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.

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 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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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.

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.

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.

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 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.

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.

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.

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 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.

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.

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.

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.

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.

The effect of extrusion temperature on the dynamic recrystallization behavior and mechanical properties of the flame-retardant Mg−6Al−3Ca−1Zn−1Sn−Mn (wt.%) alloy was investigated. The observed dynamic recrystallization mechanisms in the alloy include continuous dynamic recrystallization (CDRX) and particle simulated nucleation (PSN) during hot extrusion. A significant increase in yield strength, from 218 to 358 MPa, representing a 140 MPa increase, is achieved by decreasing the extrusion temperature. The strengthening mechanisms were analyzed quantitatively, with the enhanced strength primarily attributed to grain boundary and dislocation strengthening. The plasticity mechanism was analyzed qualitatively, and the increase in the volume fraction of unDRXed grains caused by the decrease in extrusion temperature leads to an increase in the number of  tensile twins during the tensile deformation, resulting in a reduction in plasticity.

With the aim of improving the fatigue properties of Mg alloy welded joints under cyclic loading, the effects of laser bionic treatment and ultrasonic impact bionic treatment on the fatigue crack growth (FCG) behavior of AZ31B Mg alloy TIG-welded joints were studied and compared. The results show that bionic treatment refines the grains on the joint surface and improves the microhardness. In the crack stable growth stage, both bionic samples exhibit a lower FCG rate and a higher FCG resistance. The two bionic treatment methods reduce the probability of crack initiation and partially promote crack deflection, providing a new approach for improving the FCG behavior of welded joints.

The microstructure and creep behavior of C/Y₂O₃ synergistically micro-alloyed high-Al and low-Al TiAl alloys prepared by induction skull melting (ISM) technology were investigated by advanced electron microscopy. Microstructure analysis shows that Y₂O₃ particles are dispersed in both alloys; element C is dissolved in low-Al alloys as solid solution, while it exists as Ti₂AlC particles within lamellae in high-Al alloys. Additionally, high-density nanotwins are generated in high-Al alloys. Creep data show that C/Y₂O₃ micro-alloying significantly enhances creep resistance of TiAl alloys. This benefits from the dispersion strengthening of Y₂O₃ particles, precipitation hardening of dynamically precipitated Ti₃AlC particles and lamellar stabilization caused by dissolved C atoms or Ti₂AlC particles. This strategy causes a more significant improvement on creep resistance of high-Al TiAl alloys, which is attributed to extra twin strengthening effect. At 775−850 °C, these alloys fracture in mixed ductile−brittle mode, but the fracture characteristics change with the increase of temperature.

Compressive mechanical behavior and microstructure evolution of Ti−5.7Al−2.9Nb−1.8Fe−1.6Mo− 1.5V−1Zr alloy under extreme conditions were systematically investigated. The results show that strain rate and temperature have a significant influence on the mechanical behavior and microstructure. The alloy exhibits a positive strain rate sensitivity and negative temperature sensitivity under all temperature and strain rate conditions. The hot- rolled alloy is composed of a bimodal structure including an equiaxed primary α_p phase and a transformed β phase. After compression deformation, the bimodal deformed structural features highly rely on the temperature and strain rate. At low temperature and room temperature, the volume fraction and size of α_p phase decrease with increasing temperature and strain rate. At high temperature, the volume fraction of the α phase is inversely correlated with temperature. A modified Johnson−Cook constitutive model is established, and the predicted results coincide well with the experimental results.

A unique discontinuous lamellar microstructure of titanium alloys consisting of lamellar colonies at prior β-Ti grain boundaries and internal interwoven α-laths is prepared by a TiH₂-based powder metallurgy method. The α-variants get various crystallographic orientations and become discontinuous during vacuum annealing at 700 °C. Remarkably, nanoscale phase δ-TiH compound layers are generated between α-laths and β-strips, so that dislocations are piled up at the α/δ/β interfaces during tensile deformation. This leads to dislocation slips being confined to individual α-laths, with different <a> slips and particularly pyramidal <c+a> slips being activated. The efficiency of wavy slip is promoted and the work hardening rate is enhanced. Finally, the combined effect of dispersed micro-shear bands and lath distortions is considered contributive for alleviating the stress concentration at grain boundaries, resulting in a high-promising synergy of enhanced ultimate tensile strength of 1080 MPa and good elongation to fracture of 13.6%.

