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Depending on the specific alloy composition and iron content, iron can have various effects on aluminum alloys. This work examines the influence of varying Fe content on the Charpy impact, tensile, and hardness properties of cast AlSi7Mg0.3 alloy (356). The samples contained 0.11, 0.25, 0.42, and 0.65 wt% Fe levels. The instrumented Charpy V-notch impact tests, conducted according to the ISO EN 148-3 standard, provided data on maximum impact force, crack initiation, crack propagation, and total Charpy impact resistances. Tensile tests, performed according to EN ISO 6892-1 standard, evaluated the yield strength (YS), ultimate tensile strength (UTS), and elongation (%ε) values. Hardness and density measurements were also taken. Additionally, the fracture surfaces of Charpy V-notch and tensile test samples underwent optical macroscopic and scanning electron microscopic analysis to understand the effects of Fe content. The study revealed that as the Fe content in AlSi7Mg0.3 alloy increases, the tensile properties and Charpy impact resistances decrease. [ABSTRACT FROM AUTHOR]

This study investigated the mechanical properties of a series of Fe-Cr-Mn (Mo)-N alloys. The chromium content ranged from 16 to 18 mass%. The test alloys were produced by adding nitrided ferroalloys during melting in an induction furnace. Test specimens of each alloy were prepared for mechanical testing and microstructural observation. Tensile strength (TS) and elongation (EL) were determined. By increasing or decreasing the content of the chromium, it can directly affected on the values of the mechanical properties and the final microstructure. A series of experiments showed that increasing the chromium content by 1.46 mass% in the Fe-16Cr-8Mn (Mo)-N alloy led to a decrease in the TS value by 12% and in the EL value by 16.1%, while increasing the chromium content by 0.72 mass% in the Fe-16Cr-11Mn (Mo)-N alloy caused a decrease in the TS value by 6.1% and in the EL value by 16%. The chromium content of 16 mass % in the studied alloys was found to provide sufficient strength and a relatively high elongation value. The alloys can also contain a higher mass fraction of chromium, but to obtain a complete austenitic structure it is necessary to increase the content of manganese and nitrogen. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying some properties and structure of a quasi high-entropy alloy (QHEA) of the CoCrFeMnNi system melted with the use of ferroalloys. The paper presents the results of a study of some properties and structure of a quasi-high-entropy alloy of the CoCrFeMnNi system, smelted using low-carbon ferromanganese and ferrochrome. Chemical composition, strength and microhardness have been studied. The structure contains a small number of inclusions of silicate nature. The experimental alloy demonstrated properties close to the level of properties of a similar alloy melted with the use of pure metals by 5-fold remelting. The results obtained showed the possibility of partial replacement of pure metals with ferroalloys when smelting of QHEAs, which will positively affect their cost. [ABSTRACT FROM AUTHOR]

In this paper the influence introducing various plasticizers into an initial charge on the structure and properties of iron-based powder materials alloyed with copper is considered. It is shown that introduction of copper stearate into an initial powder mixture and warm mixing, pressing and subsequent sintering makes it possible to obtain low-porosity workpieces with relative porosity of 95%. Pores within the workpieces obtained have a small size of 10–15 microns and a rounded shape. Also, bending strength is determined for sintered samples of all the compositions of powder mixtures studied and the Rockwell hardness is determined on the C scale. Powder steels based upon mixtures have the best set of mechanical properties PZhRV 2.200.28 + 0.7 wt.% Br + 0.7 wt.% Cu + 1 wt. % StCu + warm mixing—hardness HRC 58. flexural strength 600 MPa PZhRV 2.200.28 + 1.4 wt.% Br + 1.4 wt.% Cu + 1.4 wt.% C + 1.0 wt.% StFe + warm mixing—hardness HRC 100, flexural strength 530 MPa [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology 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 primary focus of this paper is to review the latest developments in iron based amorphous/nanocrystalline high velocity oxy fuel coatings. The extensive development towards the enhancement in the mechanical properties such as micro‐hardness, compressive strength, adhesion strength etc. and comparative investigations are the key objectives set by the coating material scientist. The industrial application fields of iron alloy based coating are growing rapidly and owing to the rapid increase in industrial applications, there are many more advancements in the coating deposition techniques. In the present review, various factors influencing mechanical performance of high velocity oxy fuel coating material have been listed and ranked according to the level of influence. It can be concluded that the mechanical performance of coating materials is significantly influenced by coating parameters, including spray distance, oxygen fuel ratio, coating thickness, and number of layers. [ABSTRACT FROM AUTHOR]

