Atomic-scale structure and chemistry of ceramic/metal interfaces—I. Atomic structure of {222} MgO/Cu (Ag) interfaces

Shashkov, D. A.; Chisholm, Matthew F.; Seidman, David N.

doi:10.1016/s1359-6454(99)00255-4

Cited by 38 publications

(23 citation statements)

References 40 publications

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“…[22] The presence of {111} facets was reported on the boundaries between other B1-type oxides and fcc metals. [23,24,25] Even in a Zr/ZrN system with an irrational OR, [14] an (111) ZrN facet, which corresponds to an irrational matrix plane, is observed. Those ceramic phases such as carbides, nitrides, and oxides have much higher melting temperatures (i.e., higher cohesive energies) than their matrices.…”

Section: Ormentioning

confidence: 99%

Crystallography and interphase boundary of (MnS + VC) complex precipitate in austenite

Maki¹,

Kimori²

2006

Metall Mater Trans A

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Crystallography and interphase boundary of (MnS ϩ VC) complex precipitates formed in austenite (␥) matrix are studied by transmission electron microscopy (TEM) in an austenitic Fe-36 mass pct Ni alloy containing small amounts of manganese, sulfur, vanadium, and carbon. When VC is formed directly within the ␥ matrix grain, it displays a cube-cube orientation relationship (OR) with respect to ␥. When VC is formed on MnS, which precipitated in ␥ with a cube-on-edge OR, three distinctive VC/␥ ORs are found: (1) , (2) the cube-cube OR, and (3) the cubeon-edge OR. The MnS/␥ OR becomes irrational after ␥ recrystallization. When VC forms on such incoherent MnS particles, which hold irrational ORs with respect to ␥ matrix, a wide variety of VC/␥ ORs are observed. Geometrical analysis by near coincidence site lattice (NCS) model achieves reasonable success in explanation of the observed planar facets for VC precipitates having rational ORs with respect to ␥. However, as for the VC formed on the incoherent MnS with irrational ORs, there is rather poor agreement between observation and prediction.(111) g // (001) VC , [11 0] g //[11 0] VC

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Section: Ormentioning

confidence: 99%

Crystallography and interphase boundary of (MnS + VC) complex precipitate in austenite

Maki¹,

Kimori²

2006

Metall Mater Trans A

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“…The mobility of coincidence boundary should be smaller than that of disordered boundary under the circumstance without a dragging effect by segregating impurities, resulting in the development of large facets for such boundary orientations. It should be noted that some HREM works on the atomic structure of the ͕222͖MgO/Cu interfaces produced by internal oxidation [25][26][27][28][29] demonstrated that MgO precipitates are octahedral shaped, with faceting on ͕222͖ planes of the oxide, and have a cube-on-cube orientation relationship with the metal matrix. At such a heterophase boundary, some solute segregation was reported, 28) which might affect the stability of the ͕111͖ facets.…”

Section: Crystallography Of B1-type Precipitates In Austenite and Fermentioning

confidence: 99%

Multiphase Crystallography in the Nucleation of Intragranular Ferrite on MnS+V(C,N) Complex Precipitate in Austenite

