Search Results (390)

The inlet pressure steel pipe is an important part of the hydropower unit, and its inspection tasks mainly include cleaning with high-pressure water, surface anti-corrosion layer detection and internal flaw detection. In order to accomplish the above tasks effectively, a multifunctional, non-contact magnetic, tracked climbing robot is presented in this paper. Focusing on the pressure steel pipe inspection tasks, the design of the climbing robot system is given, including the mechanism and control system. By analyzing the slippage and overturning situations, the magnetic attraction constraints for reliable adhesion are obtained, which are used as the basis for designing magnetic adhesion modules. To enable climbing robots to meet the requirement of following the welding seam during the inspections, the improved Deeplabv3+ semantic segmentation method is proposed for welding seam recognition. Experiment results show that the climbing robot can achieve reliable adsorption and flexible movement on the internal face of inlet pressure steel pipe, and the climbing robot can meet the requirements of safety and efficiency for pressure steel pipe inspection processes. Full article

Machining is a fundamental manufacturing process that entails the controlled removal of material from a workpiece to achieve desired shapes and dimensions. Super duplex stainless steel (SDSS) 2507 is a high-performance alloy which is notable for its superior mechanical strength and excellent corrosion resistance, making it particularly suitable for deployment in aggressive service environments, including offshore structures, subsea equipment, chemical industries, and marine engineering systems. Its low thermal conductivity, high hardness, and rapid work hardening pose significant challenges during dry machining, leading to accelerated tool wear. This study investigates the dry machining of SDSS 2507 by employing TiAlN-PVD (physical vapor deposition)-coated cutting inserts deposited to address these issues. The Taguchi method of experimental design was employed to evaluate the influence of key machining parameters on tool wear. The results demonstrated that PVD-coated inserts offered excellent wear resistance. Furthermore, the Taguchi signal-to-noise (S/N) ratio analysis and analysis of variance (ANOVA) identified feed rate as the primary factor influencing tool wear, with depth of cut and cutting speed ranking as secondary factors. This study highlights the effectiveness of tools with coatings for the dry machining of SDSS 2507-type difficult-to-machine material, offering a reliable solution for enhancing tool life and operational efficiency in industrial applications. Full article

The booming new energy industry has fueled a surge in global lithium demand, with the annual demand for lithium carbonate (Li₂CO₃) equivalent (LCE) projected to reach 11.2 million tons by 2050. As a key raw material for lithium extraction, spodumene generates approximately 10–15 tons of lithium slag per ton of lithium carbonate (Li₂CO₃) produced. However, the comprehensive utilization rate of lithium slag in China remains below 30%, and most of it is disposed of through landfilling, posing soil pollution risks. This review summarizes the main lithium extraction processes from spodumene: the sulfuric acid method (with a lithium recovery rate of over 96% but high acid consumption); alkali processes (achieving 96%–99% lithium recovery and featuring low equipment corrosion, yet with untested applicability to low-grade ores); salt roasting (simplifying purification processes but only achieving ~60% sulfate recovery); and chlorination roasting (with a lithium recovery rate of over 95% but requiring strict safety controls). Additionally, this review covers the resource utilization of lithium slag: 8–10 million tons of gypsum can be recovered annually (filling 16%–20% of China’s industrial by-product gypsum supply gap); the silica–alumina micro-powder can enhance concrete strength and reduce glass fiber production costs; and over 94% of tantalum (Ta) and niobium (Nb) can be recovered from fine tantalite concentrate slag. Key research gaps and future development directions are also identified to support the low-carbon development of the lithium industry. Full article

Due to their low elasticity modulus, significant fatigue strength, and good formability, titanium and titanium alloys have shown a continuous growth trend in various fields of application. However, the passivation film on the surface of titanium and titanium alloys may dissolve, leading to corrosion under certain environmental conditions. Surface modification of these materials has become an indispensable and critical step in meeting the requirements of various operating conditions of material performance. Compared to other surface treatment techniques, plasma surface treatment has advantages such as high efficiency, wide applicability, environmental friendliness, flexibility and controllability, and low-temperature treatment. This article focuses on the topic of plasma surface modification technology for titanium and titanium alloys and highlights the key limitations of Plasma chemical heat treatment, Physical Vapor Deposition (PVD), plasma-enhanced chemical vapor deposition (PECVD), Plasma immersion ion implantation (PIII), and plasma spraying (PS). The current research status of surface modification methods in improving the surface properties of titanium and titanium alloys and the prospects of surface modification technology for titanium alloys are also discussed. Full article

