scholarly journals Interaction of metals and alloys with gas media under spark discharges

2018 ◽  
pp. 19-36
Author(s):  
D.V. Mironov ◽  
V.M. Mironov ◽  
V.F. Mazanko ◽  
D.S. Gertsriken ◽  
P.V. Peretyatku
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Solid Solutions ◽  
Ambient Air ◽  
Inert Gases ◽  
Surface Layers ◽  
Near Surface ◽  
X Ray ◽  
Spark Discharges ◽  
Supersaturated Solid Solutions

The paper studies the penetration of nitrogen, oxygen, hydrogen, carbon, argon and krypton into copper, nickel, molybdenum, titanium, aluminum, iron and different steels under the action of spark discharges in various media based on radioactive indicators using step-by-step radiometric analysis, macro-, micro-, electron-microscopy and activation autoradiography, Mössbauer and Auger spectroscopy, secondary ion-ionic emission, X-ray diffraction and X-ray microanalysis. The study describes distribution features of penetrating atoms and their concentration profiles. Phase composition of near-surface layers is also determined. It is shown that supersaturated solid solutions of iron in copper and copper in iron are formed during simultaneous iron and oxygen penetration in copper and spinel (Fe6Cu3O4)4. Diffusion of iron and carbon results in supersaturated solid solutions of iron and carbon in copper, copper and carbon in iron, graphite and cementite. Inert gases and nitrogen form solid solutions with copper. Phase composition of near-surface layers in Fe is determined. Iron dioxide FeO, a carbon solid solution in iron with fcc lattice γ-Fe, tetragonal martensite and cementite, two iron (III) hydroxide FeOOH modifications, a supersaturated solid solution of nitrogen and nitride Fe4N, solid solutions of inert gases in iron are formed in the diffusion zone. Simultaneous interaction of molybdenum with iron (the anode material) and various gases results in the formation of substitutional solid solutions of iron in molybdenum and molybdenum in iron, a small amount of interstitial solid solutions of nitrogen and carbon in molybdenum and nitrogen in iron, interstitial phases: molybdenum nitrides and carbides and traces of nitrides of iron (Fe4N, Fe2N) and Fe1,9Mo (λ) phases in the form of needles. Treatment of nickel with a nickel anode in the nitrogen medium promotes formation of a solid solution of nitrogen and nitride Ni3N in the matrix with preserved hexagonal symmetry and lattice parameters that are characteristic of this phase under equilibrium conditions. Atoms of oxygen, nitrogen, carbon and argon are present in the interstitial solid solutions in treatment of nickel in ambient air; however, oxides are not found even on the surface (in the layer ~200 nm). Interaction of titanium with atmospheric gases leads to formation of a solid solution of nitrogen, oxygen, carbon, hydrogen and argon in titanium and titanium nitride Ti2N (ε). Simultaneous saturation of the titanium surface with nickel and nitrogen in the interaction zone causes formation of phases in the following order: nickel nitride; a solid solution of nitrogen and titanium in nickel and a solid solution of both alloying elements in titanium.

Phase Composition and Mechanical Properties Modification in Cr/Ti System by Short-Pulsed High Intensity Ion Beams Treatment

2015 ◽  
Vol 756 ◽  
pp. 319-324 ◽  
Author(s):  
V.I. Shymanski ◽  
G.E. Remnev ◽  
S.K. Pavlov ◽  
V.V. Uglov
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Phase Composition ◽  
Titanium Carbide ◽  
High Intensity ◽  
Ion Beams ◽  
Surface Alloys ◽  
Surface Layers ◽  
Near Surface ◽  
Structure Phase

In the present the results of research of structure, phase composition and microhardness measurement of the surface layers of the Cr/Ti system treated by short-pulsed high intensity ion beams (HPIB) are presented. It was shown that the HPIB impact on a “coating/substrate” system can serve as an affective way to produce near-surface alloys in the metals. In particular, in the Cr/Ti system the formation of solid solution β-Ti (Cr) as well as titanium carbide TiCx was revealed. The found changes in structure and phase composition of titanium caused by the HPIB impact allow to increase its microhardness in 2 times.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

Solid solutions in the system Ag2S–Ag2Se

1992 ◽  
Vol 7 (8) ◽  
pp. 2219-2224 ◽  
Author(s):  
N.E. Pingitore ◽  
B.F. Ponce ◽  
M.P. Eastman ◽  
F. Moreno ◽  
C. Podpora
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Type Structure ◽  
Solid Solution Series ◽  
X Ray Diffraction ◽  
Compositional Gradient ◽  
X Ray ◽  
Optical Electron ◽  
Discrete Phase ◽  
Diffraction Peaks

