AbstractInsufficient understanding of the nature of the interfacial interaction of reinforcing particles with the matrix alloy during repeated remelting of cast composite materials is one of the problems that limit the increase in the volume of their industrial application. This work is aimed at establishing the effect of repeated remelting of AK12 + 10 vol % SiC aluminum matrix composites on the retention and chemical stability of silicon carbide reinforcing particles. It is shown that an increase in the number of remelting iterations was not accompanied by the appearance of new phases at the interfaces between particles and the matrix, which indicates the stability of the SiC reinforcing phase in aluminum–silicon melts under the considered temperature–time and concentration conditions. During repeated remelting of aluminum matrix composites with silicon carbide, the degree of particle distribution uniformity shifts toward a more uniform distribution (on average 0.81046 at the first iteration of remelting, 0.6901 at the second, and 0.5609 at the third) and some decrease in their average sizes occurs (from 70.74 µm at the first iteration to 65.76 µm at the second and 61.21 µm at the third), apparently owing to particle fragmentation, leading to an increase in the amount of a finer fraction. At the same time, the share of the area occupied by particles in the segments of the section under consideration remains practically unchanged (10.9293, 10.9607, and 11.6483% in the first, second, and third iterations of remelting, respectively). In the course of repeated remelting of aluminum matrix composites of the Al–SiC system, processes of redistribution of reinforcing particles occur, leading to the destruction of agglomerates even in the absence of intensive mixing by an impeller. Because of this, the uniformity of particle distribution in the structure of ingots of secondary aluminum matrix composites can be significantly improved.

AbstractThe effect of warm rolling and three aging treatments on microstructure and mechanical properties of 7075 alloy was investigated via optical microscopy, electron backscattered diffraction, transmission electron microscopy and tensile tests. 7075 alloy was warm rolled and then were solution treated followed by three different aging processes viz., one-step, two-step and three-step aging. Results show that the ductility of 7075 alloy is improved during warm rolling and the strength increases with increasing total warm-rolled reduction. The average grain size decreases after aging compared with that in the solution state. The microstructure of the one-stage aged sample consists of elongated grains and equiaxed grains while almost completely equiaxed microstructure is obtained in solutionized, two-stage and three-stage aged samples. The distributions of dislocations, precipitates and grain refinement influence mechanical properties together. The one-stage aged sample possesses a combination of acceptable strength and excellent ductility. Two-stage and three-stage aged samples have higher elongations but lower strengths.

AbstractDifferent types of materials with unique performance are used together in the industry, and soluble and/or insoluble joining methods are applied to join these materials. However, the joining process is quite problematic due to the technological drawbacks that arise during the joining of materials with distinctive characteristics. For this reason, mechanical locking (frictional) joining method is recommended to reduce some of the problems emerging during the joining of different materials. Various material groups such as ferrous and non-ferrous metals could be able joined by the mechanical locking method (MLM). In this study, to the main aim is to determine the effect of rotation speed, which is one of the influential process parameters, on the process of joining CuZn30 (brass) and AA6063 aluminum alloy materials using MLM. The mechanical properties and microstructures of the specimens joined by applying different rotation speeds were examined. Consequentially CuZn30 and AA6063 materials were successfully joined using the MLM and the number of rotation speeds applied during joining had a significant effect on the joining process.

AbstractA thermodynamic assessment of the influence of alloying elements (Si, Mg, Cu, Ti) on the processes of phase formation during the production and liquid-phase processing of cast aluminum matrix composite materials with exogenous reinforcement (Al–SiC, Al–B4C) has been carried out. It is shown that without suppression of the formation of Al–Si–C and Al4C3 carbides in the range of carbon concentrations from 0 to 4.5 wt %, the equilibrium phase composition of composites of the Al–SiC system in the solid state at temperatures from 423 to 575ºC lies in the three-phase region (Al) + Si + Al4SiC4, and below a temperature of 423ºC, the Al4SiC4 ternary carbide is replaced by the Al8SiC7 compound. In the Al–SiC–Mg system, the crystallization of composites containing more than 0.58 wt % magnesium ends in the four-phase region (Al) + Al3Mg2 + SiC + Mg2Si. In the Al–SiC–Ti system, the end of crystallization is fixed in the three-phase region (Al) + Al3Ti + SiC. In the Al–B4C system, after suppression of the formation of the Al4C3 phase, with a deviation from the concentrations of elements that provide 10 vol % B4C, aluminum borides are formed in the direction of increasing boron, and free carbon is formed in the direction of decreasing boron. Under equilibrium conditions, with a silicon content of up to 0.67 wt %, the crystallization of the Al–B4C–Si system ends in the four-phase region (Al) + B4C + AlB12 + Al8SiC7, and at a higher silicon content, it ends in the region (Al) + Si + AlB12 + Al8SiC7. In the Al–B4C–Ti system, with a Ti content of less than 0.42 wt %, crystallization ends in the three-phase (Al) + TiB2 + B4C region.

