Experimental Enthalpy Increments from the Solid Phases to the Liquid Phase of Homologousn-Alkane Series (C18to C38and C41, C44, C46, C50, C54, and C60)

2003 ◽  
Vol 48 (3) ◽  
pp. 497-513 ◽  
Author(s):  
Anne-Julie Briard ◽  
Mohammed Bouroukba ◽  
Dominique Petitjean ◽  
Nathalie Hubert ◽  
Michel Dirand
Keyword(s):  
Liquid Phase ◽  
Enthalpy Increments ◽  
Experimental Enthalpy ◽  
Solid Phases

scholarly journals Removal of Tramp Elements within 7075 Alloy by Super-Gravity Aided Rheorefining Method

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 701 ◽  
Author(s):  
Lei Guo ◽  
Xiaochun Wen ◽  
Qipeng Bao ◽  
Zhancheng Guo
Keyword(s):  
Heat Treatment ◽  
Liquid Phase ◽  
7075 Aluminum Alloy ◽  
Total Removal ◽  
Tramp Element ◽  
Removal Ratio ◽  
Gravity Coefficient ◽  
Flow Through ◽  
Solid Phases ◽  
7075 Alloy

An investigation was made on the super-gravity aided rheorefining process of recycled 7075 aluminum alloy in order to remove tramp elements. The separation temperatures in this study were selected as 609 °C, 617 °C and 625 °C. And the gravity coefficients were set as 400 G, 700 G, 1000 G. The finely distributed impurity inclusions will aggregate to the grain boundaries of Al-enriched phase during heat treatment. In the field of super-gravity, the liquid phase composed of tramp elements Zn, Cu, Mg et al. will flow through the gaps between solid Al-enriched grains and form into filtrate. Both the weight of filtrate and removal ratio of tramp element improved with the increase of gravity coefficient. The total removal ratio of tramp element decreased with the fall of temperature due to the flowability deterioration of liquid phase. The time for effective separation of liquid/solid phases with super-gravity can be restricted within 1 min.

Calphad description of the Ge-Mn system

2014 ◽  
Vol 1642 ◽  
Author(s):  
Alexandre Berche ◽  
Jean-Claude Tédenac ◽  
Philippe Jund ◽  
Stéphane Gorsse
Keyword(s):  
Phase Diagram ◽  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Gibbs Energy ◽  
Critical Review ◽  
Thermodynamic Description ◽  
Calphad Method ◽  
Review Of The Literature ◽  
Solid Phases

ABSTRACTThe germanium-manganese system has been experimentally studied but no Calphad description is available yet. After a critical review of the literature concerning the phase diagram and the thermodynamic properties, a thermodynamic description of the Gibbs energy of the phases is performed using the Calphad method. The liquid phase is described with an associated model and the variation to the stoichiometry of the solid phases is taken into account.

scholarly journals Application of equilibrium phase diagrams for calculation of segregation kinetics during two-component melt cooling

2020 ◽  
Vol 63 (2) ◽  
pp. 129-134
Author(s):  
A. D. Drozin ◽  
E. Yu. Kurkina
Keyword(s):  
Liquid Phase ◽  
Equilibrium State ◽  
Cross Section ◽  
Diffusion Coefficients ◽  
Solid Phase ◽  
Equilibrium Phase ◽  
Minimum Size ◽  
Two Component ◽  
Solid Phases ◽  
Liquid And Solid Phases

