Materials

22 pages, 26983 KB

Open AccessArticle

Achieving Large-Area Hot Embossing of Anti-Icing Functional Microstructures Based on a Multi-Arc Ion-Plating Mold

by Xiaoliang Wang, Han Luo, Hongpeng Jiang, Zhenjia Wang, Ziyang Wang, Haibao Lu, Jun Xu, Debin Shan, Bin Guo and Jie Xu

Materials 2025, 18(19), 4643; https://doi.org/10.3390/ma18194643 - 9 Oct 2025

Viewed by 294

Abstract

Aluminum alloy surface microstructures possess functional characteristics such as hydrophilicity/hydrophobicity and anti-icing and have important applications in fields such as aerospace and power systems. In order to improve the filling quality of the microstructure and verify the anti-icing property of the microstructure, this [...] Read more.

Aluminum alloy surface microstructures possess functional characteristics such as hydrophilicity/hydrophobicity and anti-icing and have important applications in fields such as aerospace and power systems. In order to improve the filling quality of the microstructure and verify the anti-icing property of the microstructure, this work develops a scheme for achieving large-area hot embossing of anti-icing functional microstructures based on a multi-arc ion-plating mold. Compared with conventional steel, the hardness of the PVD-coated steel increases by 44.7%, the friction coefficient decreases by 66.2%, and the wear resistance is significantly enhanced. The PVD-coated punch-assisted embossing could significantly improve filling properties. While the embossing temperature is 300 °C, the PVD-coated punch-assisted embossing can ensure the complete filling of the micro-array channels. In contrast, under-filling defects occur in conventional hot embossing. Then, a large-area micro-channel specimen of 100 cm² was precisely formed without warping, and the average surface roughness Ra was better than 0.8 µm. The maximum freezing fraction of the micro-array channel was reduced by about 53.2% compared with the planar, and the complete freezing time was delayed by 193.3%. The main reason is that the air layer trapped by the hydrophobic structures hinders heat loss at the solid–liquid interface. Full article

(This article belongs to the Special Issue Advancements in Plastic Forming and Metal Processing: From Fundamentals to Applications)

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17 pages, 4221 KB

Open AccessArticle

Fabrication and Oxidation Resistance of Metallic Ta-Reinforced High-Entropy (Ti,Zr,Hf,Nb,Ta)B₂ Ceramics

by Bowen Yuan, Qilong Guo, Hao Ying, Liang Hua, Ziqiu Shi, Shengcai Yang, Jing Wang and Xiufang Wang

Materials 2025, 18(19), 4642; https://doi.org/10.3390/ma18194642 - 9 Oct 2025

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Abstract

High-entropy boride (HEB) ceramics combine ultra-high melting points, superior hardness, and compositional tunability, enabling service in extreme environments; however, difficult densification and limited fracture toughness still constrain their aerospace applications. In this study, metallic Ta was introduced into high-entropy (Ti_0.2Zr_0.2 [...] Read more.

High-entropy boride (HEB) ceramics combine ultra-high melting points, superior hardness, and compositional tunability, enabling service in extreme environments; however, difficult densification and limited fracture toughness still constrain their aerospace applications. In this study, metallic Ta was introduced into high-entropy (Ti_0.2Zr_0.2Hf_0.2Nb_0.2Ta_0.2)B₂ as both a sintering aid and a toughening phase. Bulk HEB-Ta composites were fabricated by spark plasma sintering to investigate the effect of Ta content on densification behavior, microstructure, mechanical properties, and high-temperature oxidation resistance. The results show that an appropriate amount of Ta markedly promotes densification; at 10 vol% Ta, the open porosity reaches a minimum of 0.15%. Hardness and fracture toughness exhibit an increase-then-decrease trend with Ta content, attaining maxima at 15 vol% Ta (20.79 ± 0.17 GPa and 4.31 ± 0.12 MPa·, respectively). During oxidation at 800–1400 °C, the extent of oxidation increases with temperature, yet the composite with 10 vol% Ta shows the best oxidation resistance. This improvement arises from the formation of a viscous, protective Ta₂O₅-B₂O₃ glassy layer that effectively suppresses oxygen diffusion and enhances high-temperature stability. Overall, incorporating metallic Ta is an effective route to improve the manufacturability and service durability of HEB ceramics, providing a composition guideline and a mechanistic basis for simultaneously enhancing densification, toughness, and oxidation resistance. Full article

(This article belongs to the Special Issue Feature Papers in Refractories and Ceramics: Microstructure, Properties and Applications (3rd Edition))

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19 pages, 6231 KB

Open AccessArticle

Synergistic Effects of Temperature and Cooling Rate on Lamellar Microstructure Evolution and Mechanical Performance in Ti-44.9Al-4.1Nb-1.0Mo-0.1B-0.05Y-0.05Si Alloy

by Fengliang Tan, Yantao Li, Jinbiao Cui, Ning Liu, Kashif Naseem, Zhichao Zhu and Shiwei Tian

Materials 2025, 18(19), 4641; https://doi.org/10.3390/ma18194641 - 9 Oct 2025

Viewed by 343

Abstract

TiAl alloys are ideal candidates to replace nickel-based superalloys in aero-engines due to their low density and high specific strength, yet their industrial application is hindered by narrow heat treatment windows and unbalanced mechanical performance. To address this, this study investigates the microstructure [...] Read more.

