scholarly journals STRUCTURE AND PHASE COMPOSITION OF COATING ON EP718 ALLOY AFTER HOT-DIP ALUMINIZING

2021 ◽  
pp. 7-11
Author(s):  
A. I. Bogdanov ◽  
V. G. Shmorgun ◽  
V. P. Kulevich ◽  
R. D. Evchits ◽  
N. V. Terpugov
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Outer Layer ◽  
Aluminum Content ◽  
Aluminide Coating ◽  
Aluminum Matrix ◽  
Heterogeneous Structure ◽  
Continuous Layer ◽  
Monoclinic Lattice

The results of studies of the structure, chemical and phase composition of the aluminide coating formed on the surface of EP718 alloy after its hot-dip aluminizing are presented. It is shown that the inner layer of the coating consists of a continuous layer of a solid solution based on chromium aluminide CrAl with a monoclinic lattice, in which some of the Cr atoms are replaced by atoms of elements from the EP718 alloy, and the outer layer, which has a pronounced heterogeneous structure, is an aluminum matrix with inclusions of CrAl aluminide. with a lower aluminum content.

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).

Changes in the structure of a thermal protective aluminum-nickel coating under the influence of a single thermal laser pulse

2021 ◽  
Vol 4 ◽  
pp. 25-30
Author(s):  
O. B. Berdnik ◽  
◽  
P. Yu. Kikin ◽  
V. N. Perevezentsev ◽  
E.N. Razov ◽  
...  
Keyword(s):  
Solid Solution ◽  
Heat Flux ◽  
Phase Composition ◽  
Nickel Coating ◽  
Microstructural Analysis ◽  
Radiation Energy ◽  
Heat Fluxes ◽  
Initial State ◽  
Nial Phase ◽  
Ni3al Phase

The regularities of changes in the structure and phase composition of the thermal protective aluminide-nickel coating (Ni — 45 %; Al — 14 %; Co — 22 %; Cr — 18.9 %; Fe — 0.15 %; Nb — 0.14 %; Y — 0.09 %; Ca — 0.06 %; Mn — 0.01 %; C — 0.15 %; Si — 0.15 %; S — 0.006 %) after exposure to short-term pulsed heat fluxes of various power, created by the radiation of a pulse-periodic laser LRS-150A with a radiation wavelength λ = 1.06 µm and a pulse duration τ = 12·10–3 s. The radiation energy was E = 5, 10, and 15 J. Microstructural analysis and the elemental composition of the resulting coating were carried out as well as analysis of the phase composition. X-ray microanalysis of the coating was also carried out. In the initial state and after irradiation of the coating with a heat flux of power P = 7·103 W/cm2, light microregions are observed in the micrographs of the surface. These regions do not have clearly defined external boundaries and consist of the NiAl phase and a small amount of the Ni3Al phase with the presence of inclusions of particles containing a solid solution of Ni – Co – Cr. After irradiation of the coating with heat fluxes of higher power (P = 1.7·104 W/cm2 and P = 2.2·104 W/cm2), large convex formations appeared on its surface, consisting mainly of Ni3Al and NiAl phases. On micrographs of the surface, they appear as white areas with well-defined outer boundaries. The content of the Ni3Al phase in them in comparison with the initial state increased, and the content of the NiAl phase decreased, while the particles of inclusions of Ni, Co, and Cr disappeared. It can be assumed that an increase in the Ni3Al content is associated with the dissolution of particles of a solid solution of Ni – Co and Cr in the melt and the subsequent diffusion of nickel into the NiAl phase. When exposed to a heat flux of power P = 2.2·104 W/cm2, microcracks appear on the areas of the coating surface covered with aluminum oxide.

Performance Studies on In Situ Spinel Solid Solution Bonded Periclase Refractories

2014 ◽  
Vol 633 ◽  
pp. 245-248
Author(s):  
Xin Lin ◽  
Yong Li ◽  
Yan Jing Li ◽  
Jun Jie Zhang ◽  
Chang He Gao ◽  
...  
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Performance Studies ◽  
Magnesium Aluminate ◽  
Spinel Solid Solution ◽  
Magnesium Aluminate Spinel ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance

Specimens were prepared using iron-rich magnesia (3~1 mm、≤1 mm) and high purity magnesia (≤0.088 mm) as the main starting materials, adding tabular alumina at different size (3~2、2~1、≤1 mm) and content:3%、6%、9%、12%、15% to discover the influence of tabular alumina on sample performance. Phase composition and microstructure were also analyzed. The results show that specimen with content of 6% of corundum possessed the best comprehensive performance:apparent porosity 17%, bulk density 2.95 g·cm-3, cold crushing strength 74 MPa, refractoriness under load 1700 °C, heat shock resistance of up to 18 times. The formations of magnesium aluminate spinel and hercynite solid solution were enhanced by Fe ion at high temperatures in the iron-rich magnesia-corundum system at the presence of iron oxides, which are able to largely dissolved in periclase.

