Phase equilibria and solidification behavior in the PbF2−AlF3 system

1991 ◽  
Vol 6 (10) ◽  
pp. 2188-2192 ◽  
Author(s):  
Linda V. Moulton ◽  
Robert S. Feigelson
Keyword(s):  
Solid Solution ◽  
Phase Equilibria ◽  
Directional Solidification ◽  
Microprobe Analysis ◽  
Binary Phase Diagram ◽  
Peritectoid Reaction ◽  
Solidification Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Relationship

The relationship between phase equilibria in the PbF2−AlF3 system and the solidification behavior of several ternary lead aluminum fluoride compounds was explored. A partial binary phase diagram for the PbF2−AlF3 system was determined from differential thermal analysis, annealing and directional solidification studies. The compounds AlF3, Pb3Al2F12, Pb9Al2F24, and a PbF2 solid solution were identified by x-ray diffraction, energy dispersive and microprobe analysis. The previously reported phases PbAlF5 and PbAl2F8 were not observed. Directional solidification studies showed that it is possible to grow crystals of AlF3, Pb3Al2F12, and the PbF2 solid solution from nonstoichiometric PbF2−AlF3 melts. The compound Pb9Al2F24 was found to decompose on heating by a peritectoid reaction (forming two other solids) and thus could not be solidified directly from a PbF2−AlF3 melt.

Peritectoid Reaction

2016 ◽  
Author(s):  
Heinz Gamsjäger ◽  
John W. Lorimer ◽  
Pirketta Scharlin ◽  
David G. Shaw
Keyword(s):  
Peritectoid Reaction

Selective Growth Of Decagonal Ai-Co Thin Films By Reactive Diffusion: Kinetic And Thermodynamic Aspects

1998 ◽  
Vol 553 ◽  
Author(s):  
E. Emeric ◽  
C. Bergman ◽  
G. Clugnet ◽  
P. Gas
Keyword(s):  
Activation Energy ◽  
Reactive Diffusion ◽  
Multilayer Structures ◽  
Peritectoid Reaction ◽  
Dsc Analysis ◽  
Reaction Step ◽  
Diffusion Kinetic ◽  
Decagonal Quasicrystal ◽  
The Enthalpy Of Formation

AbstractWe report on the formation by reactive diffusion of a pure decagonal quasicrystalline film in Al/Co bilayer and multilayer structures of overall composition Al13CO4. We show that this method is highly selective since several stable phases which exist around this composition are never observed. The quasicrystal is not the first reaction product but is obtained as a second reaction step by a peritectoid reaction between Al9Co2 and the remaining cobalt. DSC analysis allows the determination of both the enthalpy of formation of the decagonal quasicrystal (ΔHf = -31500 ± 2000 J/g-atom) and its activation energy of growth (2.6 ± 0.5 eV).

Phase Equilibria among γ-Fe, γ-Fe and Fe2Mo Phases and Stability of the Laves Phase in Fe-Mo-Ni Ternary System at Elevated Temperatures

2006 ◽  
Vol 980 ◽  
Author(s):  
Shigehiro Ishikawa ◽  
Takashi Matsuo ◽  
Masao Takeyama
Keyword(s):  
Ternary System ◽  
Phase Equilibria ◽  
Elevated Temperatures ◽  
Phase Region ◽  
Homogeneity Region ◽  
Nickel Concentration ◽  
Peritectoid Reaction ◽  
Two Phase ◽  
Three Phase ◽  
Binary Edge

