fig16
From: Residual stress mapping of additively manufactured Inconel 718 via synchrotron X-ray diffraction
Figure 16. Formation mechanism of residual stress: (A) powder spreading for the new building layer; (B) a laser scans across the powder bed, inducing localized heating, while the underlying substrate undergoes cooling; (C) the newly deposited layer (n + 1) cools and contracts, resulting in upward pulling forces on the underlying layers; (D) final state residual stress distribution after AM processing. In (B and C), the red arrows denote thermal strain direction, while the black arrows denote elastic strain direction. LD: Loading direction; TD: transverse direction; AM: additive manufacturing.
