Solution hardening in body-centered cubic quaternary alloys interpreted using Suzuki's kink-solute interaction model

2019 ◽  
Vol 165 ◽  
pp. 103-106 ◽  
Author(s):  
S.I. Rao ◽  
E. Antillon ◽  
C. Woodward ◽  
B. Akdim ◽  
T.A. Parthasarathy ◽  
...  
Keyword(s):  
Interaction Model ◽  
Body Centered Cubic ◽  
Quaternary Alloys ◽  
Solution Hardening ◽  
Solute Interaction

scholarly journals Theoretical Analysis of Net Tracer Flux Due to Volume Circulation in a Membrane with Pores of Different Sizes

1971 ◽  
Vol 57 (2) ◽  
pp. 113-124 ◽  
Author(s):  
Clifford S. Patlak ◽  
Stanley I. Rapoport
Keyword(s):  
Theoretical Analysis ◽  
Alternative Model ◽  
Interaction Model ◽  
External Pressure ◽  
Volume Flow ◽  
Artificial Membrane ◽  
Solute Interaction ◽  
Osmotic Solutes ◽  
Net Flux ◽  
Osmotic Solute

When osmotic pressure across an artificial membrane, produced by a permeable electrically neutral solute on one side of it, is balanced by an external pressure difference so that there is no net volume flow across the membrane, it has been found that there will be a net flux of a second electrically neutral tracer solute, present at equal concentrations on either side of the membrane, in the direction that the "osmotic" solute diffuses. This has been ascribed to solute-solute interaction or drag between the tracer and the osmotic solutes. An alternative model, presented here, considers the membrane to have pores of different sizes. Under general assumptions, this "heteroporous" model will account for both the direction of net tracer flux and the observed linear dependence of unidirectional tracer fluxes on the concentration of the osmotic solute. The expressions for the fluxes of solutes and solvent are mathematically identical under the two models. An inequality is derived which must be valid if the solute interaction model and/or the heteroporous model can account for the data. If the inequality does not hold, then the heteroporous model alone cannot explain the data. It was found that the inequality holds for most published observations except when dextran is the osmotic solute.

scholarly journals Estimation of diffusional effects on solution hardening at high temperatures in single phase compositionally complex body centered cubic alloys

2019 ◽  
Vol 172 ◽  
pp. 135-137 ◽  
Author(s):  
S.I. Rao ◽  
C. Woodward ◽  
B. Akdim ◽  
E. Antillon ◽  
T.A. Parthasarathy ◽  
...  
Keyword(s):  
High Temperatures ◽  
Single Phase ◽  
Body Centered Cubic ◽  
Solution Hardening

Interstitial Diffusion of Oxygen in Tantalum Obtained by Anelastic Relaxation Measurements

2006 ◽  
Vol 258-260 ◽  
pp. 146-151
Author(s):  
Odila Florêncio ◽  
Geovani F. Barbosa ◽  
Paulo Sergio Silva ◽  
Tomaz Toshimi Ishikawa ◽  
Durval Rodrigues
Keyword(s):  
Internal Friction ◽  
Body Centered Cubic ◽  
Internal Friction Peak ◽  
Interstitial Diffusion ◽  
Cubic Metals ◽  
Relaxation Parameters ◽  
Relaxation Measurements ◽  
Solute Interaction ◽  
Temperature Activation

Anelastic relaxation measurements have been used in order to obtain information about several aspects of the behavior of solutes in metals, for example, matrix-solute interaction, interstitial diffusion, etc. The diffusion coefficient for interstitial solutes in body centered-cubic metals is accurately determined by anelastic relaxation measurements. The kind of preferential occupation of the interstitial solutes in body centered-cubic metals, such as oxygen and nitrogen in tantalum, is still controversial. Internal friction and frequency measurements as a function of temperature in tantalum sample were performed using a torsion pendulum operating in a frequency oscillation in the hertz bandwidth. These results presented the following phenomenon: the intensity of the internal friction peak decreased between the first run and the other runs. These results were decomposed, by the successive subtraction method, in elementary Debye peaks, for determination of characteristic anelastic relaxation parameters (relaxation strength, peak temperature, activation energy and relaxation time). Interstitial diffusion coefficients for oxygen in tantalum were determined, for different intensities of internal friction peaks, and when compared with literature, these results introduced a better adjustment for the tetrahedral preferential occupation sites of oxygen in tantalum.

Voids in Irradiated Tungsten and Molybdenum

1969 ◽  
Vol 27 ◽  
pp. 190-191
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd
Keyword(s):  
Melting Point ◽  
Fast Neutron ◽  
Neutron Irradiation ◽  
Elevated Temperatures ◽  
Irradiation Temperature ◽  
The Body ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

A Tem Study of Slip Systems in MoSi2/WSi2 Alloys

1991 ◽  
Vol 49 ◽  
pp. 942-943
Author(s):  
Stuart A. Maloy
Keyword(s):  
Solid Solution ◽  
Solid Solution Hardening ◽  
Slip Systems ◽  
High Melting ◽  
Group 14 ◽  
Solution Hardening ◽  
Brittle To Ductile Transition ◽  
High Melting Temperature ◽  
Tetragonal Unit Cell ◽  
Structural Applications

MoSi2 has recently been investigated as a potential material for high temperature structural applications. It has excellent oxidation resistance up to 1700°C, a high melting temperature, 2030°C, and a brittle-to-ductile transition temperature at 900-1000°C. WSi2 is isomorphous with MoSi2 and has a body-centered tetragonal unit cell of the space group 14/mmm. The lattice parameters are a=3.20 Å and c=7.84 Å for MoSi2 and a=3.21 Å and c=7.88 Å for WSi2. Therefore, WSi2 was added to MoSi2 to improve its strength via solid solution hardening. The purpose of this study was to investigate the slip systems in polycrystalline MoSi2/WSi2 alloys.

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