Design Guidance for Filleting of Selective Laser Melted Metal Parts

This study used computational and experimental methods to assess the impact of a variety of fillet parameters (type, overhang length) on residual stress induced deformation in metal selective laser melted parts. Modelling results indicated increasing amounts of residual stress induced deformation with increasing unsupported overhang length. Eliminating unsupported overhang length by using large sweeping fillets was found to be an optimal strategy for reducing residual stress induced deformation and for reducing stress concentration. Computational and experimental results indicated elliptical fillets are preferred relative to circular fillets, because they reduce the amount of unsupported overhang length. Finally, introducing a tangent line when a circular or elliptical fillet becomes unsupported (to create what we call a self-supporting fillet) was found to be an effective strategy for minimizing residual stress induced deformation and should be used when unsupported overhang length becomes large.