The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community. For this purpose, deep eutectic solvents (DESs) are valued as electrolytes for their advantages of low operating temperature and wide electrochemical windows. At present, there is large amount of literature on this emerging field, but there are no specialized reviews of these studies. Here, after a brief introduction of DESs’ concept and history, we comprehensively reviewed the lastest progress on the metal/alloy electrodeposition in DESs. Additionally, we discussed the key influence factors of the electrodeposition process and analyzed the corresponding mechanisms. Based on these, we emphasized the importance of the establishment of predictive models for dealing with the challenges in large-scale applications.

Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale, a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-industrial trials were conducted. Vanadium in raw ore mainly exists in sericite, roscoelite, and limonite, predominantly in the forms of V(III) and V(IV). Under the conditions of a feed rate of 30 kg/h, an air flow rate of 28.0 m³/h, an O₂ flow rate of 4.0 m³/h, and a temperature of 900 °C in both the suspension furnace and fluidized reactor, the vanadium-bearing mica underwent dehydroxylation and transformed into illite-montmorillonite. These changes disrupted the crystal structure of mica, facilitating vanadium extraction. Compared to direct acid leaching, curing- leaching demonstrates better performance in vanadium extraction. Under the conditions of curing temperature of 130 °C, acid dosage of 40 wt.%, curing time of 6 h, and leaching time of 3 h, a V₂O₅ leaching efficiency of 83.92% was achieved.

The microstructure and mechanical properties of 2524 Al alloy after quenching in liquid nitrogen (LN₂) were investigated by TEM and compared with those of cold water quenching. The results show that the LN₂ quenching process effectively induces the formation of dislocation loops. These loops become large and unevenly distribute after aging for 15 min. Furthermore, such loops become rapidly immobilized by the precipitation of coarse S phases after 1 h aging. The alloy quenched in LN₂ demonstrates superior peak hardness and displays a more rapid response to subsequent aging treatments compared with the cold water-quenched one. Despite the short aging time, LN₂-quenched sample achieves tensile strength of 488 MPa. This enhanced strength is attributed to the strengthening effect of numerous finely dispersed Guinier-Preston-Bagaryatsky (GPB) zones, in conjunction with the inhomogeneous formation of S phase on the dislocation loops.

The angular deviations and influential factors of Burgers orientation relationship (BOR) in Ti-6Al-4V and Ti-6.5Al-2Zr-1Mo-1V alloys were investigated by optical microscope (OM), scanning electron microscope (SEM), electron backscattered diffraction (EBSD) and high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM). A spherical center angle model was introduced to calculate the angular deviations from the ideal BOR between α and β phases. The results indicate that α and β phases in α colonies of both alloys do not follow the perfect BOR during β→α phase transformation, with angular deviation values less than 3°. Through detailed microstructure characterization, the broad face of α/β interfaces viewed along two different electron incident directions shows the atomic-scale terrace-ledge structure, and many dislocations are observed within α and β phases and near α/β interfaces. Further studies reveal that the angular deviations mainly originate from lattice distortions caused by dislocations in α and β phases and lattice mismatches at α/β interfaces.

To explore high-performance cathode materials for aqueous ammonium ion batteries (AAIBs), vanadium- based Prussian blue analogue composites (VFe-PBAs) were prepared by hydrothermal coprecipitation method to enhance the reversible storage of NH₄⁺. Benefiting from the stable three-dimensional structure and spacious gap position, VFe-PBAs-2 cathode displays excellent electrochemical activity and rate performance, achieving a high specific capacity of 84.3 mA·h/g at a current density of 1000 mA/g. In addition, VFe-PBAs-2 cathode also shows impressive long-term cycle durability with 85.2% capacity retention after 3×10⁴ cycles at 5000 mA/g. The synthesized cathode materials combined with the high electrochemical activity of vanadium ions significantly promote the rapid transfer of NH₄⁺. Furthermore, NH₄⁺ embedding/extraction mechanism of VFe-PBAs-2 cathode was revealed by electrochemical kinetics tests and advanced ex-situ characterizations. The experimental results demonstrate that vanadium-modified VFe-PBAs-2 as a cathode material can remarkably improve the capacity, electrochemical activity and cycling stability of AAIBs to achieve high performance NH₄⁺ storage.

