Predicting the spreading kinetics of high-temperature liquids on solid surfaces

1998 ◽  
Vol 13 (12) ◽  
pp. 3504-3511 ◽  
Author(s):  
Douglas A. Weirauch
Keyword(s):  
High Temperature ◽  
Liquid Metals ◽  
Oxide Films ◽  
Shift Factor ◽  
Solid Surfaces ◽  
Experimental Methodology ◽  
Substrate Roughness ◽  
Liquid Drops ◽  
Interfacial Chemical Reaction ◽  
Reaction Furnace

The rate of movement of liquid drops toward their equilibrium position on smooth, horizontal solid surfaces (spreading kinetics) is considered in this study. A model for nonreactive liquid spreading which was developed for low-temperature liquids is applied to results for a set of high-temperature liquids and room-temperature liquids. These data were generated in a single laboratory following a consistent experimental methodology. The liquid-solid pairs were chosen to result in weak or no interfacial chemical reaction. Furnace atmospheres were chosen to provide data for liquid metals with submonolayer, thin or thick oxide films. Analysis of the high-temperature spreading kinetics for liquids covering a broad range of viscosity, surface tension, and density shows that they can be predicted with a constant shift factor applied to the deGennes expression for nonreactive spreading. The consequences of gravitational and inertial forces, substrate roughness, weak interfacial reactions, and liquid-metal oxide films are discussed.

scholarly journals The intimate relationship between structural relaxation and the energy landscape of monatomic liquid metals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Franz Demmel ◽  
Louis Hennet ◽  
Noel Jakse
Keyword(s):  
High Temperature ◽  
Velocity Field ◽  
Liquid State ◽  
Liquid Metals ◽  
Energy Landscape ◽  
Experimental Studies ◽  
Transport Parameter ◽  
Arrhenius Behavior ◽  
Liquid Aluminium ◽  
Potential Energy Landscape

AbstractThe characteristic property of a liquid, discriminating it from a solid, is its fluidity, which can be expressed by a velocity field. The reaction of the velocity field on forces is enshrined in the transport parameter viscosity. In contrast, a solid reacts to forces elastically through a displacement field, the particles are trapped in their potential minimum. The flow in a liquid needs enough thermal energy to overcome the changing potential barriers, which is supported through a continuous rearrangement of surrounding particles. Cooling a liquid will decrease the fluidity of a particle and the mobility of the neighbouring particles, resulting in an increase of the viscosity until the system comes to an arrest. This process with a concomitant slowing down of collective particle rearrangements might already start deep inside the liquid state. The idea of the potential energy landscape provides an attractive picture for these dramatic changes. However, despite the appealing idea there is a scarcity of quantitative assessments, in particular, when it comes to experimental studies. Here we present results on a monatomic liquid metal through a combination of ab initio molecular dynamics, neutron spectroscopy and inelastic x-ray scattering. We investigated the collective dynamics of liquid aluminium to reveal the changes in dynamics when the high temperature liquid is cooled towards solidification. The results demonstrate the main signatures of the energy landscape picture, a reduction in the internal atomic structural energy, a transition to a stretched relaxation process and a deviation from the high-temperature Arrhenius behavior of the relaxation time. All changes occur in the same temperature range at about $$1.4 \cdot T_{melting}$$ 1.4 · T melting , which can be regarded as the temperature when the liquid aluminium enters the landscape influenced phase and enters a more viscous liquid state towards solidification. The similarity in dynamics with other monatomic liquid metals suggests a universal dynamic crossover above the melting point.

scholarly journals Friction and Wear of Oxide Scale Obtained on Pure Titanium after High-Temperature Oxidation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3764
Author(s):  
Krzysztof Aniołek ◽  
Adrian Barylski ◽  
Marian Kupka
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Friction And Wear ◽  
High Carbon Steel ◽  
Oxide Films ◽  
Oxidation Temperature ◽  
Temperature Oxidation ◽  
Wear Ratio ◽  
Steel Balls

High-temperature oxidation was performed at temperatures from 600 to 750 °C over a period of 24 h and 72 h. It was shown in the study that the oxide scale became more homogeneous and covered the entire surface as the oxidation temperature increased. After oxidation over a period of 24 h, the hardness of the produced layers increased as the oxidation temperature increased (from 892.4 to 1146.6 kgf/mm2). During oxidation in a longer time variant (72 h), layers with a higher hardness were obtained (1260 kgf/mm2). Studies on friction and wear characteristics of titanium were conducted using couples with ceramic balls (Al2O3, ZrO2) and with high-carbon steel (100Cr6) balls. The oxide films produced at a temperature range of 600–750 °C led to a reduction of the wear ratio value, with the lowest one obtained in tests with the 100Cr6 steel balls. Frictional contact of Al2O3 balls with an oxidized titanium disc resulted in a reduction of the wear ratio, but only for the oxide scales produced at 600 °C (24 h, 72 h) and 650 °C (24 h). For the ZrO2 balls, an increase in the wear ratio was observed, especially when interacting with the oxide films obtained after high-temperature oxidation at 650 °C or higher temperatures. The increase in wear intensity after titanium oxidation was also observed for the 100Cr6 steel balls.

scholarly journals On the Oxide Films and Scales of Fe-Si-Al System Alloys at High Temperature

1959 ◽  
Vol 8 (11) ◽  
pp. 463-467
Author(s):  
Masataka Sugiyama ◽  
Tadayuki Nakayama
Keyword(s):  
High Temperature ◽  
Oxide Films
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