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It is shown that cooling of casting molds by water with water flow of 0,42 m3/h and internal surfaces of castings with thickness of a wall 12–14 mm with water quantity 2,5×10–4–5×10–4 m3 allows to receive procurements with completely modified microstructure without use of modifiers. External layers of the produced castings consist of the eutectic silumin with compact crystals of silicon, and internal layers – of hypereutectic silumin with crystals of high-disperse primary and compact eutectic silicon.

On the paper the influence of modifying micro additives on the refinement of primary silicon crystals in the hypereutectic AlSi21CuNi piston silumin have been examined. As the modifiers there were used micro additives of Phosphorus in the form of AlCu19P1.4 and CuP12 pre-alloys, sulfur in the form of CuS and iron in the powdered form. The modifying micro additives were used separately and together. Micro additions of iron were used together with phosphorus. Sulfur micro addition provided the fragmentation of the primary silicon crystals, but not as effective as the phosphorus micro additive. The best effect of fragmentation of the primary silicon crystals was ensured by the combined addition of phosphorus in the form of AlCu19P1,4 pre alloy with a micro additive of powdered iron which reduced the average size of the primary silicon crystals from 114 μm to 20 μm.

The results of the analysis of the elemental and phase composition, the defect substructure, strength and tribological characteristics of the hypereutectic composition silumin in the molten state and after irradiation with high-intensity electron beam are presented. The formation of the modified surface layer with thickness of up to 1000 µm, having increased strength and tribological characteristics was demonstrated as a result of irradiation.

The method of casting of hypereutectic silumin excluding liquidation of the silicon crystals is presented.

Peculiarities of structure formation in hypereutectic silumin with inverted microstructure at horizontal continuous casting have been investigated.

Silumin (an alloy of aluminum with silicon) is a cheap industrial alloy with good corrosion resistance, high specific mechanical properties and good casting properties. As a result it has found wide applications in modern industry (aircraft and mechanical engineering, instrument making, shipbuilding, etc.). The aim of this work is to analyze the regularities of transformation of the structure and phase composition of the surface layer of a hypereutectic silumin ( Al - 22 wt % Si ), subjected to irradiation with an intense pulsed electron beam. It was found that irradiation of silumin with a pulsed electron beam ( 18 keV, 25 J / cm^2, 200 μs, 3 pulses, 0,3 s^(-1)) leads to melting of the surface layer up to 60 μm thick, the high-speed crystallization of which is accompanied by the formation of a submicro-nanocrystalline multiphase structure. It is shown that aluminum (a solid solution based on fcc crystal lattice) forms cells of high-speed crystallization; nanoscale particles of the second phases are located at the cell boundaries. Analysis of three-component state diagrams of the Al - Si - Fe - Cu system (the main elements of the studied silumin) demonstrated the possibility of forming a large number of two- and three-element compounds in the alloy under equilibrium conditions. It has been shown by diffraction electron microscopy that, along with three-element phases, phases based on four and, possibly, more elements are formed in silumin.

It is shown that melting and molding of hypereutectic silumin are complicated physical and chemical nanostructural processes. The major part at these processes is played by the centers of crystallization of primary crystals of silicon, silicon nanocrystals, the dissolved and adsorbed oxygen. The part of the modifying crystals of Cu3P is reduced to decreasing of concentration of the adsorbed oxygen and an intensification of process of coagulation of nanocrystals of silicon in the centers of crystallization of primary crystals of silicon.

The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of synthetic hypereutectic alloys: AlSi15 and AlSi19. Casts were made in permanent mold cooled with water mist stream. The study was conducted for unmodified silumins on the research station allowing the cooling of the special permanent probe using a program of computer control. Furthermore the study used a thermal imaging camera to analyze the solidification process of hypereutectic silumins. The study demonstrated that the use of mold cooled with water mist stream allows in wide range the formation of the microstructure of hypereutectic silumins. It leads to higher homogeneity of microstructure and refinement of crystallizing phases and also it increases subsequently the mechanical properties of casting.

The work is a continuation of research on the use of water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation on crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled a with water mist stream. The study was conducted for unmodified AlSi20 alloy and a modified one with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream and solution heat treatment allows in wide range for the formation of the microstructure of hypereutectic silumins. It leads to the growth of microstructure refinement and spheroidizing of phases in the casting.

