The theory of stable dendritic growth within a forced convective flow field is tested against the enthalpy method for a single-component nickel melt. The growth rate of dendritic tips and their tip diameter are plotted as functions of the melt undercooling using the theoretical model (stability criterion and undercooling balance condition) and computer simulations. The theory and computations are in

The formation mechanism of porous TiAl3 intermetallics from Ti-75 at.% Al powder compact was explored through a continuous sintering process. The exothermic behavior, temperature changes and open porosity were investigated by ranging the sintering temperature from 600°C to 700°C. Results show that a thermal explosion (TE) occurs once the sample temperature reaches to 675°C, upon which it rapidly climbs

Based on the density functional theory (DFT) method, the behavioral mechanism of carbon addition to promote TiO2 chlorination is investigated based on the adsorption energy, charge transfer and density of states (DOS) in the coadsorption system of a C4 cluster and a Cl2 molecule on the TiO2 (110) surface. The investigated results indicate that C4 cluster bonding with an O atom on the TiO2 (110) surface

A carbothermic reduction of complex Kalimantan ilmenite (FeTiO3) with palm kernel shell biomass as a reducing agent using regular electric and simulated solar heating has been investigated. The results demonstrate that palm kernel shell biomass can be used as an alternative reductant for the carbothermic reduction. Incomplete ilmenite dissociation was observed at 1000°C and 1100°C for 60 min reaction

Mudan Liu’s name appeared incorrectly on the original publication of this article. It appears correctly here.

Herein, an 2024-Al/AZ31-Mg laminated composite was prepared by hot-pressing sintering using powder metallurgy integrated forming and sintering. Effects of sintering temperature on the microstructure and mechanical properties of the matrix and interface of Al/Mg laminated composites were investigated. The mechanisms of interface formation and evolution were obtained. The results indicate that with sintering

Calcium aluminum phosphate cement (CAPC) requires a practical composition for biological applications. This research aims to investigate the effect of aluminum hydroxide sources (aluminum hydroxide, boehmite, and hydratable alumina), where SECAR 71 cement and phosphoric acid are in the composition, regarding the mechanical, biological, and microstructural properties of CAPC. In vitro assessments were

Titanium-bearing magnetite ore is generically defined as magnetite with > 1% titanium dioxide (TiO2) and is usually vanadium-bearing. The iron and titanium occur as a mixture of magnetite (Fe3O4) and ilmenite (FeTiO3) with vanadium oxide usually occurring within the solid solution of the titanium-bearing magnetite phase. These ores are currently widely processed in blast furnaces via modified ironmaking

Kirkendall micro-voids observed within ϵ-Cu3Sn or at the bulk Sn solder/Cu interface are undesirable imperfections in solder joints in electronic interconnections that significantly decrease the reliability of the joint. Recent studies have shown that micro-alloying could alter these interfacial reactions and improve the mechanical properties. In this study, we investigated the Cu-Ga-Sn phase equilibria

Lead zirconate (PZ) nanopowders were synthesized by the treatment of precursors with high-energy ball milling for a relatively short time. The effects of ball milling time and rotational speed on the produced nanomaterial were investigated. The calcination temperature of the ball-milled powder was determined from the thermogravimetric analysis (TGA) and the differential scanning calorimetry (DSC) results

A series of Si-Mn/C core–shell composites as anode materials is synthesized via a hydrothermal method combined with heating treatment. X-ray diffraction, Raman spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy analysis are used to investigate the crystal structures and chemical compositions of all as-prepared composites. With the increase

To elucidate the effects of FeS on the carbothermic reduction of ilmenite, a series of tests were conducted using non-isothermal thermogravimetric analysis at heating rates of 10°C/min, 15°C/min, 20°C/min, and 25°C/min. The Malek method was used to analyze the reduction mechanism and obtain a kinetic model, and the Starink method was used to calculate the apparent activation energy. The morphology