High Nb β/γ-TiAl (HNBG) intermetallics and Ni-based superalloy (IN718) were diffusion-bonded using pure Ti foil interlayer under pulse current. The microstructure, element segregation, and mechanical properties of HNBG/Ti/IN718 joint were investigated. The effect of Ti interlayer on microstructure and mechanical properties of the joint was discussed. The typical microstructure of HNBG/Ti/IN718 joint was HNBG//β/B2, τ₃-NiAl₃Ti₂//α₂-Ti₃Al// α-Ti+δ-NiTi₂, β-Ti//δ-NiTi₂//β₂-(Ni,Fe)Ti//Cr/Fe-rich η-Ni₃Ti, η-Ni₃Ti, α-Cr, δ-Ni₃Nb//η-Ni₃Ti, γ-Ni, δ-Ni₃Nb//IN718. The gaps and Kirkendall voids exhibited a gradual disappearance with increasing bonding temperature. The mechanism of Cr, Fe and Nb elements segregation was that NiTi phase hindered the diffusion of them. The nano-indentation results demonstrated that diffusion zones on IN718 alloy side had higher hardness. The maximum shear strength of the joint (326 MPa) was achieved at bonding parameters of 850 °C, 20 min and 10 MPa. The fracture occurred in Zones IV and V, and the fracture modes were brittle fracture and cleavage fracture. The introduction of Ti interlayer resulted in improved microstructure and enhanced bonding strength of the joint.

The service performance of Al alloy sheets can be improved by controlling the rolling temperature. In this study, the corrosion resistance of Al-Mg-Mn-Sc alloy sheets was enhanced through cryorolling (CR). The corrosion resistance of the CR samples with 50% rolling reduction was superior to that of the room-temperature rolled (RTR) samples. After the sensitization treatment (ST), the maximum intergranular corrosion (IGC) depth for the CR samples was 35.2 μm, while it was 53.9 μm for the RTR samples. Similarly, the mass losses were 56.89 and 73.11 mg/cm² for the CR and RTR samples after ST, respectively. In addition, the impedance modulus of the CR sample was more than twice that of the RTR sample. Superior pitting resistance can be attributed to the thicker passivation film and the Al₆(Mn,Fe) phases being broken and interspersed in CR samples. Furthermore, the sub-grains, shear bands, dispersive Al₃(Sc,Zr) phases, fewer high-angle grain boundaries and high-density dislocations in the CR samples impeded the continuous precipitation of the β (Al₃Mg₂) phase along grain boundaries while promoting its formation inside grains instead. These microscopic characteristics significantly reduced the electrical coupling effect between β phase and the Al matrix, leading to a considerable decrease in IGC occurrence.

The effect of high pressure on the microstructure and microsegregation of Mg-11Al (mass fraction, %) alloys was studied through experiments and first-principles calculations. The results show that the Al content in the initial solid phase is high owing to the high solute partition coefficient and the large undercooling in the alloys solidified under pressures of 4-6 GPa, and the Al content in the initial solid phase increases with the increase of pressure. Consequently, the total amount of excess solute in the liquid phase in the final solidification stage decreases with increasing pressure, thus decreasing or suppressing the eutectic transformation. Furthermore, the microstructure of the alloys solidified under pressures of 5-6 GPa is a fine-grained solid solution, consisting of grains with high solubility of Al atoms and grain boundaries with abundant Al solutes. As the pressure increases, the grain boundary doping energy of Al atoms decreases, while their grain boundary segregation energy of Al atoms increases, and the charge density between the Mg—Al (Mg) bonds also rises. Therefore, the stability of the microstructure is improved, and the bond strength of grain boundaries is enhanced.

X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to systematically investigate the impact of rapid cold stamping on microstructural evolution and mechanical properties of spray-formed Al-Zn-Mg-Cu alloys under ambient conditions. The results reveal that the dislocation density increases with successive cold stamping passes, the volume fraction of the secondary phase (Mg(Zn,Cu,Al)？) increases from 15.64% to 23.94%, and the average size decreases from 1.41 to 0.75 μm. The pinning effect of the secondary phases on dislocations promotes a significant transformation from low-angle grain boundaries to high-angle grain boundaries, resulting in the average grain size decreasing from 5.75 to 0.97 μm. The strength and hardness of the samples increase with successive cold stamping passes, which is attributed to the synergistic effects of dislocation strengthening, grain boundary strengthening, and secondary phase strengthening.

