The niobium-aluminium-iridium ternary system part II. X-ray study of the intermediate phases and phase equilibria at 1100°C

1976 ◽  
Vol 45 (2) ◽  
pp. 315-321 ◽  
Author(s):  
R. Horyn
2016 ◽  
Vol 697 ◽  
pp. 565-571 ◽  
Author(s):  
Rui Zhang ◽  
Pekka Taskinen

Phase equilibria of the BaO-SiO2-Al2O3 ternary system was experimentally investigated using a quenching technique and analyzed by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Analysis (EDS) and X-ray Powder Diffraction (XRD). A ternary compound was confirmed in the present work. The liquidus composition in equilibrium with the ternary compound at 1500 °C were quantified. The isothermal sections of the BaO-SiO2-Al2O3 ternary system at 1400 °C, 1500 °C, 1600 °C, and 1700 °C were calculated. Based on the data acquired, the isothermal section at 1500 °C was constructed.


2021 ◽  
Vol 87 (2) ◽  
pp. 77-86
Author(s):  
Anatoliy Omelchuk ◽  
Igor Skryptun ◽  
Nikolay Zakharchenko ◽  
Olha Bosenko ◽  
Ruslan Savchuk ◽  
...  

The phase equilibria of the ternary system CaCl2 – NaCl – CaO in the area which enriched of calcium and sodium chloride were investigated by the methods of differential-thermal analysis and powder X-ray phase analysis. In the systems were determined the equilibrium concentration of calcium oxide and the composition of the phases, which at the same time exist in an equilibrium state at different temperatures. The surfaces of liquidus and solidus were established, the compositions of the sections of the ternary system CaCl2–NaCl–CaO were defined, which recommended for electrochemical reduction of refractory metal oxides (titanium, zirconium and other), which allow electrolysis in the temperature range from 550 to 1000 °С. Five polythermal sections of the NaCl – CaCl2 – CaO ternary system were studied. For each polythermal section the regions of existence of the liquid and solid phases were established. For each polythermal section state diagrams were constructed. Used X-Ray phase analyses it was established the compositions of liquid and solid phases for each polythermal sections. The phases of which the system consists were determined. At a constant ratio of components [NaCl]:[CaCl2] = 1.06 (mol.) in the melts of the ternary system CaCl2 – NaCl – CaO, the equilibrium content of calcium oxide reaches 12.0 mol.%, while their crystallization temperature does not exceed 550 °C. This allows us to recommend mixtures of this composition for electrochemical reduction of refractory metal oxides in a wide range of temperatures (from 550 to 1000 °C) with a high content of both calcium and sodium chlorides (not less than 40 mol.%) and oxide. calcium (up to 12.0 mol.%). The eutectic of this ternary system has a melting point of 480 ° C and corresponds to he composition (mol.%): CaCl2 (45.8) – NaCl (47.0) – CaO (7.2).


2006 ◽  
Vol 518 ◽  
pp. 343-348 ◽  
Author(s):  
E.R. Andrievskaya ◽  
V.P. Red'ko

Phase equilibria in the ternary system ZrO2-Y2O3-La2O3 at 1250 °C have been studied and isothermal section have been developed. Fine chemical technique such as co-precipitation was used to obtain ceramic nanopowders (with average particle size of 8-20 nm) available for nonisothermal sintering as well. The phase compositions of the annealed samples were studied by methods of X-ray analysis at 20 °C, petrographic and electron microprobe X-ray analyses. No ternary compounds were found. The phase equilibria in the system are determined by intermediate phases: La2Zr2O7 and LaYO3 that crystallize in the pyrochlore and perovskite-type structures, respectively. Solid solutions based on the constituent oxides such as tetragonal (T) and cubic fluorite-type structure (F) ZrO2, cubic form of rare-earth oxides (C-type) Y2O3,as well as hexagonal (A) and monoclinic (B) forms La2O3 were found at 1250 °C. The nanocrystalline powders of tetragonal zirconia actively sintered on heating up to 1150-1400 °C and the powders of lanthanum zirconate show active densification on heating up to 1550-1650 °C. The electrical properties (at 600-950 °C) of yttria-doped pyrochlore were measured, the highest conductivity has been revealed at 10 mol % Y2O3.


Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 958 ◽  
Author(s):  
Cuiping Wang ◽  
Xianjie Zhang ◽  
Lingling Li ◽  
Yunwei Pan ◽  
Yuechao Chen ◽  
...  

