The influence of temperature and orientation on fatigue crack growth behavior of a directional solidification nickel-based superalloy: Experimental investigation and modelling

•A DS nickel-based superalloy FCG tests were conducted at different temperatures.•The influence of orientation on FCG is more obvious at RT than at elevated temperature.•FCG rates increase with temperature’s growth but decrease in high ΔK regime.•A new growth parameter was proposed to show temperatu...

Full description

Saved in:
Bibliographic Details
Published in:International journal of fatigue 2019-08, Vol.125, p.505-519
Main Authors: Shi, Yi, Yang, Xiaoguang, Yang, Didi, Miao, Guolei, Qi, Hongyu, Shi, Duoqi, Li, Shaolin
Format: Article
Language:English
Subjects:
Compliance method
Crack propagation
Crack tips
Directional solidification
Fatigue crack growth
Fatigue failure
Fracture mechanics
High temperature
Materials fatigue
Nickel
Nickel base alloys
Orientation
Oxidation
Parameter modification
Superalloys
Temperature
Temperature dependence
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•A DS nickel-based superalloy FCG tests were conducted at different temperatures.•The influence of orientation on FCG is more obvious at RT than at elevated temperature.•FCG rates increase with temperature’s growth but decrease in high ΔK regime.•A new growth parameter was proposed to show temperature and orientation influence. The fatigue crack growth (FCG) behaviour of a directional solidification nickel-based superalloy DZ125 samples (L- and T-orientated directions) were conducted at 750, 850 and 925 °C. Results showed that the FCG rate at elevated temperature increased significantly compared with that at room temperature. However, the reduced difference between room and elevated temperature can be observed in later stage due to oxidation induced closure effect. In addition, the influence of orientation is limited at elevated temperature while this is more evident at room temperature. To further reveal the process of crack propagation, the fractography was also examined by SEM and EDS method, and oxidation features were found at elevated temperature. Finally a modified phenomenological parameter was proposed to make test data of different orientation and temperature fall into a narrow [1/2, 2] band, which shows less temperature dependence compared with crack tip driving force parameter ΔK under the linear elastic fracture framework.
ISSN:0142-1123
1879-3452
DOI:10.1016/j.ijfatigue.2019.04.024