Two Phase-Diagrams of the Thermal Roughening Transition in Anodic Dissolution of Polycrystalline Nickel

2019 ◽  
pp. 6658-6666
Author(s):  
M Saitou ◽  
Keyword(s):  
Phase Diagrams ◽  
Anodic Dissolution ◽  
Polycrystalline Nickel ◽  
Two Phase ◽  
Roughening Transition

scholarly journals The multivariate calculation of material balances of flowsheets for separating ternary mixtures of different physical-chemical nature

2016 ◽  
Vol 11 (3) ◽  
pp. 47-57 ◽  
Author(s):  
A. V. Frolkova ◽  
M. A. Ablizin ◽  
M. A. Mayevskiy ◽  
A. K. Frolkova
Keyword(s):  
Phase Diagrams ◽  
Chemical Nature ◽  
Material Balance ◽  
Ternary Systems ◽  
Butyl Alcohol ◽  
Ternary Mixtures ◽  
Two Phase ◽  
Physical Chemical ◽  
Alcohol Water

An approach to the determination of free variables required for calculating the material balance of the flowsheet of ternary mixtures separation is presented. Phase diagrams of the considered ternary systems are characterized by the presence of a two-phase splitting area and by the presence of different amounts of azeotropes (classes 3.1.0, 3.1.1, 3.2.1 and 3.3.1). For all the systems flowsheets containing three rectification columns and a florentine vessel for separation were suggested. The multivariance of the solution of the balance problem was shown. The approach was illustrated by the example of real ternary systems characterized by different phase diagrams (methanol - chloroform - water, butyl alcohol - water - toluene, nitromethane - hexane - water). The parameters of the rectification columns were presented.

Diffusion and its Application in NiMnGa Alloys

2018 ◽  
Vol 19 ◽  
pp. 80-95 ◽  
Author(s):  
Le Zhou ◽  
Yong Ho Sohn
Keyword(s):  
Crystal Structure ◽  
Martensitic Transformation ◽  
Phase Diagrams ◽  
Diffusion Coefficients ◽  
Diffusion Couples ◽  
Arrhenius Behavior ◽  
Ferromagnetic Shape Memory Alloys ◽  
Two Phase ◽  
Austenitic Phase ◽  
Practical Applications

Heusler NiMnGa alloys are often categorized as ferromagnetic shape memory alloys or magnetocaloric materials, which are important for both practical applications and fundamental research. The NiMnGa alloys undergo a series of diffusion and diffusionless transformation from high temperature to low temperature. Among these transformation, martensitic transformation from austenitic phase to martensitic phase is critical in determining the properties of the alloys. Although martensitic transformation is considered diffusionless, diffusion also has important applications in the research of NiMnGa alloysDiffusion couples along with equilibrium alloys have been used to determine the ternary phase diagrams in NiMnGa alloys. Phase diagrams are important in selecting NiMnGa alloys, in particular two-phase NiMnGa alloys for practical applications. Furthermore, the diffusion couples effectively assist in the determination of compositions that exhibit martensitic transformation temperature near room temperature. Diffusion coefficients have been assessed for NiMnGa alloys. Tracer diffusivity of Ni, Mn and Ga was reported in a wide temperature range and followed Arrhenius behavior. Two different activation energies were obtained, corresponding to B2 and L21 crystal structure, respectively. Interdiffusion coefficients for NiMnGa alloys with B2 crystal structure are measured, which showed that Ni diffuses the fastest, followed by Mn then Ga. The diffusion coefficients provide useful information for fabricating NiMnGa alloys through diffusional process.A combinatorial approach involving diffusion couples and advance characterization has been developed to investigate the mechanical properties, microstructure and crystallography of NiMnGa alloys rapidly and systematically over a large compositional range. The composition-dependent modulus and hardness for NiMnGa alloys was extracted from the diffusion couples with the help of nanoindentation. Martensitic phases with non-modulated and various modulated crystal structures, and austenitic phase were identified in the interdiffusion zones by transmission electron microscopy. The results demonstrate the capability of using diffusion couples to speed up the discovery of new NiMnGa alloys or other similar alloys showing martensitic transformation.

A numerical investigation of the effect of external resistance and applied potential on the distribution of periodicity and chaos in the anodic dissolution of nickel

2020 ◽  
Vol 22 (38) ◽  
pp. 21823-21834
Author(s):  
Caio da S. Rodrigues ◽  
Caio G. P. dos Santos ◽  
Renan C. C. de Miranda ◽  
Eduardo Parma ◽  
Hamilton Varela ◽  
...  
Keyword(s):  
Phase Diagrams ◽  
Numerical Investigation ◽  
Anodic Dissolution ◽  
Low Density ◽  
Applied Potential ◽  
External Resistance

Low density, elongation, and suppression of the shrimp-like structures in the resistance-potential phase diagrams have been observed in the oscillatory dissolution of nickel.

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