TY - JOUR
T1 - Inability of precipitation-hardening to improve the fatigue limit of Ni-based superalloy 718 through a perspective of shear-mode cracking threshold
AU - Tanaka, Yuya
AU - Okazaki, Saburo
AU - Ogawa, Yuhei
AU - Endo, Masahiro
AU - Matsunaga, Hisao
N1 - Funding Information:
This work was supported by JSPS KAKENHI (Grant Number JP19J10689 ).
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/10/15
Y1 - 2020/10/15
N2 - Fatigue strength of precipitation-hardened materials is well known to be lower than that expected from their high yield and tensile strengths. To elucidate the reasons behind such anomaly, torsional fatigue tests, in addition to uniaxial fatigue tests, were conducted on samples of the Ni-based superalloy 718, subjected to two different heat treatments (solution-annealing and precipitation-hardening). Despite the significant differences in tensile and yield strengths between the two samples, the torsional fatigue strengths were mutually equivalent. This result was interpreted in light of the resistance against fatigue crack-initiation and -propagation in shear-mode, which cannot be enhanced by precipitation-hardening due to the depletion of precipitates by persistent dislocations motion within localized glide-bands.
AB - Fatigue strength of precipitation-hardened materials is well known to be lower than that expected from their high yield and tensile strengths. To elucidate the reasons behind such anomaly, torsional fatigue tests, in addition to uniaxial fatigue tests, were conducted on samples of the Ni-based superalloy 718, subjected to two different heat treatments (solution-annealing and precipitation-hardening). Despite the significant differences in tensile and yield strengths between the two samples, the torsional fatigue strengths were mutually equivalent. This result was interpreted in light of the resistance against fatigue crack-initiation and -propagation in shear-mode, which cannot be enhanced by precipitation-hardening due to the depletion of precipitates by persistent dislocations motion within localized glide-bands.
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U2 - 10.1016/j.matlet.2020.128377
DO - 10.1016/j.matlet.2020.128377
M3 - Article
AN - SCOPUS:85088819681
VL - 277
JO - Materials Letters
JF - Materials Letters
SN - 0167-577X
M1 - 128377
ER -