Porosity analysis and pore tracking of metal AM tensile specimen by Micro-CT

In this study, the porosity of Ti-6Al-4V (Ti64) tensile specimen fabricated by laser powder bed fusion (L-PBF) with varying three process conditions was investigated. The variation included the energy density in fabrication (3 levels), the build location (3 levels) and the build orientation (2 levels) for a constant scan speed of 600 mm/s. The tensile specimens were scanned using a micro-CT system before and after tensile testing. The porosity of the specimens varied significantly according to the energy density and the build direction, but only a minor effect of the location change was observed. The fractured specimens showed a significant increase, more than nine percent increase in the pore volume in all cases, for the pore volume as well as the porosity percentage. Also, few large pores were tracked in some of the fractured samples and compared with the as-built counterpart to observe the change in pore morphology.