Quantitative Phase Analysis of Aluminium-Lithium Alloys

2016 ◽  
Vol 877 ◽  
pp. 258-263
Author(s):  
Sergey Betsofen ◽  
Vladislav Antipov ◽  
Maxim Knyazev ◽  
Margarita Dolgova
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Ternary Phase ◽  
Lattice Parameter ◽  
Quantitative Phase Analysis ◽  
Balance Equations ◽  
Δ Phase ◽  
Chemical And Phase Compositions ◽  
Lithium Alloys

A quantitative approach to the determination of the phase composition in the Al-Mg (Cu)-Li alloys has been developed on the basis of the balance equations of chemical and phase compositions as well as the lattice parameter measurement of the α solid solution. It is shown that, for the Al-Mg (Cu)-Li alloys, the ratio between the fractions of the δ' (Al3Li) and S1 (T1) phases is determined by the ratio between the molar fractions of Li and Mg (Cu). By means of this technique it is shown that in Al-Cu-Li alloys the proportion of δ'-phase is much higher than ternary T1-phase, and the proportion of δ'-phase and a ternary phase (S1) are approximately equal in alloys of Al-Mg-Li system. The equations for the calculation of the contents of the S1 (Al2MgLi), T1 (Al2CuLi) and δ' (Al3Li) phases in the 1420, 1424, 5090 alloys (Al-Mg-Li alloys) and in the 1440, 1441, 1450, 1460, 1461, 1464, 1469, 2050, 2090, 2091, 2094, 2098, 2099, 2195, 2198, 2199, 2297, 8090 (alloys (Al-Cu-Li alloys) are given.

Quantitative Phase Analysis of Al-Mg-Li and Al-Cu-Li Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 915-920 ◽  
Author(s):  
Sergey Betsofen ◽  
Mihail Chizhikov
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Phase Analysis ◽  
Relative Phase ◽  
Lattice Parameter ◽  
Intermetallic Phases ◽  
Phase Ratio ◽  
Quantitative Phase Analysis ◽  
Balance Equations ◽  
Percentage Ratio

On the basis of the balance equations of chemical and phase composition of the Al-Mg-Li and Al-Cu-Li alloys developed a method of determining the amount of intermetallic phases from the experimentally measured value of the lattice parameter of α-solid solution. In alloys of Al-Mg (Cu)-Li the relative phase ratio of the δ'(Al3Li) and S1(T1) are determined by the atomic percentage ratio of the Li and Mg (Cu).

scholarly journals The Effect of High-Intensity Electron Beam on the Crystal Structure, Phase Composition, and Properties of Al–Si Alloys with Different Silicon Content

2021 ◽  
Vol 22 (1) ◽  
pp. 129-157
Author(s):  
D. V. Zaguliaev ◽  
S. V. Konovalov ◽  
Yu. F. Ivanov ◽  
V. E. Gromov ◽  
V. V. Shlyarov ◽  
...  
Keyword(s):  
Solid Solution ◽  
Electron Beam ◽  
Phase Composition ◽  
Crystal Lattice ◽  
High Intensity ◽  
Materials Science ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Material Surface ◽  
Modified Layer

The study deals with the element–phase composition, microstructure evolution, crystal-lattice parameter, and microdistortions as well as the size of the coherent scattering region in the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys irradiated with the high-intensity electron beam. As revealed by the methods of x-ray phase analysis, the principal phases in untreated alloys are the aluminium-based solid solution, silicon, intermetallics, and Fe2Al9Si2 phase. In addition, the Cu9Al4 phase is detected in Al–10.65Si–2.11Cu alloy. Processing alloys with the pulsed electron beam induces the transformation of lattice parameters of Al–10.65Si–2.11Cu (aluminium-based solid solution) and Al–5.39Si–1.33Cu (Al1 and Al2 phases). The reason for the crystal-lattice parameter change in the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys is suggested to be the changing concentration of alloying elements in the solid solution of these phases. As established, if a density of electron beam is of 30 and 50 J/cm2, the silicon and intermetallic compounds dissolve in the modified layer. The state-of-the-art methods of the physical materials science made possible to establish the formation of a layer with a nanocrystalline structure of the cell-type crystallization because of the material surface irradiation. The thickness of a modified layer depends on the parameters of the electron-beam treatment and reaches maximum of 90 µm at the energy density of 50 J/cm2. According to the transmission (TEM) and scanning (SEM) electron microscopy data, the silicon particles occupy the cell boundaries. Such changes in the structural and phase states of the materials response on their mechanical characteristics. To characterize the surface properties, the microhardness, wear parameter, and friction coefficient values are determined directly on the irradiated surface for all modification variants. As shown, the irradiation of the material surface with an intensive electron beam increases wear resistance and microhardness of the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys.