Searching for alternatives to diversification of production facilities that do not require significant material and energy costs is relevant in the face of pressing external factors. One of the promising technological fields of alloy production in metallurgy is the application of aluminothermic processes of remelting of thermite charge consisting of secondary materials (scale, chips of ferrous and nonferrous metals), used to produce a wide range of metal products without significant costs associated with the reequipment of production units. The possibility of controlling the parameters of alloys and properties of the final metal product formed by aluminothermic processes is implemented primarily by reducing the temperature of the metal phase of the melt by introducing inert fillers into the composition of mixtures, as well as holding the melt in the crucible before casting. The chemical composition, structure, and physical and mechanical properties of iron-carbon alloys are significant in forming several operational characteristics. The paper presents experiments aimed at studying the effect of the initial components of thermite charge materials used to produce iron-carbon alloys in aluminothermic processes, as well as the melt holding time in a crucible before casting on the chemical composition, microstructure, hardness, strength indicators, and the fracture characteristics. The focus of experimental investigations is on industrial applications in the metallurgical and machine-building sectors. [ABSTRACT FROM AUTHOR]

The effect of additions of alloying elements (Mo and Ni), austempering time and thickness of the product section on the mechanical properties of industrial ductile iron of grade GGG-70 (EN-GJS-700-2) is studied. Standard keel blocks and crankshafts have been produced by static sand casting from unalloyed, alloyed with 0.2% Mo and 0.2% Mo + 0.6% Ni ductile iron. Austempering is carried out at 350 °C for 90, 120, 150, and 180 min in a salt bath. It is shown that the alloying has a significant effect on the ability of cast iron to austempering and its mechanical properties after heat treatment. Alloyed cast iron has the best combination of ultrahigh yield and tensile strength with high ductility. After austempering, crankshafts alloyed with 0.2% Mo + 0.6% Ni have a typical ductile iron ADI structure even in the thickest sections (58-mm-thick main bearing center) with a uniform hardness distribution. [ABSTRACT FROM AUTHOR]

Using the Al–2.5% Mg–1% Mn–0.4% Fe base alloy (wt %) as an example, the effects of calcium, scandium, and zirconium additives (at about 2.5, 0.1, and 0.2 wt %, respectively) on the strength of rolled sheets has been studied. Ingots of the alloy of the chosen composition and the hot and cold rolled sheets obtained from them were used as objects for the experimental study. Based on microstructural studies, it is shown that calcium binds iron into compact inclusions (presumably, into the Al10CaFe2 phases), which has a positive effect on the mechanical properties of the alloy, as well as on the technological plasticity during the rolling operation. Zirconium and scandium additives make it possible to form thermally stable nanoparticles of the Al3(Zr, Sc)–L12 phase, which is favorable for maintaining a partially unrecrystallized structure in cold rolled sheets during annealing at least up to 400°C. Using the alloy of the selected composition as an example, the fundamental possibility for producing sheet products from cast (unhomogenized) ingots with the properties of thermally hardenable alloys of the Al–Si–Mg–Mn and Al–Zn–(4.5)Mg–(1.5)Mn types without using quenching has been demonstrated. [ABSTRACT FROM AUTHOR]