Metallic magnesium is a strategic material with applications in mobility, energy and medicine, due to its low density, biocompatibility and use as an anode in rechargeable batteries. However, industrial production methods—such as the thermal reduction of dolomite or the electrolysis of anhydrous MgCl₂—face environmental and operational challenges, including high temperatures, emissions, and dehydration of precursors like bischofite. In response, ionic liquids (ILs) have emerged as alternative electrolytes, offering low volatility, thermal stability and wide electrochemical windows that enable electrodeposition in water-free media. This study presents a systematic review of 32 peer-reviewed articles, applying the PRISMA 2020 methodology. The analysis is structured across three dimensions: (1) types of ILs employed, (2) operational parameters and (3) magnesium source materials. In addition to electrolyte composition, key factors such as temperature, viscosity control, precursor purity and cell architecture were identified as critical for achieving efficient and reproducible magnesium deposition. Furthermore, the use of elevated temperatures and co-solvent strategies has been shown to effectively mitigate viscosity-related transport limitations, enabling more uniform ion mobility and enhancing interfacial behavior. The use of alloy co-deposition strategies and multicomponent electrolyte systems also expands the technological potential of IL-based processes, especially for corrosion-resistant coatings or composite electrode materials. This review contributes by critically synthesizing current techniques, identifying knowledge gaps and proposing strategies for scalable, sustainable magnesium production. The findings position IL-based electrodeposition as a potential alternative for environmentally responsible metal recovery. Full article

The corrosion behavior of open-cell AlSn6Cu-based composites, one reinforced with SiC particles and the other with Al₂O₃ particles, was investigated. The composites were fabricated via liquid-state processing, employing both squeeze casting and the replication method, and they produced in two distinct pore size ranges (800–1000 µm and 1000–1200 µm). Corrosion performance was systematically evaluated through gravimetric (weight loss) measurements and electrochemical techniques, including open-circuit potential monitoring and potentiodynamic polarization tests. Comprehensive microstructural and phase analyses were conducted using X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The results revealed that both reinforcement type and pore architecture have a significant impact on corrosion resistance. Al₂O₃-reinforced composites consistently outperformed their SiC-containing counterparts, and pore enlargement generally improved performance for the unreinforced alloy and the Al₂O₃ composite but not for the SiC composite. Overall, the optimal corrosion resistance is achieved by pairing a coarser-pore architecture (1000–1200 µm) with Al₂O₃ reinforcement, which minimizes both instantaneous (electrochemical) and cumulative (gravimetric) corrosion metrics. This study addresses a gap in current research by providing the first detailed assessment of corrosion in open-cell AlSn6Cu-based composites with controlled pore architectures and different ceramic reinforcements, offering valuable insights for the development of advanced lightweight materials for harsh environments. Full article

The integrity of urban water supply pipelines, an essential element of municipal infrastructure, is frequently undermined by internal defects such as corrosion, tuberculation, and foreign matter. Traditional inspection methods relying on CCTV are time-consuming, labor-intensive, and prone to subjective interpretation, which hinders the timely and accurate assessment of pipeline conditions. This study proposes YOLOv8-VSW, a systematically optimized and lightweight model based on YOLOv8 for automated defect detection in in-service pipelines. The framework is twofold: First, to overcome data limitations, a specialized defect dataset was constructed and augmented using photometric transformation, affine transformation, and noise injection. Second, the model architecture was improved on three levels: a VanillaNet backbone was adopted for lightweighting, a C2f-Star module was introduced to enhance multi-scale feature fusion, and the WIoUv3 dynamic loss function was employed to improve robustness under complex imaging conditions. Experimental results demonstrate the superior performance of the proposed YOLOv8-VSW model. This study validates the framework on a curated, real-world image dataset, where YOLOv8-VSW achieved mAP@50 of 83.5%, a 4.0% improvement over the baseline. Concurrently, GFLOPs were reduced by approximately 38.9%, while the inference speed was increased to 603.8 FPS. The findings validate the effectiveness of the proposed method, delivering a solution that effectively balances detection accuracy, computational efficiency, and model size. The results establish a strong technical basis for the intelligent and automated control of safety in urban water supply systems. Full article

