PHASE EQUILIBRIUM IN THE AS2TE3-TM2TE3 SYSTEM.

2020 ◽  
Vol 5 (8(77)) ◽  
pp. 65-68
Author(s):  
Teymur Mammad Ilyasly ◽  
Rahman Hasanaga Fatullazade ◽  
Zakir Islam Ismailov ◽  
Nigar Nadir Jafarova
Keyword(s):  
Thermal Analysis ◽  
Solid Solution ◽  
Differential Thermal Analysis ◽  
Phase Equilibrium ◽  
Physicochemical Properties ◽  
Thermal Effects ◽  
Isothermal Annealing ◽  
Intermediate Phase ◽  
Physicochemical Analysis ◽  
Two Phases

The synthesis of alloys of the system was carried out stepwise in rotary furnaces. The synthesis mode was selected based on the physicochemical properties of the elementary components. For homogenization, the alloys were subjected to isothermal annealing at 750 and 1275 K, depending on the Tm2Te3 concentration, for 250 h after homogenization of the alloys, they were subjected to physicochemical analysis. The results of differential thermal analysis showed that reversible thermal effects are observed in the alloys of the system. In alloys in a 1: 1 ratio, a new intermediate phase is formed with a composition corresponding to the TmAsTe3 compound. The homogeneity area is observed in the concentration range 52.5-47.5. It was found that in the concentration range 98.5-52.5 Tm2Te3 there are two phases - a mixture of β and of the solid solution, and in the concentration range of 47.51 mol% Tm2Te3 phases and α are in equilibrium. ) 66 The eutectic has coordinates of 11.5 mol Tm2Te3 at a temperature of 575 K.

High-Temperature Modifications of Thorium Dicarbide

1964 ◽  
Vol 8 ◽  
pp. 78-85 ◽  
Author(s):  
P. K. Gantzel ◽  
S. Langer ◽  
N. L. Baldwin ◽  
F. L. Kester
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
Thermal Effects ◽  
Room Temperature ◽  
Thermal Analyses ◽  
Tetragonal Modification ◽  
X Ray ◽  
Space Groups ◽  
Heating And Cooling

AbstractThermal analyses of samples of thorium dicarbide in equilibrium with graphite show arrests which indicate phase transitions at 1427 ± 21°C arid 1481 ± 28°C. These thermal effects have been observed on heating and cooling both in standard thermal analysis and in differential thermal analysis using graphite as a reference material. The microstructure of thorium dicarbide samples shows the characteristic “herringbone” pattern of a material which has undergone a martensitic-type transition.A high-temperature X-ray investigation has revealed that the observed thermal arrests correspond to erystallographic transformations. The monodinic modification found at room temperature is stable to 1427°C, at which temperature a tetragonal modification with a0 = 4.235 ± 0.002Å and c0 = 5.408 ± 0.002Å is formed. At 1481°C, the tetragonal is transformed to cubic with a0 = 5.809 ± 0.002 Å. The best agreement between observed and calculated intensities has been obtained with C-C units of 1.5-Å assumed bond length in space groups P42/mmc and Pa3 for the tetragonal and cubic modifications, respectively.

Study on Character of Ilmenite Modified by Thermal Treatment

2011 ◽  
Vol 284-286 ◽  
pp. 2090-2093 ◽  
Author(s):  
Xue Liang Xiong ◽  
Zhi Yang ◽  
Hong Yong Ouyang
Keyword(s):  
Thermal Analysis ◽  
Solid Solution ◽  
Differential Thermal Analysis ◽  
Thermal Treatment ◽  
Oxidation Temperature ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
X Ray

The character of ilmenite was modified by pretreatment, the effect of pre-oxidation temperature and time on structure of ilmenite were investigated by X-ray diffraction(XRD) and Thermo-gravimetric/differential thermal analysis. The results indicated that new microcrystal rutile and FeTiO3·Fe2O3 solid solution were appeared on the surface of mineral below 800°C, but evident rutile crystals and pseudobrookite Fe2O3·TiO2 were appeared above 850°C with the structure of ilmenite disrupting simultaneously. The preoxidation time increased from 15min to 60min, evident microcrystal rutile and FeTiO3·Fe2O3 solid solution were appeared by degrees without structure of ilmenite breaking.

Crystal Growth in Amorphous Binary Alloys of Zr-Ni System

2007 ◽  
Vol 26-28 ◽  
pp. 675-678 ◽  
Author(s):  
Takeshi Fukami ◽  
I. Noda ◽  
M. Asada ◽  
D. Okai ◽  
T. Yamasaki
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystal Growth ◽  
Crystallization Process ◽  
Isothermal Annealing ◽  
Binary Alloys ◽  
Isothermal Condition ◽  
Amorphous State ◽  
Dta Curves

A crystallization process in an amorphous state under isothermal condition is examined for binary alloys ZrNi and ZrNi2 by differential thermal analysis (DTA). Time dependence of DTA curves is measured at several constant temperatures just below crystallization temperature. The fraction of crystallized volume in amorphous state and its time evolution during isothermal annealing are measured. These data are analyzed by the Johnson-Mehl–Avrami formula. The Avrami exponent is 2.4±0.1 for ZrNi and 3~4 depending on the set temperature for ZrNi2. The activation energy for crystallization of amorphous ZrNi and ZrNi2 was estimated by plots of lnt1/2 vs. 1/T.

