameters for high-quality parts. The Melt Pool Monitoring (MPM) system, for example, determines the thermal radiation from the melt on the powder bed while the Laser Power Monitoring (LPM) system permanently monitors the targeted and the actual emitted laser output during the entire production process. An additional offering is the Layer Control System (LCS) which monitors the powder bed and detects possible irregularities in the coating.
To achieve high-quality builds with high density and surface quality, a clean process chamber is essential as well, because a disruption of the laser beam can reduce the amount of laser power arriving at the powder bed. Our patented sintered wall technology therefore pushes a uniform stream of gas through the chamber to prevent this disruption of the laser beam. Steady flow speed ensures reliable soot removal and prevents soot accumulation on the beam entry glass.
Compared to traditional technologies metal AM is still relatively new, however for the last decade we have talked about how engineers and designers need to start thinking differently thanks to these technologies, do you think that tide is turning and people are getting used to metal AM?
We have been working with many different people from different industries. Of course, there are industries that adapt to new technologies faster than others. The automotive and aviation industries, for example, are quite advanced. Nevertheless, we see it as our task, as the leader of additive manufacturing, to show people the advantages of SLM technology and to improve the ROI of our customers – it doesn’t matter if they are already experts or beginners. To work with customers not only as a machine provider, but as a solutions provider, also to contribute to the development of “real AM business cases” is our goal.
As the technology has matured so have considerations of health and safety, how does SLM Solutions ensure that the process is safe?
A safe machine environment, following industrial standards is a basis for the use of additive manufacturing systems in industrialised serial production. SLM Solutions machines are equipped with closed loop powder handling to limit operator contact while securing process integrity. Powder transport, sieving and storage is contained within a closed-loop, inert gas atmosphere. The closed loop powder system is also fundamental for equal powder quality during the whole build process and supports high part quality.
When talking about safety, storage and waste disposal is a particularly important issue. Byproduct of the welding process is submicronic soot and condensate, which can be pyrophoric by nature. SLM Solutions machines are equipped with a permanent filter module. The filter module traps process soot particles from the process gas stream in a sintered plate filter and coats the waste material with an inhibitor for dry disposal. Clean gas returns to the process chamber: Machine uptime is increased, gas flow stabilised, and consumable costs are reduced, all while increasing safety.
Eric Shambroom Copyright 2019 Eric Shambroom Photography
SLM Solutions SLM800
How important is it for the progress of the industry that large material companies are now invested in the technology?
To answer this question, it is necessary to look at what it needs to develop and successfully use new materials on SLM machines. First, the powder is certified for the SLM process. This process consisted of analysing the chemical composition of the material.
Once these tests are successfully completed, SLM Solutions and its team of parameter development experts are able to establish ideal printing parameters for the metal powder. SLM Solutions provides standard parameter sets for the traditional materials, but SLM machines are also open for customised parameter developments and exotic powders. This open architecture strategy is a great advantage for users and paves the way to innovative solutions and materials if required. SLM Solutions works closely together with its clients to qualify new additive manufacturing parameters that enable, for example, printing at increased thicknesses aiming at reduced production times, and reduce costs.
Would you agree that it is true that some of the best examples of AM use is from companies that are not as sexy as aviation, oil and gas etc?
We have seen that industrialisation of metal additive manufacturing requires good answers to aspects like quality, safety and productivity. However, the success of AM largely depends on the extent to which designers succeed in rethinking parts.
Our Joint Development Partner, Divergent Technologies, recently showcased where this path leads with its technology demonstration vehicle, the Czinger 21C hypercar – an all- wheel drive sports vehicle weighing 1250 kg and outputting 1350 hp through a strong hybrid powertrain. It has a multi- material chassis structure that is printed using its proprietary aluminum alloys, including an exhaust system printed in heat resistant Inconel. Additionally, the roof crash structure is printed in titanium for increased lightness at the highest point of the vehicle and added strength. Divergent-Czinger plans to produce a limited number of highly personalised vehicles to demonstrate the weight, cost and time saving benefits of the Divergent Adaptive Production System that incorporates Selective Laser Melting.
This example shows that the automotive industry is far advanced in terms of the industrial series production of SLM parts and to answer your question - if you describe the advantages of additive manufacturing as sexy, there are interesting examples in all of our core industries. Of course, not all of them look like the 21C.
What is next for SLM Solutions?
Stepping forward to industrialisation with improved productivity, parameter developments and an awesome global team of experts.
Read part two inside TCT Magazine issue 28.4 - available for free on Issuu.