A novel approach to austenite grain refinement was applied to quench and temper ductile iron in order to improve the tensile properties. Castings of two ductile iron alloys were intercritically (IC) austenitized near the upper critical temperature to produce a fine-grained lamellar austenite-ferrite structure and were subsequently quenched and tempered. The lamellar austenite + ferrite formed in the dendrite core region without forming a continuous network of austenite in the interdendritic regions. The austenite grain size was substantially finer than the polygonal austenite grain structure produced by conventional hardening above the critical temperature. In contrast to earlier researchers of IC austenitized DI who produced more ferrite by austenitizing at lower IC temperatures, the present study achieved higher austenite fractions and thus greater lamellar martensite contents after quenching. On tempering up to 540 °C (1000 °F), the supercritically heat-treated martensitic structures produced secondary graphite, whereas none was observed in the intercritically heat-treated materials. Differing upper critical temperatures and manganese and silicon contents were measured in the core and interdendritic regions for one of the as-cast irons. The resulting properties of the lamellar martensite and ferrite microstructure were determined and compared to those of conventional quench and tempered ductile iron with a fully martensitic microstructure. When the properties are compared to the minimum specifications for the Q&T grades of ASTM A536 Grade 120-90-02 and ISO 1083 Grade 900-2, the intercritically austenitized alloys exhibited the specified tensile properties with high ductility. [ABSTRACT FROM AUTHOR]

Deep cryogenic treatment has shown promise as a facile method of increasing the characteristics of many materials including alloys of iron, aluminum, and magnesium. However, there have not been any prior studies on its effect on the microstructure and thermal and mechanical properties of magnesium-based nanocomposites. In this study, a Mg/2wt.%CeO2 nanocomposite was processed using disintegrated melt deposition processing coupled with hot extrusion, followed by cryogenic treatment in liquid nitrogen for 24 h. The characterization results show increases in density (reduction in porosity), ignition temperature, compressive yield strength, compressive ductility, and microhardness. This study, for the first time, shows the significant relevance of deep cryogenic treatment in enhancing an array of properties of a magnesium-based nanocomposite that may be catalytic in improving its application spectrum. [ABSTRACT FROM AUTHOR]

The present study investigated the microstructure and mechanical properties of as-hot-rolled Fe 64 (CoCrNi) 36 (at.%) ferrous medium-entropy alloys (Fe-MEAs), demonstrating a remarkable 142 % enhancement in yield strength (YS) and a superior uniform elongation of 43.0 %, in comparison to the cold-rolled and annealed ones. The improvement of YS is attributed to dislocation strengthening, grain boundary strengthening, and hot rolling-induced defects such as stacking faults and Lomer-Cottrell (L-C) locks. Due to the enhanced yield stress, the pronounced transformation-induced plasticity (TRIP) effect supported the sustained uniform plastic deformation. These findings underscore hot rolling as an effective and straightforward strategy to reinforce Fe-MEAs. [ABSTRACT FROM AUTHOR]

The high cost of high- and medium-entropy alloys (H/MEAs) has limited their structural applications, leading to increased interest in cost-effective ferrous MEAs (Fe-MEAs), where microstructure and mechanical properties are strongly influenced by Fe content. In this study, we systematically investigated the microstructural evolution, mechanical properties and deformation mechanisms of Fe x (CoCrNi) 100-x (x = 25, 40, 50, 62, 64, 66, and71, at.%) MEAs. The results revealed that the constituent phases evolved from a single face-centered cubic (FCC) phase (Fe25, Fe40, and Fe50) to a mixture of FCC and body-centered cubic (BCC) phases (Fe62, Fe64, and Fe66), eventually forming a single BCC phase (Fe71). As the Fe content increased, the yield strength (YS) gradually decreased from ∼394.8 MPa for Fe25 to ∼206.0 MPa for Fe62, while the uniform elongation (UE) remained above 40 % for all alloys. Further increases in Fe content significantly enhanced strength, though at the cost of a substantial reduction in elongation. Fe71 exhibited a high YS of ∼831.0 MPa but with a UE of only ∼1.5 %. In addition to dislocation slip, deformation nanotwins (DTs) were observed in deformed Fe50, and deformation-induced martensitic transformation (DIMT) was detected in deformed Fe64. • A series of Fe x (CoCrNi)100-x medium-entropy alloys were obtained through arc-melting, cold rolling, and annealing. • The microstructure changed from a single FCC phase to FCC + BCC dual-phases, ultimately to a single BCC phase. • By adjusting the Fe content, various combinations of strength and ductility can be achieved. • With increasing Fe content, deformation twins and deformation-induced martensitic transformation occurred. [ABSTRACT FROM AUTHOR]

