Investigating Discrepancies in Vibration Bending Fatigue Behavior of Additively Manufactured Titanium 6Al-4V

Abstract

The vibration bending fatigue life uncertainty of additively manufactured titanium (Ti) 6Al-4V specimens is studied. In this investigation, an analysis of microscopic discrepancies between ten fatigued specimens paired by stress amplitude is correlated with the bending fatigue life scatter. Through scanning electron microscope (SEM) analysis of fracture surfaces and grain structures, anomalies and distinctions such as voids and grain geometries are identified in each specimen. These data along with previously published results are used to support assessments regarding bending fatigue uncertainty. The understanding gained from this study is important for the future development of a predictive vibration bending fatigue life model.

Vibration bending fatigue analysis of Ti‐6Al‐4V airfoil blades repaired using additive manufacturing

“…The CT information was used in tandem with the results from a vibration testing method that represented the stresses a blade of this type would experience during second bend mode while operating in an engine 37 . Grouping these data sets together allowed for SIF range calculations to be completed.…”

“…The CT information was used in tandem with the results from a vibration testing method that represented the stresses a blade of this type would experience during second bend mode while operating in an engine. 37 Grouping these data sets together allowed for SIF range calculations to be completed. The calculations established a better understanding of the causes of failure in some of the repairs that cracked away from the typical failure location.…”