Benchmarking metal powder bed Additive Manufacturing processes (SLM and EBM) to build flat overhanging geometries without supports

Metal powder Additive Manufacturing (AM) allows complex parts to be build from commercial materials. Several industries such as automotive, aerospace and medical have interests in using these technologies. However in metal powder AM, supports/ anchors are required to be melted in place to avoid process failure due to upward warping of flat overhanging geometries. This leads to additional melting of materials, processing time and thus increasing costs of parts build. A series of experiments were conducted to understand capability of processes such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM) to build flat overhang geometries. In addition, effect of preheating the powder feedstock was also performed.