Optimization of Scan Strategies in Selective Laser Melting of Aluminum Parts With Downfacing Areas

Selective laser melting (SLM) is an additive manufacturing technique in which metalproducts are manufactured in a layer-by-layer manner. One of the main advantages ofSLM is the large geometrical design freedom. Because of the layered build, parts withinner cavities can be produced. However, complex structures, such as downfacing areas,influence the process behavior significantly. The downfacing areas can be either horizon-tal or inclined structures. The first part of this work describes the process parameter opti-mization for noncomplex, upfacing structures to obtain relative densities above 99%.Inthe second part of this research, parameters are optimized for downfacing areas, bothhorizontal and inclined. The experimental results are compared to simulations of a ther-mal model, which calculates the melt pool dimensions based on the material properties(such as thermal conductivity) and process parameters (such as laser power and scanspeed). The simulations show a great similarity between the thermal model and the actualprocess. [DOI: 10.1115/1.4028620]Keywords: SLM, AlSi10Mg, downfacing structures