Three-Dimensional Modeling of Laser Sintering of a Two- Component Metal Powder Layer on Top of Sintered Layers

摘要

A three-dimensional numerical model of Selective Laser Sintering (SLS) of the metal powders for a single scan line induced by a moving laser beam interacted with a loose powder layer on top of the sintered metal layers is presented. The problem is modeled using a temperature-transforming model and the partial shrinkage induced by melting is accounted for. The heat losses at the top surface due to the natural convection and radiation are taken into account. The liquid flow of the molten low melting point metal powders, which is driven by capillary and gravity forces, is also considered and formulated by using Darcy's law. The effects of the dominant processing parameters, such as the moving heat source intensity, scanning velocity and number of the existing sintered layers underneath are investigated. A parametric study is performed and the best combination of the processing parameters is recommended.