Synthesis of Nanocrystalline Fe25Al57.5Ni17.5 by Mechanical Alloying

2012 ◽  
Vol 476-478 ◽  
pp. 1318-1321
Author(s):  
Qi Zhi Cao ◽  
Jing Zhang
Keyword(s):  
Thermal Analysis ◽  
Solid Solution ◽  
Differential Thermal Analysis ◽  
Mechanical Alloying ◽  
Ball Mill ◽  
Structural Changes ◽  
Early Stage ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray

Nanostructured Fe25Al57.5Ni17.5intermetallics was prepared directly by mechanical alloying (MA) in a high-energy planetary ball-mill. The phase transformations and structural changes occurring in the studied material during mechanical alloying were investigated by X-ray diffraction (XRD). Thermal behavior of the milled powders was examined by differential thermal analysis (DTA). Disordered Al(Fe,Ni) solid solution was formed at the early stage. After 50 h of milling, Al(Fe,Ni) solid solution transformed into Al3Ni2，AlFe3，AlFe0.23Ni0.77 phase. The power annealed at temperature 500 results in forming of intermetallics AlFe3 and FeNi3 after 5h milling. The nanocrystalline intermetallic compound was obtained after 500h milling.

scholarly journals RESEARCH OF STRAW PYROLYSIS THERMAL EFFECTS FOR ESTIMATION OF POSSIBILITY ITS IMPLEMENTA-TION IN AUTOTHERMAL MODE

2019 ◽  
pp. 271-280 ◽  
Author(s):  
Aleksandr Vladimirovich Astafev ◽  
Roman Borisovich Tabakaev ◽  
Dias Erlanovich Musafirov ◽  
Aleksandr Sergeyevich Zavorin ◽  
Yuriy Vladimirovich Dubinin ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thermal Effect ◽  
Thermal Effects ◽  
Raw Materials ◽  
Laser Flash ◽  
Raw Material ◽  
Exothermic Reactions ◽  
Calculation Results

The aim of the work is research of straw pyrolysis in various modes, the determination of process thermal effects and estimation of straw thermal processing possibility in the autothermal mode. Physical experiment and differential thermal analysis were used as research methods. Thermotechnical characteristics of raw materials are determined by ISO 1171:2010, GOST R 55660-2013 and a bomb calorimeter; thermal and physical characteristic are determined by the analyzer of thermal diffusivity Discovery Laser Flash DLF-1200. In result of the work is established that thermal effects occur in the straw after heating to 200 °C. The first shows of exothermic reactions are observed when the reactor is heated to 303 °C – in this case the temperature of the straw reaches 308.8 °C. By differential thermal analysis is established that the temperature range of heat input was set from 235 to 575 °C and value of the thermal effect in this range was set 1475 kJ/kg. For this range, the heat costs for the organization of pyrolysis in the autothermal mode and the total thermal effect of the process are calculated. The calculation results showed that the maximum thermal effect (398.9 kJ/kg) can be obtained at a pyrolysis temperature of 460 °C. For these conditions, the influence of the initial straw moisture content on the autothermality of pyrolysis process was evaluated and it was established that process can be organized due to its own thermal effects when the raw material moisture is less than 30.5%.

Investigations on the Thermal Decomposition of Coordination Polymers Based on Copper(I) Halides and 2-Methylpyrazine

2001 ◽  
Vol 56 (10) ◽  
pp. 997-1002 ◽  
Author(s):  
Chnstian Näther ◽  
Inke Jeß ◽  
Harald Studzinski
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Thermal Behaviour ◽  
Powder Diffraction ◽  
Coordination Polymers ◽  
Intermediate Phase ◽  
Compound I ◽  
X Ray

The thermal behaviour of the three coordination polymers 2∞poly[CuX(μ-2-methylpyrazine- N,N′)] (X = Cl (I), Br (II)), and 2∞poly[{Cu2l2 (μ-pyrazine-N,N′)2 } · 2-methylpyrazine] (III) was investigated using differential thermal analysis and thermogravimetry (DTA-TG) measurements as well as temperature resolved X-ray powder diffraction in argon and in air. On heating all compounds decompose in two steps. In the first step compound I and II loose one and compound III looses two of the 2-methylpyrazine ligands to form the corresponding 2:1 compounds Cu2Cl2(2 -methylpyrazine) (IV) and 2∞poly[Cu2X2 (μ-2 -methylpyrazine-N,N′)] (X = Br (V), I (VI)). From the experiments there is no evidence for the formation of a 1:1 compound of Cul and 2-methylpyrazine as an intermediate phase during the thermal decomposition. On further heating the 2:1 compounds IV, V and VI transform directly to the corresponding copper(I) halides.

Multiple Glass Transitions in Butadiene-Acrylonitrile Copolymers

1970 ◽  
Vol 43 (6) ◽  
pp. 1465-1472 ◽  
Author(s):  
L. A. Chandler ◽  
E. A. Collins
Keyword(s):  
Molecular Structure ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Order Transition ◽  
Transition Temperatures ◽  
Glass Transitions ◽  
Second Order Transition ◽  
Two Phases ◽  
Polymerization Conditions ◽  
Acrylonitrile Copolymers

Abstract The second order transition temperatures (Tg) have been determined for a range of compositions of polybutadiene-acrylonitrile copolymers. It was found that copolymers having more than 36 per cent acrylonitrile had a single Tg while copolymers with less than 36 per cent acrylonitrile had two main Tg's. The analyses were carried out with differential thermal analysis (DTA). The two Tg's are interpreted as the result of incompatible phases which differ in BD and VCN ratio. The presence of two phases is discussed in terms of polymerization conditions and molecular structure.

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