Identifying optimum process strategy to build geometrically stable cylindrical wall structures using laser directed energy deposition based additive manufacturing

Abstract

One of the bottlenecks for wider industrial acceptance of Laser Directed Energy Deposition (LDED) based additive manufacturing technique is the limited dimensional accuracy during the processing stage. This paper reports an investigation to identify the optimum process strategy to build dimensionally accurate and near-net-shaped cylindrical wall structures with minimum hump height. Four different approaches are deployed to identify the optimum process strategy by varying laser scan pattern (offset and spiral strategy), and speed ratio (SR) (dwell speed/scan speed) in an inert atmosphere of argon gas. An offset strategy with SR > 1 is found to be suitable for building near-net-shaped and stable cylindrical wall structures using LDED.