et al. 2003

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Crystallographic orientation relationships between intragranular ferrites, the MnSϩV(C, N) complex precipitates acting as ferrite nucleation sites, and austenite matrix were studied in Fe-Mn-C alloys by scanning electron and transmission electron microscopy. VC holds a cube-cube orientation relationship (͗001͘ g // ͗001͘ VC ) when it is formed directly within austenite grains in an Fe-12Mn-0.8C-0.3V alloy. When VC precipitates nucleate on incoherent MnS particles dispersed in austenite, there is no specific orientation relationship between the three phases. Intragranular ferrite idiomorphs nucleating on the MnSϩV(C, N) complex precipitate in austenite in Fe-1.5Mn-0.2C and Fe-2Mn-0.2C alloys often hold the Baker-Nutting orientation relationship ((001) a //(001) V(C, N) , [110] a //[100] V(C, N) ). Although several irrational ferrite/ V(C, N) orientation relationships were observed, misorientation for either low-index planes or directions are relatively small between ferrite and V(C, N) for those relationships. The orientation relationships between intragranular ferrite and austenite were estimated by examining the misorientations between the ferrite and the neighboring martensite lathes from the Kurdjumov-Sachs inter-variant relationships. There is no specific orientation relationship between the intragranular ferrite idiomorph and the austenite matrix because of the low-energy orientation relationships between ferrite and V(C, N).KEY WORDS: phase transformation; precipitation; steel; austenite; ferrite; carbide; nitride; sulfide; inclusion; crystallography; interface.involved for intragranular ferrite transformation.In the present study, the detail of multiphase relationship between ferrite, MnSϩV(C, N) complex precipitate and austenite is discussed based on the observation using scanning and transmission electron microcopy. Table 1 shows the chemical composition of the alloys used in the present study. In an Fe-20Cr-10Ni austenitic alloy which contains a small amount of Mn and S, MnS is fully dissolved in austenite by the solutionizing at 1 473 K and precipitate during aging at 1 273 K based on the calculation with the equation proposed by Turkdogan. Experimental Procedure10) The solution temperatures of MnS in austenite for the other three alloys are well above the melting temperature of austenite, and thus, MnS cannot be dissolved in austenite after solidification. In an Fe-12Mn-0.8C-0.3V austenitic alloy which was used in the study on intragranular pearlite transformation, 7) V(C, N) can be dissolved into austenite by solutionizing treatments at high temperatures and precipitate during aging at lower temperatures. Thus, in this alloy, the measurement of precipitate/austenite orientation relationship was made both for coherent VC which precipitate directly in austenite as well as incoherent MnSϩVC complex precipitate. The solution temperatures of V(C, N) were estimated from the Thermo-Calc calculation. The specimens were homogenized at 1 473 K for 86.4 ks, cold rolled by 70 % and solution treated at 1 473 K...

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“…Seidman and coworkers [29,30] have discussed the segregation of Ag to Cu/MgO interfaces at elevated temperatures using the Gibbs equation. Atomistic Monte Carlo simulations, e.g., [31], indicate that segregation is not limited to a single layer at the interface but a whole spectrum of segregation sites may exist.…”

Section: Dilute Phase Intercepts Along the R-axismentioning

confidence: 99%

The interaction of dissolved H with internally oxidized Pd–Rh alloys

et al. 2002

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Homogeneous fcc Pd-Rh alloys have been internally oxidized in the atmosphere at several temperatures from 1023 to 1123 K forming oxide precipitates within a Pd matrix. As shown from electron diffraction patterns of the internally oxidized Pd 0.97 Rh 0.03 alloy, the oxide that forms is a mixed oxide, PdRhO 2 . Internally oxidized Pd-Rh alloys can be reduced with H 2 (573 to 623 K) forming PdRh precipitates within a Pd matrix. This represents a way of segregating components of a substitutional solid solution binary alloy. The segregated alloy can be returned to the homogeneous Pd-Rh alloy by annealing at an elevated temperature and thus, in contrast to the internal oxidation of, e.g., Pd-Al alloys, the process can be readily reversed. The oxidation and (reduction + H 2 O loss) were monitored from weight changes.After internal oxidation/reduction "diagnostic" hydrogen isotherms (323 K) were measured to follow the extent of oxidation and to determine the extent of trapped H from the positive intercepts along the H/Pd axis in the dilute phase. The H capacities in the steeply rising hydride region of the H 2 isotherms for the internally oxidized alloys are smaller than for Pd unless the Pd in the PdRh precipitates is considered to be inactive for H 2 absorption for the calculation of H/Pd values.In the two-phase region the absorption plateau pressures were significantly greater than for Pd-H, however, they were much closer to the Pd plateau p H2 than to the unoxidized Pd-Rh alloys. The desorption plateaux were very close to that of Pd-H for X Rh =0.01 to 0.05 alloys and therefore it can be concluded that the matrix is pure Pd whose plateaux are affected by the presence of the precipitates.The techniques of TEM, SEM and SANS (small angle neutron scattering) were employed to examine the alloys after internal oxidation and both before and after reduction. SANS confirmed directly that internal precipitates form from the internal oxidation and that they are rather large with an appreciable fraction having diameters greater than 100 nm.

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Atomic-scale structure and chemistry of ceramic/metal interfaces—I. Atomic structure of {222} MgO/Cu (Ag) interfaces

Cited by 38 publications

References 40 publications

Crystallography and interphase boundary of (MnS + VC) complex precipitate in austenite

Crystallography and interphase boundary of (MnS + VC) complex precipitate in austenite

Multiphase Crystallography in the Nucleation of Intragranular Ferrite on MnS+V(C,N) Complex Precipitate in Austenite

The interaction of dissolved H with internally oxidized Pd–Rh alloys

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