| Abstract Scope |
The undesired and unpreventable spatters can significantly degrade the surface quality, dimension accuracy, and mechanical properties of the laser powder bed fusion manufactured parts. However, the mechanism and prediction for spatter formation is still challenging which depends on a large range of process conditions, material properties, and complex interactions between the laser and material. Here, we propose a spatter index based on the ratio of vapor recoil force and the surface tension force at the periphery for a melt pool. The vapor recoil force is calculated according to the alloy’s chemical composition and temperature fields. We apply a well-tested analytical model to calculate the temperature field and melt pool geometry for different alloys. The calculated temperature field and melt pool geometry are applied for the vapor recoil force, surface tension force, and spatter index calculation. The value of the spatter index suggests the spatter occurrence, spatter amount, spatter initial ejection speed, and depression depth of the melt pool top surface. The proposed easy-to-calculate and easy-to-apply spatter index in this work can help in predicting and reducing the spatter formation for different alloys under various process conditions. In addition, multiple spatter index maps are generated for different alloys under various process conditions to guide the laser powder bed fusion process optimization, to reduce spatter formation and spatter amount, and to print parts with high surface quality and mechanical properties. |