General Research Institute for Nonferrous Metals (GRINM)

The excellent recovery performance of TiNiFe shape memory alloy is closely related to the predeformation in the martensitic state. Based on the classical phenomenological constitutive model, the constitutive relationship suitable for the mechanical properties of TiNiFe alloy is constructed by introducing plastic strain. Aiming at the problems of uneven size and difficulty in characterizing stress and strain state in the deformation of ring parts after expansion deformation, the finite element simulation model of cryogenic temperature expansion deformation of shape memory alloy is established by using the UMAT interface of Abaqus. The effects of die angle and ring wall thickness on the stress state and geometric size of the TiNiFe alloy ring expansion process are investigated. The results show that for the same wall thickness, as the die angle α increases, the Mises stress increases significantly. As the wall thickness increases, the peak value of the expansion force increases significantly. The finite element simulation model established in this study can accurately predict the size of the TiNiFe alloy ring after expansion, evaluate the stress and strain state during the expansion process, and provide data support and theoretical guidance for subsequent applications.

Mn²⁺‐activated green phosphors have attracted extensive attention due to narrow emission band and high color purity, which are expected to be applied in white light‐emitting diodes (LEDs) backlight for ultrahigh color gamut liquid crystal display. However, due to the d–d forbidden transition of Mn²⁺, its luminescence intensity is greatly limited. Herein, considering the optimization principles of matrix structure, we have designed a new strategy to modify the SrAl2Si2O8 (SASO) host that La³⁺–Al³⁺ ions substitute for Sr²⁺–Si⁴⁺ and synthesized a series of Sr1 − xLaxAl2 + xSi2 − xO8:Mn²⁺ (SLxASO:Mn²⁺) phosphors by the high‐temperature solid‐state reaction. In comparison to La/Al monodoping, the codoping modification of matrix structure can optimize the local crystal structure surrounding the luminescence center. Under excitation at 450 nm, a green emission peaks at 516 nm with full‐width at half‐maximum (FWHM) of 29.3 nm. The effects of La³⁺–Al³⁺ cosubstitution on crystal structure and luminescence properties have been discussed by the fluorescence decay curves, diffuse reflectance spectra and polyhedron distortion. The luminescence intensity is greatly enhanced with the increase of La³⁺–Al³⁺ cosubstitution and reaches the maximum value at x = 0.2, which is up to 15 times as the undoped sample. This paper provides a feasible new method for improving the luminescence performance of Mn²⁺‐activated aluminosilicate green phosphor.

Cellulose ionogels gain considerable attention for their application in flexible electronic devices. However, achieving an optimal balance between their mechanical and electronic properties remains a challenge. Here, a high‐performance cellulose ionogel is reported through strengthening the hydrogen bond network and weakening electrostatic interactions within cellulose molecular framework. The resulting ionogels, under a single molecular network, exhibit impressive tensile strength of 3.5 MPa and ionic conductivity of 14.3 mS cm⁻¹. Additionally, they demonstrate a wide voltage window of up to 3.0 V and high thermal stability, withstanding temperatures exceeding 120 °C. Serving as all‐solid electrolytes, the ionogels contribute to the construction of integrated flexible energy storage devices, achieving a remarkable energy density of over 60 Wh kg⁻¹ and demonstrating significant cycle stability, with a capacitance retention rate exceeding 97% after 10 000 charge–discharge cycles. With the robust mechanical and electrical properties, the cellulose ionogel is well‐positioned to offer innovative insights for the next generation of flexible, integrated electronic devices.