According to the equilibrium state diagrams, when the melt is cooled to a certain temperature below liquidus, compositions of liquid and solid phases are uniquely determined by corresponding curves in the diagram. However, it does not happen in reality. For equilibrium (which the diagram describes), it is necessary that the melt is maintained indefinitely at each temperature, or thermal conductivity of liquid and solid phases, and the diffusion coefficients of their components, are infinitely large. We made an attempt to find out how these processes occur in reality. In this work, we consider the growth of individual crystal during cooling of a two-component melt. Mathematical model is constructed based on the following. 1. The melt area with volume corresponding to one grain, the periphery of which is cooled according to a certain law, is considered. 2. At the initial instant of time, a crystal nucleus of a certain minimum size is in the liquid. 3. At the surface of crystal, compositions of liquid and solid phases correspond to equilibrium state diagram at a given temperature on its surface. 4. Changes in temperature and composition in liquid and solid phases occur according to the laws of heat conduction and diffusion, respectively. As the melt gets cold and the crystal grows, the liquid phase is enriched in one component and depleted in another, the solid phase – on the contrary. Since the diffusion coefficients of the components in the solid phase are small, the composition of the crystal does not have time to completely equalize its cross section. The model proposed in the work allows us to study this phenomenon, to calculate for each cooling mode how the composition of the crystal will vary over its cross section. The calculations have shown that the temperature equalization occurs almost instantly, and composition of the liquid phase equalizes much slower. Equalization of the solid phase composition does not occur in the foreseeable time. The results of the work will help to improve technology of generation of alloys with an optimal structure.

scholarly journals FORMATION OF THE INTERACTION ZONE AT THE INTERLAYER BOUNDARY OF THE EXPLOSION-BOILED COMPOSITE VT1-0 + MH45 IN CONTACT MELTING

2020 ◽  
pp. 7-13
Author(s):  
V. G. Shmorgun ◽  
A. G. Serov ◽  
O. V. Slautin ◽  
S. A. Kuznetsov ◽  
A. V. Malykh
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Liquid Phase ◽  
Liquid Metal ◽  
Melting Process ◽  
Contact Melting ◽  
Layered Composite ◽  
Interaction Zone ◽  
Continuous Layer ◽  
Solid Phases

It is shown that the replacement of the MH19 alloy with the MH45 alloy in the explosion-welded layered titanium-copper-nickel composite leads to a decrease in the temperature at which the liquid (metal melted by contact melting) is in equilibrium with the solid phases from 930 ° C (L↔TiCuNi + NiTi + CuTi) up to 860 ° C (L↔ TiCu+NiTi+TiNi); to a change in the mechanism of contact melting from diffusion to diffusion; to increase the proportion of titanium in the interaction zone from ~ 50 at.% to ~ 66 at.%. The development of the contact melting process at the interlayer boundary of the VT1-0 + MH45 layered composite after the solid solution is transformed into a liquid phase film leads to the formation of an interaction zone with the phase composition TiCuNi, TiNi (Cu), TiCu (Ni), TiNi (Cu) TiCu (Ni) . On the side of the MH45 alloy, a continuous layer of the ternary intermetallic TiCuNi adjoins it, and on the titanium side, αTi + TiNi (Cu).

scholarly journals Formation of Interfacial Reaction Layers in Al2O3/SS 430 Brazed Joints Using Cu-7Al-3.5Zr Alloys

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 990 ◽  
Author(s):  
Hoejun Heo ◽  
Hyeonim Joung ◽  
Keeyoung Jung ◽  
Chung-Yun Kang
Keyword(s):  
Liquid Phase ◽  
Interfacial Reaction ◽  
Eutectic Temperature ◽  
Liquid Phases ◽  
430 Stainless Steel ◽  
Brazed Joints ◽  
Solid Phases ◽  
Α Al2o3 ◽  
Kinetics Of ◽  
Liquid And Solid Phases

The formation of interfacial reaction layers was investigated in an α-Al2O3/430 stainless steel (SS430) joint brazed using a Cu-7Al-3.5Zr active brazing alloy. Brazing was conducted at above its eutectic temperature of 945 °C and below liquidus 1045 °C, where liquid and solid phases of the brazing alloys coexists. At 1000 °C, the liquid phase of the brazing alloy was wet onto the α-Al2O3 surface. Zr in the liquid phase reduced α-Al2O3 to form a continuous ZrO2 layer. As the dwell time increased, Zr in the liquid phases near α-Al2O3 interface was used up to thicken the reaction layers. The growth kinetics of the layer obeys the parabolic rate law with a rate constant of 9.25 × 10−6 cm·s−1/2. It was observed that a number of low yield strength Cu-rich particles were dispersed over the reaction layer, which can release the residual stress of the joint resulting in reduction of crack occurrence.