Environmentally assisted cracking (EAC) can be an aggressive degradation mechanism for materials in safety-critical applications across a variety of industries, particularly when combined with cyclic mechanical loading. Corrosion fatigue, a prominent form of EAC, often affects tubular components such as piping, heat exchangers, and boiler tubes in chemical, refining, and power generation industries. This study presents the design and validation of a low-cost, automated test system for evaluating EAC under controlled laboratory conditions. The system integrates electromechanical loading, force measurement, and closed-loop control of temperature and pH. Crack growth is monitored using a compliance-based method calibrated using finite element analysis. Environmental control loops were validated for stability and responsiveness. Performance was demonstrated through tests on carbon steel specimens in acidic chloride solution and polymethylmethacrylate (PMMA) specimens in xylene solvents. The system demonstrated accurate load control, environmental stability, and sensitivity to crack extension. The test system also enabled detection of crack closure behavior in carbon steel specimens resulting from corrosion product buildup during immersion in acidic chloride solution. Additionally, the system effectively distinguished varying impacts of environmental severity in PMMA testing (100% xylene vs. 50% xylene–50% ethanol), confirming its suitability for comparative studies. This test platform enables efficient, repeatable evaluation of EAC fatigue performance across a range of materials and environments. Full article

Car wash wastewaters (CWW) bring growing environmental challenges due to the increasing number of vehicles worldwide and they require novel, optimized and sustainable treatment methods. They are highly heterogenous, typically containing complex mixtures of detergents, waxes, oils, petroleum derivatives, corrosion inhibitors and salts, with the composition depending on installation age, geographic location, season, and weather. This study aimed to select bacteria resistant to variable and potentially toxic CWW, capable of biodegrading organic pollutants. A total of 81 strains isolated from various environmental sites were screened for tolerance to CWW environments by performing growth inhibition tests in 20 real wastewater samples with chemical oxygen demand (COD) ranging from 122 to 2267 mg O₂/dm³. Seventeen strain candidates were chosen, identified with molecular proteomics, and further evaluated for biodegradation potential. Based on the most robust isolates, six microbial consortia were developed and examined. Biodegradation experiments were conducted at ambient temperature without active pH control and nutrient supplementation to reflect real conditions occurring in wastewater treatment practice. The best-performing consortium reduced COD by 86% within 7 days. These findings should help improve the treatment of complex CWW by highlighting the potential of thoroughly selected bacteria as effective tools for bioremediation of extremely harsh environments. Full article

This study presents an in situ and laboratory evaluation of an innovative biocide-free nanocomposite coating designed to provide dual anti-corrosion and anti-fouling protection for EH36 naval steel in marine environments. The coating, comprising polyaniline nanorods, titanium dioxide nanoparticles, and Fe₃O₄-functionalized multiwalled carbon nanotubes embedded in a robust resin matrix, was systematically assessed through electrochemical, microscopic, and field-based methods. Laboratory immersion tests and extended exposures at two Mediterranean sea sites (Thessaloniki and Heraklion) revealed substantial improvements in corrosion resistance and significant suppression of marine biofouling over periods of up to 24 months. Electrochemical measurements demonstrated that coated specimens maintained a corrosion inhibition efficiency exceeding 93% throughout the study, exhibiting markedly lower corrosion current densities and higher charge transfer resistances than uncoated controls. Impedance spectroscopy and equivalent circuit modeling confirmed sustained barrier properties, while digital imaging and qualitative biological assessments showed reduced colonization by both micro- and macrofouling organisms. Comparative analysis with conventional biocidal and alternative eco-friendly coatings underscored the superior durability, environmental compatibility, and anti-fouling efficacy of the developed system. The results highlight the coating’s promise as a sustainable, high-performance solution for long-term protection of naval steels against the combined challenges of corrosion and biofouling in harsh marine settings. Full article

Oxide dispersion-strengthened (ODS) alloys are regarded as one of the most promising materials for Generation IV nuclear fission systems, owing to their exceptional attributes such as high strength, corrosion resistance, and irradiation tolerance. The traditional methods for fabricating oxide dispersion-strengthened (ODS) alloys are both time-consuming and costly. In contrast, additive manufacturing (AM) technologies enable precise control over material composition and geometric structure at the nanoscale, thereby enhancing the mechanical properties of components while reducing their weight. This novel approach offers significant advantages over conventional techniques, including reduced production costs, improved manufacturing efficiency, and more uniform distribution of oxide nanoparticles. This review begins by summarizing the state of the art in Fe-based and Ni-based ODS alloys fabricated via traditional routes. Subsequently, it examines recent progress in the AM of ODS alloys, including Fe-based, Ni-based, high-entropy alloys, and medium-entropy alloys, using powder bed fusion (PBF), directed energy deposition (DED), and wire arc additive manufacturing (WAAM). The microstructural characteristics, including oxide particle distribution, grain morphology, and alloy properties, are discussed in the context of different AM processes. Finally, critical challenges and future research directions for laser-based AM of ODS alloys are highlighted. Full article

