A novel approach to fabricate uni-directional and branching slender structures using laser-based direct metal deposition

Abstract The slender structures are identified by a distinctive morphology and large aspect ratio. Contrary to most of the common products, the fabrication of slender structures is usually based on forming operations. For complex shapes; however, machining may be required. Characteristic of machining for a slender structure; however, is the very small ratio of sustained material with respect to the machined material. This paper describes a novel approach to fabricate slender structures using laser-based direct metal deposition (LBDMD) in a layer-by-layer fashion such that the thickness of each layer is infinitesimally small. The existing additive layer-by-layer deposition is guided by 2 1 2 axis movement and is characterized by intermittent steps. The proposed method, on the contrary, is similar to continuous casting such that the layer thickness can be considered infinitesimally small. The paper develops a framework for fabrication of slender structures using LBDMD. An algorithm based on geometric reasoning is proposed. Simulations based on Volume Of Fluid (VOF) method and a set of experiments are performed to determine and control various key process parameters. Simulations and experiments performed to determine the a relationship between the material flow rate and corresponding body forces that act on the molten pool as the inclination of substrate changes. A range of complex geometries that are based on linear as well as nonlinear spatial trajectories are fabricated. The fabricated geometries offer different inclinations as well as material flow rate; hence, support the applicability of proposed method.