For the purpose of exploring a potential process to produce FeMn, the effects of microwave heating on the carbothermal reduction characteristics of oxidized Mn ore was investigated. The microwave heating curve of the mixture of oxidized Mn ore and coke was analyzed in association with the characterization of dielectric properties. The comparative experiments were conducted on the carbothermal reductions

This study investigated the hot corrosion performance of a dissimilar weldment of Ni-based superalloy and stainless steel joined by CO2-laser welding and improved by high-velocity oxy-fuel (HVOF) coating in a Na2SO4-60wt%V2O5 environment at 900°C. A dissimilar butt joint of AISI 321 and alloy 825 was fabricated by CO2-laser welding with low heat input after obtaining the optimum welding parameters

Pore structure is an important factor influencing coke strength, while the property of coke is essential to maintaining gas and liquid permeability in a blast furnace. Therefore, an in-depth understanding of the pore structure evolution during the graphitization process can reveal the coke size degradation behavior during its descent in a blast furnace. Coke graphitization was simulated at different

The formation of calcium titanate in the carbothermic reduction of vanadium titanomagnetite concentrate (VTC) by adding CaCO3 was investigated. Thermodynamic analysis was employed to show the feasibility of calcium titanate formation by the reaction of ilmenite and CaCO3 in a reductive atmosphere, where ilmenite is more easily reduced by CO or carbon in the presence of CaCO3. The effects of CaCO3 dosage

Despite the existence of conventional methods for recycling chips, solid-state techniques have become popular, whereby waste metals are directly recycled into consolidated products with the desired shapes and designs. We investigated the feasibility of recycling phosphor bronze chips through a hot extrusion process using aluminum powder as a metal binder for the fabrication of a metal-fiber-reinforced

A novel method for exfoliating graphite oxide (GrO) was implemented through the mass water absorption of a GrO—poly(ethylene glycol) (GrO—PEG) composite. The GrO—PEG composite was prepared by intercalating PEG into the lamellae of GrO, and the variation of the basal spacing was measured by X-ray diffraction analysis. The yield of graphene was measured with an ultraviolet—visible spectrophotometer,

The evolution of oxide inclusions during isothermal heating of 18Cr-8Ni stainless steel with yttrium addition at temperatures of 1273 to 1573 K was investigated systematically. Homogeneous spherical Al-Y-Si(-Mn-Cr) oxide inclusions were observed in as-cast steel. After heating, most of the homogeneous inclusions were transformed into heterogeneous inclusions with Y-rich and Al-rich parts, even though

(GO/TiO2)N (GO represents graphene oxide, and N represents the period number of alternate superposition of two dielectrics) one-dimensional photonic crystal with different lattice constants was prepared via the sol-gel technique, and its transmission characteristics for photocatalysis were tested. The results show that the lattice constant, filling ratio, number of periodic layers, and incident angle

Cold metal transfer plus pulse (C + P) arc was applied in the additive manufacturing of 4043 Al alloy parts. Parameters in the manufacturing of the parts were investigated. The properties and microstructure of the parts were also characterized. Experimental results showed that welding at a speed of 8 mm/s and a wire feeding speed of 4.0 m/min was suitable to manufacture thin-walled parts, and the reciprocating

A simple and novel technique for the preparation of anatase TiO2 nanopowders using natural ilmenite (FeTiO3) as the starting material is reported. Digesting ilmenite with concentrated H3PO4 under refluxing conditions yields a white α-titanium bismonohydrogen orthophosphate monohydrate (TOP), Ti(HPO4)2·H2O, which can be easily isolated via gravity separation from unreacted ilmenite. The addition of

The main aim of this study was to investigate liquation cracking in the heat-affected zone (HAZ) of the IN939 superalloy upon tungsten inert gas welding. A solid solution and age-hardenable filler metals were further studied. On the pre-weld heat-treated samples, upon solving the secondary γ′ particles in the matrix, primary γ′ particles in the base metal grew to “ogdoadically diced cubes” of about

