Effects of Build Orientation and Heat Treatment on the Porosity Distribution and Morphology within Inconel 625 Fabricated via Laser Powder Bed Fusion

The effects of build orientation, i.e., vertical, or diagonal (45º), and heat treatment on the porosity characteristics within Inconel 625 (IN625) fabricated via laser powder bed fusion (LPBF) was experimentally investigated. Selected samples were heat treated at 1050 ℃ for 1-hour to promote evolution of pores. X-Ray Computed Tomography (XCT) was performed on samples to generate three-dimensional porosity maps. Volume Graphics (VG) software was used to inspect and quantify porosity distributions. Results indicate that build orientation and heat treatment influence measured porosity count. As-built (no heat treatment) sample microstructure was observed to have lower porosity count when compared to heat-treated samples. The vertically built sample was observed to have lower porosity relative to its diagonally built counterpart. The porosity morphology or diameter was observed to vary after heat treatment. On the other hand, the sphericity of pores was not affected by different build orientation and heat treatment.