Fraunhofer Institute for Laser Technology ILT
Fraunhofer Institute for Laser Technology ILT

Process & Systems Engineering forLPBF

The LPBF process

Since it applies layer upon layer using CAD data, LPBF can produce highly complex components from metallic materials without the need for forming tools, components that cannot be manufactured using conventional production processes such as casting or machining. The LPBF process is often described in simplified terms as "metallic 3D printing," but in reality it is influenced by numerous process parameters and disturbance variables, which make it far more complex. Only by selectively adjusting these process parameters while simultaneously controlling the disturbance variables can the user ensure that the manufactured component fulfills the desired requirements.

LPBF machines have a movable build platform onto which a powder layer is applied with an application unit. The laser radiation required for the LPBF process is deflected by a galvanometer scanner and focused by F-Theta or Vario optical systems. Metallic materials are processed in an inert gas atmosphere, with the gas circuit taking over the task of removing process by-products. The machine components used influence various properties of the overall system, such as process speed and component quality. Thus, to use laser powder bed fusion economically, a company has to appropriately select and combine individual components for the corresponding application. The experts at Fraunhofer ILT can help you optimize the LPBF process and the associated system technology individually for your application and, if necessary, develop new strategies for solving your tasks.

Support-free production thanks to geometry-adapted process control
© Fraunhofer ILT, Aachen, Germany.
Support-free production thanks to geometry-adapted process control

Tailored LPBF – Tailor-made for your application

Gantry-based LPBF large-scale plant
© Fraunhofer ILT, Aachen, Germany.
Gantry-based LPBF large-scale plant

In order to resolve the typical trade-off between component quality and productivity in LPBF manufacturing, Fraunhofer ILT is developing innovative machining strategies. By adjusting the energy temporally and locally, the institute can adapt the process control to the component that has to be manufactured and to the user's requirements, thus enabling machining that is not only very fast, but also very precise. System technology and software make it possible to selectively adjust every parameter down to the level of individual melt tracks. This ensures full control over the LPBF process.

Scalable machine designs and plant components

To industrialize LPBF, research has to scale up the machine technology – size of the building space, productivity and robustness. To this end, Fraunhofer ILT is developing innovative machine designs based on movable processing heads with local inert gas guidance, which make it easy to scale up the building space. Multi-beam systems are used to increase productivity, with both classic galvanometer scanners and novel kinematic concepts being investigated. In addition, Fraunhofer ILT is testing new types of laser beam sources with short-wavelength light, which promote efficient energy coupling, especially for highly reflective materials such as pure copper. In addition, it is developing optical systems for adaptive beam shaping, which can achieve higher build-up rates. Furthermore, in addition to conventional build platform heating, Fraunhofer ILT is developing novel systems for direct preheating at the process level, systems that reach temperatures of up to 1500 °C and enable the processing of demanding materials susceptible to distortion and cracking. This allows constant preheating ratios to be achieved regardless of the component size.

Monitoring systems for the digitization of LPBF

Innovative preheating concept
© Fraunhofer ILT, Aachen, Germany.
Innovative preheating concept

Before LPBF can be used in series production, the process and component quality has to be reproducible. To verify this, industry needs adapted systems for process monitoring. At Fraunhofer ILT, systems are used in LPBF for monitoring the remelting process and for characterizing the solidified material. Furthermore, the machine condition is monitored during the process by means of novel sensor technology. Cloud-based systems and machine learning models are being investigated to store and analyze the data.

Equipment

Our portfolio of industrial LPBF equipment includes:

  • EOS M290 (PL = 1000 W, Exposure OT)
  • TruPrint5000 (PL = 3x500 W, Tplatform, max = 500°C)
  • SLM 280 Twin (PL = 2x400 W)
  • EOS M270 (PL = 200 W)
  • Concept Laser XLine (PL = 2x1000 W)

Our LPBF laboratory systems, some of which we developed ourselves, can be flexibly adapted to your requirements as they use open hardware and software architecture. The technical specifications include, among others:

  • Different beam sources (wavelengths, beam profiles, multi-kW powers) and optics systems (e.g. multi-scanner systems, systems with interchangeable optics)
  • Different powder application systems (e.g. vibration-assisted powder application, different application tools)
  • Flexible inert gas guidance and measurement systems
  • Various LPBF preheating systems up to 1500 °C
  • LPBF plants for processing small quantities of powder
  • Systems for process monitoring (e.g. thermography) 

Range of services

  • Feasibility studies and process development using various materials and systems engineering
  • Application-specific (further) development of LPBF system components all the way up to the complete machine
  • Development of process-specific solutions (e.g. process control for multi-scanner systems, adapted laser intensity distribution, etc.)
  • Development of innovative solutions along the digital process chain (process monitoring and control, intelligent data preparation and post-processing)
  • Consulting, training and benchmarking