Post-Processing technologies for Laser additive manufacturing: A comprehensive review of process-performance mapping, synergy mechanisms, and technology selection framework

Laser additive manufacturing (LAM) has emerged as a transformative technology for producing complex metallic components in aerospace, biomedical, and automotive industries. However, LAM-fabricated parts inherently exhibit surface defects, internal defects, and residual tensile stresses, which significantly deteriorate fatigue performance and service reliability. Therefore, post-processing technologies are essential for addressing these limitations. This comprehensive review classifies post-processing technologies into subtractive, equivalent, and additive types according to material interaction mechanisms, establishing a unified analytical framework based on three key innovations. Initially, this study constructs a “process–physical field–microstructure–performance–engineering” mapping framework that correlates physical field mechanisms with microstructural evolution and performance enhancement across representative technologies. Subsequently, three sequence-dependent synergy mechanisms—reinforcement superposition, functional complementarity, and reinforcement layer destruction—are identified and mechanistically explained, revealing that improper sequencing can severely deteriorate introduced strengthening layers. Finally, a performance-oriented hierarchical technology selection framework is developed, incorporating quantitative scoring matrices across six performance dimensions and synergy effect matrices to guide engineering decision-making. The framework demonstrates that subtractive post-processing achieves significant surface quality improvements, equivalent technologies introduce residual compressive stresses with fatigue life enhancement, and additive technologies provide exceptional surface hardness increases. This approach provides scientific guidance for optimizing post-processing strategies in high-end manufacturing applications.