Study on the geometric design of supports for overhanging structures fabricated by selective laser melting

Abstract

Additional structures are usually adopted to support the overhanging structures in order to resist the deformation of parts. Improper geometric design of the support structures may result in a sharp deterioration in the surface quality and a failure of manufacture, which affects the expansion in the use of selective laser melting (SLM) technology. In this research, cuboids were added into the conventional block support for a better heat dissipation. The Taguchi method was used to analyze the effect of the geometric design of this support on the part's deformation and surface roughness. It was found that solid pieces or cuboids as support structures can reduce the deformation. However, their effects are weaker than those of teeth structures which decrease the deformation by more reliable connections. It is interesting that narrowing the gap between the cuboids and overhang can weaken the strength of teeth structures and then increases the deformation of part. In general, the distance between every two adjacent walls of support and the gap between the cuboids and the overhang have the greatest influence on the part's deformation and surface quality respectively.