Herein, dross formation (D) in used beverage can (UBC) scrap bales was investigated in laboratory-scale experiments to understand the reactions of solid can coating residues with aluminum melts. The experimental conditions were chosen according to a multi-chamber furnaces process, in which thermal pretreatment and submerged melting of the scrap bales are combined. The thermal pretreatment results show

This work focuses on ultrasonic melt treatment (UST) in a launder upon pilot-scale direct chill (DC) casting of 152-mm-diameter billets from an AA6XXX alloy with Zr addition. Two casting temperatures (650°C and 665°C) were used to assess their effect on the resulting microstructure (grain size, particle size, and number density). Structure refinement results show the feasibility of UST in the DC casting

Liquid-state interfacial reactions of p-type (Bi,Sb)2Te3 thermoelectric (TE) material with Sn and Sn-3.0 wt.%Ag-0.5 wt.%Cu (SAC305) solders, respectively, were examined at 250°C on a commercial highly orientated (Bi,Sb)2Te3 substrate with a (110) soldering plane. For the reactions with Sn, the initial reaction phase was the porous SnTe intermetallic compound (IMC). Then, a dense SnTe layer with many

Due to its superior chemical stability, mechanical strength, light weight, and flexibility, polyimide (PI) has been widely used as a polymeric substrate of flexible printed circuit boards such as flexible copper clad laminates (FCCLs). The development of an adhesiveless dual-layer structure is imperative for the application of FCCLs in globalized 5G consumer electronics. In this work, autocatalytic

The aim of this work is to produce α-alumina particles from aluminum (Al) dross via leaching–precipitation–calcination processes. In the leaching test, the effects of parameters such as the temperature, NaOH concentration, and time were investigated based on the Taguchi approach. In addition, the effect of the particle size on the Al extraction rate was determined. The Al extraction rate ranged from

The effect of using a pulsed electric current to remove impurity iron from molten polysilicon was investigated. Using optical microscopy observation and area statistics of iron-rich content, it was found that iron tends to accumulate at the bottom of an ingot under the action of a pulsed electric current. A new separation mechanism is proposed, based on the decreased solubility of iron in polysilicon

Laser powder bed fusion is a metal additive manufacturing technique that has received significant scientific and industrial attention over the past decades. However, the quality and reproducibility of parts manufactured by this technique is still a problem. Overcoming this issue requires an understanding of multiple complex physical phenomena which occur simultaneously during the process. This work

We describe a process of chlorination of fly ash with either chlorine gas or calcium chloride, which successfully decomposes mullite and permits the extraction of a number of industrially useful, acid-soluble compounds. As a guide for determining optimal input molar ratios and temperatures, the Gibbs energies for three groups of reactions of major fly ash components between 973 K and 1473 K were calculated:

Composites of hydroxyapatite (HA) and Bioglass® (BG) have been prepared to evaluate their physical, chemical, and biochemical characteristics. Several researchers have attempted to prepare these types of composites to combine the appealing characteristics of BG (such as high bioactivity and osteoinduction) with those of HA. The sintering temperature for the HA–BG composite system used in previous studies

A method for the reuse of aluminum (alloy 5754) sawing chips as a starting material for manufacturing aluminum matrix syntactic foams by powder metallurgy is described. In the tested samples, spherical Ni-superalloy hollow particles were used to increase the closed porosity of specimens up to 50 wt.%. Spark plasma sintering was used to consolidate the specimens. Only the sample with 30% hollow particles

Ultrasonic vibration has been applied to improve the penetration of adhesive into the anodized layer, thereby enhancing the strength of carbon fiber-reinforced plastic/aluminum alloy bonding joints with anodizing pretreatment. The ultrasonic vibration-assisted adhesive bonding process was designed by orthogonal experiments, then verified experimentally. The strengthening mechanism was studied by analyzing

Computational modeling has emerged as a powerful tool in estimating many of the exciting material properties of low-dimensional systems such as nanotubes. There also exists a variation in the reported strength data of nanotubes using different computational techniques. This issue is attributed to the uncertainty in determining the correct thickness of the nanotubes, a fundamental parameter to estimate

