XCT characterization and mechanical properties of Ti6Al4V produced by L-PBF using the same volumetric energy density

Volumetric energy density (VED) is an important synthetic index for predicting part density in additive manufacturing and its correct selection can significantly minimize internal porosity. This study investigates the influence of varying process parameters, all with the same nominal VED, on the porosity structure and mechanical performance of Ti6Al4V specimens produced via laser powder bed fusion (L-PBF). Tensile and fatigue samples were manufactured using different parameter combinations to assess their effects on porosity and performance. X-ray computed tomography (XCT) was conducted on the gauge sections of the specimens to acquire porosity data, which was subsequently analyzed using functional data analysis (FDA). All parameter combinations yielded a calculated density exceeding 99%. Functional analysis of variance (F-ANOVA) was employed to test the hypothesis of equal means between groups on the cumulative distributions of equivalent spherical diameter (ESD) and radial position. The results indicate that different parameter combinations lead to the formation of distinct porosity structures. Despite these variations, tensile and fatigue tests demonstrated comparable behavior across all the groups. The observed porosity structures did not significantly impact the macroscopic properties, suggesting that substantial variations in process parameters may be introduced to enhance machine productivity without compromising high part density and mechanical performance.