The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled with water mist stream. The study was conducted for unmodified AlSi20 alloy and modified with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream allows the formation of the microstructure of hypereutectic silumins. A wide range of solidification temperature of hypereutectic silumins increases the potential impact of changes in the cooling rate on a size, a number and a morphology of preeutectic silicon and eutectic α+β (Al+Si).

Rotary rolling of quenched-and-tempered hypereutectic silumins 01392 and AK18 makes it possible to refine the primary and secondary crystals of silicon and change them from plate to globule form. Adding to similar results obtained previously on hypereutectic silumins 01390 and 01391 that were not quenched and tempered, rotary rolling of quenched-and-tempered hypereutectic silumin AK18 also refines and changes the shape of the excess phase Al9FeNi that is usually present in piston-grade silumins and determines their resistance to heat. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying the structure and phase state of tungsten and tungsten-copper alloy after pulsed action of compression plasma flows and irradiation with helium ions. The compression plasma flows were used to modify the surface layer of tungsten, as well as to create an alloy based on tungsten and copper. Using scanning electron microscopy and X-ray structural analysis, the formation of radiation defects on the tungsten surface was detected in the form of local areas of exfoliation and destruction, which begin to form at helium ion irradiation doses of 2 × 1017 cm−2. It is shown that preliminary plasma treatment of the surface in the melting mode leads to the complete disappearance of surface radiation defects up to a dose of 2 × 1017 cm−2, which may be associated with the formation of a fine-crystalline grain structure, the intergranular boundaries of which serve as effective sinks for primary radiation defects. [ABSTRACT FROM AUTHOR]

The effect of melt hydrogen treatment on structure, morphology, and on physical and mechanical properties of hypereutectic alloy Al – 15% Si in cast and deformed conditions is studied. A melt is treated with hydrogen by different methods, i.e., with wet asbestos, in a steam atmosphere, and flushing with hydrogen prepared by alkali decomposition with aluminum. Ingots are deformed plastically by open forging and rolling. Alloy microstructure is studied by metallographic, electron microscopic, x-ray diffraction, and dilatometric analyses. Alloy density and microhardness are measured. Alloy atomic hydrogen content is studied by vacuum heating. It is shown that hydrogen treatment improves cast alloy structural parameters and deformability, raises post-deformation strength by a factor of 1.3 – 1.4, and lowers linear expansion coefficient. [ABSTRACT FROM AUTHOR]

Abstract—Modern materials-science techniques are used to analyze the gradient structural-phase states and the nanohardness of hypereutectic silumin after high-current electron-beam melting of the surface layer. Electron-beam treatment is shown to dissolve silicon inclusions and intermetallic compounds observed in the initial state and form an aluminum cellular high-rate solidification structure and lamella eutectic grains. The content of alloying elements decreases by a factor of 1.5–2. The hardness of the irradiated silumin is found to change nonmonotonically and achieves its maximum at a distance of 30–50 μm from the surface. The maximum value is four times higher than the hardness of the unirradiated material. The radiation-induced changes in the silumin structure and hardness are explained. [ABSTRACT FROM AUTHOR]

A mathematical model has been constructed to describe the kinematics of the movement of metal on the surface of semifinished products made of hypereutectic silumin alloys as they undergo rotary rolling. The model is based on the dependence of the pitch of the helical lines of metal flow on the deformation ε of the product and the feed angle α. The pitch is minimal when ε = 50–55%, regardless of the feed angle α. The degree of deformation ε = 50–55% is optimum for ensuring that the unit number of cycles in which the semifinished product is loaded by the work rolls is such as to produce a fine-grained structure and maximize the ductility characteristics of hypereutectic silumins. [ABSTRACT FROM AUTHOR]

