Scaling up Build Rates in Laser Powder Bed Fusion of Metals Using Dimensionless Parameters

In selective laser melting of metals, the layer thicknesses are typically kept low (20–40 µm) to achieve high geometrical accuracy and surface qualities. These settings lead to low volumetric build rates. To utilize higher layer thicknesses, process optimization and design of experiments are often necessary. In this paper, a method of scaling the process parameters based on melt pool dimensionless parameters is presented. Process parameters optimized for highest density at low laser power and low layer thicknesses were scaled up to higher laser powers and higher layer thicknesses. Due to the different layer thickness, scan rates, spot size and power, the microstructure morphology would be different. This scaling method has been tested in printing stainless steel 316L at a few layer thicknesses. The effect of the scaling on the microstructure and thus mechanical properties such as porosity.