In recent years the combination of laser-based Additive Manufacturing and Computer Numerical Controlled (CNC) machining has become increasingly popular, with several machine tool manufacturers exhibiting products based on different machine tool configurations (hybrid manufacturing). Most commonly hybrid system is based on Directed Energy Deposition (DED) AM processes.
In DED, material in the form of powder or wire filament is fed into a melt pool produced by a heat source (laser, electron beam or electric arc). As the melt pool is moved across the surface of a substrate a bead of molten metal is deposited forming a layer (as in a coating application) or multiple layers to form a geometrical feature. The DED processes (often referred to a laser melt deposition or laser cladding) predates powder bed fusion AM (at least in terms of coating and repair applications).
Unfortunately, the catchment efficiency (ratio of powder supplied to that consolidated) of blown powder DED is never 100% and can be less than 50% for some part configurations. The unfused (over spray) powder represents an economic and environmental problem, pushing up the cost of the process and contaminating the processing cell. Consequently, there is demand to increase efficiency of blown powder DED by reducing overspray and capturing excess powder. Unfortunately, there are significant challenges, including investment in equipment, with capturing and classifying the excess powder and moreover ensuring it is still suitable for use (not contaminated or degraded).
OpenHybrid focuses on the use of laser heat sources as they provide flexibility and process control. The project methods for capturing the overspray powder during the deposition stage of the process thus avoiding contamination of the powder by debris and coolant from subsequent machining operations will be developed. This should enable the powder to be recycled. Interchangeable powder + wire feed heads will be developed to provide the maximum flexibility and deposition rate.
A key objective of OpenHybrid is to make integration of the hybrid system onto any machine tool platform as easy as possible. The ability of a machine tool to be hybridised will be termed hybrid ready. The concept of hybrid ready will be tested in the project.