Parameters optimization for horizontally built circular profiles: Numerical and experimental investigation

Selective laser melting (SLM), a type of additive manufacturing (AM) process, is chosen for direct fabrication of powder-based functional metallic objects. The designing of small circular geometries or overhang surfaces built parallel to platform bed has been a subject of concern in the industrial application of SLM. This paper presents an attempt to design and fabricate horizontally built circular holes in a simple cubic model in SLM machine. The processing parameters for down-skin such as laser power, scan speed, and the number of scanned layers were found to play a significant role in the sustainability of small hole built without support structures. The lower incident energy in down-skin region prevents excess melting of powder particles. The Numerical study on ANSYS was first carried out to identify the melt pool depth with different processing parameters and later SLM machine was used to produce the specimens for visual inspection. The results were found satisfactory with the application of down-skin parameters (65 W, 1000 mm/s) subjected to scanning of 3-5 layers above the exposed surface.