Hydrogen metallurgy is a technology that applies hydrogen instead of carbon as a reduction agent to reduce CO2 emission, and the use of hydrogen is beneficial to promoting the sustainable development of the steel industry. Hydrogen metallurgy has numerous applications, such as H2 reduction ironmaking in Japan, ULCORED and hydrogen-based steelmaking in Europe; hydrogen flash ironmaking technology in

To produce a highly refined microstructure, several metals or alloys have been processed via equal-channel angular pressing (ECAP). In this work, the mechanical and microstructural changes of the 5083 aluminum alloy in H11 condition after processed by two ECAP passes were investigated. An ECAP H13 steel die with an inner angle (α) of 120° and outer curvature (β) of 20° was used. The microstructural

To better understand the stress-corrosion behavior of friction stir welding (FSW), the effects of the microstructure on the stress-corrosion behavior of the FSW in a 2198-T34 aluminum alloy were investigated. The experimental results show that the low-angle grain boundary (LABs) of the stir zone (SZ) of FSW is significantly less than that of heated affected zone (HAZ), thermo-mechanically affected

Biodegradable magnesium alloys as new biomedical implant materials have been extensively studied because of their notable biodegradability over traditional bio-inert metals. However, the extreme degradation rate of pure magnesium leads to the loss of its mechanical integrity before the tissue recovers completely. The solutions to this challenge are as follows: (1) purification, (2) alloying, (3) surface

The mineral transition and formation mechanism of calcium aluminate compounds in CaO-Al2O3-Na2O system during the high-temperature sintering process were systematically investigated using DSC-TG, XRD, SEM-EDS, FTIR and Raman spectra, and the crystal structure of Na4Ca3(AlO2)10 was also simulated by Material Studio software. The results indicated that the minerals formed during the sintering process

Interfacial Al-Ce-Cu-W amorphous layers formed through thermally driven solid-state amorphization within the (W+CeO2)/2024Al composite were investigated. The elemental distributions and interfacial microstructures were examined with an electron probe microanalyzer and a high-resolution transmission electron microscope, respectively. The consolidation of composites consisted of two thermal processes:

Froth flotation is the most effective industrial method used to separate fine-grained minerals. The main problem of complex ore flotation is the negative effect of interactions among minerals in slurry, leading to variation in surface properties during separation. In this review, studies on the interactive effect among minerals on the flotation of iron ores, magnesite ores, and scheelite ores are summarized

Nitrogen-rich Eu2+-doped Ca-α-SiAlON phosphors (Cam/2−xSi12−m−nAlm+nOnN16−n:xEu) were synthesized by a freeze-drying assisted combustion synthesis (CS) route. Fast-synthesized products with high purity and uniform particle morphology were confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The analysis of lattice parameters by comparison with empirical equations showed that

To enable the utilization of low-grade and high-sulfur bauxite, the suspension calcination was used to remove the sulfur and the activate silica minerals, and the calcinated bauxite was subjected to a desilication process in NaOH solution under atmospheric pressure. The desulfurization and desilication properties and mineralogical evolution were studied by X-ray diffraction, thermogravimetry-differential

Revealing grains and very fine dendrites in a solidified weld metal of aluminum-magnesium-silicon alloys is difficult and thus, there is no evidence to validate the micro- and meso-scale physical models for hot cracks. In this research, the effect of preheating on the microstructure and hot crack creation in the pulsed laser welding of AA 6061 was investigated by an optical microscope and field emission

Chemical vapor deposition (CVD)-grown diamond films have been developed as irradiation-resistant materials to replace or upgrade current detectors for use in extreme radiation environments. However, their sensitivity in practical applications has been inhibited by space charge stability issues caused by defects and impurities in pure diamond crystal materials. In this study, two high-quality CVD-grown

Investigating the reaction mechanism between slag and 9CrMoCoB steel is important to develop the proper slag and produce qualified ingots in the electroslag remelting (ESR) process. Equilibrium reaction experiments between molten 9CrMoCoB steel and the slags of 55wt%CaF2-20wt%CaO-3wt%MgO-22wt%Al2O3-xwt%B2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.0, 3.0) were conducted. The reaction mechanisms between molten 9CrMoCoB