Recent advances in artificial intelligence have opened up new avenues for microstructure characterization, notably in metallic materials. Physical and mechanical properties generally depend on the microstructure of the metallic material. On the other hand, microstructural characterization takes time and calls for specific techniques that don't always lead to conclusive results quickly. To address this issue, this research focuses on the application of artificial intelligence approaches to microstructural categorization. We demonstrate the advantages of the AI approach using an example of Al-Si alloy, a material that is widely employed in a variety of industries. To specify a suitable convolutional neural network (CNN) approach for the microstructural classification of the Al-Si alloy, CNN models were trained and compared using DenseNet201, Inception v3, InceptionResNetV2, ResNet152V2, VGG16, and Xception architectures. Resulting from the comparison, it was determined that the developed supervised transfer learning model can execute the microstructural classification of Al-Si alloy microstructural images. This paper is an attempt to advance methods of microstructure recognition/classification/characterization by using Deep Learning approaches. The significance of the established model is demonstrated and its accordance with the literature data. Also, necessity is shown of developing material models and optimization through systematic microstructural investigation, production conditions, and material attributes. [ABSTRACT FROM AUTHOR]

Powder aluminum-phosphorus master alloys for modifying hypereutectic silumins are developed. Optimal treatment modes of powder mixtures in a high-energy planetary mill which give minimal losses of the starting material and the microstructure with the uniform and dispersed distribution of particles of excess phases in the aluminum matrix are selected. The phase composition of formed master alloys is investigated by electron probe microanalysis. The high efficiency of modifying the hypereutectic silumin Al-17 wt % Si by introducing phosphorus (0.008 wt %) using fabricated master alloys is shown. [ABSTRACT FROM AUTHOR]

The article discusses the creation of Al-18 percent silicon hypereutectic silumin with a microcrystalline grain structure in order to investigate the superplasticity of hypereutectic silumins-aluminum alloys with a silicon content exceeding 12 percent. The said alloys render high strength and wear resistance compared to traditional alloys used to manufacture pistons for internal-combustion engines (ICEs). Due to their low plasticity, such creation maybe the solution to the topical problem.

The world’s first technology has been introduced for piecing hollows (tubes) of hard-to-deform hypereutectic silumin alloys (01390 and 01392). The tubes have the dimensions 80 mm diameter × 13.5 mm wall thickness and 74 mm diameter × 15 mm wall thickness. The are obtained on universal rotary rolling mill 20–60. The technology was developed by modeling the rotary rolling operation, studying the rheological properties of hypereutectic alloys, finding scientifically sound parameters (rolling scheme, feed angles, temperature-speed parameters) for an intermediate rotary-rolling operation performed to obtain bars with a crystalline structure and ductility properties 3–4 times better than those of the initial ingots, and the developing and introducing a piercing process that employs special spherical mandrels with a conical nose. [ABSTRACT FROM AUTHOR]

The effect of possible modification and refining effect of Al-Cu-P-based pre-alloy combined with Fe on the microstructure and the silicon morphology change in hypereutectic Al-Si cast alloy was studied. The samples in the as-cast state were observed by optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The 3D morphology of both primary and eutectic silicon was observed by using colour and deep etching in detail. The results showed that the AlCu19P1.4 pre-alloy (1.07 wt.%) combined with the addition of Fe (0.02 wt.%) has a significant effect on the change of the amount, size and morphology of primary Si. This is significantly refined and changes the shape from a coarse irregular star-shaped, polyhedral, or plate-like shape to a fine polyhedral shape. The average size of the primary Si is reduced by about of 78% from 135 μm to 28 μm and the number of primary Si particles increased from 7.4 to 237. No change in the morphology of the eutectic Si was observed; a refinement of the structure from a coarse needle/plate-like to a fine plate-like structure was seen. The depth etching method using HCl was very effective in the study of the 3D silicon morphology observed, which could be observed in detail without the presence of artefacts. [ABSTRACT FROM AUTHOR]

The aim of the study was to select the optimal content of zirconium introduced as an alloying additive to obtain the best strength properties of Al-Si alloy. A technically important disadvantage is the tendency of silumins to form a coarse-grained structure that adversely affects the mechanical properties of castings. To improve the structure, modification processes and alloying additives are used, both of which can effectively refine the structure and thus increase the mechanical properties. According to the Hall-Petch relationship, the finer is the structure, the higher are the mechanical properties of the alloy. The proposed addition of zirconium as an alloying element has a beneficial effect on the structure and properties of silumins, inhibiting the grain growth. The starting material was an aluminium-silicon casting alloy designated as EN AC-AlSi9Mg (AK9). Zirconium (Zr) was added to the alloy in an amount of 0.1%, 0.2%, 0.3%, 0.4% and 0.5% by weight. From the modified alloy, after verification of the chemical composition, samples were cast into sand moulds based on a phenolic resin. The first step in the research was testing the casting properties of alloys with the addition of Zr (castability, density, porosity). In the next step, the effect of zirconium addition on the structure and mechanical properties of castings was determined. [ABSTRACT FROM AUTHOR]