Iron is a cheap and environmentally friendly metal that is produced at the gigaton scale every year. While porous metals have long been used as filters in chemical processes and electrodes in functional devices, steel and iron‐based structures with highly tunable porosity have only recently been explored as sustainable, lightweight materials for a variety of structural, biomedical, and energy‐related applications. Here, an extrusion‐based 3D printing process is reported to manufacture steel‐ and iron‐based structures with ultrahigh porosity distributed over three hierarchical levels. Using particle‐stabilized foams as printing inks, pores are generated at multiple length scales by controlling the print path, the concentration of air bubbles in the ink, and the thermal reduction and sintering process of the metal oxide precursor particles. This enables the manufacturing of iron and iron‐based alloys with an elastic modulus above 300 MPa and a density below 1 g cm−3 while keeping the mechanical efficiency expected for porous structures. The potential applications of such hierarchical porous iron and iron alloys are illustrated by printing structures with tunable chemical compositions that are ultra‐lightweight, magnetoresponsive, and capable of spontaneously absorbing oil spills and of vaporizing liquids using low electric power. [ABSTRACT FROM AUTHOR]

Iron alloy based amorphous coating materials have enormous potential in wide range of applications such as petrochemical, aerospace, ocean, and electronic communications due to their better mechanical properties, chemical properties, magnetic properties and tribological properties. The industrial applications of coating are increasing rapidly due to many advancements in the material development and coating deposition techniques. The present paper reviewed the recent progresses in deposition technologies, development of new high order alloys and composite based coating materials. In this regard, change in microstructure, elemental composition, mechanical and tribological properties on performance of iron alloy based coating properties were presented. It can be concluded that the tribological properties of coating is dependent on pre‐coating and post‐coating factors. Pre‐coating factors include coating deposition techniques, coating layer thickness and coating parameters such as spray distance, oxygen flow rate etc. Post‐coating factors include microstructure, hardness, fracture toughness and adhesion strength. Therefore, multi‐criteria decision making techniques can be the best approach to find the optimum formulation of coating materials to achieve desired set of objectives under the conflicting criteria. [ABSTRACT FROM AUTHOR]

Medium entropy alloys (MEAs) are new emerging engineering alloys comprised of four principal elements and characterised by a low enthalpy of mixing and entropies of formation between 1 and 1.5 molar gas constant. They have high strength, wear, and thermal properties. Medium entropy alloyss have generated interest as an alternative material in the last two decades in nuclear, aerospace, and high strength engineering applications. In this research a medium entropy alloy Fe20Cr20Mn20Ni20Ti10Co5V5 with principal elements Fe, Cr, Mn, and Ni was fabricated using spark plasma sintering. The elemental powder mixture was sintered at temperatures of 870oC, 900oC, and 950oC under 35 bar pressure under an inert argon atmosphere for 45 minutes using an FCT Systeme GmbH spark plasma sintering machine. After sand blasting, the densities of the samples were measured before grinding, polishing, and etching for characterisation. Microstructure analysis was carried out using scanning electron and optical microscopy. Microhardness was measured using a Falcon 507 hardness tester, modulus using an Anton-Paar Nanoindenter, and wear using an Anton-Paar TRB3 Tribometer. The elements form a solid solution with presence of a hard µ phase and soft γ-phase were observed. The hardness of the alloys sintered at 870oC and 900oC were 397 and 424 Vickers respectively. The alloy that sintered at 950oC showed a hardness of 674 Vickers. After annealing the hardness increased to 736 Vickers. The modulus of elasticity and creep resistance increased after heat treatment at 700oC. The other alloys showed a decrease in hardness and other properties after annealing. Unlike in steels, where annealing reduces hardness, in this alloy annealing increased hardness at an appropriate temperature. The alloy Fe20Cr20Mn20Ni20Ti10Co5V5 MEA exhibited good thermal stability. Further work on the alloy will involve its crystallography and its feasibility for use in elevated temperature energy applications such as in fuel cells, turbines, and wear resistant machine components. [ABSTRACT FROM AUTHOR]