AbstractThe effect of the welding arc current (47, 57, and 67 A) on the structure and properties of the deposited samples obtained by electric arc robotic deposition has been studied. Welding wire Sv-AK5 (ER4043) of the Al-Si system was used as a filler material. The weld deposition was carried out on a substrate in the form of a plate 6 mm thick made of AMg6 alloy (Al–Mg system). In the process of surfacing, a typical two-phase structure of a hypoeutectic composition is formed in the samples, which is characteristic of alloys of the Al‒Si system with a silicon content of 5%. A trend to the enlargement of the structure in the direction from the substrate is observed along height of the deposited layers, which is associated with the accumulation of heat in the layers deposited along the height. With an increase in the welding arc current, dendrites based on α-Al and eutectic Si crystals are refined, while their density increases and microhardness decreases. The increase in density is due to a decrease in the proportion and size of gas pores and the refinement of structural components. The decrease in microhardness is associated with an increase in the proportion of the soft phase (α-Al dendrites) and a decrease in the number hard eutectic silicon crystals. The average content of silicon in the samples deposited in three modes is in the range of 5.46–5.91%, which corresponds to the chemical composition of the welding wire Sv-AK5 (ER4043). An increase in the welding arc current facilitates a growth of tensile strength and a slight decrease in the conditional yield strength and relative elongation. The patterns of the change in the mechanical properties of the deposited samples are due to the specifics of the formation of the cast structure of the deposited layers under conditions of directional solidification in the direction away from the substrate.

AbstractStudies of the extraction of impurities of calcium(II), magnesium(II), boron(III), and chloride ions from sulfate-chloride nickel solutions have been carried out. As extractants, we used di-2-ethylhexylphosphoric acid (D2EHPA), di-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), trialkylamine (TAA), tributyl phosphate (TBP), and aliphatic alcohols: octanol-1, 2-ethylhexanol, and a by-product of its production—distillation residue (TPRD). According to the results of research, it was established that a mixture of 40% TAA in 2-octanone and TPRD exhibits a high extraction ability with respect to boron(III); the degree of boron extraction is 60.7 and 74.5%, respectively. The effect of the acidity of the aqueous phase and the composition of organic mixtures on the extraction ability of organophosphorus acids D2EHPA and Cyanex272 in the extraction of calcium(II) and magnesium(II) was studied. The optimal concentration of individual extractants was found to be 20 vol % in Escaid 100 solvent and the composition of the mixture (vol %) 15 (D2EHPA) + 5 (Cyanex 272). Individual D2EHPA predominantly extracts calcium(II): extraction of 62% Ca(II) and 15% Mg(II). When using Cyanex272, the extraction of magnesium(II) predominates: extraction of 59% Mg(II) and 20% Ca(II). It is shown that the extraction mixture has higher performance than individual extractants for the extraction of Ca(II) and Mg(II) from nickel solutions in the range of pH 3.0–3.5, at which the coextraction of nickel(II) is negligible. With increasing pH values, the extraction of Ca(II) decreases owing to the increasing extraction of nickel and the displacement of calcium by it from the organic phase. The results of the extraction purification of the nickel electrolyte of JSC Kola MMC with an extraction mixture in the Ni form to exclude pH adjustment at each stage of the process are presented. The experimental data obtained make it possible to conclude that the extraction purification of nickel electrolytes of JSC Kola MMC is promising, as a result of which pure solutions of nickel sulfate with a residual content of ≤0.010 g/dm3 B(III), Ca(II), Mg(II), and chloride ions were obtained.

