Concentration Gradients near Heterophase Boundaries in Crept Single Crystal Nickel Base Superalloys

Blavette, D.; Letellier, L.; Racine, A.; Hazotte, Alain

doi:10.1051/mmm:1996114

Cited by 10 publications

(4 citation statements)

References 14 publications

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“…Such superdislocations are believed to be responsible for the acceleration of the creep deformation by relaxing coherency stresses and osmotic forces as they allow the removal of a/2h1 1 0i dislocations present at the c/c 0 interfaces [28,[34][35][36][37][38][39]. To a lesser extent, c/c 0 interface dislocations play also a role in the local chemical composition of the c phase during creep tests leading to accelerated microstructural evolutions [40,41], known to be damaging [42,43]. However, all these investigations were conducted for isothermal creep conditions and little is known on the role of the c/c 0 interfacial dislocation network under non-isothermal conditions.…”

Section: Introductionmentioning

confidence: 99%

Creep of a nickel-based single-crystal superalloy during very high-temperature jumps followed by synchrotron X-ray diffraction

et al. 2015

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Section: Introductionmentioning

confidence: 99%

Creep of a nickel-based single-crystal superalloy during very high-temperature jumps followed by synchrotron X-ray diffraction

et al. 2015

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“…However, real interfaces often have more complex three-dimensional structures or are not well separated. Only three-dimensional (3D)-atom-probe microscopy (3DAP) is capable of both identifying the topology of interfaces and measuring the local chemical composition on a nanoscale (Letellier et al, 1994;Blavette et al, 1996;Miller et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Analysis of Three-dimensional Atom-probe Data by the Proximity Histogram

Hellman

Vandenbroucke

Rüsing

et al. 2000

Microsc. Microanal.

736

315

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The three-dimensional (3D) atom-probe technique produces a reconstruction of the elemental chemical identities and three-dimensional positions of atoms field evaporated from a sharply pointed metal specimen, with a local radius of curvature of less than 50 nm. The number of atoms collected can be on the order of one million, representing an analysis volume of approximately 20 nm × 20 nm × 200 nm (80,000 nm3). This large amount of data allows for the identification of microstructural features in a sample, such as grain or heterophase boundaries, if the feature density is large enough. Correlation of the measured atomic positions with these identified features results in an atom-by-atom description of the chemical environment of crystallographic defects. This article outlines a data compilation technique for the generation of composition profiles in the vicinity of interfaces in a geometrically independent way. This approach is applied to quantitative determination of interfacial segregation of silver at a MgO/Cu(Ag) heterophase interface.

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“…The limitations associated with the resolution of experimental techniques have so far prevented direct atomic-scale imaging and interpretation of the structural and compositional transition across such interfaces. Techniques such as 3D Atom Probe (3DAP) Tomography have enabled detailed exploration of nanometer-scale elemental partitioning across interphase interfaces, including the = 0 interface in nickel base alloys [20][21][22][23][24][25][26]. In addition, developments in aberrationcorrected HRSTEM now permit Z contrast imaging (arising from the differences in atomic numbers) and interpretation at atomic resolution [27][28][29].…”

mentioning

confidence: 99%

Atomic Scale Structure and Chemical Composition across Order-Disorder Interfaces

et al. 2009

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Through a combination of aberration-corrected high-resolution scanning transmission electron microscopy and three-dimensional atom probe tomography, the true atomic-scale structure and change in chemical composition across the complex order-disorder interface in a metallic alloy has been determined. The study reveals the presence of two interfacial widths, one corresponding to an order-disorder transition, and the other to the compositional transition across the interface, raising fundamental questions regarding the definition of the interfacial width in such systems. DOI: 10.1103/PhysRevLett.102.086101 PACS numbers: 68.35.Àp, 68.37.Ma, 68.37.Vj Interfaces play an important role in determining several properties in multiphase systems [1][2][3]. Atomic-scale renditions of the interface structure have been primarily accomplished through high-resolution transmission electron microscope (HRTEM) phase-contrast images (and simulations) that allow for identification of the positions of atomic columns and structural defects at the interface [4,5]. Recent advances in HRTEM and HRSTEM have been enabled by the development of spherical aberration correctors for the electron probe as well as the image [6][7][8].In parallel, developments in first-principles based electronic structure calculations and larger scale atomistic modeling tools permit more accurate simulations of the interface structure [9,10]. Recent atomistic simulations of the interface between an ordered precipitate and disordered matrix in a nickel-base superalloy indicate that the interface is not abrupt at the atomic scale [9]. While the implications of these results on the microstructural stability [11][12][13] and high temperature mechanical properties [14][15][16][17][18][19] are substantial, there is no clear experimental evidence confirming these atomistic simulations. The limitations associated with the resolution of experimental techniques have so far prevented direct atomic-scale imaging and interpretation of the structural and compositional transition across such interfaces. Techniques such as 3D Atom Probe (3DAP) Tomography have enabled detailed exploration of nanometer-scale elemental partitioning across interphase interfaces, including the = 0 interface in nickel base alloys [20][21][22][23][24][25][26]. In addition, developments in aberrationcorrected HRSTEM now permit Z contrast imaging (arising from the differences in atomic numbers) and interpretation at atomic resolution [27][28][29]. Our study provides direct experimental evidence at the atomic scale of the true structure and composition of the = 0 interface in a nickel base alloy by coupling two advanced and complementary techniques: aberration-corrected HRSTEM and 3DAP.This work was carried out on the nickel base superalloy Rene' 88 DT [nominal composition 55.63Ni-18.02Cr-13.00Co-4.74Ti-4.45Al-2.48Mo-1.21W-0.46Nb (in at %)], with superior creep and fatigue properties for turbine disk applications [14][15][16]. The typical microstructure consists of a disordered fcc matrix with ordered ...

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Concentration Gradients near Heterophase Boundaries in Crept Single Crystal Nickel Base Superalloys

Abstract: Résumé. 2014

Cited by 10 publications

References 14 publications

Creep of a nickel-based single-crystal superalloy during very high-temperature jumps followed by synchrotron X-ray diffraction

Creep of a nickel-based single-crystal superalloy during very high-temperature jumps followed by synchrotron X-ray diffraction

Analysis of Three-dimensional Atom-probe Data by the Proximity Histogram

Atomic Scale Structure and Chemical Composition across Order-Disorder Interfaces

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