Effect of Build Orientation on Residual Stress and Microstructure in Inconel 625 Fabricated via Laser Powder Bed Fusion
Date
2022Metadata
Show full item recordAbstract
The reliability of parts produced by Laser Powder Bed Fusion (L-PBF) is still not at a great
acceptance level. One of the major defects inherited in parts fabricated from L-PBF is a high level
of residual stress. In this study, two build orientations i.e., vertical and diagonal, were used to
fabricate Inconel 625 specimens to observe its effects on the residual stress magnitude and grain
growth. A novel, Cos-α X-ray diffraction method was used to measure residual stress values along
the top surface of the samples. Electron Backscattered Diffraction (EBSD) and kernel average
misorientation (KAM) maps were employed to explain residual stress trends and differences
between samples. Results indicate that the as-printed vertical sample possessed a higher tensile
residual stress (77 ± 15 MPa) compared to the diagonally-printed sample (52 ± 12 MPa). The KAM
map of the as-printed vertically oriented sample showed more pronounced local misorientations
caused by dislocations compared to the diagonally-printed sample.