Case study: Intelligent scan systems ease machine integration and increase throughput in additive manufacturing
The Open Interface Extension, fiberSYS scan system and RTC6 EtherBox from Scanlab
There are several challenges when setting up a laser powder bed fusion (LPBF) machine, especially for industrial series production in additive manufacturing (AM). But before analysing the main parts of an LPBF machine, how can scan systems increase productivity for industrial applications?
In order to select the best laser scan solution for a machine, it is helpful to make the most important machine architecture decisions upfront. Three different aspects can be identified. The first one is to increase productivity. Shorter production times and higher throughput can be realised through simultaneous processing and overlapping image fields in a multi-head laser machine set-up.
Larger construction fields, achieved with system set-ups with flat field correction, help to increase productivity further. In addition, the control technology of the scanner itself can shorten processing times. This is realised by minimising non-productive times like skywriting or laser-off times.
The second aspect is to prioritise the precise processing of filigree and complex structures. To guarantee the highest accuracy and lowest drift, galvanometer scanners with digital encoder technology and the best long-term system stability are the perfect choice. Additionally, all machine-specific tolerances should be taken into account with the help of a calibration solution.
The third aspect to consider is process reliability and how to set up the laser equipment with emphasis on a ‘right first time’ approach. To ensure this, precise positioning and process monitoring are absolutely necessary. This is especially important in regulated industries, where real-time monitoring is often a must-have.
Easy to integrate scanning solutions
After the architectural decisions, the best-fit scanning solution must be defined. The starting point is to decide on reliable and flexible control electronics to control lasers, scan systems and peripheral devices in real time. A solution for a plug-and-play integration could be the compact RTC6 EtherBox. Thanks to a top hat rail bracket, it is very easy to install and includes an RTC6 control board with SL2-100 protocol. The Ethernet connection allows a smooth integration in automated factory layouts.
The core part of an LPBF machine is the laser scan system itself. For these components there are two main choices: one option is a scan system with specialised technical features (such as the intelliSCAN and excelliSCAN series) to meet individual process requirements and to offer the greatest flexibility.
The other option is to go for a higher integrated system, such as the slim fiberSYS, which includes a fibre adapter, a z-axis, low-drift galvanometer scanners and a process monitoring port. A further advantage of this scanner is the compact layout, which is ideally suited for multi-head systems and offers maximum image field overlap.
The last part of an LPBF machine to decide on is the process monitoring equipment. Various sensors such as pyrometers and cameras may need to be connected. An intelligent solution for synchronising this sensor and position data is the Open Interface Extension (OIE). Of course, for a smooth operation, all three sections need to interact and integrate with each other.
Selective laser in vacuum for additive manufacturing Evobeam is a machine builder for rapid beam processing. The company specialises in additive manufacturing and welding technology with electron beam and laser operation in a vacuum.
Dr Johannes Weiser, Head of Additive Manufacturing at Evobeam, comments on his experience when integrating scan systems and other machine components: “Scanlab and its pre-configured products are a perfect fit for us. The intelligent systems save us plenty of time in integration and allow us to concentrate fully on our machine building and the process development. In this way, we can reduce the time-to-market and guarantee the best set-up for various application requirements.”
Machine builders, such as Evobeam, are driving innovation in the field of additive manufacturing. It will be exciting to see which further innovations arise in the coming years.
Dr Matthias Morasch is Team leader Product Management at SCANLAB; Dr Daniel Reitemeyer is Business Development Manager, SCANLAB