A heterogeneous structure composed of elongated primary α and secondary α grains with a size of 670 nm was produced by subjecting the bimodal microstructure of a titanium alloy to hot rolling, annealing, and aging treatments. This heterogeneous structure exhibited significantly improved strength owing to a combination of heterogeneous deformation-induced strengthening and dislocation strengthening. A short-duration high-temperature heat treatment facilitated a synergistic enhancement of yield strength and elongation at both room temperature and 650 °C. The fracture elongation at room temperature and 650 °C increased by 36.7% and 130.4%, respectively, compared with that of bimodal microstructure. The stacking of geometrically necessary dislocations with a single slip system at the phase boundary and the longer effective slip length of the dislocations are the reasons for the significant improvement in elongation. The elongated primary α phase in lamellar bimodal microstructure, composed of multiple primary α grains, has better resistance to the anti-fatigue crack initiation effect.

A ZM51 magnesium alloy joint with high intensity and thermal conductivity was fabricated using friction stir welding (FSW) followed by aging heat treatment (AG). During the FSW process, β′₁ and β′₂ phases formed in the heat-affected zone (HAZ), yet new phases were absent in both the stirring zone (SZ) and thermal mechanical affected zone (TMAZ). After AG, numerous β′₁ and β′₂ phases emerged in the SZ and the TMAZ of the joint, while only the β′₂ phase precipitated in the HAZ. Due to precipitation strengthening, the average microhardness, yield strength and ultimate tensile strength of the joint reached up to 98%, 94% and 88% those of the base metal (BM), respectively. Notably, basal slip , and twinning at and were more prevalent in TMAZ, contributing to the joint’s fracture. Furthermore, the precipitation of β′₁ and β′₂ phases enhanced the joint’s thermal conductivity, averaging 121.7 W/(m·K), being 112% that of BM.

The influence of refining flux composition, refining time, refining temperature, and addition amount on the microstructure and mechanical properties of Mg-9Li-3Al-1Zn alloy was investigated with orthogonal experimental design. The flux purification process for Mg-Li alloys was optimized and the most effective ternary flux composition was identified. Results indicate that flux purification significantly mitigates Li loss during smelting by forming a protective surface layer that reduces Li oxidation and evaporation. The optimal flux composition is LiCl？LiF？CaF₂ in a 3？1？2 mass ratio, with a flux addition of 3%, refining temperature of 720 °C, and holding time of 10 min. The elongation of alloy improves to 16.2% after refinement, while the enhancement in strength remains marginal.

Metallic glass matrix composites (BMGCs) with compositions of [(Zr_0.5Cu_0.5)_0.925Al_0.07Sn_0.005]_100-xTa_x (atomic fraction, %, x=3, 5, 7) were successfully prepared via dealloying in metallic melt. The reinforcing phase in these alloys has core-shell hybrid structure with Ta-rich particles as core and B2-CuZr as shell. In this method, the dealloyed Ta from Zr-Ta pre-alloys maintained in solid state and aggregated to form the fine Ta-rich phase in the final products. This effectively decreases the size of Ta-rich phase compared with that prepared via conventional arc-melting, where the Ta-rich phase was formed through dissolving and precipitation. Among the three compositions, [(Zr_0.5Cu_0.5)_0.925Al_0.07Sn_0.005]₉₅Ta₅ showed the highest plastic strain of 11.2%, much higher than that of the arc-melted counterparts (4.3%). Such improvement in mechanical properties was related with the refined core-shell hybrid reinforcing structure, which could hinder the rapid propagation of main shear band more efficiently and cause them to branch and proliferate at the interface.

To overcome reliance on molds and the difficulty of fabricating complex geometries with traditional C/C composites, direct ink writing (DIW) with UV/heat dual curing was employed to produce high-performance C/C composites. The rheological properties of the composite inks were systematically analyzed to assess the effects of phenolic resin (PR) and carbon fiber (CF) content. Results show pronounced shear-thinning behavior and strong thixotropy—both essential for stable DIW. Additionally, UV/heat curing behavior was characterized to provide theoretical insights for optimizing curing parameters. Notably, CF addition is found to significantly attenuate UV light penetration compared to pure PR. As CF content increases, the critical UV irradiation energy rises sharply from 68.47 to 911.19 mJ/cm², necessitating precise adjustments to curing parameters. Preforms were pyrolyzed in a carbon tube furnace to examine pore-formation characteristics, and chemical vapor infiltration (CVI) was applied to filling the resulting pores, yielding C/C composites with a flexural strength of 115.19 MPa.

