Effect on Free-Edges on Melt Pool Geometry and Solidification Microstructure in Beam-Based Fabrication of Thin-Wall Structures

The success of both laser and electron beam-based fabrication processes for additive manufacturing and repair applications requires the ability to control melt pool geometry while still maintaining a consistent and desirable microstructure. To this end, previous work by the authors has employed point-heat source solutions to investigate the effects of process variables (beam power and velocity) on melt pool geometry and solidification microstructure (grain size and morphology) in beam-based fabrication of thin-wall structures. However, these results were limited to steady-state conditions away from free-edges. The current work extends the approach to investigate transient behavior in the vicinity of a free-edge.