Refractory high-entropy alloys (RHEAs) have drawn much attention in the field of materials science for their unique properties and wide compositional design space. The Nb35Zr26Ti19Hf15Mo5 alloy is important for exploring RHEAs’ potential in high-temperature applications. It can break through existing material limitations and bring benefits to related fields, especially in the aerospace field. This paper focuses on Nb35Zr26Ti19Hf15Mo5 RHEAs and studies the effects of cold rolling and heat treatment on its microstructure and mechanical properties. The alloy has a single-phase BCC structure. As rolling reduction rises from 20% to 80%, the alloy’s strength increases notably while plasticity drops. At 80% rolling reduction, the tensile strength reaches 1408 MPa, and the elongation is 10.5%. During rolling, grains deform along the rolling direction, the number of low-angle grain boundaries grows, and dislocation and solid solution strengthening effects are enhanced. With the increase in annealing temperature, recrystallized grains increase, and the change in grain-boundary structure weakens the strengthening effect, leading to a strength decrease and a plasticity increase. After annealing at 800 °C, the elongation reaches 17%, and the dislocation density in the alloy decreases with a recrystallization degree of 49%.

This study systematically investigated the effects of tailored heat treatments on the microstructural evolution, mechanical properties, and erosion–corrosion resistance of Cu-10Ni-3Al-1.8Fe-0.8Mn alloy. Four heat treatment conditions—as-cast (AC-1); homogenized (H-2); and deformation–aged at 500 °C (D-3) and 750 °C (D-4)—were applied to elucidate the interplay between microstructure and performance. The D-3 specimen, subjected to deformation followed by aging at 500 °C for 0.5 h, demonstrated superior properties: a Vickers hardness of 118 HV5 (83.3% higher than H-2) and an erosion–corrosion rate of 0.0075 mm/a (84.1% reduction compared to H-2). These enhancements were attributed to the uniform dispersion of nanoscale Ni3Al precipitates within the matrix, which optimized precipitation strengthening and reduced micro-galvanic corrosion. The D-3 specimen also formed a dense, crack-free Cu2O corrosion product film with a flat matrix interface, confirmed by SEM cross-sectional analysis and electrochemical impedance spectroscopy (EIS), exhibiting the highest charge transfer resistance and film impedance.

During the grain boundary diffusion (GBD) of Tb, the core–shell and reverse core–shell structures are the two main microstructures influencing the magnetic properties of the sintered Nd-Fe-B magnets. These two microstructures are all composed of the (Nd, Tb)2Fe14B phase, but the formation mechanisms are different. The difference in formation mechanism of the core–shell and reverse core–shell structures was studied by quenching the magnets at different temperatures and holding times. The (Nd, Tb)2Fe14B shell of the core–shell structure is the precondition for forming the reverse core–shell structure. The triple-junction phases (TJPs) area change proves that the Nd elements diffuse from the TJPs to the surface of the (Nd, Tb)2Fe14B shell to form the Tb-poor shell in the reverse core–shell structure and the Gaussian distribution of Tb in the shell of the core–shell structure. In addition, the difference in the Tb content distribution leads to different demagnetization processes, resulting in the opposite effect of these two microstructures on the coercivity. The GBD aims to increase the entire coercivity by enhancing the surface anisotropy field (HA), such as the Tb-rich shell for the grains and the Tb-rich surface (∼200 μm) for the magnets. Therefore, for the reverse core–shell structure forming in the surface of the magnets, the surface with a low HA decreases the coercivity of the grains, reducing the coercivity of the magnets.

Simultaneously stabilizing cadmium, lead, and arsenic in contaminated soils is challenging due to their significant differences in physical and chemical properties. This study developed a composite material by modifying hydrochar with iron (Fe), phosphorus (P), and sulfur (S) to address this issue. The iron–phosphorus–thiol-modified Trachycarpus fortunei hydrochar (H-PAL-Fe2-P-T) effectively stabilized these metals. Experimental results showed that the H-PAL-Fe2-P-T achieved over 90% stabilization for DTPA-extracted cadmium, lead, and arsenic. Characterization by XRD, SEM, and FTIR revealed structural and functional changes in the hydrochar. Column leaching tests simulating acid rain showed that the composite material maintained stable stabilization effects, with the fluctuations in the stabilization rates remaining below 20%. Additionally, the composite-modified hydrochar enhanced the stabilization of water-soluble, DTPA-extracted, and TCLP-extracted heavy metals in soil, demonstrating good stability and durability for long-term use. These findings suggest that Fe-, P-, and S-modified hydrochar is a promising and sustainable approach for the remediation of soils contaminated with cadmium, lead, and arsenic.