To assess the high-temperature creep properties of titanium matrix composites for aircraft skin, the TA15 alloy, TiB/TA15 and TiB/(TA15−Si) composites with network structure were fabricated using low-energy milling and vacuum hot pressing sintering techniques. The results show that introducing TiB and Si can reduce the steady-state creep rate by an order of magnitude at 600 °C compared to the alloy. However, the beneficial effect of Si can be maintained at 700 °C while the positive effect of TiB gradually diminishes due to the pores near TiB and interface debonding. The creep deformation mechanism of the as-sintered TiB/(TA15−Si) composite is primarily governed by dislocation climbing. The high creep resistance at 600 °C can be mainly attributed to the absence of grain boundary α phases, load transfer by TiB whisker, and the hindrance of dislocation movement by silicides. The low steady-state creep rate at 700 °C is mainly resulted from the elimination of grain boundary α phases as well as increased dynamic precipitation of silicides and α₂.

Laser specific energy significantly impacts the quality of composite coatings. Ti−Al/WC coatings were prepared on the TC21 alloy through laser cladding with specific energy ranging from 66.7 to 133.3 J/mm². The results indicate that the composite coatings primarily comprised Ti₂AlC, α₂-Ti₃Al, γ-TiAl, TiC, and W phases. A gradual increase in the relative intensity of the diffraction peaks of Ti₂AlC, α₂-Ti₃Al, and TiC appeared with the increase of specific energy. When the specific energy was 116.7 J/mm², the Ti−Al/WC coated alloy achieved a maximum micro- hardness of HV_0.2 766.3, which represented an increase of 1.96 times compared with TC21 alloy, and the minimum wear rate decreased dramatically. Much improvement in tribological properties was attained through the fine-grained strengthening of the (α₂+γ) matrix and the dispersion strengthening of self-lubricating Ti₂AlC and intertwining TiC. This study provides valuable insights for the development of high-performance Ti−Al composite coatings.

This study devoted to optimize the laser powder bed fusion (LPBF) parameters for the preparation of Zr−2.5Nb alloys, and was focused on power of incident laser beam and its scanning speed. The microstructure, mechanical and corrosion properties of samples prepared at different laser powers were investigated. The results show that high quality samples were obtained with the relative density over 99%, ultimate tensile strength of 980 MPa, and the elongation at fracture of 14.18%. At a scanning speed of 1400 mm/s, with increasing laser power from 120 to 180 W, two transformation processes: α' martensite coarsening and transition from an acicular into a zigzag structure (β→α'/α→α+β) occurred. Densification and α' martensite transition improved ductility and corrosion resistance at optimal value of the laser power while lower or higher laser power resulted in decreasing the ductility and corrosion resistance because of unfused particles and pores. Increasing β-Zr amount and size decreased the tensile strength due to the dislocation movement. Passive films, which were spontaneously formed at different laser powers, possessed an optimum corrosion resistance at the laser power of 160 W.

To explain the precipitation mechanism of χ phase in Co-based superalloys, the microstructural evolution of Co−Ti−Mo superalloys subjected to aging was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the needle-like χ phase is mainly composed of D0₁₉-Co₃(Ti,Mo), which is transformed from L1₂-γ′ phase, and a specific orientation relationship exists between them. χ phase is nucleated through the shearing of γ′ phase due to the influence of stacking fault. The crystal orientation relationship between L1₂ and D0₁₉ can be confirmed as {111}_L12//{0001}_D019, and . The growth of D0₁₉-χ phase depends on the diffusions of Ti and Mo, and consumes a large number of elements. This progress leads to the appearance of γ′ precipitation depletion zone (PDZ) around D0₁₉-χ phase. The addition of Ni improves the stability of L1₂-γ′ phase and the mechanical properties of Co-based superalloys.

Insufficient metallurgical compatibility between Zr and Ni can lead to the formation of brittle welds and introduce thermal stress-related challenges during the electron beam welding process. Through the implementation of beam deflection and vibration, a transformation was achieved in the primary Ni₅Zr dendrite structure, transitioning from a mass into a layered configuration, consequently resulting in the formation of an ultrafine-grained eutectic−dendrite complex structure. It is revealed that the enhanced strength−ductility synergy of this structure significantly contributes to the high tensile strength and improved plasticity observed in the welded joints. As a result, the welding cracks are effectively mitigated, and notable advancements are achieved in the mechanical properties of Zr/Ni joints, elevating the tensile strength of the joints from 36.4 to 189 MPa. This research not only highlights the potential of this technique in enhancing the strength and ductility of Zr/Ni welded joints but also serves as a valuable reference for future investigations involving welding applications of dissimilar metals.