The size and distribution patterns of bubbles within a laboratory-scale coarse-particle flotation column were examined using a high-speed camera-based dynamic measurement system. The effects of operational parameters such as superficial water velocity, air-flow rate, and frother dosage on bubble-size and distribution characteristics were investigated. This study aims to provide theoretical support for enabling fluidized-bed flotation within coarse-particle flotation columns. The results show that negative pressure for air inspiratory and bubble formation is generated by passing a high-speed jet through a throat, and the greatest number of bubbles are observed under natural inspiratory state at an air-liquid ratio of 1？3-1？2.5. Increasing the air-flow rate transforms the bubble diameter distribution from a peaked distribution to a more uniform distribution. Furthermore, the frother narrows the range of bubble-size distribution. A positive correlation exists between the bubble Sauter diameter and air-flow rate, with the bubble Sauter diameter bearing a negative correlation with the superficial water velocity and frother concentration.

In order to develop a marine engineering material with excellent mechanical properties and corrosion resistance, a novel non-equiatomic Co_1.5CrFeNi_1.5Ti_0.6 high-entropy alloy (HEA) was fabricated through mechanical alloying and spark plasma sintering. The results revealed that the sintering temperature significantly affected the microstructure and phase composition of the HEA owing to the diffusion rate, homogenization, and sluggish diffusion effect of metal atoms. At sintering temperatures below 1050 °C, HEA mainly consisted of face-centered cubic (FCC), Ni₃Ti (ε), Ni_2.67Ti_1.33 (R), and Fe-Cr (σ) phases. The microstructure of alloy comprised coarse dendritic crystals, whose content and size gradually decreased with increasing sintering temperature. However, the HEA sintered above 1100 °C contained only fine equiaxed crystals. HEA sintered at 1100 °C featured only the FCC solid solution, while the ε-phase precipitated at temperatures above 1150 °C. At a sintering temperature of 1050 °C, the alloy microstructure consisted of short rod-like dendrites and fine equiaxed crystals. This alloy achieved the highest yield strength of 1198.71 MPa owing to the effects of precipitation strengthening and grain boundary strengthening. Meanwhile, HEA sintered above 1050 °C exhibited significantly improved corrosion resistance. Considering the microstructure, mechanical, and corrosion properties, 1050 °C was identified as the optimal sintering temperature for Co_1.5CrFeNi_1.5Ti_0.6 HEA.

The vacuum volatilization kinetics of Pb in In-Pb solder was investigated. The results indicate a significant increase in the vacuum volatilization rates of Pb, 25In-75Pb, 40In-60Pb, and In with increasing temperatures from 923 to 1123 K, system pressure of 3 Pa and holding time of 30 min. The mass transfer coefficients and apparent activation energies of Pb and its alloys were determined at various temperatures. Additionally, a kinetics model was developed to describe Pb vacuum volatilization in high-temperature melts. It is obtained that the vapor mass transfer is the factor limiting the vacuum volatilization rates of Pb and In–Pb alloys under the above specified conditions.

Based on the properties of antimony (Sb) and arsenic (As), a method was proposed to enhance gold recovery during iron matte smelting. The impact of Sb and As on gold enhancement capture was investigated using an exclusion method. The results demonstrated that both Sb and As significantly improved the gold recovery rate. As the Sb or As content increased, the gold recovery rate increased. The enhancement effect of Sb was better than that of As, and the optimal results were achieved through the synergistic effects of Sb and As. Under optimized conditions, the gold recovery rate reached 97.12%, whereas the gold content in the slag decreased to 1.70 g/t. Sb captured and aggregated free gold as an Au-Sb alloy, whereas As-Fe alloy also captured free gold. The growth of the gold-captured phase size enhanced the settling velocity, thereby promoting gold recovery.

A P-wave velocity model was built in the central southern of the Tanlu Fault based on double-difference tomography. The results suggest the presence of a low-velocity anomaly extending from the surface to a depth of 25 km around the Tanlu and Feixi Faults, representing fault-related fluids caused by partial melting. The relocated earthquakes indicate a significant concentration of seismic activity above 20 km around the Tanlu and Feixi Faults, suggesting that prominent fault systems possibly serve as conduits for the upward migration of deep minerals. The proposed geodynamic model, supported by geological and geophysical data, suggests that the migration of deep mineralized materials extends along the Tanlu Fault. The obtained results serve as a crucial foundation for elucidating the intricate process of mineralization in the central southern segment of the Tanlu Fault, thereby enhancing comprehension regarding the interaction among ore body formation, fault fluids, localized melting, and seismic activity.

