scholarly journals Modeling of interfacial flows based on an explicit volume diffusion concept

2021 ◽  
Vol 33 (6) ◽  
pp. 062111
Author(s):  
B. Wang ◽  
M. J. Cleary ◽  
A. R. Masri
Keyword(s):  
Volume Diffusion ◽  
Interfacial Flows

A TEM investigation of a hyper-eutectic lead-tin alloy

1988 ◽  
Vol 46 ◽  
pp. 562-563
Author(s):  
John A. Sutliff
Keyword(s):  
Volume Diffusion ◽  
Eutectic Mixture ◽  
Precipitation Reaction ◽  
Directionally Solidified ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffusion Controlled ◽  
Discontinuous Precipitation Reaction ◽  
Controlled Precipitation

Near-eutectic Pb-Sn alloys are important solders used by the electronics industry. In these solders, the eutectic mixture, which solidifies last, is the important microstructural consituent. The orientation relation (OR) between the eutectic phases has previously been determined for directionally solidified (DS) eutectic alloys using x-ray diffraction or electron chanelling techniques. In the present investigation the microstructure of a conventionally cast, hyper-eutectic Pb-Sn alloy was examined by transmission electron microscopy (TEM) and the OR between the eutectic phases was determined by electron diffraction. Precipitates of Sn in Pb were also observed and the OR determined. The same OR was found in both the eutectic and precipitation reacted materials. While the precipitation of Sn in Pb was previously shown to occur by a discontinuous precipitation reaction,3 the present work confirms a recent finding that volume diffusion controlled precipitation can also occur.Samples that are representative of the solder's cast microstructure are difficult to prepare for TEM because the alloy is multiphase and the phases are soft.

Retention coefficients and thermal release profiles of ion-injected argon from silicates and iron

1970 ◽  
Vol 48 (12) ◽  
pp. 1472-1479
Author(s):  
Harry C. Lord III
Keyword(s):  
Volume Diffusion ◽  
Ion Irradiation ◽  
Defect Diffusion ◽  
Substrate Composition ◽  
Retention Coefficient ◽  
Thermal Release ◽  
Argon Concentration ◽  
Cold Rolled ◽  
Argon Ions ◽  
Release Profiles

Thermal release profiles and retention coefficients of injected argon ions were investigated as functions of substrate composition and prior ion-irradiation history. Samples of forsterite, enstatite, oligoclase, obsidian, and cold-rolled steel were irradiated with various sequences of 1 keV H+, 4 keV He+, and 40 keV Ar+. The release temperature of the maximum argon concentration was found to be a function of incident Ar+ dose and pre-irradiation history but not substrate composition. The hydrogen or helium pre-irradiation converted the volume diffusion argon release to a low temperature defect diffusion release. An increase in the incident dose of Ar+ ions resulted in increasing the percentage of the argon released by defect diffusion, and also decreased the argon retention coefficient.

Influence of the A2-B2 Transition and High Pressure on Volume Diffusion in Fe3Al

1997 ◽  
Vol 143-147 ◽  
pp. 359-364 ◽  
Author(s):  
Zs. Tókei ◽  
Jean Bernardini ◽  
G. Erdélyi ◽  
Patrick Gas ◽  
Dezső L. Beke
Keyword(s):  
High Pressure ◽  
Volume Diffusion

Interpretation of grain boundary grooving data for combined surface and volume diffusion

1975 ◽  
Vol 6 (8) ◽  
pp. 1653-1654 ◽  
Author(s):  
W. M. Robertson ◽  
S. R. Srinivasan
Keyword(s):  
Grain Boundary ◽  
Volume Diffusion

The volume diffusion of carbon in Fe-17 Wt Pct Cr-12 Wt Pct Ni

1974 ◽  
Vol 5 (6) ◽  
pp. 1511-1514 ◽  
Author(s):  
R. A. Perkins ◽  
P. T. Carlson
Keyword(s):  
Volume Diffusion

A Mechanism of Polycrystallization in Fully Lamellar Ti-48Al-8Nb Single Crystal Alloy Aged at Elevated Temperatures

2002 ◽  
Vol 753 ◽  
Author(s):  
Yukinori Yamamoto ◽  
Masao Takeyama ◽  
Takashi Matsuo
Keyword(s):  
Growth Rate ◽  
Diffusion Coefficient ◽  
Single Crystal ◽  
Grain Growth ◽  
Elevated Temperatures ◽  
Volume Diffusion ◽  
Activation Enthalpy ◽  
Lamellar Microstructure ◽  
Aged Sample ◽  
Fully Lamellar

ABSTRACTPolycrystallization mechanism of a fully lamellar microstructure during aging at 1473 and 1273 K has been examined using Ti-48Al-8Nb fully lamellar single crystal, which consists mostly of γ/γ interfaces (variant, perfect-twin and pseudo-twin boundaries). After a certain period of aging, a few γ grains are formed within the lamellae and the lamellar microstructure collapses rapidly to become a γ grained microstructure at both temperatures. An EBSP analysis for aged sample revealed that most of the grains follow the orientation of variant domains in the lamellar microstructure. A kinetic analysis of the grain growth during aging revealed that the activation enthalpy of the growth rate is estimated to be 390 kJ/mol, which is very close to that for volume diffusion coefficient of Al and Nb in γ-TiAl. Based on the results, it is concluded that the formation of the grains is attributed to coarsening of variant domains within the lamellar plates and coalescence of the same variant domains across the lamellae, leading to a γ grained microstructure following the orientation of variant domains. These reactions also make the number of the variant domains decrease during aging, which remains only two variant domains with perfect-twin relationship.

scholarly journals A VARIABLE-DENSITY PROJECTION METHOD FOR INTERFACIAL FLOWS

2003 ◽  
Vol 44 (6) ◽  
pp. 553-574 ◽  
Author(s):  
Ming-Jiu Ni ◽  
Mohamed Abdou ◽  
Satoru Komori
Keyword(s):  
Projection Method ◽  
Variable Density ◽  
Interfacial Flows

Silver Self-Diffusion in Al2O3/QE22 Magnesium Alloy Matrix Composite

2009 ◽  
Vol 283-286 ◽  
pp. 155-160
Author(s):  
Ivo Stloukal ◽  
Jiří Čermák
Keyword(s):  
Magnesium Alloy ◽  
Temperature Dependence ◽  
Temperature Interval ◽  
Matrix Composite ◽  
Diffusion Coefficients ◽  
Volume Diffusion ◽  
Effective Diffusion ◽  
Measured Temperature ◽  
Alloy Matrix ◽  
Self Diffusion

Self-diffusion of 110mAg has been investigated in fiber reinforced QE22 magnesium alloy matrix composite. Short Saffil fibers (97% -Al2O3 + 3% SiO2) were used as reinforcement. The diffusion measurements were carried out in the temperature interval 648 – 728 K by serial sectioning method. The volume diffusion coefficients Dv (alloy without reinforcement) and the effective diffusion coefficients Deff (alloy with reinforcement) were obtained by analysis of the penetration curves. The silver diffusion coefficient in the interface boundary matrix/Saffil Di was also estimated. The temperature dependence of volume diffusion coefficients Dv was compared with previous data measured using 65Zn in the same alloy and with literature data for Zn impurity diffusion in Mg single crystal. It was observed, that the temperature dependence of both Deff and Di was significantly non-linear in the measured temperature interval. This behavior supports previous observations with zinc diffusion in the same alloy.

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