Cyclic tests of the multicycle fatigue of commercially pure titanium were performed under normal conditions (without a magnetic field) and after exposure to a constant magnetic field of varying density (B = 0.3, 0.4, 0.5 T). It was shown that the application of the constant magnetic field of varying density led to a fold increase in the average number of cycles to destruction of the VT1-0 titanium samples by 64, 123, and 163%, respectively. Scanning electron microscopy revealed that the magnetic field led to a 1.45-fold increase in the critical length of the fracture (the width of the fatigue crack growth zone) and a 1.6-fold decrease in the distance between the fatigue striations in the accelerated crack growth zone of the destroyed titanium samples. It was established that a subgrain (fragmented) structure formed in the area of the fatigue growth of the fracture of the titanium samples. The size of the subgrains corresponded to the spaces between the fatigue striations, which had an inhibitory influence on the microcrack propagation. Collectively, the revealed facts are indicative of a higher material resistance to fatigue fracture propagation and increased operation resources under the fatigue tests in the magnetic field, which correlates with the data on the growth of the average number of cycles to fracture of the VT1-0 titanium samples. [ABSTRACT FROM AUTHOR]

In this paper, the results from studies regarding near-eutectic Al-Si alloys with Sn as an alloying addition are presented. In most Al-Si alloys, tin is regarded as a contaminant; thus, its amount is limited to up to 0.3 wt.%. The few studies that can be found in the literature regarding the behaviour of tin in aluminium alloys suggest the beneficial effect of this element on selected properties. However, these results were obtained for hypereutectic Al-Si alloys or wrought aluminium alloys. In our studies, the influence of tin contents of up to 1.7 wt.% was determined on the AlSi10 alloy. Thermal analysis, measurements of the mechanical properties of the cast and heat-treated alloy, metallographic observations (light microscopy, scanning electron microscopy), and EDS (X-ray energy dispersive spectrometry) measurement allowed us to fully describe the effect of tin on the aluminium alloy. The results of the thermal analysis showed changes in the range of the α-Al solution crystallisation and the α+β eutectic through a decrease in the alloy's solidification start point and eutectic solidification point. As a result, the elongation of the alloy was more than double in the AlSi10Sn1.7 alloy, with an A5 value of 8.1% and a tensile strength that was above 200 MPa. [ABSTRACT FROM AUTHOR]

The paper describes the two-stage modification of the surface layer of hypereutectic Al-20%Si alloy that combines electroexplosive alloying by an Al-Y2O system with subsequent irradiation by pulsed electron beam. It is shown that irrespective of the modification mode, a multilayer structure is formed consisting of the following layers: a surface layer and an intermediate layer. The surface layer is a multiphase material, the thickness of which varies within 1 µm. The intermediate layer, the thickness of which varies within 40 µm, is made up of rapid solidification cells formed due to the rapid cooling of molten layer of Al-20%Si alloy. The cells are divided by thin interlayers mostly formed by silicon nanoparticles. [ABSTRACT FROM AUTHOR]

The influence of complex MHD and thermal-forced processing of hypo- and hypereutectic silumins on their structure and properties is considered. In liquid state, the processing involves holding and electromagnetic pouring of alloys into the magnetodynamic installation (MDI). In solid state, alloys experience thermo-mechanical action. [ABSTRACT FROM AUTHOR]

