Key Words: LPBF, Production Planning, Build Time Calculation, Economic Efficiency

Innovative and Reliable Cost Calculation Tool for Modular Laser Powder Bed Machine Concepts

Over the past two decades, Laser Powder Bed Fusion (LPBF) has been evolving into a potential series production solution. The industrialization of LPBF is in full swing and it becomes clear that economic efficiency is one of the most important aspects when sustainably implementing this process in industrial applications. For this reason, LPBF machine suppliers offer modular and scalable machine concepts as well as auxiliary systems that customers can individually configure to suit their needs.

The RWTH Aachen University Chair for Digital Additive Production DAP has recently developed an innovative and reliable LPBF cost calculation tool for these modular system solutions: the virtual module emulator that is integrated into the entire digital LPBF process chain. The virtual module emulator replaces the real machine by processing the layered 2,5D geometry data and by virtually executing the contained scanning vectors. A procedural control, implemented by individual module instances in a service-oriented architecture (SOA), executes the LPBF process by calling virtual services, e.g. the virtual “coater” that executes the action “add powder”.

The build time which the virtual module emulator calculates is verified exemplarily by comparing it layer-wise to log timestamps of nine actual build jobs carried out on a dual laser LPBF machine. The mean absolute percentage error (MAPE) reaches 0.28 % for the model. The layer-wise analysis shows an average deviation below 0.2 % with a standard deviation below 1 %, resulting in a nearly geometry independent prediction of build time.

The cost calcualtion tool allows for optimized production planning and machine utilization since an almost exact build time calculation predicts when the machine operator has to take action, for instance. Additionally, the calculation accuracy enables both system suppliers as well as system operators to make dependable statements regarding economic efficiency and required degree of system modularity for an optimal production of customized componens.