The phase equilibria of the Co-Ti-Ta ternary system at 1000 °C, 1100 °C, and 1200 °C were experimentally investigated using an electron probe microanalyzer and X-ray diffraction. Experimental results show that: (1) No ternary compound exists in the studied isothermal sections; (2) the β(Ti) and β(Ta) phases form the continuous solid solution β(Ti,Ta) in the Ti-Ta side; (3) the solubility of Ta in the (αCo) is less than 5%; (4) the phases of Co2Ti(h) and γ-Co2Ta, Co2Ti(c) and β-Co2Ta form the continuous solid solutions Co2(Ta,Ti)(h) and Co2(Ta,Ti)(c), respectively.


2010 ◽  
Vol 105-106 ◽  
pp. 192-194 ◽  
Author(s):  
Chun Long Guan ◽  
Guo Qin Liu ◽  
Ying Chun Shan

Cr2AlC ceramics (Cr:Al:C =1:1.2:1 mol.%) were synthesized by powder metallurgical method in argon in the temperature range of 700 to1250°C using Cr, Al and graphite powders as the initial materials. The phase relationships during reaction in the ternary system Cr-Al-C were investigated. The products were characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). It was found that Cr9Al17, Al8Cr5 and Cr2Al intermediate phases were formed in turn with increase of temperature. Up to 1050°C, with consumption of Cr9Al17 and Al8Cr5 phases completely, the amount of Cr2Al increased significantly. Single phase Cr2AlC with small amount of Cr7C3 was produced until 1250°C. Combined with the results of differential thermal analysis (DTA) and X-ray diffraction (XRD), it is revealed that Cr2AlC phase is formed by the reaction of Cr–Al intermetallic compounds, Cr, Al and graphite. In addition, the reaction equations of the process from 660 to1250°C were given.


1991 ◽  
Vol 6 (1) ◽  
pp. 53-56 ◽  
Author(s):  
H. Klesnar ◽  
P. Rogl

Phase equilibria in the ternary system Pr–Fe–Al have been established in an isothermal section at 800 °C from room temperature x-ray powder diffraction analysis of about 50 alloys, which were melted, annealed at 800 °C, and quenched. Phase equilibria are characterized by the formation of rather extended homogeneous regions, i.e., by a random substitution of Fe/Al in Pr(Al1−xFex)2, 0 ≤ x ≤ 0.15, in Pr2(Fe1−xAlx)17, 0 ≤ x ≤ 0.65, as well as by the formation of at least four ternary compounds. Whereas the existence of PrFe4Al8 with the CeMn4Al8-type structure has been confirmed, there were no indications for a compound “PrFe6Al6” earlier claimed to crystallize with the ThMn12-type structure. Pr6(Fe1−xAlx)14, 0.16 ≤ x ≤ 0.36 with a homogeneous region parallel to the Fe–Al binary, was found to be isotypic with the La6Co11Ga3-type of structure. Pr-rich alloys are liquid at 800 °C, and all the alloys Pr2(Fe1−xAlx)17 with aluminum concentrations less than 5 at.% Al (x ∼ 0.07) enter a two-phase equilibrium with the Pr-rich liquid. At temperatures below 800 °C, alloys with compositions close to 30 at.% Pr and 5 at.% Al show a further ternary phase on solidification, whose crystal structure is related to the La6Co11Ga3-type. PrFe2Al8 is a new representative of the CeFe2Al8-type structure. The crystal structure of the ternary compound richest in Al, PrFe2Al10, has not been solved yet.


2011 ◽  
Vol 399-401 ◽  
pp. 2210-2214 ◽  
Author(s):  
Qun Luo ◽  
Feng Jin ◽  
Yang Li ◽  
Qian Li ◽  
Jie Yu Zhang ◽  
...  

The phase equilibria in Al-rich corner of the Al-Zn-Ti ternary system at 400 °C were determined by means of optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS) and X-ray powder diffraction (XRD). The results showed that this section consisted of three ternary-phase regions, namely, L+(Al)+τ, Ti2Al5+τ+(Al) and Ti2Al5+TiAl3+(Al). The XRD patterns and EDS confirmed that a Ti2Al5-structured phase with containing 4 at.% Zn was stable at 400 °C. Furthermore, the ternary new phase (τ phase) was identified in samples and in equilibrium with (Al), Ti2Al5 and liquid, respectively.


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