AbstractThe efficiency of using rare earth metals largely depends on their impurity composition, which affects the structure and properties of materials. Before the analytical control of materials based on rare earth elements (REEs) and the starting materials for their production, the task is to determine both macrocomponents with high accuracy and impurities with high sensitivity, correctness, and precision. To determine the impurities in REE-based materials in the range from 10–5 to 5.0 wt %, a complex of methods of atomic emission and mass spectral analysis is frequently used. However, the analysis of REE-based materials, even using these modern highly sensitive methods, is a difficult task due to spectral and matrix interferences. Therefore, different separation/preconcentration procedures are needed to determine both rare earth and non-rare-earth impurities. This article reviews publications of preconcentration methods for spectral and mass spectral methods of analysis of materials based on REEs and some other analytical methods. It is shown that the most common approaches are liquid extraction and chromatography. Sorption, cloud-point extraction, and precipitation are also used. There is no universal approach. Each method discussed in this article has its advantages and limitations. The analytical completion of the method confirms the effectiveness of the selected separation/preconcentration method in each specific case.

AbstractTungsten Inert Gas (TIG) welding was used successfully to weld 5 mm thick aluminum alloy plates AA5052-H32 utilizing as and 0.25 wt % Sc added ER 5356 filler rod in this study. Furthermore, the effect of adding Sc to the filler rod on TIG welded joints with mechanical and metallurgical properties was investigated. An optical microscope (OM) and a scanning electron microscope (SEM) were used to examine the microstructures of the joints The Al-Sc precipitates are distributed uniformly throughout the fusion zone of scandium added weldment. The welded joint with scandium added filler rod has fewer porosities, resulting in enhanced joint efficiency. Commercial filler rod welded joints had a coarse microstructure, but Sc modified filler rod welded junctions had a fine dendritic structure. The welded joints’ tensile characteristics and hardness were investigated. Compared to commercial filler rods, the weld junction created with scandium enhanced filler rod has twice the ductility. SEM fractography revealed brittle fractures in weld samples with commercial filler rods and ductile fractures in weld samples with scandium-added filler rods. With the addition of Sc to the filler rod, no appreciable hardness difference was observed in the fusion zone. This study paper will aid companies and researchers to better understand the metallurgical and mechanical behaviour of TIG-welded AA5052-H32 plates using scandium added filler rod, reducing the number of experimental trials and allowing for further research.

AbstractOf late, there has been an increase in the application of Metal Matrix Composites (MMCs) as they provide significant mechanical and tribological properties. In tune with the rapid global attention to this composite, this research analysis is an attempt on employing Taguchi method in order to minimize the rate of wear and friction on co-efficiency in aluminium MMC. The study involves in investing the tribological behaviour of aluminium alloy, Al-6063, by reinforcing with silicon carbide and aluminium oxide particles. As such, the investigation was carried out by fabrication the alloy by stir casting process. In addition, wear test was performed to analyse the wear and frictional properties of the metal matrix composites with the aid of a pin-on-disc wear tester. For the purpose of the process in an effective manner, Taguchi technique was adopted to perform the experiments on a fixed plan. Further, in analysing the experimental data, A L9 Orthogonal array was applied. More analyses such as the influencing effect of higher load applied, higher speed of sliding and distance found in sliding on wear rate, and the friction occurring out of co-efficiency during the process of wearing were carried out by employing ANOVA and regression equation. These measures were used for each response for the abovementioned analyses. The experimental results exhibit that the highest influence is observed in sliding distance, while the speed of load and sliding coming behind it. In order to prove the justification of this study, the experimental results were verified with the tests carried out for confirmation.

AbstractAdequate heat input provided by the proper combination of friction stir welding (FSW) parameters is critical to sound welding. Optimum parameter setting requires exhaustive trials and extensive experiments, which require considerable time, resources, and cost. This study uses simulation and modelling approaches to generate three significant tool-work heat flux generating interfaces (tool shoulder, lateral and bottom surfaces of the pin). The temperature data was acquired by performing nine experiments on 4 mm thick AA6060-T5 sheets. The effects of significant FSW parameters (Tool Rotational Speed (TRS) and welding speed (WS)) on the heat input were modelled. The calculated heat input rates at the shoulder and pin surfaces (Q1, Q2, and Q3) were numerically estimated. The experimental data was converted into a mathematical model using the response surface method to study the effect of welding parameters on heat input from each of the three surfaces. The analysis of the results showed that among three interfaces, the shoulder provides the most significant heat input due to the immense friction between this surface and the parts to be welded. The interaction between the main factors produced little heat on the three surfaces. The ANOVA test showed that the three models are a good approximation of the results of both experiments and theories.

