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
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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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Frequency and wave-form effects on the fatigue crack growth behavior of alloy 718 at 298 K and 823 K
M. Clavel,André Pineau +1 more
TL;DR: In this paper, the authors measured the fatigue crack growth rate (FCGR) of Alloy 718 on CT type specimens at 298 and 823 K and found that a substantial increase in FCGR occurred at low stress intensity levels, as the temperature was increased from 298 to 823 k and as the frequency was decreased at 823k.
Journal ArticleDOI
The effect of varying AI, Ti,and Nb content on the phase stability of INCONEL 718
TL;DR: In this article, the effects of varying the strengthening alloying elements on the microstructural stability of the superalloy INCONEL 718 have been investigated using scanning electron microscopy and X-ray and synchrotron diffractometry.
Journal ArticleDOI
Effects of cold rolling on the precipitation kinetics and the morphology evolution of intermediate phases in Inconel 718 alloy
TL;DR: In this article, the effect of cold rolling on the precipitation kinetics of intermediate phases in Inconel 718 alloy was investigated and it was found that cold rolling promotes global transformation and the morphology of γ″-phase turns more globular with increasing temperature.
Journal ArticleDOI
Microstructural and mechanical characterization of injection molded 718 superalloy powders
TL;DR: In this article, the determination of optimum production parameters for injection molding 718 superalloy parts was discussed and microstructural and mechanical characterization of these produced parts was also carried out.
Journal ArticleDOI
Microstructure and mechanical properties of Inconel 718 electron beam welds
TL;DR: In this article, a bead on plate, full penetration electron beam welds were produced in 2 mm thickness sheets of Inconel 718 in the solution treated condition, and they were subjected to an aging treatment with and without post-weld solution treatment.
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.