A comparative analysis of the phase composition and morphology of primary crystals in hypereutectic alloys of the Al–Ca–Ni–X system (where X is Fe, Si, Mn) has been carried out by calculation and experimental methods, including the construction of liquidus surfaces. Additional alloying of the base Al–6% Ca–3% Ni alloy with iron and silicon leads to the formation of coarse elongated primary crystals up to 100 μm in length. It is found that the addition of manganese, on the contrary, leads to the formation of relatively small (average size about 20 μm) compact primary crystals of two four-component phases. Presumably, they are phases based on ternary compounds Al9CaNi and Al10CaMn2. The composition of eutectics in quaternary alloys has been determined. All aluminum–calcium eutectics are characterized by a higher proportion of the second phases and a thinner structure compared to the aluminum–silicon eutectic in AK18 silumin, and they are also capable of spheroidization upon heating, starting from 500°C. The combination of compact and spherical particle morphology after annealing in the 63-2Mn alloy appears to be favorable for deformation. A comparison of the manufacturability of the experimental Al–8% Ca–1% Ni–2% Mn alloy and AK18 grade silumin shows the advantage of the former. In terms of the totality of its characteristics, the experimental alloy can be considered the basis for the development of new-generation hypereutectic alloys as an alternative to piston silumins of the AK18 type. The experimental alloy, the microstructure of which is characterized by a compact morphology and small size of primary crystals and a fine structure of the eutectic, unlke hypereutectic silumins, does not require special modification. [ABSTRACT FROM AUTHOR]

Purpose: The conducted tests were aimed at determining whether the tested material meets the requirements for wear resistance in modern turbocharged combustion engines where there is an increased temperature and higher pressure. Design/methodology/approach: The tests were performed in a pin-on-disc system, according to the ASTM G 99 standard. Findings: The article presents the results of the coefficient of friction, the amount of wear, chemical analysis and surface profile of the tested material A390.0 in combination with EN GJL-350 cast iron. Research limitations/implications: The tested materials are used in the construction of pistons for internal combustion engines, therefore the test parameters were selected to take into account the operating conditions in a turbocharged engine with a power of up to 100 kW. Practical implications: After analysing the properties of the A390.0 alloy at elevated temperatures, it was found that without additional modifications, the alloy cannot be used in modern combustion engines, in particular with turbocharging. Originality/value: Presents the results of research concerning mechanical properties (HB, HV, Rm) and yield properties (R0.2, A5, Z) of the examined alloy. [ABSTRACT FROM AUTHOR]

A laser optoacoustic method for quantitative assessment of the volumetric porosity of cast dispersion-strengthened metal-matrix composite materials has been proposed and experimentally implemented. The method is based on a statistical analysis of the distribution of amplitudes of backscattered broadband pulses of longitudinal acoustic waves in the tested materials. Laser excitation and piezoelectric recording of ultrasound is implemented with one-way access to the test object using a special laser-ultrasonic transducer. Silumin-based composites reinforced with silicon carbide microparticles in various volume concentrations (0.033–0.135) and composites obtained by reaction injection moulding based on aluminum reinforced with intermetallic (volume concentration 0.04–0.115) have been studied. For both types of composites, the distribution of amplitudes of backscattered ultrasonic signals is approximated by a Gaussian distribution function applicable for a large number of statistically independent quantities. The empirically obtained dependence of the half-width of this distribution on the volumetric porosity of composites of two different types is approximated by the same linear function regardless of the manufacturing technology, as well as of the type, size, and concentration of strengthening particles. [ABSTRACT FROM AUTHOR]

The modern concepts of the structure of liquid metals and alloys are considered. Several types of microinhomogeneity and microheterogeneity are shown to exist in liquid metal solutions. Their structural state changes as a result of variations in composition, history, temperature, and pressure or the influence of various external actions. Upon subsequent cooling at an appropriate rate, these changes can persist up to liquidus and affect the structure and properties of the solidified alloy. The main attention is paid to the influence of the heating temperature of a liquid metal. For aluminum-based alloys, the possibility of developing the optimum heat-treatment conditions for melting using the results of studying the structure and properties of melts has been shown. This optimized heat treatment of melts is shown to be an effective method to improve the quality of alloys. [ABSTRACT FROM AUTHOR]

The paper reports the results of a physical modelling study of the production of a hypereutectic aluminium alloy to be used for making an alloy vapour source for operation in the magnetron. Within the study, targets from a hypereutectic aluminium-silicon alloy were made in laboratory conditions. Thus obtained material was subjected to heat treatment, porosity analysis, and the assessment of the microstructure and fitness for being used in the magnetron. The process of melting the hypereutectic Al-Si alloy was carried out at the Department of Foundry of the Czestochowa University of Technology. The investigation into the production of the alloy vapour source for the synthesis of the dielectric material from the hypereutectic aluminium alloy has confirmed. [ABSTRACT FROM AUTHOR]

