Bcc / B2 phase equilibria and phase transformation from B2 to β’ in refractory Nb-X(Pd, Rh, Ir)-Al

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1335-1340
Author(s):  
T. Yamanouchi ◽  
S. Miura ◽  
M. Ohno ◽  
K. Ikeda
Keyword(s):  
Solid Solution ◽  
Phase Transformation ◽  
Surface Layer ◽  
Phase Field ◽  
Composition Range ◽  
Eutectic Temperature ◽  
Two Phase ◽  
Wide Composition Range ◽  
B2 Phase ◽  
Bcc Phase

ABSTRACTFor the improvement of oxidation resistance of Nb-based alloys, PdAl-B2 is expected as Al reservoir for Al2O3 surface layer because it is in equilibrium with Nbss (bcc) phase. However, PdAl forms cracks during casting caused by B2 -> β’ transformation. To suppress B2 -> β’ transformation, Rh, Ru and Ir were chosen as additive elements. It is found that bcc / B2 two-phase field in Nb-Pd-Ir-Al system is limited to be small fraction of Ir, while (Pd,Rh)Al-B2 is in equilibrium with bcc solid solution in a wide composition range and addition of Rh prevents occurrence of B2 -> β’ transformation. Composition range of (Pd,Ru)Al-B2 in equilibrium with bcc phase is wider than (Pd,Ir)Al-B2 but narrower than (Pd,Rh)Al-B2. Rh and Ru addition are also beneficial for improving eutectic temperature of Nb-bcc / B2 aluminide two-phase alloys.

Phase Equilibrium between B2 Aluminide NiAl and Nb-Mo bcc Solid Solution Phase

2014 ◽  
Vol 783-786 ◽  
pp. 1171-1175 ◽  
Author(s):  
Seiji Miura ◽  
Yoshihito Sekito ◽  
Takuya Okawa ◽  
Takuya Yamanouchi ◽  
Tetsuo Mohri
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Surface Layer ◽  
Composition Range ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Wide Composition Range ◽  
Nial Phase ◽  
Bcc Phase ◽  
Cracking Tendency

In order to understand the composition of the Nb-Mo bcc phase suitable to introduce B2-NiAl phase for the improvement of oxidation resistance as an Al reservoir layer for maintaining Al2O3 surface layer, a NiAl-Nb-Mo section of the quaternary Al-Nb-Ni-Mo phase diagram is studied. It is found that the ternary τ2 phase appears in wide composition range of alloys, both the hardness and cracking tendency decreases with increasing the Mo concentration of the alloys.

Phase equilibrium between bcc solid solution matrix and B2 aluminides in Nb-based alloy

2015 ◽  
Vol 1760 ◽  
Author(s):  
Takuya Yamanouchi ◽  
Seiji Miura
Keyword(s):  
Solid Solution ◽  
Phase Equilibrium ◽  
Phase Field ◽  
Composition Range ◽  
Basic Information ◽  
Two Phase ◽  
Nial Phase ◽  
Solid Solution Matrix ◽  
Solution Matrix

ABSTRACTB2 aluminides have a role of Al reservoir for Al2O3 surface and it is expected to increase oxidation resistance of (Nb,Mo)-bccss substrate. For the accumulation of the basic information to design the alloy composed of B2 coating on bccss matrix, bccss - B2 two-phase field was investigated in the Nb-Mo-Ni-Pd-Al system at 1273 K. It is found that Pd-rich B2-(Ni,Pd)Al phase is in equilibrium with Nb-rich bccss phase, while without Pd, the composition range of bccss coexisting with B2-NiAl phase is limited to be low Nb.

Electrical Conductivity of Zirconia-Mn Oxide Mixture

1998 ◽  
Vol 548 ◽  
Author(s):  
J. H. Kim ◽  
G. M. Choi
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Composition Range ◽  
Two Phase ◽  
Oxide Mixture ◽  
Wide Composition Range ◽  
Hysteresis Behavior ◽  
Mn Oxide ◽  
Form Solid Solution

ABSTRACTMn2O3 was added to YSZ (8 mol% yttria- doped zirconia) either to form solid solution or two-phase (Mn2O3 and Mn2O3 doped-YSZ) mixed-conducting oxide. The electrical conductivity was measured between 600 and 1000°C in air using 4-probe d.c. method in a wide composition range to determine composition-dependent conductivity. Up to 12 mol% MnO1.5 addition, the conductivity decreases and the activation energy increases. With further increase of MnO1.5 content, the conductivity of composite begins to increase slowly and then increases rapidly after 30 mol% due to the interconnected, conductive Mn2O3 particles. Above 35 Mol% MnO1.5 content, the activation energy is nearly the same as that of Mn2O3. Hysteresis behavior shown in the conductivity of composite also provides the evidence of percolation by MnO1.5.