scholarly journals Solid-liquid phase equilibria in the ternary systems H2O+ZnCl2+NaCl at temperatures of 298, 313 and 333 K

2021 ◽  
pp. 53-53
Author(s):  
Sevilay Demirci ◽  
Vedat Adiguze ◽  
Omer Sahin
Keyword(s):  
Liquid Phase ◽  
Phase Equilibria ◽  
Solid Phase ◽  
Ternary Systems ◽  
Viscosity Data ◽  
Isothermal Method ◽  
Chloride Water ◽  
Solid Phases ◽  
Solid Liquid ◽  
Liquid And Solid Phases

In this study, an economic separation method was suggested with the use of phase equilibria in order to ensure the recycling of ZnCl2 whose industrial waste amount is very high and to prevent it to form an environmental pollution. Sodium chloride-zinc chloride-water systems were examined with the isothermal method at temperatures of 298, 313 and 333 K. The analyses of the liquid and solid phases were used to determine the composition of the solid phase using the Schreinemakers graphic method. The solid-liquid phase equilibrium and viscosity data belonging to all ternary systems were identified and the solubility and viscosity changes with temperature were compared. The viscosity values were inversely proportional to the temperature as the amount of ZnCl2 in the solution increased. NaCl, 2NaCl ZnCl2 nH2O (n: 2, 0), ZnCl2 salts were observed at 298, 313, 333 K in the solid phases which are at equilibrium with the liquid phase at the invariant point.

scholarly journals Phase diagram of the β-alanine – water binary system

2021 ◽  
Vol 21 (1) ◽  
pp. 44-47
Author(s):  
Dmitry G. Cherkasov ◽  
◽  
Varvara D. Parfenova ◽  
Keyword(s):  
Phase Diagram ◽  
Liquid Phase ◽  
Binary System ◽  
Temperature Range ◽  
Visual Polythermal Method ◽  
Solid Phases ◽  
First Time

The phase diagram of the β-alanine–water binary system was studied using the visual polythermal method and the method of time–temperature curves in а temperature range of -20–90°С. There is a eutectic equilibrium at -18.3°С in the system; the solid phases of this equilibrium are ice and individual β-alanine. For the first time, the composition of the liquid phase of the eutectic state was determined.

scholarly journals Predicted Effects of Confinement on the Melting Transition in Krypton-Argon Adlayers

2002 ◽  
Vol 1 (1) ◽  
Author(s):  
Karson Bader ◽  
Michael Roth
Keyword(s):  
Molecular Dynamics ◽  
Phase Transitions ◽  
High Temperature ◽  
Liquid Phase ◽  
Computer Simulations ◽  
Melting Transition ◽  
Graphite Sheet ◽  
Solid Phases ◽  
Solid Liquid ◽  
Graphite Sheets

We report the results of (N,ρ,T) Molecular-Dynamics computer simulations of krypton-argon mixtures physisorbed between two graphite sheets. Three novel aspects of the system’s behavior emerge from this study. To begin with, new high-temperature commensurate solid phases for both argon and krypton as a result of confinement are predicted, as well as a family of confinement-induced solid-liquid phase transitions. In addition, we observe that the melting temperature of the system can be adjusted within a given range by the graphite sheet spacing. Finally, in the case of argon-krypton mixtures, certain temperatures and sheet spacings result in almost complete impurity extraction.

