Surface Properties of Ag-Cu-Zr Liquid Alloys in Relation to the Wettability of Boride Ceramics

2006 ◽  
Vol 512 ◽  
pp. 211-216 ◽  
Author(s):  
R. Novakovic ◽  
Maria Luigia Muolo ◽  
E. Ricci ◽  
E. Ferrera ◽  
D. Giuranno ◽  
...  
Keyword(s):  
Surface Tension ◽  
Surface Properties ◽  
Surface Composition ◽  
Point Of View ◽  
Ceramic Substrate ◽  
Work Of Adhesion ◽  
Experimental Point ◽  
Liquid Alloys ◽  
Wetting Phenomena ◽  
Angle Data

The wetting phenomena and adhesion between Ag-Cu-Zr molten alloys (where Zr is an active brazing element) and ZrB2-ceramic substrate have been investigated from theoretical and experimental point of view. The wetting phenomena of molten alloy/ceramic substrate depend on the bonding characteristics of liquid alloys and ceramics as well as the magnitude of interactive forces at the interface. Accordingly, the first step of this investigation is to determine the surface properties of Ag-Cu, Ag-Zr and Cu-Zr liquid alloys. The energetics of the bulk and the surface of liquid alloys have been analysed in the framework of statistical mechanical theory in conjunction with Quasi-Lattice Theory (QLT), through the study of the concentration dependence of various properties such as surface tension, surface composition, concentration fluctuations in the long wavelength limit and Warren-Cowley chemical short-range order parameter. Combining the Young and the Dupré equations, the obtained values of surface tension together with contact angle data have been used to calculate the work of adhesion.

scholarly journals Effects of surface coordination of atoms on the surface properties of Cd-X (X= Ga, Zn) liquid alloys

2018 ◽  
Vol 2 ◽  
pp. 90-95
Author(s):  
Ishwar Koirala
Keyword(s):  
Surface Tension ◽  
Statistical Mechanics ◽  
Surface Properties ◽  
Order Parameter ◽  
Surface Concentration ◽  
Concentration Fluctuations ◽  
Liquid Alloys ◽  
Model Surface ◽  
Mechanics Model ◽  
Effect Of Surface

We have investigated the effect of surface coordination of atoms on the surface properties of Cd-Ga and Cd-Zn liquid alloys by varying their surface coordination fractions using statistical mechanics model. Surface tension and surface concentration did not have significant effect on the calculation of both surface tension and surface concentration of two alloys. The computation of the concentration fluctuations at the surface revealed that it was sensitive to the surface coordination fractions of both segregating systems. In those alloys we found that the computation of the Warren-Cowley short rang order parameter was influenced by the surface coordination fractions.

scholarly journals Induction of Engineered Residual Stresses Fields and Associate Surface Properties Modification by Short Pulse Laser Shock Processing

2010 ◽  
Vol 638-642 ◽  
pp. 2446-2451 ◽  
Author(s):  
J.L. Ocaña ◽  
Miguel Morales ◽  
J.A. Porro ◽  
M. Blasco ◽  
C. Molpeceres ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Surface Properties ◽  
Short Pulse ◽  
Point Of View ◽  
Experimental Point ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
Stress Profiles ◽  
Shock Processing

Laser shock processing (LSP) is consolidating as an effective technology for the improvement of metallic materials surface properties involving their fatigue life. The main acknowledged advantage of the LSP technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Progress accomplished by the authors in the line of practical development of the LSP technique at an experimental level, aiming its integral assessment from an interrelated theoretical and experimental point of view, is presented in this paper. Concretely, experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (especially Al and Ti alloys) under different LSP irradiation conditions are presented, a correlated analysis of the residual stress profiles obtained under different irradiation strategies and the evaluation of the corresponding induced surface properties as roughness and wear resistance being also presented. Through a coupled theoretical- experimental analysis the real possibilities of the LSP technique as a possible substitutive of related traditional surface modification techniques as, for example, shot peening.

scholarly journals Transport and Surface Properties of Molten Cd-Zn Alloys

2015 ◽  
Vol 19 (1) ◽  
pp. 14-18 ◽  
Author(s):  
I Koirala ◽  
B.P. Singh ◽  
I.S. Jha
Keyword(s):  
Surface Tension ◽  
Statistical Theory ◽  
Surface Properties ◽  
Surface Concentration ◽  
Liquid Alloys ◽  
Negative Deviation ◽  
Mixing Parameters ◽  
Weak Phase ◽  
Thermo Physical Properties ◽  
Zn Alloys