Developing a highly efficient method to recover uranium from metallurgical waste can alleviate the shortage of uranium resources. However, the dissociation of uranium is limited by the ultrafine uranium particles embedded in the gangue. Dilute alkali pretreatment is an effective process to improve the dissociation rate of uranium. Moreover, the leaching kinetics of the pulverized gangue during the

A novel recycling process of spent LiNi0.6Co0.2Mn0.2O2 cathode materials has been developed. The process comprises acid leaching followed by regeneration of LiNi0.6Co0.2Mn0.2O2 materials with carbonate co-precipitation. Spent LiNi0.6Co0.2Mn0.2O2 materials were effectively leached in sulfuric acid and hydrogen peroxide solution. The leaching efficiencies were 97.8% for Li, 98.1% for Ni, 96.5% for Co

The objective of this work is to investigate the effects of electromagnetic external fields on the spatial distribution of alloying elements and the mechanical properties of Al-Mg-Si alloy prepared using twin-roll casting. The formation mechanism of macro/microsegregation and mechanical properties were examined, and the results indicated that the amount of centerline segregation defects was significantly

In the present study, we investigated the properties of graphene oxide/Ti6Al4V(GO/TC4) nanocomposites with different laser powers (120 W, 140 W, 160 W, 180 W and 200 W) prepared by selective laser melting (SLM). The temperature distribution was simulated by ANSYS Mechanical APDL 15.0 software, and the microhardness, surface compactness and tribological properties were characterized using a Vickers

Powder casting was developed to produce metal components with near-theoretical density from low-cost, loose powder using hydrogen sintering and phase transformation. This has significant implications for non-beam metal additive manufacturing processes (e.g., metal extrusion AM, binder jetting, and ordered powder lithography), which produce green parts with relatively low densities. Additionally, powder

Although a significant amount of technical, commercial, and academic resources have been invested in laser and electron beam-based additive manufacturing (AM) of metals and alloys over several decades, challenges and limitations associated with repeated local melting and processing complexity along with the cost of equipment and operation have sparked interest in research on solid-state AM methods

Conducting experiments in an inert shielding-gas environment limits the likelihood for experiencing significant mass loss or compositional shifts due to differential relative evaporation. Species-specific evaporation is proven to be below prescribed limits and near-real time monitoring of the potential for exposure is shown to be an effective tool to ensure astronaut safety. The activity coefficients

This work explores the impact of thermally preprocessing recycled austenitic stainless-steel powder for solid-state cold spray metal additive manufacturing with a focus on increasing deposition quality and coating density while maintaining mechanical integrity. The recycled stainless-steel scrap was gas-atomized using a novel mobile foundry manufactured by MolyWorks Materials Corporation. The powder

In this study, we investigated the transformation kinetics of martensite → reverted austenite in 18 wt.% grade 300 Ni maraging steel. The kinetics was evaluated based on the in situ synchrotron x-ray diffraction data collected during isothermal heat treatment at 570°C. The onset of transformation martensite → reverted austenite was detected after ~ 5 min of aging. The austenite fraction increased as

Pure, low-oxygen zirconium samples have been observed to nucleate a solid phase under conditions during which the sample was expected to remain liquid. This phenomenon was first seen during Spacelab Mission MSL-1R (materials science laboratory) experiments and has since also been observed in the International Space Station (ISS) electromagnetic levitation (EML) facility on a different sample. Current

With the gradual decrease in the grade of copper ores being processed, copper concentrates have become more complex with higher impurity and gangue content. This trend has had a detrimental effect on smelters as they have to increase throughput to maintain copper metal production, while increasing operating costs due to processing the increased amounts of secondary products (slag, acid) and stabilizing

The recyclability of 316L stainless steel powder in the binder jetting process has been determined. The powder characterization results demonstrated a 22% increase in the number of coarse particles (> 30 µm) and an 18.2% reduction in the number of small particles (< 10 µm) after recycling up to 16 times. A few elongated and irregular-shaped particles were found after recycling, possibly due to particle