The structure, phase composition and tribological properties of surface layers of hypoeutectic silumin after the complex processing including the electroexplosion alloying with the yttrium oxide powder in different regimes and the subsequent electron beam processing have been analyzed by the methods of modern physical material science. With respect to the initial silumin the ≈20-fold increase in the wear resistance and ≈1.5-fold decrease in the friction coefficient have been detected. The complex processing is accompanied by the formation of the multiphase submicro—nanocrystalline layer up to 80 μm in thickness enriched by yttrium and oxygen atoms responsible for the multiple increase in the wear resistance. At the complex processing according to the first regime of electroexplosion alloying (EEA) (Y2O3 powder mass—0.0589 g, discharge voltage—2.8 kV) with the subsequent electron beam irradiation, the major phase of the modified layer is the solid solution based on Al (≈71.2 mass %), the remaining phases are SiO2, YAlO3, YSi2. The 1.5-fold increase in the mass of Y2O3 powder at EEA and 1.1-fold decrease in the discharge voltage is accompanied by the increase in the quantity of phases, the significant (more than 2.5-fold) decrease in the content of the solid solution based on Al, the ≈2.2-fold increase in the content of silicon oxide, the presence of yttrium oxide and metallic yttrium. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Physics of Metals / Uspehi Fiziki Metallov is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The structural phase states and silumin's defect substructure of silumin hypoeutectoid composition subjected to electron beam processing with the following parameters: energy density—25 J/cm2, pulse duration—150 µs, number of pulses—3, pulsed repetition rate—0.3 Hz were analyzed by methods of modern physical material science. The irradiation of the surface leads to the melting of the surface layer, the structure formation of high-speed cellular crystallization of submicron dimentions and the repeated precipitation of the second phase particles. The cells formation of two types: those free from precipitations of the second phase and those containing the lamellar eutectic Al–Si was revealed. The cells are separated by the second phase interlayers containing the particles of Cu15Si14Al4Cu9, silicon and copper. As the distance from the surface of irradiation increases the layer containing the second phase inclusions of quasi—equilibrium shape are defined along with the crystallization cells. It is indicative of the occurance of the globularization processes of silumin's structure on electron beam processing. [ABSTRACT FROM AUTHOR]

By the method of modern physical material science (optic microscopy scanning and transmission electron microscopy) the analysis of structural phase states, the morphology of the second phase inclusions and defect substructure of Al-Si alloy (silumin) of hypoeutectic composition, subjected to electron beam processing was done with the following parameters: energy density 25-35 J/cm2, beam length 150 µs, pulse number - 3, pulse repetition rate - 0.3 Hz, pressure of residual gas (argon) 0.02 Pa. The surface irradiation results in the melting of the surface layer, the dissolution of boundary inclusions, the stricture formation of high speed cellular crystallization of submicron sizes, the repeated precipitation of the second phase nanodimentional particles. With the increased distance from the irradiation surface the layer containing the second phase inclusions of quasi-equilibrium shape along with the crystallization cells was revealed. It is indicative of the processes of Al-Si alloy structure globalization on electron beam processing. [ABSTRACT FROM AUTHOR]

The two-dimensional formulation and the methods of numerical experiments are used to analyze the peculiarities of the redistribution of the lines of a uniform electric field in the volume of molten metal at the interface of nanosized phases with conductivity different from that of the matrix. It is shown that the gradients of the electric and thermal fields are determined by the shape of the phase and the phase conductivity-matrix conductivity ratio. The analyzed surface effects are also determined by the location of the sector of the inclusion surface with the respect to the current lines. [ABSTRACT FROM AUTHOR]

Abstract—: The microstructure and nanomechanical properties of the Al-7% Si-1% Fe as-cast alloy produced by blowing oxygen into the melt have been studied. Blowing oxygen into liquid aluminum alloy results in the formation of Al2O3 nanoparticles, which increase the strength of the alloy after subsequent cooling and crystallization. Scanning electron and atomic force microscopy (EDS and EBSD analyses) have been used to examine the microstructure of the Al-7% Si-1% Fe alloy. The nanohardness and Young’s modulus of α-Al in microvolumes are measured using nanoindentation. Blowing oxygen into the melt has been found to significantly decrease the random scatter of Young’s modulus of α-Al. The results have been considered through the lens of modern knowledge of how composite materials of the aluminum matrix are strengthened. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Physics of Metals / Uspehi Fiziki Metallov is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)