AbstractIn magnesium alloys castings, the casting defects such as shrinkage porosity often occur. Such defects can be suppressed by repair welding or surfacing using a special filler rod. Unfortunately, in Russia, a low amount of filler rod is consumed. Therefore, domestic enterprises do not manufacture it, limiting themselves to imports or homemade low-quality substitutes. Nevertheless, there is a need for filler rod, and recently it has become unprofitable to replace them with imported materials owing to a significantly increased price. Therefore, there is a need to study the technology of its production to replace imported filler rod with domestic material. Magnesium alloys based on the Mg–Zn–Zr (La, Nd) system SV1, SV122, and ZK51 (ML12) that used as a filler rod for repair welding of ZK51 alloy castings were studied in this work. The samples were obtained by permanent mold casting into aluminum molds followed by hot extrusion into a filler rod with a diameter of 4 mm. It was shown that all the investigated alloys could be obtained in the form of a rod with a diameter of 4 mm. Therefore, the investigated rod samples from the SV122 alloy were used as filler material for repair welding of ZK51 magnesium alloy castings. The weld seam in the T1 condition has an ultimate tensile strength (UTS) about 80% of the UTS of the casting material.

AbstractIn Russia, most aluminum smelters are equipped with cells with self-baking anodes for which the task of reducing of anode paste consumption is relevant, since the fraction of anode materials in the cost of aluminum varies from 8 to 20%. To solve this problem, it is necessary to determine the need for anode paste. The method for calculating the specific anode paste consumption used at the enterprises of the aluminum industry has a large error. The article discusses the main errors of this technique, shows the stages of calculating the flow rate of the anode paste, assesses the adequacy of the calculations, and gives recommendations for improving the technique. In general, the considered methodology adequately reflects the processes of carbon consumption; however, the final result of the calculations may differ significantly from the real one. The values taken constant to simplify the calculation, in fact, can change during the electrolysis, which leads to a significant change in the final result of the calculations. For example, an increase in the fraction of CO2 from 0.45 to 0.5 leads to a decrease in the anode paste consumption by 15.3 kg/t Al. At the same time, it is known that, with the onset of the anode effect, the composition of the anode gases changes sharply: the fraction of CO2 decreases, and the fraction of CO increases. In summer, at high ambient temperatures, both the proportion of vaporized pitch and the proportion of anodes with an increased surface temperature rise. A change in the latter to 0.25 leads to an increase in anode paste consumption by 6.6 kg/t Al. The same applies to oxidation in air. The number of depressurized cells may increase, which will increase the carbon consumption. It is necessary to pay attention to the factors affecting the quality of the anode. Incorrectly selected particle size distribution or worn equipment can significantly degrade the quality of the anode and lead to an increase in carbon consumption. To correctly take into account the peculiarities of the formation of carbon monoxide, it is necessary to make adjustments to the calculation.

AbstractIn this study, A356 powder was alloyed with elemental Nickel (Ni) powder in different ratios using a mechanochemical alloying method. Alloyed A356/XNi powders were cold pressed along one axis under a load of 350 MPa and sintered at 600°C. To determine the effect of intermetallic phases formed on the microstructure in proportion to the amount of Ni, the A356/XNi alloys were characterized by X-ray diffraction (XRD) analysis, density, and microhardness values. As a result, after mechanical alloying, the spherical microstructure of the A356 alloy turned into a spongy form due to the sponge-like Ni elemental powders. After sintering, it was determined by optical microscopy and scanning electron microscopy (SEM) examinations that the grain size of A356/XNi alloys increased with an increasing amount of Ni. In addition, it was determined that the relative density and amount of porosity increased with an increasing amount of Ni. According to the XRD analysis results, it was determined that AlNi, Al3Ni2, Al3Ni and AlFeNi intermetallic phases formed in the microstructure due to the mechanochemical and sintering process.

AbstractThe results of the studies on the use of collector reagents in the form of a reverse microemulsion (RME) of the water-in-oil type (i.e., water droplets are suspended in the oil phase) for the flotation extraction of lead and zinc minerals are presented. Lead and zinc concentrates and a lead–zinc ore are used as the initial samples for flotation. The concentration of galena in the lead concentrate is 74.7%, and the concentration of sphalerite in the zinc concentrate is 78.7%. Basic collector reagents in the composition of the RME are potassium butyl xanthate (PBX) and kerosene. A nonionic surfactant (NSA) is used to stabilize the RME. Casein is used as additives to the main reagents to eliminate the negative effect of osmotic pressure upon preparing the RME. The transformation of casein to the active soluble form is carried out using sodium sulfide. The particle size in the reverse microemulsion is 12.38 nm. The following options for supplying reagents to the flotation pulp are studied in flotation tests: RME, RME + foaming agent, and potassium butyl xanthate + foaming agent. A T-92 reagent is used as the foaming agent. The consumption of PBX in the composition of the RME and in the classical supply is 26 g/t. The results of laboratory tests show that the method of supplying flotation reagents in the form of an RME leads to an increase both in the flotation rate of lead and zinc sulfides and in their recovery into a foam product. Tests with the use of an RME in the collective flotation cycle of a lead–zinc ore show an increase in the extraction of lead into the total concentrate by 10.8% and zinc by 38.5% in comparison with the classical supply of reagents (collector + foaming agent) in addition to an increase in the flotation rate. An increased selectivity of the action of an RME in relation to zinc sulfides in comparison with lead sulfides is noted. The flotation rate coefficient of sphalerite is 7.8-fold higher when compared to galena. The gain in the extraction into the total zinc concentrate is also higher and is 16.78%, while the gain into the lead concentrate is 1.9% under the same conditions.