Ga₂O₃ is considered a potential anode material for next-generation lithium-ion batteries due to its high theoretical capacity and unique self-healing capability. To develop a novel preparation method and in-depth understanding of the electrochemical reaction mechanism of Ga₂O₃, a brand-new liquid-liquid dealloying strategy was exploited to construct porous α-Ga₂O₃ nanowire networks. Profiting from the well-designed porous structure, the material exhibits impressive cycling stability of a reversible capacity of 603.9 mA·h/g after 200 cycles at 1000 mA/g and a capacity retention of 125.2 mA·h/g after 100 cycles at 0.5C when assembling to Ga₂O₃//LiFePO₄ full cells. The lithiation/delithiation reaction mechanism of the porous Ga₂O₃ anodes is further revealed by ex-situ Raman, XRD, TEM measurements, and density functional theoretical (DFT) calculations, which establishes a correlation between the electrochemical performance and the phase transition from α-Ga₂O₃ to β-Ga₂O₃ during cycling.

The effect of W-doping on the structure and properties of TiAlSiN coatings was investigated through scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and nanoindentation. Tungsten doping in the coatings forms both substitution solid solution of Ti and/or Al in TiAlN and W simple substance. W-addition improves the surface quality of the coatings. Ti_0.46Al_0.45Si_0.09N, Ti_0.43Al_0.46Si_0.08W_0.03N, and Ti_0.41Al_0.46Si_0.07W_0.06N present similar hardness of (29.1±0.4), (29.7±1.1), and (30.2±1.0) GPa, respectively. During annealing, Ti_0.41Al_0.46Si_0.07W_0.06N achieves peak hardness of (35.3±1.0) GPa at 1100 °C, whereas those of Ti_0.46Al_0.45Si_0.09N and Ti_0.43Al_0.46Si_0.08W_0.03N are only (33.1±0.8) and (33.9±0.8) GPa at 1000 °C. Furthermore, moderate W-addition (3 at.%) upgrades the oxidation resistance of TiAlSiN. After oxidation at 1000 °C for 10 h, the oxide thicknesses of Ti_0.46Al_0.45Si_0.09N, Ti_0.43Al_0.46Si_0.08W_0.03N, and Ti_0.41Al_0.46Si_0.07W_0.06N are ~0.70, ~0.52, and ~0.90 μm, respectively.

The microstructure and mechanical properties of the Ti-5Al-5Mo-5V-1Cr-1Fe (Ti-55511) alloy under different strains were investigated through the design of step-shaped die forging. The results indicate that continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) occur in the high strain region. The orientation of the grains produced by CDRX is random and does not weaken the fiber texture. á100？-oriented grains expand gradually with increasing strain, thereby enhancing the strength of {100} texture. Significant anisotropic mechanical properties are observed in the large strain region and analyzed through in-situ tensile experiments. When the loading direction is parallel to the longitudinal (L) direction, strain concentration is observed near the dynamically recrystallized (DRXed) grains and inside grains oriented along á100？, leading to crack initiation. Furthermore, the small angle between the loading direction and the c-axis hinders the activation of prismatic and basal slip, thereby enhancing the strength. When the loading direction is parallel to the short transverse (ST) direction, cracks are initiated not only within grains oriented along á100？, but also at the grain boundaries. Regarding impact toughness, the elongated β grains in the L direction enhance the resistance to crack propagation.

Elements (As, Bi) and (Cu, Fe) exhibiting two typical segregation behavior in liquid Sb alloys were selected as solute atoms for analysis. Ab initio molecular dynamics (AIMD) simulations were employed to study the molten Sb alloy at different temperatures. By analyzing its pair correlation function (PCF), bond pairs, bond angle distribution function (BADF), and Voronoi polyhedron (VP), the short-range order (SRO) of the alloy was investigated. In the Sb melt, the solute atoms Cu and Fe, which have smaller distribution coefficients, exhibit a stronger affinity for Sb than the solute atoms As and Bi, which have larger distribution coefficients. The BADF of As and Bi with larger distribution coefficients shows a lower probability of small-angle peaks compared to large-angle peaks, whereas the BADF of Cu and Fe with smaller distribution coefficients exhibits the opposite trend. The BADF reveals that Sb-As and Sb-Bi approach pure Sb melt, while Sb-Cu and Sb-Fe deviate significantly. Compared to Sb-Cu and Sb-Fe, the Sb-As and Sb-Bi systems exhibit more low-index bonds, suggesting weaker interactions and more disorder. The VP fractions around As and Bi atoms are lower than those around Cu and Fe, and the VP face distributions around As and Bi are more complex. There are differences in the VP around different solute atoms, primarily due to the varying bond pair fractions associated with each solute atom. Fe has the smallest diffusion coefficient, primarily due to its compact local structure.

