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

Abstract

AbstractThe repair of airfoil blades is an enabling technology to extend the operational life of gas turbine engines. Directed energy deposition (DED) additive manufacturing (AM) provides the ability to add material by melting blown powder using a directed energy source. Seventeen Ti‐6Al‐4V airfoil blades were repaired using DED AM and analyzed to determine what effect the repair will have on the blade performance in high cycle vibration fatigue testing. Volumetric computed tomography (CT) was used to quantify the pores from the AM process. The blades were then subjected to vibrational bending fatigue, used to simulate turbine engine loading conditions, until failure. Only three blades failed in the repaired sections. The identified pore sizes and fatigue stress distribution in the blade were used to suggest that understanding the impact of internal and near surface level pores arising from the AM repair is critical towards the implementation of AM repair in aerospace components under fatigue loading.