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

Purpose - The mechanical characterization of selective laser melting (SLM) parts is an industrial challenge. This paper aims to propose a methodology 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 refined design of experiment (DOE) is 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 -This study results show that the fatigue limit of the specimens manufactured by SLM (471.7 MPa at 107 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 the SLM process and control the fatigue life of 17-4Ph stainless steel. The study results are compared with other research works and provide an increase of 18% to the fatigue limit. Originality/value - This study showcases a DOE methodology to optimize the SLM parameters to achieve fatigue performance as great as that of solid 17-4Ph stainless steel.