Photoelectrochemical (PEC) water splitting offers the capability of harvesting, storing, and converting solar energy into clean and sustainable hydrogen energy. Metal oxides are appealing photoelectrode materials because of their easy manufacturing and relatively high stability. In particular, metal oxides prepared by electrochemical anodization are typical of ordered nanostructures, which are beneficial

Metal/intermetallic laminate composites can improve the mechanical properties of intermetallic materials using metal layers. In recent years, titanium aluminide intermetallics have received increasing attention due to their excellent performance properties, such as high melting point, high specific strength and stiffness, and good corrosion resistance. However, the low fracture toughness of Al3Ti alloys

This study focused on the comparison of the Pechini and sugar-based combustion synthesis methods to produce nano-zirconia. Zirconium hydroxide was utilized as metal precursor and citric acid, sucrose, and fructose were used as chelating agents, followed by calcination at 500, 600, and 700°C in air, respectively. Characterization was conducted by thermal analysis, specific surface area measurement,

Hydrostatic cyclic expansion extrusion (HCEE) process at elevated temperatures is proposed as a method for processing less deformable materials such as magnesium and for producing long ultrafine-grained rods. In the HCEE process at elevated temperatures, high-pressure molten linear low-density polyethylene (LLDPE) was used as a fluid to eliminate frictional forces. To study the capability of the process

FeNiCoCrTi0.5 coatings with different process parameters were fabricated by laser cladding. The macro-morphology, phase, micro-structure, hardness, and wear resistance of each coating were studied. The smoothness and dilution rate of the FeNiCoCrTi0.5 coating generally increased with the increase of specific energy (Es), which is the laser irradiation energy received by a unit area. FeNiCoCrTi0.5 coatings

Additive manufacturing (AM) of Ni-base superalloy components can lead to a significant reduction of weight in aerospace applications. AM of IN718 by selective laser melting results in a very fine dendritic microstructure with a high dislocation density due to the fast solidification process. The complex phase composition of this alloy, with three different types of precipitates and high residual stresses

An improvement in the corrosion resistance of alloys at elevated temperature is a factor for their potential use in gas turbines. In this study, CoNiCrAlY has been coated on the L605 alloy using air plasma spray (APS) and high-velocity oxygen fuel (HVOF) coating techniques to enhance its corrosion resistance. Hot corrosion studies were conducted on uncoated and coated samples in a molten salt environment

Cemented paste backfill (CPB), a mixture of tailings, binder, and water, is widely and extensively used for the recovery of mineral resources, the prevention of ground subsidence, and the management of mine waste. When installed, the CPB is subjected to complex environmental conditions such as water content, temperature, and power, which have a significant impact on its efficiency. Thus, this study

Multi-layered functionally graded (FG) structure Ni-W/Er2O3 nanocomposite films were prepared by continuously changing the deposition parameters, in which the Er2O3 and W contents varied with thickness. The microstructure and chemical composition of the electrodeposited Ni-W/Er2O3 films were determined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The anti-corrosion

6061 aluminum alloy semisolid billet was prepared by the equal-channel angular processing (ECAP)—recrystallization and partial (RAP) process (a combination of equal-channel angular processing and recrystallization and partial remelting). The effects of different process parameters on the alloy microstructure were studied and the quantitative relationship between the process parameters and microstructure

The bainitic transformation of the steels with different mass fractions of N, ~0.002% and 0.021%, was observed in situ by using high-temperature metalloscope. Micrometer- and nanometer-sized aluminum nitride (AlN) particles were found in the steel with 0.021% N. Grain boundaries, the interior of the grains, and AlN particles were used as initial nucleation sites of bainitic ferrite, and bainitic ferrite

This study introduced a novel fabrication of aluminum—carbon nanotube (CNT) composites by employing bulk acoustic waves and accumulative roll bonding (ARB). In this method, CNT particles were aligned using ultrasonic standing wave in an aqueous media, and the arrayed particles were precipitated on the aluminum plate substrate. Then, the plates rolled on each other through the ARB process with four

The original version of this article unfortunately contained two mistakes due to the PDF file conversion through different softwares. The presentation of Figs. 2 and 4 was incorrect. The correct versions are given below:

Nanostructured ZnFe2O4 was synthesized by the heat treatment of a mechanically activated mixture of ZnO/α-Fe2O3. X-ray diffraction (XRD) and differential thermal analysis (DTA) results demonstrated that, after 5 h of the mechanical activation of the mixture, ZnFe2O4 was formed by heat treatment at 750°C for 2 h. To improve the characteristics of ZnFe2O4 for adsorption applications, the chemical activation

The aim of this study is to evaluate the effect of various molar ratios of glycine to chromium salt (Gly: Cr) and different current densities on the corrosion and wear behaviors of Cr(III) electroplated coatings. The morphology and thickness of the coatings were investigated by scanning electron microscopy. The wear properties of the coatings were studied using pin on disk and hardness tests, while

Alkaline sulfur-containing lixiviants, including thiosulfate, polysulfides, and alkaline sulfide solutions, stand out as a promising class of alternatives to cyanide because of their low toxicity, high efficiency, and strong adaptability. In this paper, we summarized the research progress and remaining challenges in gold extraction using these noncyanide reagents. After a brief introduction to the

The present study aimed to investigate the durability and microstructure evolution of road base materials (RBM) prepared from red mud and flue gas desulfurization fly ash. The durability testing showed that the strength of RBM with the blast furnace slag addition of 1wt%, 3wt% and 5wt% reached 3.81, 4.87, and 5.84 MPa after 5 freezing–thawing (F–T) cycles and reached 5.21, 5.75, and 6.98 MPa after

Column leaching experiments with ion adsorption-type rare earth ores for different lixiviant concentrations and different column heights were carried out. A mathematical model of column leaching was constructed based on the experimental data. Two parameters (a and b) in the model were determined according to the following methodology: the ore column was divided into several units; each unit was treated

A new process for preparing high-purity iron (HPI) was proposed, and it was investigated by laboratory experiments and pilot tests. The results show that under conditions of a reduced temperature of 1075°C, reduced time of 5 h, and CaO content of 2.5wt%, a DRI with a metallization rate of 96.5% was obtained through coal-based direct reduction of ultra-high-grade iron concentrate. Then, an HPI with

The effect of graphene oxide (GO) and reduced graphene oxide (RGO) nanosheets on the microstructure and mechanical properties of welded joints of mild steel was evaluated by flux-cored arc welding. GO was synthesized by the Hummer's method and was reduced under hydrothermal conditions at a pressure of 1.1 MPa at 180°C for 12 h. 1, 3, and 10 mg/mL paste fillers were used in GO and RGO, and applied to

We investigated whether the vertical roller mill can be efficiently used in the beneficiation of low-grade magnesite and whether it can improve upon the separation indices achieved by the ball mill. We conducted experiments involving the reverse flotation and positive flotation of low-grade magnesite to determine the optimum process parameters, and then performed closed-circuit beneficiation experiments

Ni–48.5at%Ti thin films were irradiated in the austenite phase by different energy-level protons at a dose rate of 1.85 × 1012 p/(cm2·s), and the total dose was 2.0 × 1016 p/cm2. The microstructures of the thin films before and after irradiation were evaluated by transmission electron microscopy (TEM) and grazing-incidence X-ray diffraction (GIXRD), which showed that the volume fraction of Ti3Ni4 phase

Carbonated decomposition of hydrogarnet is one of the vital reactions of the calcification-carbonation method, which is designed to dispose of low-grade bauxite and Bayer red mud and is a novel eco-friendly method. In this study, the effect of the silica saturation coefficient (x) on the carbonation of hydrogarnet was investigated from the kinetic perspective. The results indicated that the carbonation

Li-ion batteries (LIBs) have demonstrated great promise in electric vehicles and hybrid electric vehicles. However, commercial graphite materials, the current predominant anodes in LIBs, have a low theoretical capacity of only 372 mAh·g-1, which cannot meet the ever-increasing demand of LIBs for high energy density. Nanoscale Si is considered an ideal form of Si for the fabrication of LIB anodes as

The effect of carbonation on the chloride resistance of low-carbon steel and two Cr-bearing alloy steels in simulated concrete pore solutions was investigated. The chloride threshold values of steels were determined on the basis of corrosion potential (Ecorr) and polarization resistance (Rp). Moreover, the chloride-induced corrosion behavior of steels was evaluated using electrochemical impedance spectroscopy

