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
Coherency strengthening in Ni base alloys hardened by DO 22 γ' precipitates
TL;DR: The strengthening phase in nickel-base Alloy 718 is a metastable DO22 precipitate termed γ′ which is based upon Ni3Nb as discussed by the authors, and it can be controlled by the application of stress during aging.
Journal ArticleDOI
Rationalization of Microstructure Heterogeneity in INCONEL 718 Builds Made by the Direct Laser Additive Manufacturing Process
Yuan Tian,Donald McAllister,Hendrik O. Colijn,Michael J. Mills,Dave F. Farson,Mark Nordin,S. Suresh Babu +6 more
TL;DR: In this article, the authors showed that the microstructure heterogeneities within the builds in different length scales including interdendritic and interprecipitate regions were correlated to primary solidification, remelting, and solid-state precipitation kinetics induced by solute segregation, as well as multiple heating and cooling cycles induced by the laser additive manufacturing process.
Journal ArticleDOI
Superior creep strength of a nickel-based superalloy produced by selective laser melting
M. Pröbstle,Steffen Neumeier,J. Hopfenmüller,Lisa P. Freund,Thomas Niendorf,Dieter Schwarze,Matthias Göken +6 more
TL;DR: In this paper, the creep properties of a polycrystalline nickel-based superalloy produced via selective laser melting were investigated, and it was shown that the additively manufactured material showed superior creep strength compared to conventional cast and wrought material.
Journal ArticleDOI
Aging of the Inconel 718 alloy between 500 and 750 °C
C. Slama,C. Servant,G. Cizeron +2 more
TL;DR: In this paper, the aging of the NC 19 Fe Nb alloy (Inconel 718), previously quenched from 990{degree}C, is characterized by a hardness peak at 650°degree, then a maximum in hardness at about 750°degree.
Journal ArticleDOI
Effect of heat treatment on microstructure evolution of Inconel 718 alloy fabricated by selective laser melting
X. Li,J.J. Shi,C.H. Wang,Guanghui Cao,Alan M. Russell,Zhongjiao Zhou,Chang-Peng Li,Guofeng Chen +7 more
TL;DR: Inconel 718 superalloy was fabricated by selective laser melting (SLM) and subsequently subjected to different heat treatments as discussed by the authors, and the morphology, distribution and crystallography of precipitates and their formation mechanisms are discussed and analyzed.
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.