scholarly journals Diffusion coefficients in multiphase Ni80Cr20-Ti system

2021 ◽  
Vol 57 (1) ◽  
pp. 137-144
Author(s):  
B. Wierzba ◽  
D. Serafin ◽  
W.J. Nowak ◽  
P. Wierzba ◽  
A. Ciecko ◽  
...  
Keyword(s):  
Ternary System ◽  
Diffusion Couple ◽  
Diffusion Coefficients ◽  
Effective Diffusion ◽  
Intermetallic Phases ◽  
Reactive Diffusion ◽  
Intrinsic Diffusion ◽  
Two Phase ◽  
Effective Diffusion Coefficients

In this paper, the reactive diffusion in Ni80C20r?Ti ternary system is discussed at 1173K. The diffusion couple was prepared and annealed for 100 h. The two intermetallic phases and two two-phase zones occurred, namely: Ti2Ni, TiNi, TiNi+Cr, and TiNi3+Cr. Based on the experimental results (molar fractions, thicknesses of the intermetallic phases), the intrinsic diffusion coefficients of all components in each phase were numerically approximated. The Wagner method was used in the pure intermetallic phases. In the two phase zones the approximation was based on the generalized Darken and Wagner methods. The presented methods allowed for determination of the effective diffusion coefficients in each presented phase.

The Sequence of the Phase Growth during Diffusion in Ti-Based Systems

2019 ◽  
Vol 38 (2019) ◽  
pp. 151-157 ◽  
Author(s):  
Bartek Wierzba ◽  
Wojciech J. Nowak ◽  
Daria Serafin
Keyword(s):  
Theoretical Analysis ◽  
Entropy Production ◽  
Diffusion Coefficients ◽  
Intermetallic Phase ◽  
Intermetallic Phases ◽  
Diffusion Couples ◽  
Intrinsic Diffusion ◽  
Phase Growth ◽  
Diffusion Paths

AbstractThe interdiffusion in Ti-based alloys was studied. It was shown that during diffusion at 1,123 K formation of four intermetallic phases occurs. The diffusion paths for six different diffusion couples were determined. Moreover, the entropy production was calculated – the approximation used for determination of the sequence of intermetallic phase formation. In theoretical analysis, the intrinsic diffusion coefficients were determined from the modified Wagner method.

Analysis of Operating Conditions on Osmotic Dehydration of Plums (Prunus Domestica L.) and 3D-Numerical Determination of Effective Diffusion Coefficients

2017 ◽  
Vol 13 (11) ◽  
Author(s):  
María M. Rodríguez ◽  
Javier R. Arballo ◽  
Laura A. Campañone ◽  
Rodolfo H. Mascheroni
Keyword(s):  
Diffusion Coefficients ◽  
Osmotic Dehydration ◽  
Process Analysis ◽  
Effective Diffusion ◽  
Operating Conditions ◽  
Process Time ◽  
Process Conditions ◽  
Effective Diffusion Coefficients ◽  
Solution Type

AbstractThe objective of this work was to analyze the relevant process conditions on osmotic dehydration of plums and to determine the diffusion coefficients related to this process. The influence of solution (type and concentration of solute, temperature, fruit/solution ratio) and process time on water loss, water content and solutes gain were studied. Process analysis was performed experimentally by means of a set of 16 duplicate tests and numerically by mathematical modeling of the unsteady-state mass transfer phenomena. Experiments were carried out with glucose and sorbitol solutions (40–60 % w/w), dehydrating plum pieces during 2 h at temperatures of 25 and 40ºC, with fruit/solution ratios of 1/4 and 1/10. For calculating effective diffusion coefficients, a novelty inverse-method was applied, the approximate shape of food-pieces was considered using Finite Elements Method. Calculated diffusion coefficients ranged from 1.13 × 10−09to 4.71 × 10−09m2s−1and 0.44 × 10−09to 3.46 × 10−09m2s−1, for water and solutes, respectively.

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