Foreign Object Damage characteristics and their effects on high cycle
fatigue property of Ni-based superalloy GH4169
Abstract
In this study, high-speed ballistic impact tests were conducted on
GH4169 alloy samples with the aeroengine compressor blade leading edge
feature to simulate the notch-type foreign object damages (FOD).
Macroscopic and microscopic characterization of FOD and high cycle
fatigue tests were performed to investigate the effect of FOD depth on
GH4169 alloy fatigue strength along with numerical analysis using
Kitagawa-Takahashi diagram. Results show the incident side of notch-type
FOD is relatively smooth, whereas the exit side is rugged. The FOD depth
ranges from 0.18mm to 1.33mm, and the fatigue strength of damaged
samples is 37.93%~97.04% of the undamaged samples. As
FOD depth increases, damage length, material losses and stress
concentration coefficient of the FOD increase significantly along with
the increasing adiabatic shear bands, micro voids and cracks, resulting
in fatigue strength reduction. Numerical analysis indicates that the
Kitagawa-Takahashi diagram can provide a basic model for the design of
FOD tolerance.