Diffusion Paths for Interstitial Impurities in Different Polymorphic Modifications of Niobium Silicide Nb5Si3

2018 ◽  
Vol 63 (3) ◽  
pp. 319-326 ◽  
Author(s):  
N. A. Kuzmina ◽  
N. N. Eremin ◽  
E. I. Marchenko ◽  
I. L. Svetlov ◽  
N. A. Muromtsev ◽  
...  
Author(s):  
E. U. Lee ◽  
P. A. Garner ◽  
J. S. Owens

Evidence for ordering (1-6) of interstitial impurities (O and C) has been obtained in b.c.c. metals, such as niobium and tantalum. In this paper we report the atomic and microstructural changes in an oxygenated c.p.h. metal (alpha titanium) as observed by transmission electron microscopy and diffraction.Oxygen was introduced into zone-refined iodide titanium sheets of 0.005 in. thickness in an atmosphere of oxygen and argon at 650°C, homogenized at 800°C and furnace-cooled in argon. Subsequently, thin foils were prepared by electrolytic polishing and examined in a JEM-7 electron microscope, operated at 100 KV.


Author(s):  
L. P. Lemaire ◽  
D. E. Fornwalt ◽  
F. S. Pettit ◽  
B. H. Kear

Oxidation resistant alloys depend on the formation of a continuous layer of protective oxide scale during the oxidation process. The initial stages of oxidation of multi-component alloys can be quite complex, since numerous metal oxides can be formed. For oxidation resistance, the composition is adjusted so that selective oxidation occurs of that element whose oxide affords the most protection. Ideally, the protective oxide scale should be i) structurally perfect, so as to avoid short-circuit diffusion paths, and ii) strongly adherent to the alloy substrate, which minimizes spalling in response to thermal cycling. Small concentrations (∼ 0.1%) of certain reactive elements, such as yttrium, markedly improve the adherence of oxide scales in many alloy systems.


Food Industry ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 29-36
Author(s):  
Alexander Vereshchagin ◽  
Irina Reznichenko ◽  
Nikolay Bychin

The article concerns the research specificity of model systems such as cocoa butter – palm olein, cocoa butter – sucrose and cocoa butter – glucose syrup by the differential scanning calorimetry (DSC) method. The researchers run experiments in the temperature range from –100 to –50°C at a heating rate of 10 °C/min. In the cacao butter – palm olein system an eutectic occurs with a palm olein content of 30.0 % indicating the limited solubility of palm olein in cocoa butter. In the cocoa butter – sucrose system, cocoa butter crystallizes as in the α-form (10,0– 30,0; 60.0–90.0 % MK), and as a mixture of α-and β-forms of MK (40.0; 50,0; 70,0 and 80.0 %). Sucrose stabilizes low-temperature polymorphic modifications of cocoa butter. In the cocoa butter – glucose syrup system, temperature of samples melting is 21-22 °C. This composition is promising for use as a filling of confectionery products and glazes production. In this regard, a man can use glucose syrup only in the candy cases production. The role of surfactants used for the formation and stabilization of cocoa butter polymorphs and increasing the thermal stability of the shock-lad without the introduction of palm stearin requires separate consideration.


2019 ◽  
Vol 7 (23) ◽  
pp. 13910-13916 ◽  
Author(s):  
Masatomo Yashima ◽  
Takafumi Tsujiguchi ◽  
Kotaro Fujii ◽  
Eiki Niwa ◽  
Shunta Nishioka ◽  
...  

Experimentally visualized two-dimensional O2−–O2–O3– diffusion paths rotating around Ba cations in oxygen deficient Ba3MoNbO8.5−δat 1100 °C.


2021 ◽  
Vol 70 (1) ◽  
pp. 91-98
Author(s):  
N. E. Kuz’mina ◽  
S. V. Moiseev ◽  
V. S. Kuz’min ◽  
M. D. Khorol’skiy ◽  
A. I. Luttseva

2021 ◽  
Author(s):  
Carlos Marino ◽  
Juan Basbus ◽  
Ana L. Larralde ◽  
Jose Antonio Alonso ◽  
Maria Teresa Fernandez-Diaz ◽  
...  

This work presents the results of the structural characterization of LaSrGa1-xMgxO4-δ oxides with x=0.0-0.2 (LSGM'); these oxides with layered K2NiF4-type structure are potential electrolytes of oxygen ions with applications in...


1981 ◽  
Vol 24 (4) ◽  
pp. 338-342
Author(s):  
V. A. Klimenko ◽  
S. I. Masharov ◽  
A. F. Rybalko ◽  
N. M. Rybalko ◽  
N. I. Timofeev

2008 ◽  
Vol 277 ◽  
pp. 119-124 ◽  
Author(s):  
Ü. Ugaste ◽  
J. Priimets ◽  
Tony Laas

The impact of thermodynamic factors on deviation from linearity of diffusion path in the ternary system Cu-Fe-Ni is analyzed. For that the slope function of the diffusion path for the diffusion couples 65Ni30Cu5Fe –29.5Ni16.5Cu54Fe, 49.5Ni50.5Fe – 51Ni49Cu and 84Cu16Ni – 50Ni50Fe, annealed at 1000°C for 196h, were calculated by an approximate equation using only thermodynamic data. Results of the calculation were compared with the values of the slope function obtained directly from experimental data. It is shown that despite of the fact that the tracer diffusion coefficients of the components in the system Cu-Fe-Ni are not equal the coincidence between the calculated and experimental values of the slope function is remarkable. This allows us to conclude that at least in this case the deviation of the diffusion path from linearity depends mainly on the thermodynamic properties of the system.


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