AbstractThe effect of the cold rolling reduction ratio (εh) on the microstructure and the complex of mechanical and technological properties of cold-rolled sheets from aluminum alloy V-1579 of the Al–Mg–Sc system has been studied. The influence of the final annealing temperature of sheets rolled with different reduction ratios has been examined as well. The character of plastic anisotropy has been found to change slightly with an increase in εh during cold rolling; an increase in tensile strength and yield strength with a decrease in relative elongation is observed. In this case, the anisotropy of the ultimate strength and yield strength is nearly absent. With an increase in the reduction ratio to 30–40%, the anisotropy of the relative elongation increases: the relative elongation in the rolling direction decreases more rapidly. However, after rolling with εh > 50%, the elongation anisotropy almost disappears. Regardless of the annealing temperature, samples rolled with a higher reduction ratio have higher strength characteristics. With an increase in the annealing temperature, the ultimate strength and yield strength decrease, while the relative elongation increases. In this case, softening with the annealing temperature occurs more intensely for samples rolled with a lower reduction. For all analyzed regimes, the character of the distribution of anisotropy indices in the sheet plane does not decrease after annealing and corresponds to the deformation type of textures. Moreover, the in-plane anisotropy coefficient decreases after annealing in comparison with a cold-rolled sample. At the same time, the technological properties of samples rolled with a higher degree of deformation are higher after annealing than those of samples rolled with a lower reduction regardless of the annealing temperature.

AbstractAt the present time, aluminum alloys with silicon are the most widespread construction materials. In order to increase the mechanical properties of aluminum alloys, modifying with Sr, Ti, and B is used. However, in the foundries, when using scrap and secondary aluminum alloys, the modifying elements are accumulated in alloys in the form of intermetallic particles, which can lead to a decrease in the level of castability. This is connected with the fact that the used modifiers exert a short-term effect and cannot be activated upon remelting. Hence it is necessary to add the modifiers without taking into account the intermetallic particles already contained in the melt. This paper is devoted to studies on the effect of additions of Sr, Ti, and B on the fluidity of an A356.2 grade aluminum alloy determined by means of vacuum fluidity testing. It is shown that, when AlSr10 and AlTi5B1 commercial master alloys are used (containing up to 0.3 wt % Sr and 0.5 wt % Ti), no decrease in fluidity is observed. However, adding the same amount of Ti with the use of a homemade AlTi4 master alloy leads to a considerable decrease in the fluidity. With the help of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), the microstructure and phase composition of master alloys and of an A356.2 grade alloy after adding the mentioned master alloys have been investigated. Additionally, the Thermo-Calc software package has been used to evaluate the effect of modifier addition exerted on the phase composition and phase transition temperature of the alloy. It has been established that the effect of the modifier addition on the fluidity of the A356.2 grade alloy is connected with the shape and size of crystals containing the modifying elements in the master alloy structure. When there are coarse crystals formed by such phases, it is quite possible that the crystals are dissolved incompletely, which could hinder the free flow of melt.

AbstractIn order to investigate the structure and performance of specific ceramic materials, red mud, steel slag, and talc, which are commonly used as ceramic building materials, were fabricated by molding. The influences of particle size and composition on the properties of the ceramic materials were studied by differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. The results indicate that the main crystalline phases were diopside and anorthite. The ceramics possessed the best mechanical properties when sintered at about 1170°C, the particle size of the raw material powders was less than 74 μm, and the ceramic composition comprised 60–70% red mud, 20–30% steel slag, and 10% talc. The results of this work are useful for recycling of steel slag and red mud on a large scale.

