Abstract Scope |
It has been shown that defect and microstructure features can dictate the fatigue performance of AM components. The actual relationships between defects, microstructure, applied stress, and fatigue life, however, are not fully understood. Therefore, an investigation was performed to examine fatigue performance of AM alloy 718 components of three different processing pedigrees which helped solidify the dependence of fatigue life on defect content and microstructure. Failure defect size, microstructure size and the applied stress were noted, and these values were related to the total life of the part. It was shown that pores behave differently under different applied stresses, and that microstructure size has a direct correlation to the growth life of the component. Using the data collected here, a method for identifying critical pore sizes for AM inspection efforts was developed, and methods for rapid characterization of fatigue properties were introduced which facilitates AM material qualification and modeling efforts. |