scholarly journals The influence of heat treatment on the structural phase state and durometric properties of small-sized castings from a copper alloy Cu-Cr-Al

2020 ◽  
pp. 22-25
Author(s):  
E. I. Marukovich ◽  
V. A. Kukareko ◽  
V. A. Kharkov ◽  
V. A. Kushnerov ◽  
I. O. Sazonenko
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Crystal Lattice ◽  
Copper Alloy ◽  
Phase State ◽  
Structural Phase ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Al Alloy ◽  
Structural Phase State

The effect of heat treatment on the structural-phase state and hardness of small-sized castings made from the Cu-Cr-Al copper alloy obtained by casting in a water-cooled metal mold is studied. Using X-ray diffraction analysis, it was found that the castings consist of a matrix solid solution based on copper. The increased value of the crystal lattice parameter of the copper phase is associated with aluminum atoms dissolved in it. After a low-temperature (450 °C) tempering for 10 hours, the crystal lattice parameter of the matrix solid solution decreases, which is associated with the formation of the Al8Cr5 intermetallic compound on the surface of the casting.It is established that after heat treatment (hardening and tempering), the hardness of castings from the Cu-Cr-Al alloy increases by 1.5 times.

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.

Investigation of the Influence of Electrolytic-Plasma Processing on Structural-Phase State and Mechanical Properties of the 40CrNiAl Alloy

2014 ◽  
Vol 1044-1045 ◽  
pp. 67-70
Author(s):  
Mazhyn Skakov ◽  
Gulnara Yerbolatova ◽  
Nurgamit Kantai ◽  
Michael Scheffler
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Phase State ◽  
Structural Phase ◽  
Plasma Processing ◽  
Structural Phase State ◽  
Dispersed Particles ◽  
Electrolytic Plasma Processing

It is shown that as a result of electrolytic plasma carburization is released from the solid solution carbides dispersed particles based alloy components, i.e. hardening occurs. Found that after processing the surface of the alloy samples 40CrNiAl modified form reinforced layers whose thickness depends on the time, temperature and processing of components of the electrolyte.

FEATURES OF THE FORMATION OF THE STRUCTURAL-PHASE STATE OF THE EP648 ALLOY DURING SELECTIVE LASE MANUFACTURE

2021 ◽  
pp. 3-11
Author(s):  
O.G. Ospennikova ◽  
◽  
S.A. Naprienko ◽  
P.N. Medvedev ◽  
D.V. Zaitsev ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Uniform Distribution ◽  
Crystallographic Texture ◽  
Phase State ◽  
Fine Particles ◽  
Structural Phase ◽  
Hot Isostatic Pressing ◽  
Initial State ◽  
Plastic Properties ◽  
Structural Phase State

The paper shows the features of the formation of the structural-phase and textural state of the EP648 alloy obtained by the SLM method in the initial state, after hot isostatic pressing and heat treatment. It was found that in the process of synthesis, a limited crystallographic texture of the γ-phase is formed, which does not undergo significant changes in the process of subsequent treatments. The uniform distribution of fine particles of the hardening phases, apparently, leads to an increase in both the strength and plastic properties of the material obtained by the SLM method in comparison with the material obtained by the traditional technology.

Structural and Phase Changes in Tin Coatings Subjected to Thermal Treatment

2020 ◽  
Vol 839 ◽  
pp. 131-136
Author(s):  
Aidar Kenesbekov ◽  
Bauyrzhan K. Rakhadilov ◽  
Rauan Kozhanova ◽  
Olga Stepanova
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Phase Transformations ◽  
Thermal Annealing ◽  
Phase State ◽  
Structural Phase ◽  
Phase Changes ◽  
Structural Phase State ◽  
Tin Coatings ◽  
Structural Phase Transformations

This work presents the experimental results of the study of the effect of heat treatment on the structural-phase state of TiN coatings on the surface of 67KH5B alloy. It is determined that thermal annealing leads to structural phase transformations at the interface between the coating and the substrate. It was established that after annealing at Т=800 °С, due to the redistribution of the coating elements and the substrate, a modified coating is formed consisting of the TiN, Ti2N and NiTi phases.

Yttrium effect on the structural-phase state in situ of Mo – 15.3 V – 10.5 Si composite

2020 ◽  
pp. 19-28
Author(s):  
A. V. Larionov ◽  
◽  
K. V. Pikulin ◽  
S. V. Zhidovinova ◽  
L. Yu. Udoeva ◽  
...  
Keyword(s):  
Solid Solution ◽  
Phase State ◽  
Structural Phase ◽  
Volume Ratio ◽  
Metallic Phase ◽  
Homogeneity Region ◽  
Structural Phase State ◽  
X Ray ◽  
Quaternary Compounds ◽  
Nonequilibrium Crystallization

The effect of yttrium on the structural-phase state of the Mo – 15.3 V – 10.5 Si hypereutectic alloy has been investigated using X-ray phase analysis and scanning electron microscopy with energy-dispersive X-ray analysis. It has been established that the main phases of Mo – (14.3 – 15.4) V – (9.8 – 10.6) Si – (0.3 – 5.3) Y alloys obtained under nonequilibrium crystallization are the metal solid solution (Mo1 – xVx)ss-matrix, silicide solid solution (Mo1 – xVx)3Si and silicide Y5Si3. In alloys doped with yttrium up to 1.0 at. %, the space between the dendrites of the (Mo1 – xVx)ss metal phase is filled with (Mo1 – xVx)3Si solid solution, and Y5Si3 is located at the boundaries of the metal solid solution. At a concentration of yttrium in alloys above 3.0 at. % the space between (Mo1 – xVx)ss dendrites is filled with Y5Si3 silicide, inside which (Mo1 – xVx)3Si grains are formed. Triple or quaternary compounds containing yttrium were not detected. Elemental composition of alloy phases of the Mo – (14.3 – 15.4) V – (9.8 – 10.6) Si – (0.3 – 5.3) Y alloys is almost identical and is characterized by non-stoichiometry with respect to silicon. According to well-known literature data, the silicon contents in the (Mo1 – xVx)ss and (Mo1 – xVx)3Si phases are within the acceptable limits of the homogeneity region, and the silicon concentration in Y5Si3 (≈ 35.4 at.%) is beyond the established limits. Doping of the Mo – 15.3 V – 10.5 Si alloy with yttrium increases the dispersion of the structure. Particles of the main structural components become close in size. Wherein the volume ratio of the metallic phase to the silicide with increasing yttrium content in the alloys increases. The density of alloys varies between 8.7 – 9.0 g/cm3.

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.

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