Rapid initiation and growth life characterization of additively manufactured alloy 718 through compliance monitoring

Abstract Additive manufacturing offers significant design versatility which can be leveraged for complex geometries and microstructural tailoring through the manipulation of numerous process parameters. Structurally critical components require significant material characterization and qualification for each material iteration. Traditional methods for characterizing fatigue performance of materials is expensive and time consuming, so new test methods to rapidly quantify important fatigue characteristics and behavior is necessary to supplement standard data and increase the production of fatigue data for advanced alloys. Toward this end, specimen compliance is initially investigated to detect crack initiation in AM components under fatigue loading. Initial results indicate that this method detects crack initiation earlier and cheaper than optical or thermal imaging methods. The observations made in this investigation provide valuable insight on the dependence of fatigue initiation and growth life on applied stress and pore size which is critical for designing for AM components.