AbstractPhase equilibria among the bcc Fe(α), fcc Fe(γ) and Fe2Mo(λ)_phases in Fe-Mo-Ni ternary system, particularly paying attention to the existence of the γ+λ two-phase region, have been examined at elevated temperatures below Tc (1200 K), the peritectoid reaction temperature in Fe-Mo binary system: λ?α+Fe7Mo6 (μ). At 1173 K the α+γ+μ three-phase coexisting region exists near the Fe-Mo binary edge and no λ phase region was identified. At 1073 K the λ phase in equilibrium with α and γ phases exists, although the composition homogeneity region of the ternary λ phase was limited to its binary edge toward the equi-nickel concentration direction up to about 3at % Ni. Instead, large two-phase region of γ+μ was extended along the same direction up to 20 at% Ni. The γ+λ two-phase region appears below Tc through a transition peritectoid reaction: α+μ¨γ+λ. The γ phase in equilibrium with λ phase is stable only at elevated temperatures, and it transforms martensitically to α phase during cooling. The addition of Ni stabilizes γ and μ phases against α and λ phases, thereby decreasing the relative stability of the λ phase.

A Pseudo-Binary Diagram of the (Bi,Pb)-Sr-Ca-Cu-O System

2013 ◽  
Vol 750 ◽  
pp. 184-187
Author(s):  
X.Y. Lu ◽  
D. Yi ◽  
H. Chen
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Binary Phase Diagram ◽  
Eutectic Reaction ◽  
Peritectoid Reaction ◽  
Solution Composition ◽  
Solid Solution Composition ◽  
Binary Diagram ◽  
Composition Point ◽  
Two Phases

A pseudo-binary phase diagram of the (Bi,Pb)-Sr-Ca-Cu-O system along the Bi1.6Pb0.4Sr2Can-1CunOx line is constructed. This resulting phase diagram shows three kinds of peritectic reactions, one eutectic reaction and one peritectoid reaction. The equilibrium solid phases in this diagram are the 2201 (n=1), 2212 (n=2), 2223 (n=3) and (Sr,Ca)CuO2 (n→∝) phases. The 2201 phase is solid solution which is stable at 1≤n≤1.2. The eutectic composition point is close to the maximum solid solution composition of the 2201 phase. The temperature interval between the peritectic reaction of L + (Sr,Ca)2CuO3 + (Sr,Ca)CuO2 → 2212 and the eutectic reaction of L → 2201 + 2212 is only about 3°C. For the composition of n=3, CaO and the liquid phase are stable at temperatures above 940°C. During the cooling, these two phases react peritectically to (Sr,Ca)2CuO3. At around 890°C, (Sr,Ca)2CuO3 reacts with the liquid to produce (Sr,Ca)CuO2. At around 865°C, (Sr,Ca)2CuO3 and (Sr,Ca)CuO2 react with the liquid to produce the 2212. The 2223 phase is transformed by a peritectoid reaction of the 2212 phase and residual (Sr,Ca)2CuO3, (Sr,Ca)CuO2.

Lattice defects in deformed and irradiated Zr3al

1978 ◽  
Vol 36 (1) ◽  
pp. 404-405
Author(s):  
L.M. Howe ◽  
M.H. Rainville
Keyword(s):  
High Temperature ◽  
Stacking Faults ◽  
Antiphase Domain ◽  
Lattice Defects ◽  
Peritectoid Reaction ◽  
High Temperature Annealing ◽  
Burgers Vector ◽  
Partial Dislocations ◽  
Domain Boundaries ◽  
Ordered State

Zr3Al is an ordered f.c.c. alloy of the Ll2 type which forms via a peritectoid reaction. It has not been possible to disorder Zr3Al by quenching and no antiphase domain boundaries have been observed, in either annealed or quenched material which indicates that Zr3Al is normally present in a highly ordered state. In deformed Zr3Al the superlattice dislocations were observed to be extended i.e. they consisted of intrinsic stacking faults on {111} bounded by partial dislocations (figure 1). The total Burgers vector is of the type <110> and the superlattice dislocations have dissociated as follows:. The Burgers vectors were determined using the criterion that the partial dislocations will be out of contrast for g.b = 0, ± 1/3 as well as for g.b = -2/3 when s > 0.During high temperature annealing of the deformed material, dislocation networks were produced in which all of the dislocation nodes were extended: hence intrinsic (I) and extrinsic (E) stacking faults must alternate at the nodes (figure 2).

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