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A comparative analysis of a wire of the Al–7% REM thermostable conductive alloy produced by casting into an electromagnetic crystallizer (EMC) and using the granular technology (RS/PM) method has ...been carried out. The effect of the annealing temperature (up to 600°C) on the structure of Al–7% REM rods produced using the EMC technology has been studied. Mechanical properties and specific electrical resistivity of the thermostable aluminum wire have been analyzed. It has been shown that the physicomechanical properties of the wire made of the rod cast into an EMC are comparable to those of RS/PM-produced wire.
Aluminum alloys are one of the most common structural materials. To improve the mechanical properties, an alloy of the Al-Zn-Mg-Ca-Fe system was proposed. In this alloy, when Fe and Ca are added, ...compact particles of the Al
CaFe
compound are formed, which significantly reduces the negative effect of Fe on the mechanical properties. Because of the high solidification rate (about 600 K/s) during cylindrical ingot (~33 mm) production, the electromagnetic casting method (ECM) makes it possible to obtain a highly dispersed structure in the cast state. The size of the dendritic cell is ~7 μm, while the entire amount of Fe is bound into eutectic inclusions of the Al
CaFe
phase with an average size of less than 3 μm. In this study, the effect of radial shear rolling (RSR) on the formation of the structure and hardening of the Al-8%Zn-3.3%Mg-0.8%Ca-1.1%Fe alloy obtained by EMC was studied. Computer simulation of the RSR process made it possible to analyze the temperature and stress-strain state of the alloy and to select the optimal rolling modes. It was shown that the flow features during RSR and the severe shear strains near the surface of the rod (10 mm) provided a refining and decrease in the size of the initial Fe-containing particles.
A calculation technique (Thermo-Calc software code) and experimental methods (scanning and transmission electron microscopy and X-ray spectral analysis) have been used to study the effect of ...thermodeformation treatment on the structure and strengthening of the Al–7.1% Zn–2.8% Mg–1.4% Ni–1.1% Fe alloy produced via casting in an electromagnetic crystallizer (EMC). It has been shown that at a cooling rate higher than 10
3
K/s, the entire amount of iron, which exceeds its content in the grade AZ6NF alloy (GOST 4784–2019) by two times, is bound into eutectic inclusions of the Al
9
FeNi phase of a submicron size. The combination of high hardness (more than 190 HV) and ductility indicates the advantages of applying the EMC technology to this alloy.
The article represents a multidisciplinary numerical model for electromagnetic casting of aluminum ingots, as well as the results of its application when casting aluminum ingots diam. 25–30 mm. The ...numerical model is based on a calculation of the electromagnetic field by solving an additional equation in Fluent combined with the modeling of processes connected with free surface crystallization. The obtained electromagnetic field sources are used in motion and energy equations for solving the magneto-hydrodynamics problem. A solution to the problem of determining the set of technological parameters for ensuring the stable formation of an ingot with the required diameter is provided along with the results of emergency mode modeling. In addition, the article presents the results of applying the established emergency modes at the laboratory casting unit with the electromagnetic mold for the production of ingots using Nikolin and Altsimak experimental alloys as part of ElmaCast® technology.
The impact of thermomechanical treatment on the structure, electrical resistance, and hardness of the Al–4% Cu–3% Mn alloy, which was obtained by casting in an electromagnetic crystallizer, has been ...investigated using computational and experimental methods. It has been shown that at the cooling rate of more than 1000 K/s, the whole amount of manganese and half of the copper content are dissolved in the aluminum solid solution. This enables the formation of a structure with the maximum possible number of Al
20
Cu
2
Mn
3
dispersoids after subsequent thermomechanical treatment, resulting in a significant improvement in the thermal resistance compared to the known alloys of Al–Cu–Mn system.
The article presents the results of studies on the production of wire with a diameter of 0.5 mm from aluminum alloy 01417 with a content of rare-earth metals (REM) in the amount of 7-9% for aircraft ...construction needs. The deformation modes, the experimental technique and equipment for the implementation of the proposed technology described. The wire was obtained by drawing and bar rolling with subsequent drawing from a rod with a diameter of 5 mm, obtained previously using the process of combined rolling-extruding (CRE) from a continuous ingot with a diameter of 12 mm, cast in an electromagnetic mold (EMM). The wire obtained by the presented technology was subjected to 4 different heat treatment modes with annealing temperatures from 350 to 500 °C and holding time of 1 h in the furnace to achieve mechanical and electrophysical properties corresponding to TS 1-809-1038-2018. The level of strength and plastic properties obtained in the course of research required only one intermediate annealing. The microstructure of the wire was investigated and the modes were revealed that made it possible to obtain the required level of mechanical properties and electrical resistivity, satisfying TS 1-809-1038-2018.
