JOM最新文献

Neutron and electron diffraction was employed to evaluate the effectiveness of thermal management strategies in suppressing the formation of the equilibrium-ordered B2 (CsCl) phase in equiatomic binary Fe-Co specimens fabricated by laser powder bed fusion additive manufacturing. Specimens with a tensile dogbone geometry were fabricated using various combinations of process parameters (laser power and raster speed) and thermal management strategies (no support struts, struts only in the top gauge section, and struts throughout the gauge section). Diffraction results demonstrate that the rapid solidification during PBF-L effectively minimized B2 formation, with laser power and effective scan velocity having no significant impact on the degree of ordering. The inclusion of support struts in the top grip region had no perceivable impact on ordering, whereas specimens with support struts in the gauge region exhibited no detectable ordering. Results are discussed in the context of thermal finite element analysis predictions.

Acid wastewater (AWW) from the non-ferrous metal smelting industry is characterized by a high level of acidity and a high concentration of As. Sulfiding agents are commonly used for arsenic removal from acid wastewater because of their high efficiency. To address the issues associated with traditional sulfiding agents, such as the release of harmful hydrogen sulfide gas and the introduction of large amounts of sodium ions, this paper proposes a new process of ultrasound-enhanced ZnS for arsenic removal from acid wastewater by sustained release in situ. The low solubility of ZnS provides the advantages of matching the reaction rate to arsenic removal efficiency, inhibiting the escape of H₂S gas, and preventing the introduction of other cations. Ultrasound can open the ZnS surface encapsulation and accelerate the reaction rate. Experimental research has shown that the arsenic removal rate reached 99.96% and the arsenic concentration was only 0.42 mg/L at an acidity of 120 g/L, S/As molar ratio of 3:1, reaction temperature of 60°C, and ultrasonic power of 100 W for 120 min. The development of this process is of great significance as an application prospect for the arsenic removal from acid wastewater in zinc smelting.

A neural network interatomic potential (NNIP) has been developed for the ternary system of (alpha )-iron, carbon, and hydrogen to clarify the degradation behavior of Fe-C steels in hydrogen-rich environments. The NNIP was trained on an extensive reference database generated from spin-polarized density functional theory (DFT) calculations. It demonstrates remarkable performance in various scenarios relevant to Fe and Fe-C systems under hydrogen, including the diffusion kinetics of H and C in Fe and their thermodynamic interactions with iron vacancies, grain boundaries, screw dislocations, cementite, and cementite–ferrite interfaces. Using this NNIP, we conducted large-scale (one-million-atom) molecular dynamics (MD) simulations of uniaxial tensile tests on C-containing (alpha )-Fe both with and without H, showing that hydrogen enhances defect accumulation during plastic deformation, which may eventually lead to material failure.

The increasing demand for sustainable materials recovery has sparked renewed interest in repurposing metals extracted from spent lithium-ion batteries. This study examines the direct integration of recovered Co, Ni, Mn, and Li oxides, sourced from mobile phone and laptop batteries, into the formulation of functional enamel frits used in industrial applications. Two types of frits, acid-resistant black and easy-to-clean (ETC) black frits, were produced by substituting traditional raw materials with recycled metal oxides. Characterization of the recycled materials was conducted using X-ray fluorescence, X-ray diffraction, scanning electron microscopy, and atomic absorption spectroscopy. The resulting frits were evaluated for their color, surface quality, acid resistance, flowability, adhesion, and ETC properties. All tested parameters exhibited performance comparable to or exceeding those of frits made with virgin raw materials. The use of battery-derived materials produced darker enamel hues due to interactions with cobalt, resulting in uniform adhesion and chemical resistance on coated surfaces. Furthermore, this approach enabled a 15–20% reduction in production costs by substituting high-purity commercial oxides with lower-cost alternatives. The findings present a viable pathway for implementing a circular economy in the ceramic coatings industry by combining waste recovery with high-performance product design.

Mycelium-based composites hold great promise as sustainable, biodegradable materials for applications spanning packaging, construction, and beyond. To fully realize their potential, optimizing the mechanical properties is essential, and seeking structural designs from the remarkable examples in natural fungi can offer valuable inspiration for such optimization strategies. Here, we systematically examine the fruiting bodies of the trimitic bracket fungus Ganoderma lucidum. Using scanning electron microscopy (SEM), micro-computed tomography (µCT), and Fourier transform infrared spectroscopy (FTIR), we describe a hierarchical structure composed of a dense protective crust, a porous yet aligned context, and vertically oriented, segmented hymenial tubes. We further demonstrate that mechanical properties differ by developmental stage and region: stipe-proximal samples exhibit a higher modulus, while hymenial tubes outperform the loosely entangled context. µCT reveals that tubular geometry predominantly absorbs energy via buckling, with crack deflection providing additional dissipation; meanwhile, segmentation enables staged collapse and helps mitigate lateral splitting. Additionally, we 3D-printed biomimetic prototypes, showcasing enhanced buckling resistance and design opportunities for resilient, lightweight, and compostable materials. This approach underscores the bioinspired potential of G. lucidum’s segmented-tube engineering for structural and environmental demands.

