JOM最新文献

Electrodeposition (ED) and electrophoretic deposition (EPD) are commonly used techniques to create nickel–zinc (Ni-Zn) coatings that exhibit enhanced mechanical and electrochemical properties. Recent developments in Ni-Zn composite coatings reinforced with carbonaceous allotropes (graphene, carbon nanotubes, graphene oxide, diamond, and fullerenes), as well as ceramic and polymer additives, are compiled in this study. Carbonaceous reinforcements continuously improve hardness (e.g., Ni-Zn–CNT coatings reaching ~ 160 HV vs. ~ 120 HV for pure Ni–Zn) and decrease corrosion rates (I_corr dropping from ~ 6.5 μA cm^-2 to ~ 2.1 μA cm^-2, E_corr shifting favorably by ~ 50 to − 100 mV) when compared to unreinforced Ni-Zn. The addition of graphene also enhances the elastic modulus by approximately 39% and reduces the corrosion rate from approximately 37.7 to 1.3 mils/year. Hybrid GO-Al₂O₃ reinforcements increase the charge transfer resistance by up to around 1200 Ω cm². Polymer-based additives, like PTFE, improve coating compactness and further reduce I_corr (~ 0.9 μA cm^-2). These quantitative improvements highlight the synergetic effects of combining carbonaceous nanomaterials with Ni-Zn, enabling multifunctional coatings with superior wear resistance, corrosion protection, and electrochemical stability. These results highlight the promise of Ni-Zn-carbonaceous systems for scaled uses in electronics, energy storage, automotive, marine, and aerospace.

This topic aims to provide a comprehensive overview of the current state-of-the-art technologies for lithium recovery from primary and secondary sources, while emphasizing key challenges and potential directions for advancing this rapidly evolving field. Lithium has emerged as one of the most critical metals driving revolutions in clean energy technologies. The surging demand for lithium, largely driven by the widespread adoption of electric vehicles, has intensified efforts to identify alternative sources and develop innovative recovery methods. Recent advancements have demonstrated significant progress in extracting lithium from unconventional sources, including consumer waste streams, industrial byproducts, and emerging natural resources. Notable breakthroughs include the adoption of environmentally sustainable chemical agents, such as ionic liquids and deep eutectic solvents, replacing traditional inorganic acids with high carbon footprints. Furthermore, innovations in thermal treatments, novel additives, and advanced separation techniques have contributed to the sustainable and economical recovery of lithium. In the meantime, the integration of computation modeling, supported by artificial intelligence and machine learning, has significantly improved our understanding of the material–structure–property–process relationships that govern lithium extraction and recovery. Advances in characterization techniques have further unveiled critical insights into microstructures, molecular-level interactions, and mechanisms underpinning both established and emerging lithium recovery processes.

In this study, a more sustainable, cost-effective, and environmentally friendly approach for selective lithium extraction via water leach assisted by planetary mill mechanical activation was applied on clayey wastes of the Kırka Boron Plant. A detailed systematic study on wastes was performed to optimize both mechanical activation and leaching conditions and to characterize the active powders by XRD, FTIR and EDS/EDX. The results show that lithium can be recovered at relatively low leach temperatures of 50–60°C and short leach times of 3–5 min, achieving leach recoveries of 44.71 (without salt addition) and 57.71% (with 20% salt addition, w/w) without the need for pre-concentration of the waste. Despite relatively low lithium recoveries, water leaching of activated powder produced remarkably low concentrations of co-leached ionic impurities less than 10 ppm Mg, 20 ppm Ca, and 250 ppm K, compared to significantly higher concentrations observed during 1 M acid leaching (9422 ppm Mg, 564.5 Ca, and 72.5 ppm K, upon 1 M acid leaching, respectively). The presence of Mg ions, in particular, is known to be highly detrimental competing ion in metal recovery processes. Therefore, the proposed method offers both economic and environmental advantages by enabling higher purity lithium recovery under much milder conditions.