Tunable magnetic pole inversion in multiferroic BiFeO3–DyFeO3 solid solution

2017 ◽  
Vol 5 (16) ◽  
pp. 4063-4067 ◽  
Author(s):  
Jiangtao Wu ◽  
Zuzhen Liao ◽  
Ting Sun ◽  
Lun-Wei Su ◽  
Jian Bi ◽  
...  
Keyword(s):  
Solid Solution ◽  
Composition Range ◽  
Magnetic Pole ◽  
Wide Composition Range ◽  
Multiferroic Bifeo ◽  
Multiferroic Bifeo3 ◽  
Magnetic Ion

We report an unusual magnetic pole inversion behaviour in multiferroic BiFeO3–xDyFeO3 solid solution, which can be tuned by varying the concentration of the magnetic ion Dy in the solid solution. It is found that the temperature-induced magnetic pole inversion occurs in a wide composition range (x = 0.14–0.90). Moreover, multiple magnetic pole inversions are observed in the solid solution compounds of high Dy-concentrations.

scholarly journals Solid-Solution Alloy Nanoparticles of the Immiscible Iridium-Copper System with a Wide Composition Range for Enhanced Electrocatalytic Applications

2018 ◽  
Vol 130 (17) ◽  
pp. 4595-4599 ◽  
Author(s):  
Fenglong Wang ◽  
Kohei Kusada ◽  
Dongshuang Wu ◽  
Tomokazu Yamamoto ◽  
Takaaki Toriyama ◽  
...  
Keyword(s):  
Solid Solution ◽  
Composition Range ◽  
Solid Solution Alloy ◽  
Alloy Nanoparticles ◽  
Wide Composition Range

scholarly journals The Fine Line between a Two-Phase and Solid-Solution Phase Transformation and Highly Mobile Phase Interfaces in Spinel Li4+ x Ti5 O12

2016 ◽  
Vol 7 (9) ◽  
pp. 1601781 ◽  
Author(s):  
Swapna Ganapathy ◽  
Alexandros Vasileiadis ◽  
Jouke R. Heringa ◽  
Marnix Wagemaker
Keyword(s):  
Solid Solution ◽  
Phase Transformation ◽  
Mobile Phase ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Two Phase ◽  
Fine Line

scholarly journals Особенности спектральных характеристик различных структурных модификаций Lu-=SUB=-1-x-=/SUB=-RE-=SUB=-x-=/SUB=-BO-=SUB=-3-=/SUB=-

2021 ◽  
Vol 63 (10) ◽  
pp. 1617
Author(s):  
С.З. Шмурак ◽  
В.В. Кедров ◽  
А.П. Киселев ◽  
Т.Н. Фурсова ◽  
И.И. Зверькова ◽  
...  
Keyword(s):  
Solid Solution ◽  
Surface Layer ◽  
Structural State ◽  
Spectral Characteristics ◽  
Luminescence Spectra ◽  
Exciting Light ◽  
Ir Absorption ◽  
Two Phase ◽  
Near Surface ◽  
Absorption And Luminescence Spectra

The structure, IR absorption and luminescence spectra of the microcrystals of Lu1-xEuxBO3, Lu0.99-xTbxEu0.01BO3, and Lu0.99−xYxEu0.01BO3 orthoborates (0 ≤ x ≤ 0.25) synthesized at 970°С were studied. An increase in х leads to a sequential change of the structural state of the orthoborates. At х ≤ 0.07 – 0.09, the compounds form a solid solution with the calcite structure and microcrystal size of 8 – 20 µm. Then, they become two-phase: the vaterite phase arises along with the calcite structure. At х ≥ 0.2 – 0.25, the entire bulk of a sample has the vaterite structure. A correspondence between the structure and spectral characteristics of these compounds was established. Luminescence spectra were investigated at different wavelengths of exciting light. This allowed obtaining information on the structure of a near-surface layer and the bulk of microcrystals of the investigated samples. It is shown that the vaterite phase arises both in the bulk of large microsrystals (8 – 20 µm) and in the form of small microsrystals (1 – 2 µm).

scholarly journals Preparation and characterization of WMo solid solution nanopowders with a wide composition range

2020 ◽  
Vol 823 ◽  
pp. 153760 ◽  
Author(s):  
Qiuyu Chen ◽  
Shuhua Liang ◽  
Junlu Zhang ◽  
Xiaochuan Zhang ◽  
Chan Wang ◽  
...  
Keyword(s):  
Solid Solution ◽  
Composition Range ◽  
Wide Composition Range
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