This paper reviews the progress of solidification processing of cast metal matrix composites over 50 years since their original discovery, which was first published in 1969. Current use of metal matrix composite components in automotives, railways, space, computer hardware, and recreational equipment are presented. Some cast metal matrix composites which are discussed include aluminum reinforced with

Silver/graphite oxide/chitosan and silver/reduced graphene oxide/chitosan organic–inorganic nanocomposite materials have been synthesized by a precipitation procedure using graphite oxide or reduced graphene oxide acting as stabilizer, silver acetate as Ag0 precursor, sodium hydroxide as reducing medium, and chitosan as covering agent. The synthesized nanomaterials were thoroughly characterized and

Copper smelting open-circuit (CSO) dust contains various valuable metals, such as copper, lead, and zinc, as well as undesirable toxic elements such as arsenic. Thus, the comprehensive recovery of valuable elements from CSO dust is highly significant from both economic and environmental perspectives. In this review, pyrometallurgical, pyrohydrometallurgical and hydrometallurgical processes are evaluated

Aluminum–silicon alloy reinforced with titanium diboride particles (2 wt.%, 5 wt.%, and 7 wt.%) were successfully synthesized using a stir-casting method. Dipotassium titanium hexafluoride and potassium tetrafluoroborate salts were used to obtain an in situ titanium diboride phase in a molten matrix. These in situ composites have shown significant improvements in their mechanical properties, such as

The influence of the cooling rate on the precipitation behavior of gamma prime (γ′) in a newly developed Co-based superalloy has been investigated by using differential scanning calorimetry. In addition, changes to the γ′ precipitate morphology and size were analyzed by scanning electron microscopy. It was observed that increasing the rate at which the alloy was cooled from high temperatures increased

A critical evaluation and optimization of the Na2O-SiO2-As2O5 system was conducted using the CALPHAD method to obtain a consistent set of Gibbs energy functions for all solid, liquid and gas phases within the system. The available and reliable thermodynamic and phase diagram data of the unary As2O5 system and binary Na2O-As2O5 system were all well reproduced in the present optimization. The phase diagram

Inclusion agglomeration and flotation during levitation melting in a cold crucible were investigated. The morphology, number and chemical composition of inclusions were characterized by scanning electron microscopy and transmission electron microscopy with energy-dispersive x-ray spectroscopy analysis. In the billet, inclusions were mainly single mixed inclusions (oxide as the core, nitride as the

Graphene nanoplatelets (GNPs) were introduced as conductive additives in the lithium iron phosphate (LiFePO4) composite cathode material through a facile slurry approach to study the effect on battery performance at high current rates (C-rates). The incorporation of GNPs helps to create a flexible three-dimensional conductive network through a plane-to-point connection with the LiFePO4 particles. Comparison

The β-phase stability and deformation behavior patterns of two β-type titanium bioalloys, viz. Ti-Nb-Ta-Zr (TNTZ) type and Ti-Nb-Ta (TNT) type, processed by a series of intense plastic deformations have been investigated theoretically and experimentally. Firstly, theoretical analysis was carried out, including an estimation of possible deformation mechanisms based on the electronic parameters of the

Li3/8Sr7/16−xAxZr1/4Nb3/4O3 (A = Ca, Ba) ceramics were prepared by the conventional solid-state reaction method. The structures of prepared ceramic materials changed from cubic perovskite to tetragonal tungsten bronze with increasing barium (Ba) content as indicated by the x-ray diffraction (XRD) patterns. Li3/8Sr7/16−xBaxZr1/4Nb3/4O3 (x = 0.05, 0.10) samples are mixtures of perovskite and tetragonal

The study of submerged entry nozzle clogging dynamics mainly focuses on the interface wetting behavior. So as to understand the effect of the interface electric field on the wetting behavior between the immersion nozzle and the molten steel, electrowetting experiments and field industrial tests were performed. The results show that the wettability between the iron droplet and the nozzle constituent