During the acidic leaching of flotation zinc oxide concentrates, CO2 released from carbonate decomposition generates viscous foams that disrupt process stability. This study introduces an innovative synergistic defoaming process combining air flotation and mechanical methods. Fine air bubbles destabilize the foam, while mechanical defoaming enhances the removal of residual bubbles. The results indicate that the defoaming process combining air flotation with mechanical stirring effectively reduces foam generation during the acid leaching of zinc oxide concentrates, enhances leaching efficiency, and improves process stability. This method provides an effective solution for foam control and offers a new approach for the treatment of zinc oxide concentrates.

Zinc-ion batteries (ZIBs) are an ideal choice for large-scale energy storage due to their high safety, environmental friendliness, and low cost. However, their performance is constrained by challenges related to cathode materials, such as poor conductivity, dissolution of active materials, and structural instability during cycling. In this study, α-MnO2 cathode material with a tunnel structure was synthesized via a hydrothermal method, and MnSO4 was introduced into the ZnSO4 electrolyte to optimize the electrochemical performance of ZIBs. Characterizations through XRD, SEM, and BET revealed excellent crystal morphology and nanorod structures, which provided superior ion transport pathways. With the addition of MnSO4, the discharge specific capacity of ZIBs at 0.1 A g⁻¹ was significantly improved from 172.9 mAh g⁻¹ to 263.2 mAh g⁻¹, the cycling stability was also notably enhanced, namely, after 1000 cycles with the current density of 1 mA cm⁻², the capacity settled at 50 mAh g⁻¹, which is a 47.4% increase in relation to the case of absent additive. The experimental results indicate that MnSO4 additives effectively suppress manganese dissolution, improving the rate capability and reducing self-discharge. This study provides a novel approach to the development of high-performance aqueous zinc-ion batteries.

Owing to the low solid solubility and active chemical properties of rare-earth elements in aluminum matrix, the precipitation strengthening effect brought about by rare-earth modification in aluminum alloys has emerged as a focal point among researchers. The objective of this study was to elucidate the effect of cerium (Ce) modification on the high-temperature strength and microstructures of 2024 aluminum alloy (AA2024). The investigation conducted by us primarily focuses on mechanical property testing under ambient/high-temperature conditions, in-depth microstructural analysis, and systematic studies of phase transformations. By introducing 0.46 wt.% of Ce doping into AA2024, the presence of Ce-containing Al24Cu8Ce3Mn and Al11Ce3 phases, along with the finer θ′(Al2Cu) phases, collectively contribute towards enhancing the high-temperature strength of AA2024. Ce effectively inhibited the precipitation and coarsening process of aging strengthening phases in AA2024, resulting in the formation of denser and finer θ′ phases during high-temperature deformation. The ultimate tensile strength of the 0.46 wt.% Ce-modified AA2024 reaches 202 MPa at 300°C, representing a 23.17% increase compared to the pure AA2024.

The O3-type layered oxide represents a highly promising candidate for sodium-ion batteries (SIBs). However, the intrinsic stability law of these cathodes remains elusive due to the complex phase transition mechanism and migration of transition metal (TM) ions. Here, we underscore how the ratio between the spacings of alkali metal layer and TM layer (R = dO-Na-O/dO-TM-O) plays a critical role in determining the structural stability and the corresponding electrochemical performance. We design a peculiar family of NaxMn0.4Ni0.3Fe0.15Li0.1Ti0.05O2 (0.55 ≤ x ≤ 1) composition that is thermodynamically stable as an O3-type structure even when R is as high as 1.969, far exceeding 1.62 that normal O3-type structures can reach at most. The high R-value puts the O3 cathode in the preparatory stage for the O3-P3 phase transition, resulting in a rapid yet smooth phase transition process. It also induces a significantly stretched interstitial tetrahedral structure to the Na layer, thus effectively impeding TM migration. Leveraging this mechanism, we reexamine the underlying cause for enhanced stability in P2/O3 hybrid structure. Besides the conventional wisdom of an interlocking effect, the high R-value nature of its O3 sub-phase also plays a pivotal role.

