'The University of Texas at Austin, Bureau of Economic Geology'
Abstract
Laser Beam Melting is a promising Additive Manufacturing technology for the production of complex
metal components. During batch production of multiple identical parts in a single build job, we observed parts
with deviating surface roughness in certain areas, which all faced away from the laser. This suggests a dependency
of surface roughness on the part position in the build chamber. In this work we systematically reproduce and
analyze this effect. We place hollow pyramids with twelve faces and two different overhanging angles at nine
positions on the substrate plate and build this setup twice, using an imaging setup for process documentation.
Surface roughness is measured by contact profilometry on three lines for each pyramid face. Our experiments
reproduce the effect. Based on these findings we present a hypothesis for the cause and show metallographic
images to support our theory. As a consequence, the position relative to the laser should be considered in the
design phase for parts with high surface quality requirements.Mechanical Engineerin
