L-PBF 공정에서 경사 오버행 구조의 열변형 해석

초록

This study investigates heat transfer and thermo-elastoplastic behavior during the Laser Powder Bed Fusion –(L-PBF) process of inclined structures using finite element analysis (FEA). The numerical results for a 60°overhang agreed well with experimental data in terms of vertical deformation. Analysis of various inclination angles revealed that, for 30° and 45°, the maximum displacement remained below the critical threshold defined by the 40 m layer thickness, ensuring process stability. However, at an inclination angle of 60°,deformation increased significantly, exceeding the layer thickness and potentially causing recoater interference. Furthermore, the effect of layer thickness (40, 80, 120 m) was examined for the 60° overhang condition, showing that although the absolute deformation increased with thickness, the 120 m case remained below its corresponding threshold and was therefore advantageous. Importantly, the results show that grouping multiple layers into a single simulation step can cause significant discrepancies in overhang deformation analysis, indicating that the FEA mesh size and deposition steps must correspond to the actual layer thickness and experimental conditions. These findings provide essential guidelines for optimizing process parameters and improving numerical modeling for complex additive manufacturing geometries.

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