Journal ArticleDOI
Morphology of y’ and y” precipitates and thermal stability of inconel 718 type alloys
R. Cozar,André Pineau +1 more
- Vol. 4, Iss: 1, pp 47-59
TLDR
In this article, the precipitation microstructure varies rapidly with aging temperature and composition, and the influence of composition and aging temperature on the conditions that bring about this compact morphology has been investigated.Abstract:
The precipitation of the γ’ (Ll2) and γ" (DO22) phases has been studied in four alloys Fe-Ni-Cr-Ti-Al-Nb containing a higher Ti + Al/Nb ratio than that of the INCONEL 718 alloy. For these alloys, the precipitation microstructure varies rapidly with aging temperature and composition. Bct γ"particles have always been found to precipitate on γ’ phase. Moreover, by aging three alloys above a critical temperature, a “compact ntorphology” has been observed: cube-shaped γ’ particles coated on their six faces with a shell of γ" precipitate. This microstructure has proved to be very stable on prolonged aging. A thermal stability better than that encountered in nominal INCONEL 718 alloy can thus be achieved. The influence of composition and aging temperature on the conditions that bring about this “compact morphology” has been investigated. A minimal Ti + Al/Nb ratio between 0.9 and 1 has been determined, allowing the “compact morphology” to be obtained.read more
Citations
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Journal ArticleDOI
Impurity Removal and Microstructural Analysis of Inconel 718 Refined by Hydrogen Plasma Arc Melting
TL;DR: In this paper, the high-temperature melting and removal of gaseous and metallic impurities from Inconel 718 by hydrogen plasma arc melting (HPAM) were investigated.
Journal ArticleDOI
Constant Stress Creep of XD ™ TiAl Containing Nitrogen
TL;DR: In particular, fine coherent particles have been observed to decorate dislocations and the interior of TiAl grains as discussed by the authors, and the presence of these particles is thought to explain the creep resistance of this alloy.
Journal ArticleDOI
Understanding the microstructural stability in a γ′-strengthened Ni-Fe-Cr-Al-Ti alloy
Bharat Gwalani,Shivakant Shukla,Donovan N. Leonard,Jonathan D. Poplawsky,Dean T. Pierce,Libor Kovarik,Govindarajan Muralidharan,Arun Devaraj +7 more
TL;DR: In this paper, a microstructure consisting of a face-centered cubic (γ) matrix with homogeneously precipitated, nanoscale ordered γ′ precipitates similar to that found in traditional Ni-based superalloys with a significantly greater Ni content was investigated.
Journal ArticleDOI
Analysis of the effects of isothermal aging and Laser Shock Peening on the flow properties, fatigue crack growth, and fracture toughness of Inconel 718
Vania M. Rodríguez,Carlos Rubio González,Santiago Flores García,Héctor Carreón Garcidueñas,Víctor Hugo López Morelos,A. Ruiz +5 more
Book ChapterDOI
Tailoring the γ-γ′-γʺ Dual Superlattice Microstructure of INCONEL® 725 by High Temperature Aging and Nb/Ta Additions for Superior Creep Properties
TL;DR: In this paper , a phase stability phase stability study with up to 10,000 h exposure at 700 °C revealed that the compact morphology helped in slightly reducing coarsening of the γ′ precipitates, although the effect on creepCreep was not significant.
References
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Journal ArticleDOI
The Determination of the Elastic Field of an Ellipsoidal Inclusion, and Related Problems
TL;DR: In this paper, it is shown that to answer several questions of physical or engineering interest, it is necessary to know only the relatively simple elastic field inside the ellipsoid.
Journal ArticleDOI
Déformations de cohérence d'un précipité quadratique
TL;DR: In this paper, exact expressions for the elastic field due to a perfectly coherent precipitate having the form of a rectangular parallelepiped, the material being supposed elastically homogeneous and isotropic.
Journal ArticleDOI
The microstructure of 706, a new Fe−Ni-base superalloy
TL;DR: In this article, the phase relationships of Alloy 706 alloy were investigated and it was shown that on the basis of chemistry and micro-structural response, Alloy 606 alloy can be considered to be intermediate to the well-known alloys, 718 and 901.
Journal ArticleDOI
Heterogeneous precipitation of metastable γ′-ni3ti in a nickelbase alloy
TL;DR: In this article, the effect of prior deformation on the precipitation of L12 γ′-Ni3Ti in nickel-base Alloy 901 was investigated by thin foil microscopy.
Journal ArticleDOI
Fine Faults and Crystal Structures of Precipitates in Fe-Mo and Fe-W Alloys
Kōhei Yagisawa,Hiroshi Fujita +1 more
TL;DR: In this paper, the crystal structure and two-dimensional faults of the precipitates in Fe-Mo alloys were investigated using electron microscopic method, and the faults were found on {00.1}hex, {10.0}hex and {100}hex planes.