Multilayer iron-based superalloy FeCo45 was prepared on Q235 stainless steel by laser melting deposition (LMD) in this work, and effect of different orientations of the samples on microstructure, mechanical property and wear resistance were investigated. It was found that the structure of sample is composed of columnar crystals and cellular secondary dendrites, and the secondary dendrites exhibit smaller size in longitudinal section. The excellent mechanical properties of the alloy demonstrated the superiority of LMD technology. Affected by the degree of stress concentration and the difference in the crack direction, there is a difference in the tensile strength in the two directions. The ultimate tensile strength of the specimen sampled along the laser scanning direction is 1114.8 MPa, and the yield strength is 818.3 MPa; the ultimate tensile strength of the specimen sampled along the vertical laser scanning direction is 1077.1 MPa, and the yield strength is 758.5 MPa. Increased adhesive wear behavior led to wear resistance of the section perpendicular to the scanning direction decrease. In contrast, the section parallel to the laser scanning direction exhibits a smaller wear rate and better wear resistance. [ABSTRACT FROM AUTHOR]

Fe-25Cr-15Co (wt.%) permanent magnets were fabricated via selective laser melting (SLM) and in situ alloying from a blend of Fe, Cr and Co elemental powders. Under the optimal laser scanning process, the as-built Fe-25Cr-15Co alloy has a homogeneous composition distribution without defects such as holes or un-melted particles, and presents a single α phase with the bcc crystal structure. The density of as-built samples was 7.705 g/cm3 (the relative density is 99.32%). The preferred magnetic properties of the sample in the isotropic state were obtained as Hc = 22.84 kA/m, Br = 0.86 T and (BH)max = 7.98 kJ/m3. The hardness and yield strength of Fe-25Cr-15Co permanent magnets are above 331.5 HV and 800 MPa, respectively. The results of this study verified the feasibility of fabricating Fe-Cr-Co permanent magnets by SLM in situ alloying and can be extended to a wide range of applications that require complex shapes with variable magnetic circuit characteristics or gradient structures. [ABSTRACT FROM AUTHOR]

Heavy tungsten alloys are of great importance in the engineering and mining industries as well as the military and medical applications because of their stability at high temperatures, high strength and dense structures. The present study develops a novel technology for the production of heavy tungsten alloys via thermal treatment of nano-sized metal oxides based on simultaneous reduction and sintering processes. Heavy tungsten alloy (95W-3Ni-2Fe) was produced from the reduction of mixed nano-sized metal oxides precursor in H 2 at 1000 o C followed by sintering at 1350–1450 o C for 30–90 min. The reduced and sintered samples were characterized by XRD to follow up the crystallinity, total porosity measurement was used to find out the densification properties, the grain structure and morphology were examined by RLM and SEM attached with EDAX. Micro-hardness tester was also used to investigate the influence of sintering conditions on the grain densification. A fundamental study on the kinetics of reduction of mixed nano-sized metal oxides precursor was performed by isothermal and non-isothermal techniques. Both results from isothermal and non-isothermal tests were used to calculate the activation energy which was correlated with macro- and micro-structures to predict the corresponding reduction mechanism. However, the influence of sintering temperature and time on the crystallinity of the produced phases, grain structure, morphology, total porosity, pore-size distribution, bulk and apparent densities, and the hardness of sintered compacts was extensively investigated. The results revealed that the presence of NiO and/or Fe 2 O 3 in the mixed metal oxides precursor was very important to ease the reducibility of WO 3 as the metallic phases of Ni and/or Fe act as a catalyst for the reduction of WO 3. The rate of reduction proceeds faster in the following order: NiO > Fe 2 O 3 > mixed oxide > WO 3. In non-isothermal experiments, it was found that the heating rate has a considerable effect on the reduction of precursor, i.e., the lower the heating rate, the higher the degree of reduction. It might be reported that the use of nano-sized metal oxides particles in the fabrication of heavy tungsten alloys greatly affects the main properties of the produced alloy. With the increase in sintering time, larger sizes of dense grains were developed, and the matrix became denser as a result of sintering and re-crystallization effects. The higher the sintering time, the higher the grain densification and the less pores formed in the matrix. On the other hand, with the increase in the sintering temperature, the grain boundaries were well defined in which the grains were composed of tungsten metal and surrounded by inter-metallics. The higher the temperature, the higher the XRD peak intensities of metallic tungsten and intermetallics as a result of sintering and re-crystallization. • A novel approach for the manufacturing of heavy tungsten alloys from nano-sized powder is introduced. • A fundamental comprehensive study on the reduction kinetics of mixed oxide precursor containing W-Ni-Fe was demonstrated. • The mechanism of reduction of mixed oxide precursor containing W-Ni-Fe reduction was analyzed. • A correlation between the operational parametersof sintering processes and properties of heavy tungsten alloy was analyzed. [ABSTRACT FROM AUTHOR]

