Residual stress heterogeneity evolution in laser powder bed fusion manufacturing chains: an energy-based simulation–experimental framework

Abstract Residual stress heterogeneity in laser powder bed fusion (L-PBF) components arises from the inherent temperature-gradient mechanism of the process and is subsequently modified by post-processing and finishing. Although L-PBF residual stresses have been studied in isolation, the cumulative effect of full manufacturing chains and the decisive role of operation sequencing on residual stress heterogeneity remain insufficiently understood. This study introduces a novel multi-stage finite element (FE) simulation framework in which residual stress and plastic-memory fields are transferred between successive process models, enabling the propagation and modification of the inherited stress state throughout complete manufacturing chains comprising stress relief, base removal, grinding, and shot peening. The framework is validated against X-ray diffraction measurements, reproducing experimentally the trends observed in residual stress magnitude and heterogeneity. In the as-built condition, tensile residual stresses averaged 335.4 MPa with a heterogeneity indicator of 189.3 MPa, approximately 56% of the mean stress level, demonstrating that mean-stress metrics alone are insufficient to characterize the L-PBF stress state. Stress relief reduced the mean stress to -1.5 MPa but decreased heterogeneity by only 27%, while base removal redistributed inherited gradients through constraint release. Grinding amplified heterogeneity by 82%, whereas shot peening reduced it by 68%. Process sequencing proved decisive: applying shot peening before grinding yielded a final heterogeneity 256% lower than the reverse order. These results are interpreted through an energy-based framework, supporting the design of L-PBF manufacturing chains; its applicability to other manufacturing processes remains to be investigated in future work.