Journal ArticleDOI
Rafting in single crystal nickel-base superalloys - An overview
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TLDR
In this article, the effect of stress state on γ/γ′ rafting, kinetics and morphological evolution are discussed with the recent experimental results, and the nature and influence of rafting on creep properties including pre-rafted conditions are discussed.Abstract:
Currently nickel-base single crystal (SX) superalloys are considered for the manufacture of critical components such as turbine blades, vanes etc., for aircraft engines as well as land-based power generation applications. Microstructure and high temperature mechanical properties are the major factors controlling the performance of SX superalloys. Rafting is an important phenomenon in these alloys which occurs during high temperature creep. It is essential to understand the rafting mechanism, and its characteristics on high temperature properties before considering the advanced applications. In this review article, the thermodynamic driving force for rafting with and without stress is explained. The nature and influence of rafting on creep properties including pre-rafted conditions are discussed. In addition, the effect of stress state on γ/γ′ rafting, kinetics and morphological evolution are discussed with the recent experimental results.read more
Citations
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Journal ArticleDOI
Damage accumulation during creep deformation of a single crystal superalloy at 1150 °C
TL;DR: In this article, microstructural degradation in the CMSX-4 single crystal superalloy during creep deformation at 1150°C and 100MPa is studied. And it is shown that the high strain rates and shear stresses associated with the rupture process are sufficient to cause realignment of the rafted γ′ structure with respect to the γ matrix.
Journal ArticleDOI
Coupling between Re segregation and γ/γ′ interfacial dislocations during high-temperature, low-stress creep of a nickel-based single-crystal superalloy
TL;DR: In this paper, a detailed characterization of interfacial dislocations in a DD6 superalloy after 12h at high temperature and low stress was carried out using transmission electron microscopy and high-angle annular dark field scanning transmission electron microscope techniques.
Journal ArticleDOI
Phase field study of precipitate rafting under a uniaxial stress
M. P. Gururajan,T.A. Abinandanan +1 more
TL;DR: In this article, a phase field model of an elastically inhomogeneous alloy was used to calculate elastic stress and strain fields for two-phase microstructures under a uniaxial applied stress.
Journal ArticleDOI
Observations of a〈0 1 0〉 dislocations during the high-temperature creep of Ni-based superalloy single crystals deformed along the [0 0 1] orientation
TL;DR: A NASAIR-100 superalloy single crystal was tested in tension creep at 1000°C at a stress of 148 MPa, for a time period of 20h and to a strain of 1.1% as mentioned in this paper.
Journal ArticleDOI
Atom probe informed simulations of dislocation-precipitate interactions reveal the importance of local interface curvature
Aruna Prakash,Julien Guénolé,J. Wang,Julian George Müller,Erdmann Spiecker,Michael J. Mills,Ivan Povstugar,Pyuck-Pa Choi,Dierk Raabe,Erik Bitzek +9 more
TL;DR: In this paper, the authors used atomistic simulation samples generated from atom probe tomography data of a single crystal superalloy to study the interactions of matrix dislocations with a γ ′ precipitate in molecular dynamics simulations.
References
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Journal ArticleDOI
New microstructural concepts to optimize the high-temperature strength of γ′-hardened monocrystalline nickel-based superalloys
TL;DR: In this article, the authors seek new microstructural concepts in order to optimize the high-temperature creep and fatigue strength by suitable measures to prevent rafting and by exploitation of the directionality of intentionally introduced raft structures.
Journal ArticleDOI
Creep of CMSX-4 single crystals of different orientations in tension and compression
TL;DR: In this paper, the authors performed creep tests of strengthened superalloy CMSX-4 single crystals of different orientations at 950 °C, in both tension and compression at constant load (initial stress 250 MPa) as well as at constant stress (250 MPa).
Journal ArticleDOI
Microscopic model for directional coarsening of precipitates in alloys under external load
TL;DR: In this article, the authors carried out computer simulations of a binary alloy decomposition in two dimensions under external stress using a Metropolis exchange dynamics with an effective long-range, anisotropic, spin Hamiltonian.
Journal ArticleDOI
Thickening behaviour of γ' precipitates in nickel base superalloys during rafting
W. Chen,J.P. Immarigeon +1 more
TL;DR: In this article, a phenomenological description of the thickening behavior of {gamma prime} precipitates during rafting is formulated to explain experimental data reported in the literature, and the practical implications are briefly discussed.
Book
High-Temperature Materials in Gas Turbines - proceedings of the symposium on high-temperature materials in gas turbines - Brown, Boveri & company limited, Baden, Switzerland, 1973
P. R. Sahm,Markus O. Speidel +1 more
TL;DR: In this article, resistance des : materiaux; turbine a gaz; proprietes : critiques; temperature Reference Record created on 2005-11-18, modified on 2016-08-08