Laser Directed Energy Deposition (LDED) has gained prominence as an advanced additive manufacturing technology, offering high precision, efficiency, and environmental benefits. However, component deformation and micro-defects remain considerable obstacles, driving ongoing research into optimizing process parameters such as laser power, overlap ratio, and scanning strategies. This study presents a hybrid deposition strategy aimed at mitigating the issue of heat accumulation from repeated thermal cycling in LDED. Effective thermal management is crucial for minimizing defects and is a key metric for evaluating deposition strategy performance. By alternating circular scanning and zigzag scanning deposition paths between adjacent layers, the thermal history and stress distribution are systematically modulated, resulting in reduced interlayer defects and improved mechanical properties. The global deformation of the 316 L specimens is evaluated through surface topography analysis in both the hybrid deposition strategy and the conventional circular scanning deposition. A comparative and analytical study of the defects, microstructure, and Vickers hardness around the interface bonding region, as well as metallographic characterization, has been conducted. The experimental and numerical results reveal that the proposed hybrid scanning deposition approach can achieve more desired mechanical characteristics and forming precision in 316 L stainless steel parts.
Zhang et al. (Sun,) studied this question.