Design for additive manufacturing and post processing of cellular lattice structure

Traditional manufacturing which is subtractive in nature generally has been associated with more material and energy wastage than required. Final products manufactured exceeds the level of performance as materials are added in similar concentration even in non-stress region. Hence human made load bearing structures are dense solids like steel, concreate, glass, etc., but nature design its structure with cellular solids like cedarwood, cork, trabecular bone, etc. This is difficult to achieve through traditional manufacturing techniques due to manufacturing constraint associated with subtractive manufacturing. Hence, a very promising technology to fabricate and replicate the natural cellular structure in design is Additive Manufacturing (AM). Design for additive manufacturing and post processing (DfAM&PP) is an important concept for designing a product with additive manufacturing. This study is on design for additive manufacturing and post processing with lattice structure and classification of this lattice structure. Material extrusion process is used for additive manufacturing of lattice structure. Presently two most often used AM post processing steps are support removal and surface finish which accounts most of the AM technology. Support removal process is most tedious and challenging process which accounts more than half of the total process time in additive manufacturing. Further during support removing the printed parts often gets damaged and further surface finish operation is employed to smoothen the surface which was earlier supported by the support structure. Design of supportless lattice structure could solve the post processing challenge and bring high speed printing concept. Scanning electron microscope (SEM) is done to analyse the defect and material testing is done with uniaxial compression test for strength analysis.