Productivity-oriented SLM process parameters effect on the fatigue strength of Inconel 718

The low productivity of the SLM process is known to be a limiting factor, but speeding up the process can lead to material defects. Two sets of SLM process parameters enhancing its productivity by 50 % were devised and tested in comparison with baseline sets, in terms of material microstructure, porosity, surface roughness, static mechanical properties, and HCF behavior, in the as-built and aged conditions. The as-built surface was investigated. Despite a significant increase in the porosity and surface roughness, the fatigue strength was reduced by 5 %. The Murakami √(area_R) parameter effectively correlates the fatigue strength and surface roughness variations.