Customized photonic devices for defectless laser based manufacturing
Different beam shaping technologies, appeared in recent years enable to tailor energy delivery using a tailored spatial and temporal power distribution in laser beam. This makes possible to solve relevant metallurgical problems, such as hot cracking in Laser Beam Welding (LBW) and Laser-based Powder Bed Fusion of Metals (PBF-LB/M). However, the desired thermal history (temperature range and cooling rates) is specific for each material. In other words, it is material- and process-specific so the exact beam shape must be customized to the specific alloy and process in question. This is not exclusive to LBW and PBF-LB/M, but also to other laser-based manufacturing scenarios where a certain thermal history is needed for precise microstructure tailoring. CUSTODIAN aims to develop a methodology of application-driven laser beam tailoring of the material microstructure and deploy this beam to solve hotcracking in LBW and PBF-LB/M. CUSTODIAN will rely on beams with specific shape and spatial energy distribution, designed upon the metallurgical studies and multiphysics simulation for each combination of process and material. To accomplish the deployment of customized beam shapes in relevant industrial environment, the consortium will perform a twofold photonic development: (1) a compact, robust and dynamic beam shaping technology (Multi Plane Light Conversion, MPLC) and (2) a closed loop inline control system based on uncooled SWIR/MWIR sensors and an FPGA architecture to ensure the quality and dynamicity of the beam shape requirements. The application scenarios of CUSTODIAN are: LBW of austenitic steel for exhaust systems in automotive and PBF-LB/M of nickel superalloys in energy and aeronautical sectors. The developed methodology for application-driven beam shape design will be protocolized to facilitate its future extension to other laser-based processes with (e.g. laser metal deposition) or without material addition (laser tempering, laser softening, etc.) as well as to other shaping technologies.