Optical, electron microprobe, and x-ray diffraction analysis of 88 samples of various compositions between Ag2S and Ag2Se synthesized at high temperature in sealed quartz tubing indicates the presence of two solid-solution series in this system at ambient (room) conditions. One series extends from Ag2S to approximately Ag2S0.4Se0.7 and has the Ag2S-III-type structure (monoclinic). The second series ranges from Ag2S0.3Se0.7 to Ag2Se and is characterized by the Ag2Se-II-type structure (orthorhombic). Members of both series, in appropriate proportions, characterize the apparent compositional gap between the two solid solutions. Gradual shifts in the locations of the x-ray diffraction peaks along the compositional gradient of each solid solution revealed an expansion of the d-spacing as the larger Se ion was substituted for S in the Ag2S-III-type structure and a contraction as S was substituted for Se in the Ag2Se-II-type structure. The reported discrete phase, Ag4SSe (aguilarite, orthorhombic), appears to be simply a member of the monoclinic Ag2S-III-type solid solution.

Spinel solid solutions in the systems MgAl2O4–ZnAl2O4 and MgAl2O4–Mg2TiO4

1997 ◽  
Vol 12 (10) ◽  
pp. 2584-2588 ◽  
Author(s):  
M. A. Petrova ◽  
G. A. Mikirticheva ◽  
A. S. Novikova ◽  
V. F. Popova
Keyword(s):  
Solid Solution ◽  
Phase Diagrams ◽  
Melting Temperature ◽  
Solid Solutions ◽  
Spinel Structure ◽  
Room Temperature ◽  
Binary Systems ◽  
Continuous Series ◽  
X Ray ◽  
Spinel Solid Solutions

Phase relations in two binary systems MgAl2O4–ZnAl2O4 and MgAl2O4–Mg2TiO4 have been studied and phase diagrams for them have been constructed. Based on the data of x-ray phase and crystal-optical analyses, the formation of a continuous series of solid solutions with spinel structure between the terminal members of the systems studied has been established. In the MgAl2O4–ZnAl2O4 system the solid solution is stable in the range from room temperature to melting temperature. In the MgAl2O4–Mg2TiO4 system the solid solution decomposes below 1380 °C, yielding the formation of limited regions of homogeneity on the basis of MgAlM2O4 and Mg2+2δ Ti1–δO4. Decomposition of the solid solution is accompanied by crystallization of MgTiO3.

Effect of Synthesis Conditions and Actinide Contents on Phase Composition of Actinide Bearing Ceramics

2003 ◽  
Vol 807 ◽  
Author(s):  
A. G. Ptashkin ◽  
S. V. Stefanovsky ◽  
S. V. Yudintsev ◽  
S. A. Perevalov
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Phase Composition ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Reducing Conditions ◽  
Dispersive System ◽  
Scanning Electron

ABSTRACTPu-bearing zirconolite and pyrochlore based ceramics were prepared by melting under oxidizing and reducing conditions at 1550 °C. 239Pu content in the samples ranged between ∼10 and ∼50 wt.%. Phase composition of the ceramics and Pu partitioning were studied using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive system (SEM/EDS). Major phases in the samples were found to be the target zirconolite and pyrochlore as well as a cubic fluorite structure oxide. Normally the Pu content in the Pu host phases was 10–12 wt.%. This corresponds to the Pu content recommended for matrices for immobilization of excess weapons plutonium. At higher Pu content (up to 50 wt.%) additional phases, such as a PuO2-based cubic fluorite-structured solid solution, perovskite, and rutile were found.

scholarly journals Characterization of the Surface Layer of Mg Enriched with Al and Si by Thermochemical Treatment

2017 ◽  
Vol 17 (4) ◽  
pp. 195-199 ◽  
Author(s):  
R. Mola ◽  
E. Stępień ◽  
M. Cieślik
Keyword(s):  
Solid Solution ◽  
Thermochemical Treatment ◽  
Heating Time ◽  
Substrate Material ◽  
Surface Layers ◽  
X Ray ◽  
Three Phase ◽  
Distribution Of Elements ◽  
Modified Surface