The mechanical properties and wear resistance of the ultrafine bainitic steel austempered at various temperatures were investigated. Scanning electron microscopy (SEM) and X-ray diffraction were used to analyze the microstructure. The worn surfaces were observed via laser scanning confocal microscopy and SEM. Results indicated that, under low austempering temperatures, the mechanical properties differed

The efficient development and utilization of high-phosphorus oolitic hematite is of great strategic significance for the sustainable supply of iron-ore resources in China. In this paper, the mechanism of high-temperature pretreatment for enhancing the effect of iron enrichment and dephosphorization in the magnetization roasting-leaching process was studied by X-ray diffraction (XRD), vibration sample

Mechanical activation (MA) of malachite was carried out by dry planetary grinding (DPG) and wet Isa grinding (WIG) methods. When the rotational speed was increased to 400 r/min in DPG, the specific surface area of malachite reached the maximum and the particle size reached the minimum of 0.7–100 µm. Agglomeration occurred between mineral particles when the rotational speed was increased to 580 r/min

Dual-phase accelerated cooling (DPAC) was applied to X80 pipeline steel to obtain its microstructure with different amounts of bainite and ferrite. The microstructure, hardness, and polarization behaviors of the steel, cooled to different temperatures, were investigated. Results showed that, with decreasing cooling temperature, the amount of polygon ferrite (PF) increased while that of acicular ferrite

The effect of rolling temperature on both two- and single-phase regions and annealing in a temperature range of 700–950°C on the microstructure and mechanical properties of Ti—5Al—4V—2Fe—1Mo alloy was investigated. The results indicated that the best balance of strength and ductility is obtained by rolling in the two-phase region due to the globularization of the alpha phase and increase in its volume

Abstract The present paper deals with the investigation of microstructure and high-temperature hot corrosion behavior of high-velocity oxy fuel (HVOF)-produced coatings. Two powder coating compositions, namely, Ni22Cr10Al1Y alloy powder and Ni22Cr10Al1Y (80wt%; microsized)-silicon carbide (SiC) (20wt%; nano (N)) powder, were deposited on a T-22 boiler tube steel. The hot corrosion behavior of bare

Abstract Aiming at the problem of negative segregation under a bloom surface, a coupling macrosegregation model considering electromagnetic field, flow, heat, and solute transport was established based on the volume average method to study the effect of in-mold electromagnetic stirring (M-EMS) on the negative segregation under the bloom surface. In the model, the influence of dendrite structure on

Abstract To ensure the quality of heavy plate products as determined by ultrasonic inspection, it is necessary to effectively control defects such as cracks and shrinkage cavities in heavy plates. Generally, some defects such as large size cracks exist due to insufficient deformation in the center of traditionally rolled plates. Compared with the traditional rolling process, gradient temperature rolling

Abstract Coalfield fires are considered a global crisis that contributes significantly to environmental destruction and loss of coal resources and poses a serious threat to human safety and health. In this paper, research related to the initiation, development, and evolution of coalfield fires is reviewed. The existing detection and control techniques of coalfield fires are also reviewed. Traditional

Abstract The machine-learning approach was investigated to predict the mechanical properties of Cu—Al alloys manufactured using the powder metallurgy technique to increase the rate of fabrication and characterization of new materials and provide physical insights into their properties. Six algorithms were used to construct the prediction models, with chemical composition and porosity of the compacts

Abstract The effect of austempering time after the bainitic transformation on the microstructure and property in a low-carbon bainite steel was investigated by metallography and dilatometry. The results showed that by prolonging the austempering time after the bainite transformation, the amount of large-size martensite/austenite islands decreased, but no significant change of the amount and morphology

Abstract Al composites are of interest due to their appropriate ratio of strength to weight. In our research, an Al/Co3O4 nanocomposite was generated using a sintering technique. The powders of Al with various Co3O4 nanoparticle contents (0wt%, 0.5wt%, 1.0wt%, 1.5wt%, 2.0wt%, and 2.5wt%) were first blended using planetary milling for 30 min, and compressed in a cylindrical steel mold with a diameter