Different from the current measurement methods for Young’s modulus of metal materials, the Young’s modulus of intermetallic compounds (IMCs) was obtained by a non-destructive method based on Brillouin light scattering (BLS) in this paper. The single-phase regions of CoSn, CoSn₂, Cu₃Sn and Cu₆Sn₅ phases required for BLS test were obtained by applying long-term thermal stabilization through adjusting temperature gradient. The volume fractions of the corresponding phases near the solid-liquid interfaces of the samples were 98.3%, 94.2%, 99.6% and 95.9%, respectively. All the independent elastic coefficients and Young’s moduli of IMCs were obtained by Brillouin scatterometer. The Young’s moduli of CoSn, CoSn₂ and Cu₃Sn and Cu₆Sn₅ phases obtained through the present method are 115.0, 101.7, 129.9 and 125.6 GPa, respectively, which are in a good agreement with the previous experimental results. Thus, the effectiveness of BLS in measuring the Young’s moduli of IMCs in bulk alloys is confirmed.

The Cu/1010 steel bimetal laminated composites (BLCs) were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties. The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions, percentage spread, and cladding ratios. The formation of strong texture induces larger strength of the rolled samples, and as the volume fraction of 1010 steel is larger in Route-A, its strength is consistently greater than that in Route-B. The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion, inducing dislocation density gradient when the rolling reduction is low in Route-A. The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain, while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.

Additive manufacturing (AM) technology has emerged as a viable solution for manufacturing complex- shaped WC−Co cemented carbide products, thereby expanding their applications in industries such as resource mining, equipment manufacturing, and electronic information. This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides. The fundamental principles and classification of AM techniques are introduced, followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides. These techniques are classified as either direct AM technology (DAM) or indirect AM technology (IDAM), depending on their inclusion of post-processes like de-binding and sintering. Through an analysis of microstructure features, the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology, such as binder jet printing (BJP), which integrates AM with conventional powder metallurgy.

Some active metal oxides (Al₂O₃, TiO₂, and Cr₂O₃) were selected as dopants to the Al₂O₃-based ceramic shells for investment casting of K417G superalloy. The effects of dopant types and contents (0, 2, 5, and 8 wt.%) on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment. The results show that increasing the Al₂O₃ doping contents (0−8 wt.%) reduces the porosity (21.74%−10.08%) and roughness (3.22−1.34 μm) of the shell surface. The increase in Cr₂O₃ dopant content (2−8 wt.%) further exacerbates the interfacial reaction, leading to an increase in the thickness of the reaction layer (2.6−3.1 μm) and a decrease in the wetting angle (93.9°−91.0°). The addition of Al₂O₃ and TiO₂ dopants leads to the formation of Al₂TiO₅ composite oxides in the reaction products, which effectively inhibits the interfacial reaction. The increase in TiO₂ dopant contents (0−8 wt.%) further promotes the formation of Al₂TiO₅, which decreases the thickness of the interfacial reaction layer (3.9−1.2 μm) and increases the wetting angle (95.0°−103.8°). The introduced dopants enhance the packing density of the shell surface, while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.

The dependence of shrinkage porosities on microstructure characteristics of Mg−12Al alloy was investigated. The distribution, morphology, size, and number density of shrinkage porosities were analyzed under different cooling rates. The relationship between shrinkage porosities and microstructure characteristics was discussed in terms of temperature conditions, feeding channel characteristics, and feeding capacity. Further, the feeding behavior of the residual liquid phase in the solid skeleton was quantified by introducing permeability. Results show a strong correlation between the solid microstructure skeleton and shrinkage porosity characteristics. An increase in permeability corresponds to a declining number density of shrinkage porosities. This study aims to provide a more complete understanding how to reduce shrinkage porosities by controlling microstructure characteristics.

The effect mechanism of electroshock treatment (EST) on microstructure evolution and mechanical property variations of Ti−8Al−1Mo−1V alloy was investigated. The results show that EST results in the phase transformation from the acicular secondary α_s to β phase. While the EST time is 0.12 s, the acicular martensitic phase (α_M) precipitates. The results of electron backscattered diffraction (EBSD) reveals that the average grain size decreases from 3.95 to 2.53 μm after EST, indicating that the grains are refined, and the significant recrystallization behavior and martensitic transformation occur. The orientation distribution reveals a more uniform distribution of texture, which is caused by the variation of crystal orientation after the phase transformation. The compression fracture behavior of materials indicates that EST significantly enhances the yield strength while reduces the fracture strain. The improvement of yield strength is mainly attributed to the precipitation of martensitic phase. All results indicate that EST is an effective approach for manipulating the microstructure and optimizing the texture distribution of titanium alloys.