The polymer industry gained increasing importance due to the ability of polymers to replace traditional materials such as wood, glass, and metals in various applications, offering advantages such as high strength-to-weight ratio, corrosion resistance, and ease of fabrication. Among key performance indicators, melt flow rate (MFR) plays a crucial role in determining polymer quality and processability. However, conventional offline laboratory methods for measuring MFR are time-consuming and unsuitable for real-time quality control in industrial settings. To address this challenge, the study proposes a leveraging artificial intelligence with machine learning-based melt flow rate prediction for polymer properties analysis (LAIML-MFRPPPA) model. A dataset of 1044 polymer samples was used, incorporating six input features such as reactor temperature, pressure, hydrogen-to-propylene ratio, and catalyst feed rate, with MFR as the target variable. The input features were normalized using min–max scaling. Two ensemble models—kernel extreme learning machine (KELM) and random vector functional link (RVFL)—were developed and optimized using the pelican optimization algorithm (POA) for improved predictive accuracy. The proposed method outperformed traditional and deep learning models, achieving an R² of 0.965, MAE of 0.09, RMSE of 0.12, and MAPE of 3.4%. A SHAP-based sensitivity analysis was conducted to interpret the influence of input features, confirming the dominance of melt temperature and molecular weight. Overall, the LAIML-MFRPPPA model offers a robust, accurate, and deployable solution for real-time polymer quality monitoring in manufacturing environments. Full article

This study develops a machine learning potential (MLP) based on the Moment Tensor Potential (MTP) method for the TaN-Ce system. This potential is employed to investigate the interfacial structure and wetting behavior between liquid Ce and solid TaN. Molecular dynamics (MDs) simulations reveal that liquid Ce exhibits significant wetting on the TaN surface at high temperatures. The interfacial region undergoes pre-melting and component interdiffusion, forming an amorphous transition layer. Nitrogen atoms display high diffusivity, leading to surface mass loss, while tantalum atoms demonstrate excellent thermal stability and penetration resistance. These findings provide theoretical support for the design of interfacial materials and corrosion control in high-temperature metallurgy. Full article

This study investigates contaminants in metalworking fluids (MWFs) from an industrial band saw, focusing on microparticle classification and microbial quantification linked to fluid degradation. Most particles were under 50 µm, primarily aluminum and iron oxides from tool wear; oxygen- and sulfur-containing particles suggested corrosion. Microbiological analysis showed high contamination, with culturable microorganisms exceeding 1000 CFU/mL. A pathogenic strain associated with biodeterioration was identified, underscoring the need for microbial control. Filtration and ozonation have been used as decontamination methods to improve the purity and biological stability of the process fluid. Filtration enabled selective removal of metallic microparticles. Among six nanofiber filters, the Berry filter achieved the highest efficiency (70.8%) for particles ≥ 7.3 µm, while other filters were faster but less efficient. Ozonation proved highly effective for microbiological decontamination, reducing viable microorganisms by over 95%, improving visual clarity, and lowering pH from 9 to 8 while remaining within operational limits. Unlike filtration, ozonation significantly reduced microbial load. The combination of both methods is proposed as a sustainable strategy for maintaining process fluid quality under industrial conditions. These findings support integrated decontamination approaches to extend fluid life, reduce fresh MWF consumption and waste, and enhance workplace hygiene and safety in machining operations. Full article

We present a straightforward emulsion-induced interfacial anisotropic assembly method for in- situ synthesis of bowl-shaped, self-encapsulated mesoporous polydopamine (BMPDA) nanocontainers (M-M@P) loaded with 2-mercaptobenzimidazole (2-MBI). Results showed that the loading capacity of the bowl-shaped mesoporous polydopamine reaches 24 wt.%. The M-M@P exhibits a cumulative MBI release of 91.61% after immersion in a 3.5 wt.% NaCl solution at pH = 2 for 24 h, accompanied by a corrosion inhibition efficiency of 95.54%. Additionally, the acid-responsive M-M@P not only enables controlled release of MBI but also synergistically promotes the formation of a protective film on the carbon steel substrate via the chelation of PDA-Fe³⁺, thereby enhancing the self-healing performance of waterborne epoxy coatings. Full article