In this work, 0.5 mol L−1 HCl and 0.13 mol L−1 FeCl3 have been used as leaching solution of industrially wasted copper at room temperature. Copper recovery from the leaching solution has been studied by batch electrodeposition at room temperature and either by using different constant current densities or by pulsing the current. The deposits obtained at 20 mA cm−2 show low efficiencies and are mainly

Controlled diffusion solidification (CDS) is a promising casting process. It depends on mixing two precursor alloys that have different masses and temperatures. After the mixing, anomalous grains with many morphologies form in the CDS microstructure. The formation, solidification, and stability of the anomalous grains are investigated in the present study. The high impingement velocity between the

Lubrication-free deep drawing with metal matrix composite (MMC) tool surfaces leads to scores and grooves due to particle penetration into the formed sheet metal, and results in high local contact pressure in the radius of the deep drawing tool. To improve on this, the ratio of contacting area to total area must locally be increased in high-load regions of the tool surface. Multi-stage laser melt injection

Corresponding author designation is missing for Jin Chen in the original publication of this article.

To improve our understanding of prehistoric casting methods and materials, simulations for copper arsenic (As-Cu) alloys with up to 15 wt.% As were calculated. Cooling curves and the secondary dendritic arm spacings (SDAS) for the alloy were plotted and calculated, respectively, under non-steady-state conditions with a time-stepping procedure for prehistoric mold materials (e.g., quartz sand, sandstone

Michael J. Zehetbauer’s name appears incorrectly in the original electronic version of this article. It has been corrected here.

The electrochemical performance of fluorinated multiwalled carbon nanotubes (F-MWCNTs) as a new type of conductive agent for Li–SnO2 batteries has been studied. Multiwalled carbon nanotubes (MWCNTs) were fluorinated to obtain F-MWCNTs with core–shell structure (fluorocarbon atomic ratio C/F = 1:1). The unique tubular structure of the F-MWCNTs allows more Li+ ions and electrons to enter the channel

Metallurgical simulation and evaluation of the resource efficiency of whole production processes are of key importance for sound environmental impact assessments. Exergy dissipation analysis is suitable to quantify the theoretical limits of a process and pinpoint hotspots for improvements along the value chain. Production of NdFeB permanent magnets is evaluated herein using a simulation-based life

With the rapid increase of photovoltaic (PV) system production and installation, the recycling of end-of-life PV modules has become an important issue. In this paper, the recovery of Si by separating the layers of end-of-life PV modules using KOH-ethanol solution was investigated. Compared with traditional swelling or dissolving reagents (such as benzene and trichloroethylene), KOH-ethanol is a green

High-quality silica was prepared from copper smelting slag through a method of in situ modification. The effects of the addition of an amount of polyethylene glycol-6000 as a modifier, the modification temperature and the modified endpoint pH on the particle size and specific surface area of the silica were systematically studied. It has been shown that the particle size, specific surface area, and

Almost every metal mass product goes through a blanking process. Especially when processing aluminum, adhesive wear is the main determinant of cost efficiency. Many investigations on wear-influencing factors have been conducted so far, but one major determinant is almost unnoticed, thermoelectric phenomena. Due to the Seebeck effect, thermoelectricity arises in every blanking tool. Recently published

One of the technical challenges with the recovery of valuable materials from end-of-life (EOL) photovoltaic (PV) modules for recycling is the liberation and separation of the materials. We present a potential method to liberate and separate shredded EOL PV panels for the recovery of Si wafer particles. The backing material is removed by submersion in liquid nitrogen, while the encapsulant is removed

The recovery of crystalline silicon from diamond-wire cutting waste with microwave-assisted hydrochloric acid leaching was studied. The experimental results indicated that the optimum conditions for the hydrochloric acid concentration, liquid–solid ratio, leaching time, leaching temperature and particle size were 2 mol/l, 6:1 ml/g, 10 min, 100 °C and 98 nm, respectively. Under optimal conditions, the