Laser-flash calorimetry IV. Heat capacity of gallium from 80 to 600 K in two solid phases and liquid phase

1983 ◽  
Vol 15 (1) ◽  
pp. 65-81 ◽  
Author(s):  
Yoichi Takahashi ◽  
Hidekimi Kadokura ◽  
Harumi Yokokawa
Keyword(s):  
Heat Capacity ◽  
Liquid Phase ◽  
Laser Flash ◽  
Solid Phases

Hydrothermal fluids of apatite-magnetite ores of the Tomtor carbonatite massif (NE, Russia)

2020 ◽  
Author(s):  
Leonid Baranov ◽  
Alexander Tolstov ◽  
Ilya Prokopyev
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Fluid Inclusions ◽  
Siberian Platform ◽  
Hydrothermal Fluids ◽  
Fluid Composition ◽  
Russian Science ◽  
Medium Temperature ◽  
Solid Phases ◽  
Complete Homogenization

<p>The Tomtor carbonatite complex, with an area of 250 km<sup>2</sup>, is confined to the eastern framing of the Anabar Anteclise; it is located withtin the Ujinsky province of ultrabasic alkaline rocks and carbonatites (Northeast of Siberian Platform) (Erlich, 1964). The complex has a concentric zonal structure: the outer ring is composed of alkaline and nepheline syenites, the inner incomplete ring is nepheline-pyroxene rocks of the foidolite family, the core is represented by carbonatites. All rocks of the massif are intersected by dikes and explosion tubes of picrites and alneites. Onkuchakh apatite-magnetite deposit is located on the northeastern border of the carbonatite core. Apatite-magnetite ores (camaforites, phoscorites, nelsonites) form a series of ore steeply dipping (75-80<sup>o</sup>) lenticular bodies of north-western strike. The resources of the apatite-magnetite ores of the Tomtor massif are about 1 billion tons of iron (Tolstov, 1994). Primary and pseudo-secondary fluid inclusions were studied in apatite, calcite and potassium feldspar of camaforites. Inclusions have isometric or elongated shapes up to 50 microns. Most of the studied inclusions have a negative crystal form located in the central parts and zones of apatite growth.</p><p>Apatite contains a multiphase (crystal-fluid) inclusions with gas, liquid and 1-5 visible crystalline phases. The gas phase is represented by CO<sub>2</sub>, contains subordinate amounts of H<sub>2</sub>O, H<sub>2</sub>S and SO<sub>2</sub>. The liquid phase is represented by H<sub>2</sub>O with SO<sub>4</sub><sup>2-</sup>, HSO<sup>4-</sup> and HCO<sup>3-</sup> ions. The solid phases in the inclusions are represented by mainly halite (NaCl) and sylvite (KCl), with strontianite (SrCO<sub>3</sub>), barite (BaSO<sub>4</sub>) and Ca-Sr-REE F-carbonate crystals. Complete homogenization occurs in the temperature range from 290 to 350 °C, the concentration is 30-45 wt. % of NaCl-eq. Calcite has the similar in composition fluid inclusions. The solid phases are mainly represented by halite (NaCl) and sylvite (KCl), as well as the dolomite (CaMg(CO<sub>3</sub>)<sub>2</sub>), strontianite (SrCO<sub>3</sub>), REE phosphates and sulfates of Sr and Ba. Complete homogenization occurs at 250-300 °C, the concentration is 35-55 wt. % of NaCl-eq. The gas phase of the fluid inclusions in K-feldspar is predominantly CO<sub>2</sub>; the liquid phase is H<sub>2</sub>O. The solid phases are represented by witherite (BaCO<sub>3</sub>) and calcite (CaCO<sub>3</sub>). The homogenization temperature of fluid inclusions occurs at 350-375 °C.</p><p>The results show that the hydrothermal fluids of camaforites of the Tomtor massif are represented by the concentrated high-medium temperature sulfate-carbonate-chloride solutions of complex composition . The fluid composition is explained by the evolution of the carbonatite melt.</p><p>The work was supported by the Russian Science Foundation (RSF), project # 19-17-00013.</p><p>References</p><ol><li>Erlich, E.N., 1964. The new province of alkali rocks on the north of Siberian platform and its geological aspects. Proc. All-Soviet Mineral.Soc.93,682–693.</li> <li>Tolstov, A.V., 1994.Mineralogy and geochemistry of apatite-magnetite ores of the Tomtor Massif (NorthwesternYakutia). Russ.Geol. Geophys.35,76–84.</li> </ol>

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