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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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
An investigation of precipitation strengthened Inconel 718 superalloy after triode plasma nitriding
TL;DR: In this paper , the microstructural evolution, surface hardening and general corrosion properties of a precipitation-strengthened Ni-superalloy after triode-plasma nitriding (TPN) at low treatment temperatures of 400-450 °C and a high treatment temperature of 700 °C were investigated.
Journal ArticleDOI
A Fast-Acting Method for Simulating Precipitation During Heat Treatment of Superalloy 718
S. L. Semiatin,Jaimie Tiley,F. Zhang,Timothy M. Smith,Ruiyao Zhang,Hongbiao Dong,P. Gadaud,Jonathan Cormier +7 more
TL;DR: In this paper, a mean-field method for simulating precipitation of the γ′′ and γ´′ phases during aging of superalloy 718 following super-delta-solvus solution treatment was formulated and validated using observations in the literature.
Journal ArticleDOI
Low cycle fatigue behaviour of modified and conventional superalloy Inconel 718 at 650°C
TL;DR: In this article, the study and comparison of low cycle fatigue (LCF) behavior of modified IN 718 alloy with higher Al+Ti/Nb and Al/Ti ratios of 0.458 and 0.870 was conducted.
Proceedings ArticleDOI
Effects of Grain Boundary Precipitation on Creep Rupture Properties of Alloys 706 and 718 Turbine Disk Forgings
TL;DR: Loria et al. as discussed by the authors investigated the effect of grain boundary precipitation introduced by an intentional stabilizing treatment in the temperature range of 780 to 900 “C. They concluded that the beneficial effect of stabilizing treatments for alloy 706 is attributed to the wavy grain boundary formation and the dispersions of creep strain at these wavy boundaries.
Journal ArticleDOI
Unveiling the strengthening mechanism of laser welded fusion zone of dissimilar Ni-based superalloys
TL;DR: In this article, the authors studied the strengthening mechanism of a laser welded fusion zone between two dissimilar Ni-based superalloys and found that the formation of dislocation cellular structure endows fusion zone with higher strength particularly at 600 and 650°C.
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.