Processing parameter has an important effect on Selective Laser Melting (SLM) and
Electron Beam Melting (EBM) processes. Defects are easily formed by deviating from optimized
processing parameters. This study purposely fabricated Ti-6Al-4V specimens with defects by
varying process parameters from the factory default settings in both SLM and EBM equipment.
Specimen’s density was measured based on the Archimedes method for estimating porosity.
Microscopy of specimen’s top surface were observed to compare melt pool and overlap. “Marginal
Parameters” is identified to describe the processing parameters which are capable of fabricating
specimens with certain porosity. As a result, a correlation between defect regularity and marginal
parameters has been established. The effect of marginal parameters on the melt pool is discussed
to explain defect formation.Mechanical Engineerin
