After a call for projects addressing Additive Manufacturing standardisation gaps, Fraunhofer ILT, Aachen, Germany, has been selected by ASTM International to develop guidelines on standardising and simplifying the maintenance and servicing of Laser Beam Powder Bed Fusion (PBF-LB) machines with ASTM support.
Since 2009, ASTM International has been working towards the standardisation of AM in Committee F42. Additionally, as of 2018, ASTM has been working with representatives from government, industry, and academia at the Manufacturing Center of Excellence (AM CoE). AM CoE aims to accelerate standardisation through conducting short-term, targeted R&D projects, as well as providing education and workforce development, certification, and advisory services.
The monitoring of PBF-LB systems plays a very important role in the entire process, because the high-precision, wear-sensitive, expensive optics of the machine place high demands on cleanliness (i.e., as very fine metal powder is used, optical systems can become contaminated during processing). The machines must, therefore, be regularly cleaned as a preventive measure and, with the increasing number of optical systems and the ever-higher laser powers used, this issue will only be exacerbated.
“Manufacturers’ current maintenance guidelines are often still far too conservative,” stated Niklas Prätzsch, project manager in the Laser Powder Bed Fusion competence area at Fraunhofer ILT. “In contrast to long-established manufacturing technologies, there is no – or only a comparatively small – database available as a basis for making decisions whenever maintenance cycles need to be determined.”
For this reason, users might replace components before it’s necessary, increasing operation costs through both unproductive downtimes and the increased need for spare parts.
Fraunhofer ILT is now focusing on selecting and qualifying imaging sensor technology for monitoring highly loaded optical systems of PBF-LB machines. In addition, it is deriving recommendations for end-users of the technology. It aims to help end-users independently assess the condition of optical systems and plan maintenance cycles by using more up-to-date information about the actual condition of the system. The new cycles will no longer be based on subjective perception or experience, but on real data, meaning maintenance is less likely to be carried out too early or too late. This should significantly reduce costs for the end-user.
Prätzsch added, “We are providing end-users with recommendations that simplify their use of cost-effective imaging sensor technology for condition monitoring of optical systems in LB-PBF systems. Based on the data, they can then make informed decisions about whether or not maintenance is necessary.”
With the standardisation, Fraunhofer ILT hopes to enable end-users to efficiently generate their own database, making it easier for them to correctly classify and interpret the data. The end goal is a standardised decision-making best-practice that recommends to the end-user when and how to conduct maintenance or calibration.