The Effect of Sulfur on the Contact Angle between Liquid Eutectic Fe-V-C Alloy and VC Substrate and on the Microstructure of the Alloy

2014 ◽  
Vol 790-791 ◽  
pp. 361-366 ◽  
Author(s):  
Mário Boccalini Júnior ◽  
Alzira Vicente de Oliveira Corrêa
Keyword(s):  
Contact Angle ◽  
Interfacial Energy ◽  
Sessile Drop ◽  
Eutectic Reaction ◽  
Sessile Drop Technique ◽  
Eutectic Morphology ◽  
Drop Technique

The sessile drop technique was used to evaluate the contact angle between liquid eutectic Fe-11wt%V-2.3wt%C alloy and VC substrate. This alloy solidifies through a eutectic reaction that starts at 1320°C and leads to the formation of the faceted/non-faceted austenite-VC eutectic. The effect of sulfur on the contact angle and on morphology of the austenite-VC eutectic in both non-directionally and unidirectionally solidified specimens was investigated. It was shown that sulfur increases the contact angle and modifies the eutectic morphology, thus indicating a relationship between eutectic morphology and liquid eutectic/faceted phase VC interfacial energy.

Wetting and Interfacial Behaviors of Molten Ag, Cu and Ag-28Cu on WC-8Co Cemented Carbide

2016 ◽  
Vol 697 ◽  
pp. 555-560 ◽  
Author(s):  
Hao Fu ◽  
Xiang Zhao Zhang ◽  
Gui Wu Liu ◽  
Zi Wei Xu ◽  
Tie Zheng Pan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Sessile Drop ◽  
Testing Temperature ◽  
Cemented Carbide ◽  
Equilibrium Contact Angle ◽  
Sessile Drop Technique ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Drop Technique ◽  
Scanning Electron

The wetting and spreading of molten Cu, Ag and Ag-28Cu (wt.%) on the WC-Co cemented carbide were investigated by the sessile drop technique at different temperatures, and the interfacial behaviors of the metal/WC-Co couples were analyzed by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The experimental results showed that the testing temperature and the composition of drop can play a key role in the wetting and spreading, and the good wettability with contact angle of less than 40o can be obtained. Moreover, the strongest interactions can be produced between the molten Cu and the WC-Co substrate at the higher temperature of 1100 oC due to the strong interdiffusion and solid solution between Cu and Co, resulting in the lowest equilibrium contact angle of ~0o. In addition, smooth and clean interfaces, without formation of visible interfacial reaction layer, were observed in all the three wetting systems. This work may also provide guidance to brazing of the cemented carbide.

Determination of Surface Free Energy and Contact Angle for Hydrolyzed Shellac

2012 ◽  
Vol 506 ◽  
pp. 270-273 ◽  
Author(s):  
P. Kraisit ◽  
S. Limmatvapirat ◽  
J. Nunthanid ◽  
Manee Luangtana-Anan ◽  
K. Terada ◽  
...  
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Polar Group ◽  
Sessile Drop Technique ◽  
Hydrolysis Process ◽  
Polar Force ◽  
Drop Technique

The purpose of this research was to determine surface free energy and contact angle of hydrolyzed shellac by using sessile drop technique. It is a method for determination of contact angle by placing a drop of liquid on a substrate and the surface free energy is then calculated by using the Wus equation. The substrate in this study was the hydrolyzed shellac prepared by hydrolysis of the native shellac at various times; 0, 15, 30 and 45 min using 2.0 %w/w sodium hydroxide. Water, formamide and ethylene glycol were liquids used for the investigation of the contact angle and surface free energy. The effect of hydrolysis time tended to reduce the contact angle and increase in the total surface free energy and polar force of hydrolyzed shellac. The result could be due to the breaking of the ester bonds of shellac during the hydrolysis process causing the higher free carboxyl group giving the higher polar group indicating by higher polar force and surface free energy. Therefore, the contact angle and surface free energy detected by sessile drop technique could be of benefit for the determination of hydrolysis process.

Wetting of mullite by Y2O3–Al2O3–SiO2 and B2O3–SiO2 glasses

2001 ◽  
Vol 16 (11) ◽  
pp. 3223-3228 ◽  
Author(s):  
T. S. Huang ◽  
M. N. Rahaman ◽  
B. T. Eldred ◽  
P. D. Ownby
Keyword(s):  
Contact Angle ◽  
Borosilicate Glass ◽  
Sessile Drop ◽  
Glass Composition ◽  
Interfacial Region ◽  
Sessile Drop Technique ◽  
Glass Corrosion ◽  
A Value ◽  
Drop Technique

The wetting of mullite (3Al2O3 · 2SiO2) by a Y2O3–Al2O3–SiO2 (YAS) glass and by a B2O3–SiO2 (borosilicate) glass was investigated in air as a function of temperature through a sessile drop technique. The wetting behavior was found to be strongly dependent on the glass composition and on the temperature. For the YAS glass, the contact angle showed a rapid decrease from 100° to 20° in the temperature range of 1400 to 1450 °C followed by a more gradual decrease to a value of 10–15° at approximately 1600 °C. In the case of the borosilicate glass, the change in the contact angle with temperature was more uniform, with the value decreasing from 100° to 45° between 1300 and 1600 °C. Microstructural observations of the interfacial region between the solidified sessile drop and the mullite substrate revealed significant corrosion of the interface and penetration into the mullite grain boundaries by the YAS glass. In the case of the borosilicate glass, corrosion was limited and the interface was clearly defined. The consequences of the data for the design of in situ toughened mullite are discussed.

