Vibration fatigue behavior and life prediction of [1 1 1] oriented γ ′-rich Ni- based single-crystal superalloy with film cooling holes

Release time:2026-04-15 Hits:

Journal:International Journal of Fatigue

Key Words:γ′-rich Ni-based single crystal superalloy; [111] crystal orientation; Film cooling hole; Vibration fatigue; Life prediction

Abstract:Vibration fatigue is a critical failure mode for high-pressure turbine blades incorporating film-cooling holes (FCHs). A γ′-rich [111]-oriented Ni-based single-crystal superalloy was studied. Under first bending-mode resonance, the [111] orientation shows higher vibration fatigue resistance than the [001] orientation and several [001]-oriented Ni-based single-crystal alloys. This advantage is attributed to activation of only three <111> slip-plane pairs and the reduced γ/γ′ strength differential that promotes γ/γ′ co-deformation. By contrast, FCH-induced stress concentrations alter the local shear-stress field and generate interlaced cleavage steps, while accelerating dislocation transmission across γ/γ′ interfaces and γ′ shearing, leading to a marked reduction in the fatigue strength at different cycle counts. Based on the stress-concentration effect of FCHs, a Line Method-Vibration Fatigue (LM-VF) method is proposed to predict the S–N response of FCH-containing specimens, achieving prediction errors within ±10% and providing substantially higher accuracy than the conventional line method (LM) within the Theory of Critical Distance (TCD) framework.

Indexed by:Journal paper

First-Level Discipline:Materials Science and Engineering

Document Type:J

Translation or Not:no

Date of Publication:2026-04-15

Included Journals:SCI、SSCI