Stabilized lithium isotopes (⁶Li, ⁷Li) play an important role in related fields such as energy and defense. With the advancement of nuclear technology, the demand for lithium isotopes is expected to increase significantly. Although the separation of lithium amalgam is effective, it poses greater pollution risks. Therefore, it is very important to establish an efficient, green and sustainable lithium isotope separation method. Lithium isotopes are extremely difficult to isolate, but the discovery of their differences in migration (diffusion) rates, optical excitation, magnetic field response, and chemical binding has enable their potential separation lithium isotopes. Among the various lithium isotope separation methods developed, electrochemical migration stands out as a technique with industrial potential due to its high single‐stage separation factor. Hence, this paper focuses on the research progress of lithium isotope separation methods with significant industrial potential. It elucidates the merits and challenges of various techniques, explores key obstacles to their industrialization. Finally, a method for separating lithium isotopes using solid electrolytes is described in the context of lithium‐ion battery technology and related research on lithium isotope separation. Despite being in its infancy, this method warrants further research and experimentation.

To achieve selective leaching of ion adsorption rare earth, it is necessary to thoroughly reveal the differences in the adsorption mechanisms of aluminum and rare earth elements. In this study, we investigated the adsorption processes of Dy and Al on the surface of K–homoionic kaolinite using batch experiments and sequential chemical extractions. The results revealed that the adsorption of Dy and Al, as well as the desorption of K, followed the Langmuir model. The maximum ion-exchangeable capacity of Dy was higher (9.39 mmol·kg−1) than that of Al (6.30 mmol·kg−1). The ion exchange stoichiometry ratios of Dy–K and Al–K derived from the Langmuir model were 2.0 and 2.6. The analysis of X-ray absorption fine structure (XAFS) and density functional theory (DFT) revealed that Dy and Al were adsorbed onto kaolinite as outer-sphere hydrated complexes via hydrogen bonds. Dy was adsorbed as [Dy(H2O)10]3+, and Al was adsorbed as [Al(OH)2(H2O)4]+. In particular, the adsorption of Al resulted in protonation of the hydroxyl groups on the surface of the kaolinite. Based on the above insights, the higher ion exchange stoichiometry ratios are attributed to closer adsorption distances (6.04 Å for Dy and 3.69 Å for Al) and lower adsorption energies (− 223.72 kJ·mol−1 for Dy and − 268.33 kJ·mol−1 for Al). The maximum ion-exchangeable capacity is related to the change of the surface electrical properties of kaolinite. The zeta potential was increased to − 7.3 mV as the protonation resulted from aluminum adsorption, while Dy adsorption had a minor effect, maintaining a value of − 17.5 mV.

High-nickel ternary silicon-carbon lithium-ion batteries, which use silicon-carbon materials as anodes and high-nickel ternary materials as cathodes, have already been commercialized as power batteries. The increasing demand for high-energy density and rapid charging characteristics has heightened the urgency of improving their fast charging cycle performance while establishing degradation mechanisms. Based on a pouch battery design with an energy density of 285 Wh·kg−1, this work studied 3 Ah pouch batteries for fast charging cycles ranging from 0.5C to 3C. Non-destructive techniques, such as differential voltage, incremental capacity analysis, and electrochemical impedance spectroscopy, were employed to investigate the effects of charging rates on battery cycling performance and to establish the degradation mechanisms. The experimental results indicated that capacity diving was observed at all charging rates. However, at lower rates (0.5C–2C), more cycles were achieved, while at higher rates (2C–3C), the cycle life remained relatively stable. Computed tomography, electrochemical performance analysis, and physicochemical characterizations were obtained, using scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectrometry. The mechanisms of capacity decrease during 3C fast charging cycles were investigated. It is proposed that the primary causes of capacity diving during 3C fast charging are the degradation of SiOx, anode polarization, and the simultaneous dissolution of metal ions in the cathode which were deposited at the anode, resulting the continuous growth and remodeling of the SEI membrane at the anode, thereby promoting more serious side reactions.