The radon control mechanism of Na₂O·nSiO₂−CaCl₂ modified soil was studied through the laboratory simulation experiment of tailing covering radon control. The radon exhalation rate (J) is negatively correlated with the coverage thickness (H), and it has a non-linear relationship with the temperature. The moisture content variation rate of the covering soil significantly decreases, which helps to reduce soil damage and enhance the resistance of the covering soil to ambient temperature interference. The formation of silicic gel and C−S−H gel effectively optimizes the pore structure and permeability, reduces the diffusion and migration of radon gas in the covering soil, and the average radon exhalation rate is decreased by 1.01×10⁻² Bq/(m³·s). The research results show that the Na₂O·nSiO₂−CaCl₂ modified covering soil can effectively improve the radon control performance of the covering soil and reduce the cost of cover treatment.

The loss pathways of Ni and Co during Al and Sc enrichment were analyzed in the HNO₃ leach liquor of saprolitic laterite ore. Although over 99% of Al and Sc can be enriched, about 40% of Ni and Co are also lost. The adsorption of Al−Sc precipitate is an important cause of Ni and Co loss. Subsequently, the precipitation behavior of metal ions in the different nitrate solutions was studied. The results confirm that Ni²⁺ and Co²⁺ do not hydrolyze to form their respective hydroxides. Ni²⁺, Co²⁺ and Mg²⁺ can form composite hydroxides with precipitated Al(OH)₃, decreasing the pH at which Ni²⁺ and Co²⁺ begin to precipitate, causing their co-precipitation loss. A high Mg²⁺ concentration enhances the formation of these composite hydroxides. Finally, titration curves for different nitrate systems were determined, further demonstrating the formation of Me−Al composite hydroxides and revealing a formation trend of Mg−Al > Co−Al > Ni−Al.

Low-density superalloys often exhibit low yield strength in the intermediate temperature range (300−650 °C). To enhance yield performance in this range, the CALPHAD method was used to design a new Co-based superalloy. The Co−30Ni−10Al−3V−6Ti−2Ta alloy, designed based on γʹ phase dissolution temperature and phase fraction, was synthesized via arc melting and heat treatment. Phase transition temperatures, microstructure evolution, and high-temperature mechanical properties were characterized by differential scanning calorimetry, scanning electron microscopy, dual-beam TEM, and compression tests. Results show that the alloy has low density (8.15 g/cm³) and high γʹ dissolution temperature (1234 °C), along with unique yield strength retention from room temperature to 650 °C. The yield strength anomaly (YSA) is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism, contributing to superior high-temperature stability of the alloy. The yield strength of this alloy outperforms other low-density Co-based superalloys in the temperature range of 23−650 °C.

The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate (ADD) was studied. Molecular simulation (MS) calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the form of S—P bond. The ADD adsorption on argentite and sphalerite surface in Ag⁺ system was revealed by ICP, Zeta potential and XPS analyses. It is shown that the dissolved Ag⁺ from argentite surface can be absorbed on sphalerite surface in the form of silver hydroxide, and AgOH hydrophilic colloid prevents the adsorption of ADD on sphalerite surface. The ADD adsorption on argentite and sphalerite surface in the pulp containing silver and zinc ions was revealed by adsorption capacity and surface wettability analyses. It is shown that the combined Zn(OH)₂ and AgOH hydrophilic colloid leads to greater ADD adsorption capacity on argentite surface and stronger surface hydrophobicity than sphalerite. Flotation tests demonstrate that ADD enables efficient separation of argentite from sphalerite in the pulp containing silver and zinc ions.

The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding (RFSSW), and the microstructural evolution and corrosion behavior of the joints were investigated. Based on microstructural analysis, the welded joints exhibit distinct microstructural zones, including the stir zone (SZ), thermomechanically affected zone (TMAZ), and heat-affected zone (HAZ). The grain size of each zone is in the order of HAZ > TMAZ > SZ. Notably, the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ, with particle size in the HAZ increasing at higher rotational speeds. Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ > TMAZ > SZ > BM, with greater sensitivity observed at increased rotational speeds. Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps, but not from the changes in the microstructure.