Biodegradable implant researches are enhancing nowadays, enduring challenges in programmed degradability and cytocompatibility with connecting tissues. These materials used to implanted, proliferate cellular interaction, degrade and replaced by regenerated natural bone in the living bodies. Distinctive metallic, ceramic and polymer materials were considered and found compatible, enhancing osteoblast and cellular response. Apart from magnesium, zinc and iron metals, alloys and composites are consistent due to their high load-bearing capability, controlled degradation and promising designed biomechanical properties. The properties of various degradable and non-degradable materials are studied here and compared with developed samples' biomechanical properties. The samples are prepared and fabricated using casting techniques and examined using tensile, compression, hardness and cellular tests. The results are found similar, thus concluded with comparable in-vivo results of previous researchers. Mg.Li and (Zn.Mg).Mn composition is found cytocompatible with programmable biomechanical properties, able to replace Ti-based alloys. [ABSTRACT FROM AUTHOR]

The first stage of this study investigates the precipitation of free ferrite from the austenite on fully austenitized ductile iron. Several sets of samples of low alloy ductile iron are fully austenitized and then cooled down to different temperatures and different times within the intercritical austeniteferrite-graphite phase field. Based on these results, heat treatment cycles aimed at obtaining microstructures composed of free ferrite and ausferrite are carried out. Tensile, impact and toughness tests are performed to characterize the mechanical properties. The results show that, related to the high strength austempered ductile iron grades, the best combinations of properties were obtained from the mixed structures composed of 5% free ferrite and 95% ausferrite, resulting from the austempering at 280°C. These amounts of free ferrite allow obtaining an increase of the elongation (about 50%) and impact toughness (about 10%) while the tensile strength and fracture toughness decrease by about 1.5 and 15% respectively. [ABSTRACT FROM AUTHOR]

AlSi10Mg is the most widely additively manufactured and commercialized aluminum alloy and has been used in this study to analyze the effect of heat treatment on its microstructure and mechanical properties. Although research indicates AlSi10Mg parts produced by selective laser melting have characteristically very fine microstructures, there is a need for more intensive study to comprehend the effect of heat treatment on the mechanical properties of this alloy by analyzing its microstructure. In this study, AlSi10Mg specimens heat-treated at varying temperatures were analyzed by optical and electron microscopes. Micro-indentation hardness and tensile tests were performed to evaluate mechanical properties while considering the specimen build orientation. Observation shows that it is nearly impossible to completely dissolve the evolved second phase silicon-rich particles, which may have significant effects on the mechanical characteristics. Electron microscopy images show the evolution of iron-rich particles in the Al matrix, which may have a significant influence on the mechanical properties of the alloy. [ABSTRACT FROM AUTHOR]

The deterioration of the refractory lining represents a significant problem for the smooth operation in the ferroalloys industry, particularly in the production of silicomanganese, due to the periodic requirements of substitution of the damaged refractory. Within this context, magnesia refractories are commonly employed in the critical zones of the furnaces used in silicomanganese production since the slag involved in the process has a basic character. The behavior of MgO–ZrO2 ceramic composites with different ZrO2 nanoparticles (0, 1, 3, and 5 wt.%) contents in the presence of silicomanganese slags is proposed in this manuscript. XPS, XRD and SEM–EDX were used to evaluate the properties of the ceramic composite against the silicomanganese slag. The static corrosion test was used to evaluate the corrosion of the refractory. Results suggest that corrosion is controlled by the change in slag viscosity due to the reaction between CaZrO3 and the melted slag. Besides, ZrO2 nanoparticles located at both triple points and grain boundaries act as a barrier for the slag advance within the refractory. The utilization of MgO refractories with ZrO2 nanoparticles can extend the life of furnaces used to produce silicomanganese. [ABSTRACT FROM AUTHOR]