Introduction Stabilization of heavy metals through phosphate-solubilizing bacteria (PSB) induced phosphate precipitation and urease-producing bacteria (UPB) induced carbonate precipitation are promising bioremediation methods. However, little attention has been conducted on the combined action of the above two bioremediations to stabilize heavy metals. Methods PSB and UPB were isolated from the environment and their growth characteristics and antagonistic properties were studied. A simulated solution of acidic leachate was prepared based on heavy metal contaminated soil. Microbial consortium of PSB and UPB were constructed for the stabilization of heavy metals by optimizing carbon and nitrogen sources. The microstructural and compositional changes during the biostabilization process were more deeply analyzed using XRD, FT-IR and SEM-EDS. Results and discussion The precipitation of heavy metals could be promoted effectively when soluble starch (10.2 g/L) was used as carbon source and urea (7.8 g/L) as nitrogen source. The stabilization rates for Cu, Zn, Cd, and Pb were 98.35, 99.78, 99.09, and 92.26%, respectively. The stabilization rates of the combined action of PSB and UPB were significantly higher than that of the two microorganisms alone. An in-depth analysis showed that the composite metals were precipitated as dense precipitate encased in carbonate and phosphate, and additionally could be stabilized in the form of biosorption. Finally, the stabilization mechanism of heavy metals based on biomineralization and biosorption is proposed. These findings provide new theoretical support for sustainable remediation and management strategies for composite heavy metal polluted areas.

Al–Zn–Mg–Cu alloys are widely used in aerospace, with recrystallization significantly influencing their stress corrosion resistance. This study examines the impact of recrystallization morphology on corrosion resistance in a high‐alloying Al–Zn–Mg–Cu alloy, focusing on lath‐shaped and equiaxed recrystallized grains. The findings reveal that, at the same recrystallization fraction, the equiaxed sample has a 2.83 times higher corrosion current density and a 1.15 times higher stress corrosion cracking susceptibility index than the lath sample. However, its critical stress intensity factor is only 89.3% of the lath alloy's. Lath recrystallization demonstrates superior stress corrosion resistance due to larger grain sizes, wider grain boundary precipitate spacing, lower Zn and Mg content, and higher Cu content. Finite element simulations and in‐situ tensile tests show that the equiaxed sample experiences more stress concentration and cracking at grain boundaries under the same applied stress. These results provide insights into optimizing the stress corrosion resistance of Al–Zn–Mg–Cu alloys.

An efficient two-step plasma oxidation and reduction process was proposed to recover value-added high-purity iron utilizing recycled pig iron (P-Fe). We researched the influence of different additions of industrial grade iron oxide (Fe2O3) and processing combinations on impurity removal. This involved 15 minutes of argon plasma arc melting (APAM) oxidation or followed by 5 minutes of hydrogen plasma arc melting (HPAM) reduction at 105 (N m−2). Meanwhile, thermodynamic/kinetic elimination models were introduced to describe processes of plasma oxidation, reduction, and evaporation. The obtained 3N high-purity iron demonstrated that, in the first APAM step with 18 pct Fe2O3 addition, over 85 pct of Si, C, and Ti in P-Fe were removed, increasing the purity from 91.7 to 99.906 pct. Thermodynamic and kinetic analyses, alongside studies using electrolytic iron (E-Fe), verified that the removal was attributed to the vaporized gaseous SiO, CO, and the stable TiO2. In the second HPAM step, residual O, N, and S were reduced to less ppm, achieving removal efficiencies of 99.99, 91.7, and 93.6 pct, respectively. The decarburization kinetics revealed high apparent rate constant of 0.00686 s−1 for APAM and 0.00701 s−1 for APAM–HPAM, both with 18 pct Fe2O3 as the oxidant. Furthermore, the kinetic model for Mn evaporation unveiled that gas interface mass transfer, with a rate of 1.399 E−7 m s−1 at 1800 K, was identified as the rate-limiting step.