Diffusion of Ti, V and Nb in Ni3Al at Elevated Temperatures

2010 ◽  
Vol 297-301 ◽  
pp. 384-389 ◽  
Author(s):  
Haruhiko Fukaya ◽  
Md. Moniruzzaman ◽  
Yoshinori Murata ◽  
Masahiko Morinaga ◽  
Toshiyuki Koyama ◽  
...  
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficients ◽  
Binary Systems ◽  
Elevated Temperatures ◽  
Diffusion Mechanism ◽  
Impurity Diffusion ◽  
Diffusion Couples ◽  
Different Temperatures ◽  
Series Of Experiments ◽  
Interdiffusion Coefficients

Interdiffusion coefficients of Al replacing elements in Ni-Al-X (X=Ti, V and Nb) were estimated by a series of experiments using diffusion couples of Al rich pseudo-binary systems at three different temperatures of 1423, 1473 and 1523K. In order to obtain interdiffusion coefficients of the pseudo-binary systems, the experimental data was analyzed by the Sauer and Freise method, and also impurity diffusion coefficients of Ti, V and Nb in Ni3Al were estimated by applying the Darken-Manning equation. The magnitude of interdiffusion coefficient decreased in order of V, Ti and Nb at all three temperatures. Impurity diffusion coefficients were described by the expressions: , , . The activation enthalpies obtained from the experimental data confirmed the retardation of Ti, V and Nb diffusion in Ni3Al by the anti-site diffusion mechanism. These results are consistent with our previous work on diffusion of Re and Ru in Ni3Al .

scholarly journals An Effective Approach to Acquire the Impurity Diffusion Coefficients in Binary Alloys with Quantified Uncertainties

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 809
Author(s):  
Yueheng Zhang ◽  
Jianpeng Zou ◽  
Xiaoke Wu ◽  
Chunming Deng ◽  
Lijun Zhang
Keyword(s):  
Diffusion Coefficients ◽  
Noble Metals ◽  
Binary Systems ◽  
Binary Alloys ◽  
Radioactive Tracer ◽  
Distribution Functions ◽  
Impurity Diffusion ◽  
Stable Region ◽  
Practical Applications ◽  
Interdiffusion Coefficients

In this paper, we started from the composition-dependent interdiffusion coefficients with quantified uncertainties in binary alloys by integrating the Matano-based method, distribution functions, and uncertainty propagation approach. After carefully defining the numerically stable region for the interdiffusion coefficients, the suitable pre-set functions were screened to achieve the reasonable fit to the D-c and μ-c data according to the Akaike information criterion. With the fitted D-c and μ-c curves, the impurity diffusion coefficients with uncertainties can be directly determined. Benchmark tests in five hypothetical binary systems with different preset D-c relations were then utilized to validate the presently effective approach, followed by practical applications in five real cases, i.e., fcc Ni-Co, fcc Cu-Al, fcc Pt-Ni, hcp Mg-Zn, and bcc Ti-V alloys. The impurity diffusion coefficients with uncertainties derived by the presently effective approach were found to be in excellent agreement with the data by tracer experiments, indicating that this effective approach can serve as a standard one for acquiring the high-quality impurity diffusion coefficients in binary alloys with quantified uncertainties, especially for the noble metals and the cases without suitable radioactive tracer isotopes.

Novel Method of Evaluation of Diffusion Coefficients in Ti-Zr System

2008 ◽  
Vol 279 ◽  
pp. 53-62 ◽  
Author(s):  
K. Bhanumurthy ◽  
A. Laik ◽  
G.B. Kale
Keyword(s):  
Diffusion Couple ◽  
Diffusion Zone ◽  
Diffusion Coefficients ◽  
Extended Period ◽  
Impurity Diffusion ◽  
Diffusion Couples ◽  
Simple Method ◽  
Elegant Method ◽  
Method Of Evaluation ◽  
Interdiffusion Coefficients

The incremental diffusion couples are used for evaluating interdiffusion couples in a narrow composition range and these results are extrapolated to get an estimate of impurity diffusion coefficients. In fact, several incremental couples are needed to get impurity diffusion coefficients at different compositions. This process is generally tedious. The present method describes a relatively simple method for evaluating the diffusion coefficients using “step diffusion couples”. A simple experimental method is described to prepare a step diffusion couple. This method involves preparation of diffusion couples in two stages. In the first stage, diffusion couple is made between the two materials in a conventional way and annealed for extended period of time to have a large diffusion zone typically of the order of 2-3 mm. In the second stage, the starting materials are placed on the diffusion couple in a direction perpendicular to the diffusion zone and annealed at a suitable temperature for diffusion to occur between the diffusion zone and the starting materials. This method is applied to study the interdiffusion behavior in the b phase of the Ti-Zr system. Boltzmann-Matano and Hall’s methods were used to determine the interdiffusion coefficients and their composition dependence. Kirkendall shift is observed towards Ti side and the intrinsic diffusion coefficients of Ti is approximately three times that of Zr. The width of the diffusion zone is strongly dependent on the composition of the step diffusion couple. It is observed that the interdiffusion coefficients evaluated at the terminal compositions matched well those published values in the Ti-Zr system. This experimental technique offers an easy and elegant method to determine the diffusion parameters without the tedious preparation of incremental diffusion couples.