scholarly journals Synthesis, Characterization and Wettability of Cu-Sn Alloy on the Si-Implanted 6H-SiC

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 906 ◽  
Author(s):  
Xiang Zhao Zhang ◽  
Pu Hao Xu ◽  
Gui Wu Liu ◽  
Awais Ahmad ◽  
Xiao Hui Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Sessile Drop ◽  
Contact Angles ◽  
Graphite Layer ◽  
Sessile Drop Technique ◽  
Sic Ceramics ◽  
Sic Ceramic ◽  
Interfacial Chemical Reaction ◽  
Drop Technique

The wettability of the metal/SiC system is not always excellent, resulting in the limitation of the widespread use of SiC ceramic. In this paper, three implantation doses of Si ions (5 × 1015, 1 × 1016, 5 × 1016 ions/cm2) were implanted into the 6H-SiC substrate. The wetting of Cu-(2.5, 5, 7.5, 10) Sn alloys on the pristine and Si-SiC were studied by the sessile drop technique, and the interfacial chemical reaction of Cu-Sn/SiC wetting couples was investigated and discussed. The Si ion can markedly enhance the wetting of Cu-Sn on 6H-SiC substrate, and those of the corresponding contact angles (θ) are raised partly, with the Si ion dose increasing due to the weakening interfacial chemical reactions among four Cu-Sn alloys and 6H-SiC ceramics. Moreover, the θ of Cu-Sn on (Si-)SiC substrate is first decreased and then increased from ~62° to ~39°, and ~70° and ~140°, with the Sn concentration increasing from 2.5%, 5% and 7.5% to 10%, which is linked to the reactivity of Cu-Sn alloys and SiC ceramic and the variation of liquid-vapor surface energy. Particularly, only a continuous graphite layer is formed at the interface of the Cu-10Sn/Si-SiC system, resulting in a higher contact angle (>40°).

Effect of Various Types of Hydroxypropyl Methylcellulose (HPMC) Films on Surface Free Energy and Contact Angle

2014 ◽  
Vol 1060 ◽  
pp. 107-110 ◽  
Author(s):  
Pakorn Kraisit ◽  
Manee Luangtana-Anan ◽  
Narong Sarisuta
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Hydroxypropyl Methylcellulose ◽  
Physicochemical Characteristics ◽  
Basic Knowledge ◽  
Sessile Drop Technique ◽  
Buccal Films ◽  
Drop Technique

The aim of this study was to investigate the physicochemical characteristics of various viscosity grades of hydroxypropyl methylcellulose (HPMC) for mucoadhesive buccal films. The HPMC used in this study was K4M, K15M and K100M which their viscosity were 4000, 15000 and 100000 mPas respectively. Using HPMC as film forming base matrix, all intrinsic characteristics of each HPMC grade is required as basic knowledge for the development of mucoadhesive buccal films. To understand the primary essential parameters, surface free energy and contact angle of various HPMC grades were determined. Sessile drop technique was used in this study to determine contact angle of HPMC and surface free energy was then evaluated by using the Wu’s equation. The results showed that the increase in viscosity of HPMC film tended to decrease the polar force and total surface free energy but increased the contact angle. These parameters indicated that the hydrophilic character of HPMC was influenced by its viscosity. Our study suggested that the polar and dispersive force detected by sessile drop technique could be beneficial for the further design and development of mucoadhesive buccal films.

Studies of the wetting characteristics of liquid iron on dense alumina by the X-ray sessile drop technique

2003 ◽  
Vol 34 (2) ◽  
pp. 193-199 ◽  
Author(s):  
E. Kapilashrami ◽  
A. Jakobsson ◽  
S. Seetharaman ◽  
A. K. Lahiri
Keyword(s):  
Liquid Iron ◽  
Sessile Drop ◽  
Sessile Drop Technique ◽  
X Ray ◽  
Drop Technique

scholarly journals Wetting ofAl2O3by Molten Aluminum: The Influence ofBaSO4Additions

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Joaquin Aguilar-Santillan
Keyword(s):  
High Temperatures ◽  
Firing Temperature ◽  
Molten Aluminum ◽  
Sessile Drop ◽  
Contact Angles ◽  
Sessile Drop Technique ◽  
Pure Alumina ◽  
Two Temperatures ◽  
Drop Technique

The effects ofBaSO4additions on the wetting of alumina by molten aluminum were studied by the sessile drop technique. To study the effect ofBaSO4decomposition(1100–1150∘C), the additions were treated at two temperatures700∘C(973 K) and1450∘C(1723 K), respectively.BaSO4additions at low and high temperatures did not improve the nonwetting character of these compositions. However, at higher firing temperature, the formation ofBA6 (BaO•6Al2O3)has a nonwetting trend with increasing its content. To address theBA6specifically a pureBaO•6Al2O3was produced and tested. It was more nonwetting than the pure alumina. After the analysis of the contact angles for theBaSO4and theBA6 (BaO•6Al2O3), it was concluded that these additions to alumina do not inhibit wetting by molten aluminum. In fact, at the addition levels common for refractories, the wetting tendency of molten aluminum is enhanced. Alternative explanations for the effectiveness ofBaSO4additions to alumina refractories are discussed.

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