A novel analytical approach to describe the simultaneous diffusional growth of multilayer stoichiometric compounds in binary reactive diffusion couples

2021 ◽  
Vol 191 ◽  
pp. 111-115
Author(s):  
Sa Ma ◽  
Fangzhou Xing ◽  
Chunming Deng ◽  
Lijun Zhang
Keyword(s):  
Analytical Approach ◽  
Reactive Diffusion ◽  
Diffusion Couples ◽  
Diffusional Growth

The diffusional growth of the binary compound, kinematic model of the reactive diffusion

1995 ◽  
Author(s):  
K. Holly ◽  
E. Bobula ◽  
M. Danielewski ◽  
K. Szyszkiewicz
Keyword(s):  
Kinematic Model ◽  
Binary Compound ◽  
Reactive Diffusion ◽  
Diffusional Growth

Diffusion Behavior and Interfacial Reaction of Heterogeneous Metal Systems Controlled by High Magnetic Fields

2012 ◽  
Vol 706-709 ◽  
pp. 2910-2915 ◽  
Author(s):  
Dong Gang Li ◽  
Qiang Wang ◽  
Kai Wang ◽  
Chun Wu ◽  
Guo Jian Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Diffusion Process ◽  
Flux Density ◽  
Reactive Diffusion ◽  
Magnetic Flux Density ◽  
High Magnetic Fields ◽  
Diffusion Couples ◽  
Diffusion Layers

The interdiffusion behaviors and interfacial reaction in solid Cu/solid Ni, liquid Bi/solid Bi0.4Sb0.6, liquid Al/solid Cu, and gas Al/solid Cu diffusion couples have been experimentally studied under a high magnetic field of up to 12T. The effects of magnetic flux density and the direction of magnetic field (B) on the evolution of interfacial microstructure (including interfacial migration, phase composition and thickness of diffusion layers) have been examined systematically. We found that (1) The shift distance of Kirkendall marker and the inter-diffusion coefficient in solid Cu/solid Ni diffusion couples increased with increasing magnetic flux density in case of the direction of diffusion parallel toB; (2) The migration of the Bi/Bi0.4Sb0.6interface due to the self-diffusion of the liquid metal into the solid alloy decreased markedly with the increase of magnetic flux density; (3) High magnetic fields exerted a non-monotonic influence on the thickness of diffusion layers during the reactive diffusion process between liquid Al and solid Cu; (4) The application of a high magnetic field during chemical reactive-diffusion process of gas Al/solid Cu system induced a significant change in the final products.

scholarly journals Nb/Sn Liquid-Solid Reactive Diffusion Couples and Their Application to Determination of Phase Equilibria and Interdiffusion Coefficients of Nb-Sn Binary System

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 113
Author(s):  
Jiali Zhang ◽  
Jing Zhong ◽  
Qin Li ◽  
Lijun Zhang
Keyword(s):  
Phase Equilibria ◽  
Local Equilibrium ◽  
Theoretical Data ◽  
Experimental Information ◽  
Reactive Diffusion ◽  
Phase Identification ◽  
Diffusion Couples ◽  
Melting Points ◽  
Activation Energy For Diffusion ◽  
Interdiffusion Coefficients

Nb3Sn plays an irreplaceable role in superconducting parts due to its stable performance under high field conditions. Accurate phase equilibria and interdiffusion coefficients are of great significance for designing novel Nb3Sn superconductors. However, the related experimental information is still in a state of scarcity because of the difficulty in fabrication of Nb-Sn alloys caused by the large difference in melting points of Nb and Sn. In this paper, a simple but pragmatic approach was first proposed to prepare the Nb/Sn liquid-solid reactive diffusion couples (LSDCs) at 1100 °C and 1200 °C, of which the phase identification of the formed layer and the measurement of composition-distance profiles were conducted. The formed layer in Nb/Sn LSDCs was confirmed to be Nb3Sn compound. While the measured composition profiles were employed to determine the phase equilibria according to the local equilibrium hypothesis and the interdiffusion coefficients with an aid of the latest version of HitDIC software. The determined phase equilibria of Nb3Sn, (Nb) and liquid show good agreement with the assessed phase diagram. While the calculated interdiffusion coefficients and activation energy for diffusion in Nb3Sn are consistent with both experimental and theoretical data in the literature. Moreover, the growth of the formed Nb3Sn layer in Nb/Sn LSDCs was also found to be diffusion controlled. All the obtained phase equilibria and interdiffusion coefficients are of great value for further thermodynamic and kinetic modeling of the Nb-Sn system. Furthermore, it is anticipated that the presently proposed approach of fabricating liquid-solid reactive diffusion couple should serve as a general one for various alloy systems with large differences in melting points.

