Fatigue life optimization for 17-4Ph steel produced by selective laser melting

International audiencePurpose: The mechanical characterization of Selective Laser Melting (SLM) parts is an industrial challenge. In this paper, a methodology is proposed to control the fatigue life of 17-4Ph stainless steel by selecting the most relevant manufacturing parameters: i.e., laser power, laser travel speed, hatch spacing and laser defocusing. Design/methodology/approach: A rough and a refined Design Of Experiment (DOE) are carried out to target the best combination of process parameters. A response surface model is then constructed to predict the parameter combination that optimizes the fatigue performance. Findings: Our results show that the fatigue limit of the specimens manufactured by SLM (471.7 MPa at 10 7 cycles) has reached near 90% of the value found in samples machined from a bar. This demonstrates the applicability of the method proposed to optimize SLM process and control the fatigue life of 17-4Ph stainless steel. Our results are compared to other research works and provide an increase of 18% to the fatigue limit. Originality: This research work showcases a DOE methodology to optimize the SLM parameters to achieve fatigue performance as great as that of solid 17-4Ph stainless steel