The process of selective laser melting (SLM) is complex and instantaneous, which communicates with a variety of physical phenomena such as solid–liquid phase transition. The microstructure and material properties are favorable evidence to explain the SLM forming mechanism. In this paper, the forming properties of the iron-based alloy, titanium-based alloys, and aluminum-based alloys are discussed, which are relatively mature in research. The influence of processing strategy on the density and quality of metal specimens is briefly introduced. The research progress of microstructure and mechanical properties of metal specimens formed by SLM is mainly introduced. Also, the influence of processing parameters and heat treatment on the microstructure and the effect of microstructure on mechanical properties are summarized. The corrosion behavior of metal specimens formed by SLM is analyzed. Furthermore, the research development of copper-based alloys, shape memory alloys, and high-entropy alloys is presented. Finally, the problems encountered in the alloys forming process are described, and the future development direction has prospected. [ABSTRACT FROM AUTHOR]

The advantages of the Al–Ca–Mn–Fe alloys are their lightness, good ductility, high corrosion resistance, and excellent casting properties, but the main disadvantage is their low strength. Therefore interest in current work lies in improving the strength properties of these alloys though the severe plastic deformation method. The Al–4Ca–0.8Mn–(Fe) eutectic-type alloys with an iron content 0.5 and 1.3 wt% were processed by severe plastic deformation using the high-pressure torsion technique (HPT). HPT of the 20-mm diameter samples was carried out at room temperature through three revolutions. To characterize the samples we used the microstructural studies by an optical microscope, scanning microscope, and transmission microscope, the microhardness measurements, the hardening's thermal stability analysis, the tensile tests, and the electrical conductivity measurements. It was found that as a result of HPT, a bimodal, but predominantly nanocrystalline microstructure was formed in the alloys and a simultaneous improvement in strength (4–6.5 times) and relative elongation (1.1–1.7 times) was achieved while maintaining a moderately low electrical resistance. Increasing the iron content from 0.5 to 1.3 wt% in the alloy provides a smaller grain size and a higher level of strength after HPT. The microstructural mechanisms of increasing strength and ductility in the alloys with different iron content are discussed. The effect of post-processing annealing on the mechanical properties of the alloys was studied. • The Al–4Ca–0.8Mn–(0.5, 1.3)Fe (wt%) alloy was processed through HPT • A bimodal nanocrystalline structure with a low density of intracrystalline defects is formed. • Increasing the iron content from 0.5 to 1.3 wt% provides a smaller grain size and a higher strength. • HPT increases both strength and ductility. • 900 MPa-ultimate tensile strength and 3%-relative elongation were achieved. [ABSTRACT FROM AUTHOR]

Multi-scale Al7Cu2Fe and AlFeCu phases are formed in Al-Zn-Mg-Cu-Fe alloys after thermomechanical processing. These multi-scale particles significantly affect the size, morphology, and orientation of recrystallised grains and their corresponding mechanical properties. With increasing concentrations of iron-rich phase particles, the grain size in alloys is significantly reduced from 29.3 µm (0.0Fe wt.%) to 19.9 µm (0.2Fe wt.%) and 17.5 µm (0.4Fe wt.%). The volume fractions of copper, CubeND, and Q all decrease, and the R, Brass, and P textures form with high volume fractions in the #2 alloy. Both the yield and ultimate tensile strengths of the alloys decrease with an increasing iron-rich phase concentration. The highest r value (0.698) is obtained in the #2 alloy due to the improved microstructure and texture distributions from multi-scale iron-rich phases. Finally, the mechanisms of the iron-rich phase evolution, recrystallisation, and high formability in the alloys are introduced. [ABSTRACT FROM AUTHOR]