The effect of NbC porosity on reaction-layer microstructure in NbC|Si diffusion couples

2000 ◽  
Vol 15 (1) ◽  
pp. 248-252 ◽  
Author(s):  
J. Woodford ◽  
C-Y. Yang ◽  
Y. A. Chang
Keyword(s):  
Reaction Layer ◽  
Powder Compact ◽  
Particle Morphology ◽  
Reactive Diffusion ◽  
High Porosity ◽  
Diffusion Couples ◽  
Two Phase ◽  
Nucleation Sites ◽  
The Matrix ◽  
Sic Particle

Further experimental observations have allowed us to refine and confirm some aspects of our recently proposed mechanism for reactive diffusion between Si single crystal and NbC powder compact, particularly regarding the prediction of Si as the dominant diffusing species and the nature of the dependence of SiC particle morphology on the presence of voids in the NbC end member. In Si|NbC diffusion couples annealed at either 1300 or 1350 °C, a two-phase NbSi2 + SiC reaction layer formed. Although NbSi2 was the matrix in all of the reaction layers, the SiC phase morphology depended upon NbC porosity: when high-porosity NbC was used, SiC was present as discontinuous particles greater than 1-μm-across, while when low-porosity or void-free NbC was used, SiC grew cooperatively with NbSi2 in the form of lamellae less than 0.5 μm thick. We propose that this difference arises from the effect of voids both as nucleation sites for SiC particles and as channels for unrestricted SiC growth. Marker experiments conclusively show that Si is the dominant diffusing species in the reaction layer.

Grain Boundary Induced Lateral Propagation of Intermetallic Phases in Nano-Grained Cu-Sn Thin Film Couples

2009 ◽  
Vol 7 ◽  
pp. 59-68 ◽  
Author(s):  
Yuri S. Kaganovsky ◽  
Lyudmila N. Paritskaya ◽  
V.V. Bogdanov
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Grain Boundary ◽  
Tracer Diffusion ◽  
Coarse Grained ◽  
Reactive Diffusion ◽  
Diffusion Couples ◽  
Cu3sn Phase ◽  
Phase Propagation ◽  
Kinetics Of

The kinetics of lateral Cu6Sn5 and Cu3Sn phase propagation induced by grain boundary (GB) interdiffuson in thin-film diffusion couples Cu-Sn were studied in a temperature range 160-180oC by optical microscopy, AFM, SEM, and energy-dispersive X-ray spectroscopy (EDS). Nano-grained Cu and Sn films were sequentially deposited on glass substrates with 5 – 20 µm overlap. To prevent surface diffusion and thus separate GB-diffusion contribution into kinetics of phase propagation, the surfaces of diffusion couples were covered by a thin (20 – 40 nm) carbon layer. It was found that the rates of lateral Cu6Sn5 and Cu3Sn phase spreading in thin-film couples exceed several times the spreading rates of the same phases over the surface of coarse-grained samples and 50 – 70 times exceed the rates in the bulk of massive samples. Kinetics of lateral phase spreading both in thin-film and in massive diffusion couples obeys parabolic law. Similarly to A and B regimes for GB tracer diffusion, A and B regimes of GB reactive diffusion were found in the spreading Cu3Sn phase. The kinetics of the phase propagation turned out independent of the film thickness (in the range 40 – 200 nm) if the films possessed similar grain size, whereas the kinetics was rather sensitive to the grain size and GB structure. Theoretical analysis of the phase propagation kinetics accelerated by GB diffusion has been done and the phase propagation rates have been calculated. By comparison experimentally measured phase propagation rates with the calculated ones we determined the GB diffusion coefficients of Sn in both growing phases.