Effect Of Elevated Temperatures On Complete Concrete Deformation Diagrams

2019 ◽  
pp. 9-14
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Elevated Temperatures ◽  
Peak Load ◽  
Relative Deformation ◽  
Deformation Characteristics ◽  
Compression Tests ◽  
Strain Behavior ◽  
Different Temperatures ◽  
Deformation Diagrams

The analysis of the previous results of the study on concrete stress-strain behavior at elevated temperatures has been carried out. Based on the analysis, the main reasons for strength retrogression and elastic modulus reduction of concrete have been identified. Despite a significant amount of research in this area, there is a large spread in experimental data received, both as a result of compression and tension. In addition, the deformation characteristics of concrete are insufficiently studied: the coefficient of transverse deformation, the limiting relative compression deformation corresponding to the peak load and the almost complete absence of studies of complete deformation diagrams at elevated temperatures. The two testing chambers provided creating the necessary temperature conditions for conducting studies under bending compression and tension have been developed. On the basis of the obtained experimental data of physical and mechanical characteristics of concrete at different temperatures under conditions of axial compression and tensile bending, conclusions about the nature of changes in strength and deformation characteristics have been drawn. Compression tests conducted following the method of concrete deformation complete curves provided obtaining diagrams not only at normal temperature, but also at elevated temperature. Based on the experimental results, dependences of changes in prism strength and elastic modulus as well as an equation for determining the relative deformation and stresses at elevated temperatures at all stages of concrete deterioration have been suggested.

scholarly journals Impurity Diffusion Coefficients of Al and Zn in Mg Determined from Solid-to-Solid Diffusion Couples

2014 ◽  
pp. 505-509
Author(s):  
Catherine Kammerer ◽  
Nagraj Kulkarni ◽  
Robert Warmack ◽  
Kelly Perry ◽  
Irina Belova ◽  
...  
Keyword(s):  
Diffusion Coefficients ◽  
Impurity Diffusion ◽  
Diffusion Couples ◽  
Solid Diffusion

Interdiffusion in Nb-Mo, Nb-Ti and Nb-Zr Systems

2012 ◽  
Vol 323-325 ◽  
pp. 491-496 ◽  
Author(s):  
Soma Prasad ◽  
Aloke Paul
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Diffusion Couple ◽  
Impurity Diffusion ◽  
Impurity Diffusion Coefficient ◽  
Different Temperatures ◽  
Diffusion Couple Technique ◽  
Interdiffusion Coefficients

Diffusion couple technique is used to study interdiffusion in Nb-Mo, Nb-Ti and Nb-Zr systems. Interdiffusion coefficients at different temperatures and compositions are determined using the relation developed by Wagner. The change in activation energy for interdiffusion with composition is determined. Further, impurity diffusion coefficient of the species are determined and compared with the available data in literature.

scholarly journals Role of different factors affecting interdiffusion in Cu(Ga) and Cu(Si) solid solutions

2014 ◽  
Vol 470 (2161) ◽  
pp. 20130464 ◽  
Author(s):  
Sangeeta Santra ◽  
Hongqun Dong ◽  
Tomi Laurila ◽  
Aloke Paul
Keyword(s):  
Solid Solutions ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Impurity Diffusion ◽  
Factors Affecting ◽  
The Matrix ◽  
Bond Strengths ◽  
Interdiffusion Coefficients ◽  
Formation Energies

A detailed diffusion study was carried out on Cu(Ga) and Cu(Si) solid solutions in order to assess the role of different factors in the behaviour of the diffusing components. The faster diffusing species in the two systems, interdiffusion, intrinsic and impurity diffusion coefficients, are determined to facilitate the discussion. It was found that Cu was more mobile in the Cu–Si system, whereas Ga was the faster diffusing species in the Cu–Ga system. In both systems, the interdiffusion coefficients increased with increasing amount of solute (e.g. Si or Ga) in the matrix (Cu). Impurity diffusion coefficients for Si and Ga in Cu, found out by extrapolating interdiffusion coefficient data to zero composition of the solute, were both higher than the Cu tracer diffusion coefficient. These observed trends in diffusion behaviour could be rationalized by considering: (i) formation energies and concentration of vacancies, (ii) elastic moduli (indicating bond strengths) of the elements and (iii) the interaction parameters and the related thermodynamic factors. In summary, we have shown here that all the factors introduced in this paper should be considered simultaneously to understand interdiffusion in solid solutions. Otherwise, some of the aspects may look unusual or even impossible to explain.