Simple statistical theory has been used to report the thermo-physical properties of mixing in liquid Cd-Zn alloys. The energetic of mixing in liquid alloys has been analyzed through the study of surface properties (surface tension, surface concentration) and transport properties (diffusivity, viscosity). Negative deviation from Raoultian behaviour has been observed in the computed mixing parameters (viscosity, surface tension) of the alloys. The computed results support a weak phase-separation tendency in molten Cd-Zn system.Journal of Institute of Science and Technology, 2014, 19(1): 14-18

High-Tc superconductors from the experimental point of view

1988 ◽  
Vol 156 (9) ◽  
pp. 117-135 ◽  
Author(s):  
L.P. Gor'kov ◽  
N.B. Kopnin
Keyword(s):  
Point Of View ◽  
Experimental Point

Characterization of Tilt Boundaries by Ultra High Resolution Electron Microscopy

1984 ◽  
Vol 41 ◽  
Author(s):  
W. Krakow ◽  
J. T. Wetzel ◽  
D. A. Smith ◽  
G. Trafas
Keyword(s):  
High Resolution ◽  
Grain Boundary ◽  
Structural Information ◽  
Theoretical Work ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Experimental Point ◽  
Structure Information ◽  
Resolution Electron ◽  
Tilt Boundaries

AbstractA high resolution electron microscope study of grain boundary structures in Au thin films has been undertaken from both a theoretical and experimental point of view. The criteria necessary to interpret images of tilt boundaries at the atomic level, which include electron optical and specimen effects, have been considered for both 200kV and the newer 400kV medium voltage microscopes. So far, the theoretical work has concentrated on two different [001] tilt bounda-ries where a resolution of 2.03Å is required to visualize bulk lattice structures on either side of the interface. Both a high angle boundary, (210) σ=5, and a low angle boundary, (910) σ=41, have been considered. Computational results using multislice dynamical diffraction and image simulations of relaxed bounda-ries viewed edge-on and with small amounts of beam and/or specimen inclina-tion have been obtained. It will be shown that some structural information concerning grain boundary dislocations can be observed at 200kV. However, many difficulties occur in the exact identification of the interface structure viewed experimentally for both [001] and [011] boundaries since the resolution required is near the performance limit of a 200kV microscope. The simulated results at 400kV indicate a considerable improvement will be realized in obtain-ing atomic structure information at the interface.

Determination of In-plane Shear Strength of Unidirectional Composite Materials Using the Off-axis Three-point Flexure and Off-axis Tensile Tests

2010 ◽  
Vol 44 (21) ◽  
pp. 2487-2507 ◽  
Author(s):  
G. Vargas ◽  
F. Mujika
Keyword(s):  
Shear Strength ◽  
Composite Materials ◽  
Tensile Tests ◽  
Unidirectional Composite ◽  
Point Of View ◽  
Experimental Point ◽  
Plane Shear ◽  
Lift Off ◽  
Flexure Test

The aim of this work is to compare from an experimental point of view the determination of in-plane shear strength of unidirectional composite materials by means of two off-axis tests: three-point flexure and tensile. In the case of the off-axis three-point flexure test, the condition of small displacements and the condition of lift-off between the specimen and the fixture supports have been taken into account. Some considerations regarding stress and displacement fields are presented. The in-plane shear characterization has been performed on a carbon fiber reinforced unidirectional laminate with several fiber orientation angles: 10°, 20°, 30°, and 45°. Test conditions for both off-axis experimental methods, in order to ensure their applicability, are presented. Off-axis flexure test is considered more suitable than off-axis tensile test for the determination of in-plane shear strength.

Increasing Storage Modulus, Contact Angle and Surface Tension of Airway Mucus Increases Clearance by Simulated Cough Through a Model Trachea

2010 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Storage Modulus ◽  
Surface Properties ◽  
Respiratory Diseases ◽  
Interactive Effects ◽  
Altered Surface ◽  
Human Trachea ◽  
Tension Increase ◽  
And Storage

Altered surface and viscoelastic material properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effects of the surface properties (contact angle and surface tension) and storage modulus with relatively unchanged viscosity on displacement of the simulated mucus aliquot during simulated cough through a model adult human trachea is investigated. For the mucus simulants used in this study contact angle and surface tension increase significantly as storage modulus increase while viscosity remains practically unchanged. Displacement of mucus simulant aliquots increased significantly with increasing storage modulus (and contact angle) at a given cough velocity in the range between 5 meters/second (m/s) and 30 m/s with duration 0.3 s. Results suggest that the interactive effects of elasticity and surface properties may help facilitate mucus displacement at low cough velocities.

Surface properties of Bi–Pb liquid alloys

2002 ◽  
Vol 515 (2-3) ◽  
pp. 377-389 ◽  
Author(s):  
R. Novakovic ◽  
E. Ricci ◽  
D. Giuranno ◽  
F. Gnecco
Keyword(s):  
Surface Properties ◽  
Liquid Alloys
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