The novel core−shell SiC@CoCrFeNiMn high-entropy alloy (HEA) matrix composites (SiC@HEA) were successfully prepared via mechanical ball milling and vacuum hot-pressing sintering (VHPS). After sintering, the microstructure was composed of FCC solid solution, Cr₂₃C₆ carbide phases, and Mn₂SiO₄ oxy-silicon phase. The relative density, hardness, tensile strength, and elongation of SiC@HEA composites with 1.0 wt.% SiC were 98.5%,  HV 358.0, 712.3 MPa, and 36.2%, respectively. The core−shell structure had a significant deflecting effect on the cracks. This effect allowed the composites to effectively maintain the excellent plasticity of the matrix. As a result, the core−shell SiC@HEA composites obtained superior strength and plasticity with multiple mechanisms.

To modify the stable thermodynamics and poor kinetics of magnesium hydride (MgH₂) for solid-state hydrogen storage, MIL-100(Fe) was in situ fabricated on the surfaces of TiO₂ nano-sheets (NS) by a self-assembly method, and the prepared TiO₂ NS@MIL-100(Fe) presents an excellent catalytic effect on MgH₂. The MgH₂+ 7wt.%TiO₂ NS@MIL-100(Fe) composite can release hydrogen at 200 °C, achieving a decrease of 150 °C compared to pure MgH₂. Besides, the activation energy of dehydrogenation is decreased to 70.62 kJ/mol and 4 wt.% H₂ can be desorbed within 20 min at a low temperature of 235 °C. Under conditions of 100 °C and 3 MPa, MgH₂+7wt.%TiO₂ NS@MIL-100(Fe) absorbs 5 wt.% of H₂ in 10 min. Surprisingly, 6.62 wt.% reversible capacity is maintained after 50 cycles. The modification mechanism is confirmed that the presence of oxygen vacancies and the synergistic effect of multivalent titanium in TiO₂ NS@MIL-100(Fe) greatly enhance the kinetic and thermodynamic properties of MgH₂.

A method combining finite difference method (FDM) and k-means clustering algorithm which can determine the threshold of rock bridge generation is proposed. Jointed slope models with different joint coalescence coefficients  (k) are constructed based on FDM. The rock bridge area was divided through k-means algorithm and the optimal number of clusters was determined by sum of squared errors (SSE) and elbow method. The influence of maximum principal stress and stress change rate as clustering indexes on the clustering results of rock bridges was compared by using Euclidean distance. The results show that using stress change rate as clustering index is more effective. When the joint coalescence coefficient is less than 0.6, there is no significant stress concentration in the middle area of adjacent joints, that is, no generation of rock bridge. In addition, the range of rock bridge is affected by the coalescence coefficient (k), the relative position of joints and the parameters of weak interlayer.

The ion coordination affinities of the commonly found metal ions were evaluated using DFT calculations. The results indicate that the lowest unoccupied molecular orbital (LUMO) energy of metal ions correlates positively with their binding energies with O(S) ligands, and some metal ions with various valence states also present different affinities. Besides, due to the steric hindrance effects, the mono- and hexa-coordinated metal ions may exhibit different affinities, and the majority of the studied hexa-coordinated metal ions exhibit oxophilicity. These affinity differences perfectly illustrate the activation flotation practice in which the oxyphilic ions are applied to activating oxide minerals, while thiophilic ions are applied to activating sulfide minerals.

An approach for coal-based direct reduction of vanadium−titanium magnetite (VTM) raw ore was proposed. Under the optimal reduction conditions with reduction temperature of 1140 °C, reduction time of 3 h, C-to-Fe molar ratio of 1.2∶1, and pre-oxidation temperature of 900 °C, the iron metallization degree is 97.8%. Ultimately, magnetic separation yields an iron concentrate with an Fe content of 76.78 wt.% and efficiency of 93.41%, while the magnetic separation slag has a Ti grade and recovery of 9.36 wt.% and 87.07%, respectively, with a titanium loss of 12.93%. This new strategy eliminates the beneficiation process of VTM raw ore, effectively reduces the Ti content in the iron concentrate, and improves the comprehensive utilization of valuable metals.