Mesoscopic simulation of overlapping behavior in laser powder bed additive manufacturing

Abstract

The prediction of the flow behavior of Metal micro-molten pool is prerequisite for high-quality Laser Powder Bed Fusion (L-PBF). In this study, mesoscopic scale numerical simulation modelling for L-PBF process was used to help understand the melting process of pure copper micro-melt pool. In this study, the orthogonal test was designed to study the influence of laser power, laser scanning velocity, hatching space on the flow behavior of molten pool and the overlapping rate of adjacent molten tracks. The results shows that laser scanning speed has the greatest influence on both the size and overlapping rate of the molten pool, and the overall trend was that the size of molten pool continues to increase as the volume energy density increases, and the maximum molten pool size was 243.6 um × 110 um with volume energy density 370.037 J mm ^−3 , overlapping rate of adjacent molten tracks was 48.84% with volume energy density 285.71 J/mm ^3 . The optimized pure copper laser process parameters were obtained: laser power 300 KW, laser scanning speed 500 mm/s, hatching space 0.07 mm, overlapping rate 48.84%.

Keywords

• L-PBF
• molten pool
• pure copper
• numerical simulation