The Influence of Thermodynamic Properties of Alloys on Effective Interdiffusion Coefficients in Ternary Systems

2007 ◽  
Vol 263 ◽  
pp. 141-146 ◽  
Author(s):  
Ü. Ugaste ◽  
Tony Laas ◽  
T. Škled-Gorbatšova
Keyword(s):  
Thermodynamic Properties ◽  
Diffusion Coefficients ◽  
Reasonable Agreement ◽  
Ternary Systems ◽  
Tracer Diffusion ◽  
Diffusion Couples ◽  
Experimental Values ◽  
Tracer Diffusion Coefficients ◽  
Interdiffusion Coefficients ◽  
The Relationship

To prove the validity of Dayananda’s phenomenological model of interdiffusion in ternary systems the effective interdiffusion coefficients for a few diffusion couples in the system Cu-Ni-Fe, annealed at 1000 oC, are calculated on the basis of this model using available tracer diffusion and thermodynamic data. It is found that the calculated values of effective interdiffusion coefficients are in reasonable agreement with experimental values extracted independently from experimental concentration--penetration curves. Using the relationship between effective interdiffusion coefficients, tracer diffusion coefficients and thermodynamic factors, it is shown that thermodynamic properties of alloys play a significant role in interdiffusion processes in the system Cu-Fe-Ni.

scholarly journals Impurity Diffusion Coefficients of Al and Zn in Mg Determined from Solid-to-Solid Diffusion Couples

2013 ◽  
Author(s):  
Catherine Kammerer ◽  
Nagraj S Kulkarni ◽  
Robert J Bruce Warmack ◽  
Kelly A Perry ◽  
Irina Belova ◽  
...  
Keyword(s):  
Diffusion Coefficients ◽  
Impurity Diffusion ◽  
Diffusion Couples ◽  
Solid Diffusion

The Growth Rates of Intermediate Phases in Co/Si Diffusion Couples: Bulk Versus Thin-Film Studies

1989 ◽  
Vol 148 ◽  
Author(s):  
C. H. Jan ◽  
J. C. Lin ◽  
Y. A. Chang
Keyword(s):  
Experimental Data ◽  
Growth Rates ◽  
Film Studies ◽  
Bulk Diffusion ◽  
Diffusion Equations ◽  
Diffusion Couples ◽  
Intermediate Phases ◽  
Diffusion Controlled ◽  
Composition Profiles ◽  
Interdiffusion Coefficients

ABSTRACTBulk diffusion couples of Co/Si were annealed at 800, 900, 1000, 1050 and 1100°C for periods ranging from 24 hours to one month. Growth rates of the intermediate phases, Co2Si, CoSi and CoSi2, as well as the composition profiles across the couples were determined by optical microscopy and electron probe microanalysis (EPMA). Using the solution to the multiphase binary diffusion equations and the experimental data, the interdiffusion coefficients for Co2Si, CoSi and CoSi2 are obtained as a function of temperature. The activation energies obtained are 140, 160 and 190 KJ/mole for Co2Si, CoSi and CoSi2, respectively. The generally small interdiffusion coefficient of CoSi2 and its high activation energy cause the growth rate of CoSi2 to be extremely small at low temperatures.The interdiffusion coefficients for Co2Si, CoSi and CoSi2 at 545°C are obtained by extrapolation of the high-temperatures data. Using these data and solving numerically the diffusion equations with the appropriate boundary conditions, the growth of Co2Si, CoSi and CoSi2 is calculated as a function of time. The calculated results are in good agreement with the experimental data reported in the literature. This study demonstrates clearly that the initial absence of the CoSi2 phase is due to diffusion-controlled rather than nucleation-controlled kinetics. This phenomenon may be quite common in many thin-fiflm metal/Si couples.

scholarly journals The Optical Properties of InGaAs(P)/InP Under Group V Sublattice Two-phase Interdiffusion

1995 ◽  
Vol 417 ◽  
Author(s):  
E. Herbert Li ◽  
Joseph Micallef ◽  
W. C. Shui
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Transition State ◽  
Diffusion Coefficients ◽  
Concentration Ratio ◽  
Diffusion Mechanism ◽  
Time Dependent ◽  
Two Phase ◽  
Group V ◽  
Lattice Matched

AbstractUsing the fundamental transition state, we will investigate the two phase interdiffusion of group V sublattice in a strained lattice matched InGaAs/InP quantum well (QW) structures. The model employs three parameters namely the diffusion coefficients in the barrier (Db)and in the well (Dw)and the concentration ratio (k) of the diffused species at the heterstructure. The QW model includes the effects of strain and the exciton. A pseudo time dependent calculation is also considered and results are fitted to the reported experimental data. These parameters which characterize the diffusion mechanism can be measure to form a better understanding of the interdiffsion process for group V sublattice.

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