AbstractThe quality of metal powder composition (MPC) made of heat resistant alloy EP648 (Ni–Cr–W–Mo) used for fabrication of parts by direct metal deposition (DMD technology) has been analyzed. It has been established that, regarding the main requirements (chemical composition, particle size distribution, purity, bulk density, yield, moisture content), the MPC meets the requirements of Technical Specifications TU 136-225-2019. The influence of the parameters of direct laser deposition (power of laser radiation, cladding speed) on the structure and microhardness of experimental specimens has been analyzed. The highest number of defects (multiple shrinkage cavities and incomplete fusion) is formed in the specimen fabricated at the power of laser radiation P = 1000 W and the cladding speed v = 40 mm/s. At the same time, the defects have the maximum dimensions. The minimum number of defects is observed in the specimens fabricated at P = 1400 and 1600 W and v = 45 and 38 mm/s. In this case, the most homogeneous structure of laser cladding is formed owing to complete fusion of powder particles and melt spreading. Nevertheless, the structure of the specimen deposited at P = 1600 W and v = 38 mm/s contains cracks located at the subgrain boundaries in the center of cladding tracks. Their formation is caused by overheating of the metal due to higher power of laser radiation and accumulation of high internal stresses after previously deposited layers. The microhardness of the specimens fabricated by all modes of direct laser deposition changes insignificantly in the range of 270–310 HV. On the basis of the obtained experimental results, it has been determined that the most optimum structure is formed in the specimen at the laser power of 1400 W and the cladding speed of 45 mm/s.

AbstractThe thiosulfate system for silver extraction has numerous characteristics such as high efficiency, low consumption, and environmental protection, and it has good application prospects. However, the high cost of metal recovery in thiosulfate systems limits its industrial application. A previous study indicated that Ag2S/Ag nanocomposite clouds were precipitated from silver thiosulfate complex (AgTS) through ultraviolet photolysis, whereas the semiconductor-metal nanopowders synthesized through the hydrothermal synthesis process are usually important composites that can be used in photocatalysis, broad-spectrum antibacterial, and other environmental fields. Therefore, this study aims to develop high-value utilization of AgTS hydrometallurgical systems based on the photocatalytic properties of nanocomposites, and proposes research on the visible-light photocatalytic activity of Ag2S/Ag photocatalytic systems precipitated from AgTS through ultraviolet photolysis. First, the morphology and optical properties of the Ag2S/Ag nanocomposite were investigated. Next, the visible light photocatalytic activity of the Ag2S/Ag nanocomposite was evaluated, and finally, the new high-value utilization research method of “ultraviolet absorption → ultraviolet photolysis → photocatalysis” was proposed. In this study, we demonstrate a novel method of high-value utilization of silver thiosulfate lixivium with a high photocatalytic efficiency of the Ag2S/Ag nanocomposite of up to 47.98% after three cycles.

AbstractThis review is devoted to known theoretical and experimental results in the field of using physical methods for processing melts in the preparation of metal matrix composite materials in conditions of casting and metallurgical technological processes. The possibilities, advantages, and disadvantages of various methods of physical influences are considered from the standpoint of their influence on the structural and morphological characteristics and physicomechanical and operational properties of cast composite materials based on aluminum and its alloys. A classification is presented and a detailed description of physical methods for processing melts when obtaining metal matrix composites is presented, depending on the state of the melt during the processing period (during melting, pouring, and crystallization) and according to the physical principle of imposed effects (thermal, electromagnetic, cavitation, mechanical, and others). The modern concepts of the laws and mechanisms of the influence of the processing of the melt by physical methods on the processes of structure and phase formation of metal matrix composites in the cast state are presented. From a qualitative and quantitative point of view, the currently known effects of exposure to the structure of composites are described, in particular, those associated with a change in the wettability of particles, their distribution, dispersion, and morphology, as well as with a change in the structural state of the matrix material. Data on the physicomechanical, operational, and technological properties of metal matrix composites obtained with the use of physical effects on the melt during melting and crystallization are systematized. The prospects for the development and practical application of methods of physical effects on melts in the production of metal matrix composites based on various matrix materials and reinforcement systems, including endogenously reinforced, exogenously reinforced, and complex-reinforced composite materials, are shown. Priority areas of theoretical research and experimental development are discussed; areas of discussion and issues in the field of obtaining metal matrix composites using physical effects on melts during melting and crystallization are revealed. On the basis of a systematic analysis of the key problems that limit the widespread industrial use of physical methods for processing melts, areas for future research in this direction are proposed.