Frame blades were used to replace traditional propeller blades to enhance the leaching step efficiency of Becher process. A combined approach of leaching, electrochemical experiments, and numerical simulations was employed. Results demonstrate a significant improvement in leaching efficiency using frame blades compared to propellers, reducing reaction time from 15 to 10 h. Even at a stirring speed of 300 r/min, frame blades perform better than propellers at 500 r/min. Kinetics analysis indicates that the leaching process is controlled by surface chemical reactions. CFD−PBM simulations reveal that frame blades at 300 r/min generate larger bubbles and higher turbulent kinetic energy than propeller blades at 500 r/min. Frame blades enhance leaching efficiency by refining bubble size to improve oxygen mass transfer and by increasing turbulent kinetic energy for better mixing.

The evolution of the S' precipitate in Al−Cu−Mg alloy was investigated using transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF−STEM), molecular dynamics (MD) simulations, and other analytical techniques. The precipitation behavior during different aging stages of the supersaturated solid solution formed after rapid cold punching was focused, which induces rapid dissolution of precipitates. The findings reveal that the precipitation sequence is significantly influenced by aging temperature. At higher aging temperatures, which mitigate lattice distortion in the matrix, the precipitation sequence follows the conventional path. Conversely, at lower aging temperatures, where lattice distortion persists, the sequence deviates, suppressing the formation of Guinier−Preston−Bagaryatsky (GPB) zones. MD simulations confirm that the variations in solute atom diffusion rates at different aging temperatures lead to the differences in the S' phase precipitation sequence.

The Sn−2Al filler metal was utilized to bond W90 tungsten heavy alloys by the ultrasonic-assisted coating technology in atmospheric environment at 250 °C. The effects of ultrasonic power and ultrasonic time on microstructure and interfacial strength of Sn−2Al/W90 interface were investigated. The ultrasound improved the wettability of Sn−2Al filler metal on W90 surface. As the ultrasonic power increased and ultrasonic time increased, the size of Al phase in seam decreased. The maximum value of Sn−2Al/W90 interfacial strength reached 30.1 MPa. Based on the acoustic pressure simulation and bubble dynamics, the intensity of cavitation effect was proportional to ultrasonic power. The generated high temperature and high pressure by cavitation effect reached 83799.6 K and 1.26×10¹⁴ Pa, respectively.

In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation of ω_iso phase during aging, regulation of isothermal ω precipitation was investigated in Ti−15Mo alloy. The results show that the sample is brittle when direct aging (A) is applied at 350 °C for 1 h after solution treatment (ST). If pre-deformation (D) is performed on the ST sample to induce {332} twins and secondary α′′ phase, subsequent aging at 350 °C (STDA350) improves the strength to 931 MPa with a good ductility of about 20% maintained. However, when aging is performed at 400 °C or 450 °C (STDA400/450), the strength can be further improved, but the ductility is dramatically reduced. Atomic-scale characterizations show that the partial collapse of ω phase in the STDA350 sample effectively eliminates aging-induced embrittlement, but complete collapse leads to poor ductility in the STDA400/450 sample.

A Mg−3.2Bi−0.8Ca (BX31, wt.%) ternary alloy with a yield strength of ~358.1 MPa was fabricated by hot extrusion, room-temperature (RT) rotary swaging and subsequent aging treatment. A fine grain structure (~2 μm) and a few secondary phases were observed in the as-extruded alloy, accompanied by a weak non-basal texture. After RT rotary swaging, the average grain size was reduced to ~1 μm via continuous dynamic recrystallization (CDRX). In addition, a large number of residual dislocations piled up within the grain interior, along with the dynamic precipitation of nano-phases. Peak aging occurred rapidly at 448 K for 35 min. After aging, the grain size hardly changed, the density of residual dislocations slightly decreased, and a large number of nano-precipitates were introduced at the dislocation pile-up sites. The grain boundary strengthening, dislocation strengthening and precipitation strengthening co-dominated the strength of the as-aged alloy.

The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titanium- containing and silicon-containing minerals during the Bayer digestion process were investigated. Thermodynamic analysis, artificial mineral experiments, and an evaluation of the digestion effect of natural diasporic bauxite were conducted. The results indicate that hydrogarnet shows a preferential reaction with anatase, and this preference becomes more pronounced as the silicon saturation coefficient increases. In contrast, quicklime participates in non-selective reactions with both anatase and desilication products (DSP). The preference of hydrogarnet for anatase significantly enhances the utilization efficiency of CaO in the high-temperature Bayer digestion process.