Recently, the laser powder bed fusion (L-PBF) manufacturing technique has gained popularity among aerospace and defense sectors as a cost-effective approach for fabricating intricate designs in near-net shapes. During the L-PBF process, the rapid solidification conditions coupled with repeated heating and cooling cycles constrain the design potential and printability of complex-shaped structures, especially for part-scale components. Process-induced residual stress, porosity, and crystallographic texture are the most challenging obstacles when designing quality components using this process. The present work used sequentially coupled thermo-mechanical simulation to simulate residual stress during the laser powder bed fusion process. The simulated residual stress was validated with the help of the X-ray diffraction technique. Flow curves were generated from a thermo-mechanical simulator using Gleeble 3800® and were used to calibrate material property input to FEM simulation. FEM simulation of residual stress with calibrated material property provides good agreement with experimentally measured residual stress. X-ray tomography and Electron back scattered diffraction (EBSD) techniques were utilized to quantify the process-induced porosity (distribution and size) and crystallographic texture in the solidified component. The mechanical performance of the deposited components was evaluated using uniaxial tensile tests. The cracking behavior in fractured samples was studied using SEM-based fractography.
The manufacturing orientation considerably influences the magnitude and distribution of residual stress during the LAM processing of part-scale components. Mechanical performance and fracture behavior are heavily influenced by production orientation.