Residual stress of typical parts in laser powder bed fusion

Laser powder bed fusion (LPBF) can be directly used to fabricate the metal components with complex structures and high performances. However, the extremely high temperature gradient induces the high residual stress, which leads to deformation or even cracking during the process. A layer-by-layer model was developed to investigate the residual stress of the typical part fabricated by LPBF. The maximum stress was found at the position where the part corner joined with the substrate. The second-largest stress occurred at the top center for the solid parts while occurred at the top center of the long side for the hollow and semi-hollow parts. The residual stress levels of the hollow and semi-hollow parts were obviously less than that of the solid parts, and the residual stress at the middle of the inclined-wall part is lower than that of the thin-walled part. Using the rounded corner instead of the sharp corner and using the arc structure instead of the straight-line structure were helpful in reducing the residual stress in LPBF. The simulated results were in good agreement with the experimental data obtained by the hole-drilling method. The investigated results of this paper can be used to reduce the residual stress in LPBF.