The use of ductile irons in thermo-mechanically loaded components is increasing, necessitating more knowledge of material properties at intermediate temperatures. A study of the mechanical properties of ductile irons at intermediate temperatures was conducted, investigating the effect of different pearlite fractions along with silicon content tests in fully ferritic microstructures. The effect of the pearlite fraction and silicon content on tensile and yield strength was measured at different temperatures, from room temperature to 450 °C. Models of tensile and yield strengths were developed based on those measurements. These resulting regression models were tested with data from the literature. Such models can be applied in various design tools, such as FEM calculations and in the optimisation of thermally and cyclic loaded ductile iron components. [ABSTRACT FROM AUTHOR]

The effects of substitution of Fe in the boron-rich Fe-B-C alloys, containing 10.0-14.0% B and 0.1-1.2% C, 0-5.0 % Cr, V, Mo or/and Nb (in % wt.), are studied with combined analysis of optical microscopy, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy. The microstructure of the master Fe-B-C alloys consists mainly of primary dendrites of Fe(B, C) solid solution and Fe2(B, C) crystals peritectically formed from Fe(B, C) phase and the rest of the melt. As found, chromium or vanadium have high solubility in the constituent phases of the Fe-B-C alloys, with preferential solubility observed in the Fe(B, C) dendrites, where Cr or V occupy Fe positions. The addition of Cr or V to the Fe-B-C alloys helps to modify their brittleness: while it slightly decreases microhardness values, addition of these elements notably improves the fracture toughness of the constituent phases. Molybdenum or niobium are shown to be present in secondary phases identified as Мо2В, Мо2(B, C) or NbB2, respectively. The level of Mo or Nb contents in the Fe(B, C) and Fe2(B, C) solid solutions and quantity of the observed secondary phases indicate a very small Mo and no Nb solubility in the constituent phases. The Mo or Nb enhances a hardness of the master Fe-B-C alloy due to secondary phases' precipitation. To enhance performance characteristics of the boron-rich Fe-B-C alloys, the 1.0-2.0% Cr, 0.5-1.0%V, 1.0-3.0% Nb, 1.0-3.0% Mo are simultaneously added to the master alloy. The properties improve due to the formation of Cr- and Vcontaining Fe2(B, C) and Fe(B, C) solid solutions as well as Mo- and Nb-based secondary phases. The developed multicomponent alloy is recommended as a filler of macroheterogeneous composite coatings for strengthening of parts working in abrasive or gas-abrasive media at elevated temperatures. [ABSTRACT FROM AUTHOR]

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Macro-segregation is an irreversible defect in non-ferrous alloy casts. This can only be significantly minimized by controlling the melt and its flow trajectory during casting. The study identified runner angle inclination as a critical parameter that impacts the development, size and volume of macro-segregation occurrence in binary alloys. The methodology entails variation of runner angles to include 90°, 105°, 120°, 135°, and 150° at a constant casting speed of 100mm/s being the optimum casting speed established in previous study. The casts microstructure was examined using both optical and electron microscopes complemented with energy dispersive spectrometry. Results show that runner position at 120° is the most appropriate for the casting of aluminium-zinc alloy as this gave a highly homogeneous distribution of solute element in the microstructure with corresponding improved mechanical properties [ABSTRACT FROM AUTHOR]

The DRECE method belongs to the severe plastic deformation (SPD) processes used for the refinement of sheet metal elements. A forming device used in this method is currently being installed in the workplace in the Centre of Advanced Innovation Technologies, VSB Technical University of Ostrava. In the present work the structural characteristics and fracture morphology of Ck55 carbon steel after the application of the DRECE method with a forming tool angle of 118° are presented. The microstructure results are linked to selected mechanical properties. The tensile, hardness, and fatigue tests are performed. The methodology of non-destructive residual stresses measurement in the carbon steel after the extrusion and application of tensile tests on small samples are important for their use in technical practice. The paper presents the original results of selected properties after the application of the DRECE method on Ck55 steel, which will be used in the future to assess the application of the DRECE method and to determine other directions of the processing of ferrous alloys and steels. [ABSTRACT FROM AUTHOR]