Crack growth in a single crystal superalloy at elevated temperature

1984 ◽  
Vol 15 (9) ◽  
pp. 1711-1719 ◽  
Author(s):  
J. S. Crompton ◽  
J. W. Martin
Keyword(s):  
Elevated Temperature ◽  
Single Crystal ◽  
Crack Growth ◽  
Single Crystal Superalloy

Estimation of Applied Stress at Fatigue Cracks of a Single Crystal Superalloy

2020 ◽  
Author(s):  
Daisuke Kobayashi ◽  
Katsuhiro Takama ◽  
Tomihiko Ikeda
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Fracture Surface ◽  
Single Crystal ◽  
Crack Growth ◽  
Applied Stress ◽  
Fatigue Crack Growth Rate ◽  
Single Crystal Superalloy

Abstract Needless to say, it is important to estimate the stress applied to a material when conducting failure analysis. In recent years, a material assessment method using electron back-scatter diffraction (EBSD) has been developed. It has been reported that a characteristic misorientation distribution corresponding to the fracture mode is seen in cross-sectional EBSD observation near the fracture surface of a Ni-based superalloy. Furthermore, the authors discovered EBSD striations on the crack cross-section, which is formed with each fatigue crack growth during a turbine shut-down process. This was discovered in misorientation analysis on a single-crystal superalloy blade used in a commercial land-based gas turbine. Since Ni-based superalloys have high deformation resistance, they do not undergo enough ductile deformation to form striations at the crack tip on the fracture surface during fatigue crack growth, and, as a result, striations corresponding to cyclic loadings are rarely observed in fractography. Even in such a Ni-based superalloy with brittle crack growth, the fatigue crack growth rate and the applied stress can be estimated by measuring EBSD striation spacing in misorientation analysis. However, a practical problem in assessment is that the resolution limit fixed with field emission scanning electron microscopes (FE-SEM) determine the range in which crack growth rate can be assessed. Hence, it is difficult to clearly discriminate the EBSD striations when the fatigue crack growth rate is too low, such as in the low stress intensity factor range (ΔK) region. The applied stress can be calculated from ΔK. Therefore, in this paper, in order to estimate the applied stress during fatigue crack growth, we focused on estimating ΔK by measuring the plastic zone size along the crack growth.

Oxidation behavior of a novel nickel-based single crystal superalloy at elevated temperature

Vacuum ◽  
2020 ◽  
Vol 175 ◽  
pp. 109284 ◽  
Author(s):  
Z.H. Tan ◽  
X.G. Wang ◽  
W. Song ◽  
Y.H. Yang ◽  
J.L. Liu ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Single Crystal ◽  
Oxidation Behavior ◽  
Single Crystal Superalloy

Stress dependence of dislocation networks in elevated temperature creep of a Ni-based single crystal superalloy

2019 ◽  
Vol 742 ◽  
pp. 132-137 ◽  
Author(s):  
Quanzhao Yue ◽  
Lin Liu ◽  
Wenchao Yang ◽  
Taiwen Huang ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Stress Dependence ◽  
Temperature Creep

Fifth generation Ni based single crystal superalloy with superior elevated temperature properties

2007 ◽  
Vol 2 (1) ◽  
pp. 19-25 ◽  
Author(s):  
A. Sato ◽  
A.-C. Yeh ◽  
T. Kobayashi ◽  
T. Yokokawa ◽  
H. Harada ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Fifth Generation
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