Monday  |  Heritage D  |  01:50 PM–02:10 PM

#17658, Effect of Intentionally Seeded Defects on the Fatigue Crack Initiation and Fatigue Life in L-DED Inconel 625

One approach to ensure the quality of additively manufactured parts is through in-situ monitoring during the build process. Signal measurements correlated to part defects can be monitored in order to eliminate costly and time-consuming non-destructive evaluation post-build. This study simulated anomalies in the build parameters leading to defects that might compromise the quality outcome of components manufactured with laser directed energy deposition(L-DED). For this, a method to deliberately introduce defects into the part was developed and test specimens were manufactured with defects incorporated at specific locations and with different densities. The effect of these intentionally induced defects on the fatigue crack initiation and fatigue life of L-DED built Inconel 625 were investigated. High cycle fatigue tests were performed and the fracture surfaces were analyzed using scanning electron microscope images. Fatigue results showed that the influence of defects on the fatigue life were primarily dependent on the hatch type used during the build process. Fractography results showed that while defects were present in the specimen, they were not necessarily the primary factor for fatigue crack initiation. The data from the study helped in corelating build process anomalies with the defects and, thereby, helped in predicting which of those defects would actually degrade the fatigue behavior leading to a well-informed adoption of additively manufactured parts in commercial components.

Joseph Indeck   Boeing Research & Technology
Baily Thomas   Boeing Research & Technology
Harikrishnan Rajendran   Boeing Research & Technology
Zachary Theimer   Boeing Research & Technology
Jessica Johnson   Boeing Research & Technology
Matt Callaway   Boeing Research & Technology
Lawrence Pado   Boeing Additive Manufacturing
Taisia Lou   Boeing Additive Manufacturing
Dan Driemeyer   Boeing Research & Technology