Defect Formation in EBM Parts Built in Horizontal Orientation

Abstract

EBM built parts in a horizontal orientation, particularly with bottom curved surfaces, are prone to variations in dimensional accuracy and defect formation. These defects likely occur due to the nature of the supports utilized and the build strategy. To understand the effect of support structures and scan direction on these defects, a series of cylindrical parts were built using different diameters, support structures and scan strategies. The as-built samples were mechanically tested and sample cross sections were analyzed. Pore formation and balling effects were observed in the lower section of some samples. The study looks at the effects of supports, geometry and scan strategy on the minimization of these defects and improving the dimensional accuracy of horizontally built samples.