scholarly journals Влияние высоких давлений на формирование новых соединений в сплаве Al-=SUB=-86-=/SUB=-Ni-=SUB=-2-=/SUB=-Со-=SUB=-6-=/SUB=-Gd-=SUB=-6-=/SUB=--=SUP=--=SUP=-*-=/SUP=--=/SUP=-

2022 ◽  
Vol 64 (2) ◽  
pp. 149
Author(s):  
С.Г. Меньшикова ◽  
В.В. Бражкин
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
High Pressure ◽  
Phase Composition ◽  
Precipitation Hardening ◽  
Supersaturated Solid Solution ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shrinkage Cavities

Abstract The structure, elemental and phase composition of the eutectic alloy Al86Ni2Со6Gd6 (hereinafter referred to as at.%) During the solidification of the melt from 1500oC at a rate of 1000oC/s under high pressure of 3 and 7 GPa have been investigated by X-ray diffraction analysis and electron microscopy. Solidification of the melt under high pressure leads to a change in the phase composition of the alloy and the formation of an anomalously supersaturated solid solution of α-Al (Gd). At a pressure of 7 GPa, new phases were synthesized: Al3Gd * (like Al3U) containing Co and Ni, with a primitive cube structure (cP4/2) with a lattice parameter a = 4.285 ± 0.002 Angstrem and Al8Co4Gd * (like Al8Cr4Gd) with a tetragonal structure (tI26/1) with parameters a = 8.906 ± 0.003 Angstrem and c = 5.150 ± 0.003 Angstrem. The structure of all the samples obtained is homogeneous, dense, finely dispersed, without shrinkage cavities and pores. The average microhardness of the samples is high due to solid solution and precipitation hardening.

High-Temperature Instability of A Cr2Nb-Nb(Cr) Microlaminate Composite

1996 ◽  
Vol 54 ◽  
pp. 374-375
Author(s):  
M. Larsen ◽  
R.G. Rowe ◽  
D.W. Skelly
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Aircraft Engine ◽  
Lattice Parameter ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Cross Sectional ◽  
Bcc Structure

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.

Laboratory Determination of the Solid Phase Composition of Technogenically Salinized Peatlands: Possibilities and Limitations

2020 ◽  
Vol 75 (3) ◽  
pp. 131-137
Author(s):  
Yu. N. Vodyanitskii ◽  
N. A. Avetov ◽  
A. T. Savichev ◽  
S. Ya. Trofimov ◽  
E. A. Shishkonakova
Keyword(s):  
Phase Composition ◽  
Solid Phase ◽  
Laboratory Determination ◽  
Solid Phase Composition

scholarly journals Selective Anisotropy of Mechanical Properties in Inconel718 Alloy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3869
Author(s):  
Yu Liang ◽  
Jun Ma ◽  
Baogang Zhou ◽  
Wei Li
Keyword(s):  
Solid Solution ◽  
Crack Nucleation ◽  
Rolling Direction ◽  
Mechanical Anisotropy ◽  
Solution Temperature ◽  
Weak Anisotropy ◽  
Nucleation Sites ◽  
Micro Cracks ◽  
Δ Phase ◽  
Rupture Properties

Mechanical anisotropy behaviors are investigated in slightly rolled Inconel718 alloy with string-like δ phase and carbides produced during various solid-solution and aging treatments. A weak anisotropy in the strengths and rupture properties at 650 °C is visible, whereas ductility, i.e., reduction in area (RA) and impact toughness (CVN), presents a sound anisotropy behavior. MC carbides promote the operation of slip systems and thus are conducive to weakening the strength anisotropy. The RA anisotropy mainly stems from high-density δ phase particles that provide more crack nucleation sites and stimulate rapid propagation because of the shorter bridge distance between micro-cracks at the rolling direction. In contrast, CVN anisotropy arises from both δ phase and carbides at a lower solid-solution temperature of 940 °C but only depends on carbides at 980 °C where the δ phase fully dissolves. Apart from dislocation motions operated at room temperature, the activated grain boundary processes are responsible for the weak anisotropy of rupture properties at the elevated temperature. This work provides a guideline for technological applications in the hot working processes for Inconel718 alloys.

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