A critical review on mechanical properties regulation strategies of laser additive manufacturing (LAM) metal components: Process optimization, composition and structural design

Laser additive manufacturing (LAM) technique has demonstrated broad application prospects in the high-level equipment manufacturing field due to its outstanding advantages, including high material utilization rate, forming precision, and structural design freedom. However, the intense thermal cycling and rapid solidification during the LAM process can easily lead to microstructural inhomogeneity and defects, becoming a crucial bottleneck that limits mechanical properties of components. Research progress on mechanical properties regulation strategies for LAM metal components were systematically reviewed from two aspects: process optimization, composition and structure design. Firstly, the study summarized the regulation mechanisms of forming parameters and the crucial effect in enhancing mechanical properties. The mechanism and applicability of multi-field coupling technology and post-processing techniques in achieving microstructural homogenization and optimizing mechanical properties were discussed in detail. Then, the strengthening mechanisms of alloying elements and particle reinforcement strategies were discussed, exploring the influence patterns of different elements, particle types, and their distribution characteristics on microstructural evolution and mechanical properties. Additionally, the strengthening effects of functionally graded structures and biomimetic composite structures on stress, interfacial bonding, and crack suppression were analyzed. Finally, the development trends of LAM in intelligent process optimization and multi-scale structural design were prospected. This study provides theoretical support and technical reference for improving the mechanical properties of LAM metal components.