Reactive Diffusion between Ti and Cu-9.3Sn-0.3Ti Alloy at Solid-State Temperatures

2011 ◽  
Vol 172-174 ◽  
pp. 470-474
Author(s):  
Masanori Kajihara ◽  
Shingo Nakamura
Keyword(s):  
Solid State ◽  
Diffusion Couple ◽  
Volume Diffusion ◽  
Interface Reaction ◽  
Reactive Diffusion ◽  
Diffusion Couples ◽  
Experimental Conditions

The reactive diffusion between Ti and a bronze was experimentally examined using sandwich diffusion couples consisting of Ti and a Cu-9.3Sn-0.3Ti alloy. The diffusion couples were isothermally annealed at temperatures ofT= 923-1023 K. During annealing, CuTi, (Cu, Sn)4Ti3and (Sn, Cu)5Ti6compounds are formed as layers at the interface in the diffusion couple. The overall growth of the compound layers is controlled by volume diffusion atT= 1023 K but by boundary and volume diffusion atT= 923-973 K. Hence, the interface reaction is not the bottleneck for the growth of the compound layers under the present experimental conditions.

Kinetic Features of Solid-State Reactive Diffusion between Au and Sn-Base Solder

2007 ◽  
Vol 539-543 ◽  
pp. 2473-2478 ◽  
Author(s):  
M. Kajihara ◽  
T. Takenaka
Keyword(s):  
Solid State ◽  
Diffusion Couple ◽  
Diffusion Bonding ◽  
Experimental Results ◽  
Reactive Diffusion ◽  
Diffusion Couples ◽  
Kinetics Of ◽  
Bonding Technique ◽  
Kinetic Features

The kinetics of the solid-state reactive diffusion between Au and Sn was experimentally observed using Sn/Au/Sn diffusion couples prepared by a diffusion bonding technique. The diffusion couples were isothermally annealed at a temperature of T = 453 K. Due to annealing, AuSn, AuSn2 and AuSn4 compound layers are formed at the interface in the diffusion couple. The experimental results were used to evaluate quantitatively the effect of Ni on the growth of the Au–Sn compounds. The evaluation indicates that the addition of Ni into Sn between 1 and 5 mass% accelerates the growth of the Au–Sn compounds at T = 433–473 K.

A mechanism for reactive diffusion between Si single crystal and NbC powder compact

1996 ◽  
Vol 11 (4) ◽  
pp. 850-854 ◽  
Author(s):  
C. R. Kao ◽  
J. Woodford ◽  
Y. A. Chang
Keyword(s):  
Single Crystal ◽  
Reaction Layer ◽  
Powder Compact ◽  
Reactive Diffusion ◽  
Particle Sizes ◽  
Diffusion Couples ◽  
Two Phase ◽  
Grain Sizes ◽  
The Matrix ◽  
Sic Particle

Based on our recent experimental observations, a growth mechanism for the reactive diffusion between Si single crystal and NbC powder compact is proposed. In Si–NbC diffusion couples annealed at 1300 °C, a two-phase NbSi2 + SiC reaction layer formed with NbSi2 as the matrix and SiC as discontinuous particles. The NbSi2 grain sizes and SiC particle sizes are both in the μm range. We propose that the SiC particles nucleated at the void surfaces in the NbC powder compact. This proposed nucleation mechanism offers a potential way of controlling the SiC particle size by changing the void size and void density of the NbC powder compact. It is also pointed out that this microstructure requires Si to be the dominant diffusing species. Si must diffuse through the reaction layer, while C only has to undergo local rearrangement, and Nb need not diffuse at all.

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