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.

Ionic conductivity, phase composition, and local defect structure of ZrO2-Gd2O3system solid solution crystals

2019 ◽  
Vol 23 (9) ◽  
pp. 2619-2626 ◽  
Author(s):  
Ekaterina A. Agarkova ◽  
Mikhail A. Borik ◽  
Tatiana V. Volkova ◽  
Alexey V. Kulebyakin ◽  
Irina E. Kuritsyna ◽  
...  
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Ionic Conductivity ◽  
Defect Structure ◽  
Local Defect

Structural Analysis of Hydroxyapatite Sinters with Addition of ZrO2 Phase

2010 ◽  
Vol 638-642 ◽  
pp. 658-663 ◽  
Author(s):  
Agata Dudek ◽  
Zygmunt Nitkiewicz
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Phase Composition ◽  
Structural Analysis ◽  
Zirconium Dioxide ◽  
Volume Density ◽  
Ceramic Powders

A range of benefits of implants containing hydroxyapatites results, among other things, from their phase composition and degree of porosity. Poor mechanical properties of hydroxyapatite (HA) ceramics considerably limit its wider use. One of the methods for improvement of poor HA properties is addition of solid solution of Y2O3 in ZrO2. [1-8]. The investigations focused on compositions of ceramic powders based on hydroxyapatite with addition of zirconium dioxide (ZrO2 + 8%wt. Y2O3 and ZrO2 + 20%wt. Y2O3). The powders were axially compacted and then sintered at the temperature of 13000C for two hours. After the process of sintering the samples were subjected to analysis of microstructure, phase composition and geometrical measurements in order to determine volume density in each sample.

Effect of Synthesis Conditions and Actinide Contents on Phase Composition of Actinide Bearing Ceramics

2003 ◽  
Vol 807 ◽  
Author(s):  
A. G. Ptashkin ◽  
S. V. Stefanovsky ◽  
S. V. Yudintsev ◽  
S. A. Perevalov
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Phase Composition ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Reducing Conditions ◽  
Dispersive System ◽  
Scanning Electron

ABSTRACTPu-bearing zirconolite and pyrochlore based ceramics were prepared by melting under oxidizing and reducing conditions at 1550 °C. 239Pu content in the samples ranged between ∼10 and ∼50 wt.%. Phase composition of the ceramics and Pu partitioning were studied using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive system (SEM/EDS). Major phases in the samples were found to be the target zirconolite and pyrochlore as well as a cubic fluorite structure oxide. Normally the Pu content in the Pu host phases was 10–12 wt.%. This corresponds to the Pu content recommended for matrices for immobilization of excess weapons plutonium. At higher Pu content (up to 50 wt.%) additional phases, such as a PuO2-based cubic fluorite-structured solid solution, perovskite, and rutile were found.

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.

Study of Structural and Catalytic Properties of Pt/WOх/ZrO₂, Modified by Lanthanum Cations

2020 ◽  
pp. 133-141
Author(s):  
Svetlana A. Naumova ◽  
Anastasia V. Obukhova ◽  
Ludmila I. Kuznetsova
Keyword(s):  
Solid Solution ◽  
Catalytic Activity ◽  
Phase Composition ◽  
Structural Properties ◽  
Catalytic Properties ◽  
Surface Layers ◽  
Tetragonal Modification ◽  
Nanocrystalline Zirconia ◽  
Positive Effect

The effect of the addition of La3+ cations on the structural properties of Pt/WOх/ZrO₂ catalysts and the characteristics of catalytic activity in the process of hydroisomerization of n-heptane and benzene mixture was studied. The phase composition of the catalysts is represented by a solid solution of lanthanum cations in nanocrystalline zirconia of tetragonal modification with localization of lanthanum in the surface layers predominantly. The positive effect of La3+ additives on the selectivity and yield of isomerized products was shown

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