This study investigated the influence of heat treatment on the cyclic behavior of a damaged 2017A aluminum alloy in the T6 condition under low cycle fatigue (LCF). In the present study, tubular specimens were subjected to various levels of damage (D = 0.05 to 0.3) under fully strain-controlled fatigue tests at ε_zz = ± 0.5% using MTS 809 and were heat-treated (annealed) at 400°C for 10 min. The cyclic evolution of work hardening (isotropic and kinematic) in response to different damage rates was studied. Optical microscopy (OM) and scanning electron microscopy (SEM) were employed to observe and analyze the fracture morphology and microstructural evolution. The results demonstrate that heat treatment significantly alters the microstructure and mechanical properties of the damaged alloy. Compared with untreated specimens, we observed a notable decrease in the cyclic amplitude, an increase in the cyclic hardening, and a modification of the hysteresis loops. Microstructural analysis revealed fine precipitation and redistribution of the Al₂Cu particles, contributing to improved fatigue behavior. This study provides new insights into the effect of post-damage heat treatment and opens avenues for optimizing the fatigue life of 2017A aluminum alloy components.

Under open-air stockpiling, heavy metals (HMs) in mineral metallurgical residues are released via weathering and rainwater leaching. Clarifying their environmental release behavior and control mechanisms is urgent for resource recovery and risk mitigation. This study used Tessier five-step sequential extraction, dynamic column leaching, Automatic Mineral Identification and Characterization System (AMICS) mineral mapping and XPS to explore pH-sensitive mechanisms of HM release and mineral interfacial kinetics in high-silica nickel slag (HSNS). The results showed that 51.08% of Cu existed in mobile and potentially mobile forms. Moreover, the exchangeable fraction of Cu increased significantly with changes in leaching pH. A logarithmic time-cumulative release kinetic model revealed mechanism differentiation characterized by mineral dissolution-dominated processes under acidic conditions versus surface desorption-controlled pathways in neutral environments. XPS analysis showed that the proportion of C-O bonds in the slag increased by 41.47% after leaching. This increase promotes the migration of HMs through complexation. Meanwhile, the reduced Fe³⁺/Fe²⁺ ratio activates redox-sensitive elements. Dynamic leaching tests indicated that the cumulative release of HMs exceeded China’s Class V surface water standards by 3–40 times. Among all HMs, Cu posed the highest environmental risk. These findings support HSNS stockpile intelligent containment and nickel metallurgical solid waste risk control.

A three-dimensional steady-state turbulent flow and solidification model has been developed using the finite volume method (FVM) to examine how cladding materials, preheating temperatures, and substrate strip thicknesses influence fluid flow and heat transfer during the fabrication of bimetallic clad strips via the horizontal single-belt casting (HSBC) process. Whereas effective solidification requires transferring heat from the molten cladding through the substrate strip to the belt, the study found that cladding material and substrate characteristics significantly affect heat transfer,absorption, and thermal resistance, along with process parameters, and the results show that fluid flow stability is closely related to strip quality, with higher-density cladding enabling more uniform melt distribution. Additionally, the heat that can be absorbed by the substrate is reduced as the substrate preheating temperature increases. An increase in substrate thickness delays heat transfer from the molten cladding to the belt, raising thermal resistance. These insights help optimize processing parameters for high-quality bimetallic strip production in HSBC.

This study investigates the high-temperature oxidation behavior of 430F and 430FR1 stainless steels using the weight gain method. Oxidation kinetics, oxide scale morphology, and phase composition were analyzed to understand the oxidation mechanism. The results show that oxidation of 430FR1 steel follows a parabolic rate, controlled by diffusion. The oxide scale is mainly composed of spinel-type oxides containing O, Si, Cr, and Mn, with slight compositional variations. The oxide scale on the 430F steel is significantly thicker than that on the 430FR1 steel, with cracks forming beneath the 430FR1 scale. Silicon oxide is located in the inner layer, while manganese–chromium oxides form the middle and outer layers. Both steels exhibit intergranular oxidation, and Si enhances Cr diffusion, slowing intergranular oxidation in 430FR1. The rapid oxidation of Si forms voids near the surface, where MnS migrates and aggregates. Mn then oxidizes further, migrating to the surface and causing microcracks. The surface oxide scale is composed of SiO₂, MnCr₂O₄, Cr₂O₃, and Fe₂O₃ in sequence.