A review on design and removal of support structures in metal additive manufacturing

Abstract

Additive manufacturing (AM) enables the rapid fabrication of complex metallic components via a layer-by-layer method. Support structures are essential to ensure the successful printing of overhang features, and they have to be removed after printing. However, the usage of a support structure increases the material waste, printing time, and cost for post-removal. Hence, some studies are conducted to reduce the use of support structures by optimizing their design and by changing the build orientations. Some researchers managed to develop novel techniques for support structure removal to replace the current labor-intensive methods. So far, however, there is little comprehensive review focusing on both the design and removal aspects of support structures in metallic additive manufacturing (MAM). In this review, the design methodology and the state-of-the-art removal techniques of support structures are reviewed and discussed. The advantages and disadvantages of topology optimization and build orientation selection in reducing the volume of support structures are analyzed. The support removal methods are summarized in terms of the material difference between the workpiece and the support structure. It is concluded that more efforts need to be rallied towards the effective removal of the support structure in MAM.