Spinel LiMn₂O₄ is one of the most promising cathode materials for rechargeable lithium-ion batteries. However, issues such as manganese dissolution and the Jahn–Teller effect lead to rapid capacity fading, especially at high temperatures over prolonged cycling. In this study, a synergy strategy with Al-doping and spherical particle morphology has been utilized to enhance the electrochemical performance of LiMn₂O₄. Initially, the spherical Al-doped Mn₃O₄ was prepared by a corrosion–oxidation method, which serves as the manganese source for the synthesis of spherical Li_1.04Mn_1.96−yAl_yO₄ via high-temperature solid-state reaction. Al-doping inhibits the Jahn–Teller effect, thus improving the cyclic performance of the material. Simultaneously, the spherical morphology possesses a higher energy density, efficiently balancing the capacity loss caused by doping. Compared with the undoped Li_1.04Mn_1.96O₄, the optimally designed Li_1.04Mn_1.92Al_0.04O₄ sample exhibited superior cycling stability and rate capability while maintaining a high discharge capacity. It exhibited a capacity retention of 97.7% after 200 cycles at 1 C and 25 °C, with an initial discharge capacity of 122.1 mAh/g. Notably, under high current conditions of 10 C, it still demonstrated a capacity of 110.9 mAh/g. This study offers a simple and effective approach for the large-scale production of high-performance spinel LiMn₂O₄.

This study explores the structural and mechanical characteristics of alumina (Al₂O₃) nanoceramic coatings deposited on A37 steel substrates via atmospheric plasma spray (APS) at an operating temperature of 12,000°C. By varying the number of plasma torch passes, coatings of differing thickness were fabricated and analyzed using Rietveld refinement of X-ray diffraction (XRD) patterns and Vickers microhardness testing. The results reveal a composite microstructure consisting of nanocrystalline γ-Al₂O₃ domains embedded in an amorphous alumina matrix. Notably, the amorphous phase fraction increases with coating thickness, while a reduction in γ-Al₂O₃ crystallite size enhances microhardness. This crystallite size-dependent hardening effect underscores the tunability of mechanical properties via process parameters. These findings demonstrate the potential of plasma-sprayed alumina coatings for surface engineering applications requiring high wear resistance and tailored stiffness. The integration of phase analysis, microstructure control, and mechanical optimization highlights APS as a versatile method for advanced ceramic–metal interface design.

In this work, the inherently low electrical conductivity of NiOOH was addressed by incorporating reduced graphene oxide (rGO) as a conductive additive, resulting in enhanced electron transport and superior practical capacitance. A binder-free two-step electrochemical deposition method was employed, where rGO was first deposited onto nickel foam (NF) via electrophoretic deposition, followed by galvanostatic growth of NiOOH nanoneedles and subsequent annealing. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful formation of NiOOH, while field-emission scanning electron microscopy (FESEM) revealed a nanoneedle-like morphology. To assess the electrochemical properties, a three-electrode cell containing a 2 M KOH solution was used. The results show that the rGO-supported NiOOH hybrid electrode exhibits a high specific capacitance of 1304 F g⁻¹ at a current density of 1 A g⁻¹. Furthermore, galvanostatic charge-discharge (GCD) measurements demonstrate excellent cycling stability, with a capacitance retention of 95.7% after 2000 cycles. In addition, the synthesized rGO-supported NiOOH hybrid electrode exhibits an impressive energy density of 45.3 Wh kg⁻¹ at a power density of 916 W kg⁻¹, highlighting its strong potential for a broad range of practical energy storage applications. These results indicate that the incorporation of rGO into the hybrid electrode structure facilitates rapid ion diffusion and reduces resistance at the electrolyte-electrode interface, thereby enhancing the electrochemical performance of the electrode material. Overall, the rGO-supported NiOOH hybrid electrode paves a new way for practical applications of supercapacitors in energy storage due to its cost and time efficiency, as well as its ease of preparation.

In the area of thermoelectric implementation, the development of thermoelectric materials takes a crucial role, especially in areas with substantial thermal differentials, aiming to convert these differentials into electrical signals. This study systematically describes the production and characterization of Ca_2.7−xAg_0.3Eu_xCo₄O₉ materials for use in thermoelectric applications, necessitating robust systems capable of harnessing temperature differences for power generation. These ceramics are synthesized using the sol–gel technique using precursor materials. After the gelation process, the obtained xerogel was desiccated and calcined to acquire the final Ca_2.7−xAg_0.3Eu_xCo₄O₉ bulk materials. Comprehensive characterization, encompassing thermal, structural, microstructural, and thermoelectric characteristics, is performed with methods such as XRD, DTA-TG, XPS, FTIR, SEM, and thermoelectric measuring instruments. XRD and XPS results confirmed the crystalline nature of the synthesized Ca_2.7−xAg_0.3Eu_xCo₄O₉ ceramic powders and verified the inscription of Eu and Ag dopants into Ca₃Co₄O₉ ceramic powder materials, illustrating the successful fabrication of p-type thermoelectric materials. Thermoelectric results showed that electrical resistivity and the Seebeck coefficient were measured as 9.39 mΩcm, and 242.15 µV/K respectively, which yields a maximum power factor of 0.62 smW/mK² at 800°C. According to these results, the study determines that the manufactured semiconducting ceramic materials illustrate high performance for high-performance thermoelectric generator fabricating.