Easy-To-Remove composite support material and procedure in additive manufacturing of metallic components using multiple material laser-based powder bed fusion

Support structures are always associated with laser-based powder-bed fusion (L-PBF) processes, particularly for additive manufacturing of metallic components of complex geometry with overhang structures and for reducing component distortion. Existing L-PBF processes use the same material for both built components and support structures. Removing the metallic support structures from L-PBF fabricated components by the traditional post-treatment method is difficult and time-consuming. This paper demonstrates an easy-to-remove composite support material and related processing procedures in an L-PBF process. For additive manufacturing of 316L components, a SiC-316L composite was developed as a support material. This is combined with hybrid powder-bed and point-to-point selective powder deposition for the additive manufacturing of the components. A specific experimental multiple material L-PBF system was developed and employed to produce 316L components with SiC-316L composite as support structures successfully. An interfacial grid structure using 316L steel was used to avoid component contamination and inferior surface roughness of the 316L component. The experimental results demonstrated that the SiC-316L composite with 40 vol. % 320 grit SiC was feasible to be applied as a support material for 316L stainless steel component additive manufacture in a modified PBF system.