Creep strengthening mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy at steady-state conditions under compressive stresses

Xu，Zhen1,2; Lv，Zhiwei1,2; Guo，Chuan1,2; Zhou，Yang1,2; Li，Gan1,2,3; Hu，Xiaogang1,2; Li，Xinggang2; Zhu，Qiang1,2

2023-03-24

10.1016/j.msea.2023.144781

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING   Impact Factor & Quartile

0921-5093

1873-4936

The strengthening mechanism of steady-state creep is a critical factor in developing advanced superalloys. In this study, the steady-state creep mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy are investigated with the creep conditions of 750 °C/800 MPa, 900 °C/420 MPa and 1000 °C/137 MPa. Results suggest that the microstructures of steady-state creep samples are significantly different under the above three experimental conditions. A detailed TEM study shows that, Lomer-Cottrell locks and stacking faults interactions are responsible for the low creep rate at low temperature and high stress creep regime, dislocations cross-slip and the dislocation tangles contribute the main creep resistance at intermediate temperatures and moderate stress creep regime, interactions of stacking faults and dislocation networks are the strengthening mechanism for the high temperature and low stress creep regime. The steady-state creep rate of investigated alloy follows the classical power law equation, and the creep activation energy calculated by the power law equation is 378.46 kJ/mol. The results of this study provide insights into the effects of temperature and stress on steady-state creep mechanisms, and high activation energy makes the γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy an attractive candidate for further study as a high temperature structural material.

Co-based superalloys Creep Deformation mechanisms Steady-state creep

SCI

English

First ; Corresponding

Shenzhen Science and Technology Innovation Commission, China["JCYJ20210324104610029","JCYJ20170817111811303","KQTD20170328154443162"] ; Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, China[ZDSYS201703031748354] ; National Natural Science Foundation of China[91860131] ; National Key Research and Development Pro- gram of China[2017YFB0702901]

Science & Technology - Other Topics ; Materials Science ; Metallurgy & Metallurgical Engineering

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000990140000001

ELSEVIER SCIENCE SA

MATERIALS SCIENCE

2-s2.0-85148543341

Scopus

1.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials,Shenzhen,518055,China
3.Department of Mechanical Engineering,City University of Hong Kong,Kowloon,Hong Kong

Xu，Zhen,Lv，Zhiwei,Guo，Chuan,等. Creep strengthening mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy at steady-state conditions under compressive stresses[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2023,869.

Xu，Zhen.,Lv，Zhiwei.,Guo，Chuan.,Zhou，Yang.,Li，Gan.,...&Zhu，Qiang.(2023).Creep strengthening mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy at steady-state conditions under compressive stresses.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,869.

Xu，Zhen,et al."Creep strengthening mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy at steady-state conditions under compressive stresses".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 869(2023).