The article contains the overview of mathematical modeling of electromagnetic field and magnetohydrodynamic process of the ingot moulding during casting into the electromagnetic mold. We have ...formulated the system of equations describing the molding process. The authors describe the principle of casting into the electromagnetic mould to produce small diameter ingots, as well as the results obtained. This article gives the analysis of magnetohydrodynamic flows in the area of molding and their impact on the resulting ingot. It is shown that the intensity of the MHD processes is influenced by the frequency of the supply voltage and the shape of the crystallization front. The calculations are based on favorable conditions for the formation of a homogeneous, fine-grained structure. The experimental studies were conducted using samples of aluminum alloy 01417.
OKBM Afrikantov possesses unique experience in developing different types of highly reliable pumping equipment. The pumping equipment developed at the enterprise possesses high safety and reliability ...metrics at minimum operating cost. OKBM accomplishments in the design and manufacture of pumping equipment over the last 20 years are shown and the basic phases involved in the development of electric pumps for nuclear steam-generating plants, other systems on naval ships and vessels, and pumps for NPP and research and experimental reactor installations as well as electric pumps for the non-nuclear market are described.
Aluminium alloys containing small additions of scandium exhibit unique operating properties. Alloying material with scandium significantly improves product weldability, reduces the tendency towards ...hot cracks and improves welded joint mechanical properties. The aim of this work is to increase the scandium extraction into a master alloy by preliminary transformation of scandium oxide into fluoride and introduction into the composition of an aluminium powder alloying additive. Results are provided of laboratory experiments for preparation of aluminium-scandium master alloy by aluminothermic reduction of scandium fluoride using sodium fluoride and aluminium powder within the alloy composition. Scandium fluoride is prepared by treating scandium oxide with 40% hydrofluoric acid. The overall extraction of scandium from oxide into fluoride and from fluoride to the aluminium-scandium master alloy is 88.5% with an average scandium concentration in the master alloy of 1.90 wt.%. The microstructure of the master alloy obtained is represented by scandium aluminide Al
3
Sc crystals with a size from 10 to 25 μm uniformly distributed within the master alloy. An additional reserve for increasing the extraction of scandium into the master alloy and reducing its cost is processing of slags formed in the preparation of the ligature. The use of an aluminium powder with high specific surface area in the composition of the alloying additive increases scandium extraction into the master alloy due to better contact of the reacting phases. The resultant Al–Sc master alloy has uniform distribution of Al
3
Sc particles within the volume of the metal.
Aluminium alloys containing small additions of scandium exhibit unique operating properties. Alloying material with scandium significantly improves product weldability, reduces the tendency towards ...hot cracks and improves welded joint mechanical properties. The aim of this work is to increase the scandium extraction into a master alloy by preliminary transformation of scandium oxide into fluoride and introduction into the composition of an aluminium powder alloying additive. Results are provided of laboratory experiments for preparation of aluminium-scandium master alloy by aluminothermic reduction of scandium fluoride using sodium fluoride and aluminium powder within the alloy composition. Scandium fluoride is prepared by treating scandium oxide with 40% hydrofluoric acid. The overall extraction of scandium from oxide into fluoride and from fluoride to the aluminium-scandium master alloy is 88.5% with an average scandium concentration in the master alloy of 1.90 wt.%. The microstructure of the master alloy obtained is represented by scandium aluminide Al.sub.3Sc crystals with a size from 10 to 25 mum uniformly distributed within the master alloy. An additional reserve for increasing the extraction of scandium into the master alloy and reducing its cost is processing of slags formed in the preparation of the ligature. The use of an aluminium powder with high specific surface area in the composition of the alloying additive increases scandium extraction into the master alloy due to better contact of the reacting phases. The resultant Al-Sc master alloy has uniform distribution of Al.sub.3Sc particles within the volume of the metal.
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