AbstractThe modified surface layers of Mg enriched with Al and Si were fabricated by thermochemical treatment. The substrate material in contact with an Al + 20 wt.% Si powder mixture was heated to 445°C for 40 or 60 min. The microstructure of the layers was examined by OM and SEM. The chemical composition of the layer and the distribution of elements were determined by energy dispersive X-ray spectroscopy (EDS). The experimental results show that the thickness of the layer is dependent on the heating time. A much thicker layer (1 mm) was obtained when the heating time was 60 min than when it was 40 min (600 μm). Both layers had a non-homogeneous structure. In the area closest to the Mg substrate, a thin zone of a solid solution of Al in Mg was detected. It was followed by a eutectic with Mg17Al12and a solid solution of Al in Mg. The next zone was a eutectic with agglomerates of Mg2Si phase particles; this three-phase structure was the thickest. Finally, the area closest to the surface was characterized by dendrites of the Mg17Al12phase. The microhardness of the modified layer increased to 121-236 HV as compared with 33-35 HV reported for the Mg substrate.

Mineral analysis of river sand around Mt. Tsukuba for provenance estimation of Atamadai type pottery (2500–1500 BC) from Hinoki site (Tochigi, Japan)

2019 ◽  
Vol 34 (2) ◽  
pp. 159-163
Author(s):  
S. Ichikawa ◽  
Y. Sakito ◽  
T. Kurisaki
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Manufacturing Process ◽  
Mineral Analysis ◽  
Solution Composition ◽  
River Sand ◽  
Solid Solution Composition ◽  
X Ray ◽  
Geological Characteristics ◽  
Mineral Analyses

A total of 77 pottery shards originating from the Middle Jomon period (2500–1500 BC) were excavated from the Hinoki site in Tochigi, Japan. Fifty-five of those were Atamadai type pottery, which might contain some temper fragments from the manufacturing process. The pottery shards were analyzed by X-ray diffractometry (XRD). The mineral analyses were compared with the river sands around Mt. Tsukuba to demonstrate the temper's origin of the Atamadai type pottery. Their XRD profiles revealed the following solid solutions which could be fingerprint minerals: biotite for the temper and plagioclase, and hornblende for the clay and temper. These minerals might indicate the origin of each sample because their d-spacings depended on the solid solution composition reflecting their geological characteristics.

Study of Structural and Catalytic Properties of Pt/WOх/ZrO₂, Modified by Lanthanum Cations

2020 ◽  
pp. 133-141
Author(s):  
Svetlana A. Naumova ◽  
Anastasia V. Obukhova ◽  
Ludmila I. Kuznetsova
Keyword(s):  
Solid Solution ◽  
Catalytic Activity ◽  
Phase Composition ◽  
Structural Properties ◽  
Catalytic Properties ◽  
Surface Layers ◽  
Tetragonal Modification ◽  
Nanocrystalline Zirconia ◽  
Positive Effect

The effect of the addition of La3+ cations on the structural properties of Pt/WOх/ZrO₂ catalysts and the characteristics of catalytic activity in the process of hydroisomerization of n-heptane and benzene mixture was studied. The phase composition of the catalysts is represented by a solid solution of lanthanum cations in nanocrystalline zirconia of tetragonal modification with localization of lanthanum in the surface layers predominantly. The positive effect of La3+ additives on the selectivity and yield of isomerized products was shown

X-ray powder diffraction characterization of Bi14(Sr,Ca)12O33 solid solutions

1996 ◽  
Vol 11 (4) ◽  
pp. 268-275 ◽  
Author(s):  
Winnie Wong-Ng ◽  
F. Jiang ◽  
Bryan R. Jarabek ◽  
Gregory J. McCarthy
Keyword(s):  
Solid Solution ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Cell Parameter ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Solid Solution Range

Powder X-ray diffraction was used to investigate the solid solution range of the Bi14SrxCa12−xO33 series in the Bi–Sr–Ca–O system. Solid solution forms over the range 1≤x≤7 in Bi14SrxCa12−xO33. Experimental X-ray reference patterns of selected members with x=1, 3, 5, and 7 have been prepared for the powder diffraction file (PDF). These phases are monoclinic, C2/m, with cell parameter a ranging from 21.473(4) to 21.868(4) Å, b from 4.3564(9) to 4.3898(9) Å, c from 12.753(2) to 12.962(2) Å, β from 102.91(2)° to 102.79(1)°, and V from 1162.9(3) to 1213.5(3) Å3, respectively. These parameters increase monotonically as Ca is continuously replaced by the larger Sr.

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