TiAl alloys are ideal candidates to replace nickel-based superalloys in aero-engines due to their low density and high specific strength, yet their industrial application is hindered by narrow heat treatment windows and unbalanced mechanical performance. To address this, this study investigates the microstructure and mechanical properties of Ti-44.9Al-4.1Nb-1.0Mo-0.1B-0.05Y-0.05Si (TNM-derived) alloys hot-rolled in the (α₂ + γ) two-phase region. The research employs varying heat treatment temperatures (1150–1280 °C) and cooling rates (0.1–2.5 °C/s), combined with XRD, SEM, EBSD characterization, and 800 °C high-temperature tensile tests. Key findings: Discontinuous dynamic recrystallization (DDRX) of γ grains is the primary mechanism refining lamellar colonies during deformation. Higher heat treatment temperatures reduce γ/β phases (which constrain colony growth), increasing the volume fraction of lamellar colonies but exerting minimal impact on interlamellar spacing. Faster cooling shifts γ lamella nucleation from confined to grain boundaries to multi-sites (grain boundaries, γ lamella peripheries, α grains) and changes grain boundaries from jagged and interlocking to smooth and straight, which boosts nucleation sites and refines interlamellar spacing. Fine lamellar colonies and narrow interlamellar spacing enhance tensile strength, while eliminating brittle βo phases and promoting interlocking boundaries with uniform equiaxed γ grains improve plasticity. Full article

(This article belongs to the Section Metals and Alloys)

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17 pages, 2708 KB

Open AccessArticle

Bending Behavior of Fiber Metal Laminate Plates Under Thermo-Mechanical Loads

by Like Pan, Tong Xing, Yingxin Zhao, Yuan Yuan and Caizhi Yang

Materials 2025, 18(19), 4640; https://doi.org/10.3390/ma18194640 - 9 Oct 2025

Viewed by 273

Abstract

An exact analytical model based on three-dimensional (3D) thermo-elasticity theory is developed to investigate the bending behavior of fiber metal laminate (FML) plates under thermo-mechanical load. The temperature-dependent properties and the orthotropy of the component materials are considered in this model. The analytical [...] Read more.

An exact analytical model based on three-dimensional (3D) thermo-elasticity theory is developed to investigate the bending behavior of fiber metal laminate (FML) plates under thermo-mechanical load. The temperature-dependent properties and the orthotropy of the component materials are considered in this model. The analytical model is based on the heat conduction theory and thermoelasticity theory, and the solutions are determined by employing the Fourier series expansion, the state space approach and the transfer matrix method. Comparison study shows that the FE results are generally in good agreement with the present analytical solutions, exhibiting relative errors of less than 2%, except in the regions near the upper and lower surfaces. The present solution is close to the experimental values for the laminated plate within the linear range, with errors less than 10%. The decoupling analysis indicates that the thermo-mechanical performance of FML plates no longer strictly adheres to the traditional superposition principle, with errors reaching 30.39%. A modified principle accounting for modulus degradation is introduced to address this discrepancy. Furthermore, parametric studies reveal that the temperature and the lamina number have significant effect on the stresses and displacements of the FML plate. Full article

(This article belongs to the Special Issue Modeling and Mechanical Analysis of Materials and Structures in Civil Engineering)

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29 pages, 1600 KB

Open AccessReview

Integration of Multi-Scale Predictive Tools of Bone Fragility: A Structural and Material Property Perspective

by Muhammad Ateeq, Laura Maria Vergani and Federica Buccino

Materials 2025, 18(19), 4639; https://doi.org/10.3390/ma18194639 - 9 Oct 2025

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Abstract

Bone fragility represents a significant global health burden, characterized by the deterioration of bone strength, increased brittleness, and heightened fracture susceptibility. Osteoporosis substantially elevates the risk of fragility fractures, the principal clinical manifestation of the disease. Current diagnostic approaches, including biomedical imaging, bone [...] Read more.

Bone fragility represents a significant global health burden, characterized by the deterioration of bone strength, increased brittleness, and heightened fracture susceptibility. Osteoporosis substantially elevates the risk of fragility fractures, the principal clinical manifestation of the disease. Current diagnostic approaches, including biomedical imaging, bone strength assessment, and bone mineral density measurement, are closely linked to identifying bone fragility through various predictive models and tools. Although numerous studies have employed predictors to characterize fragility fractures, few have comprehensively examined the morpho-structural features of bone across multiple hierarchical scales, limiting the ability to fully elucidate the underlying mechanisms of bone fragility. This review summarizes recent advancements in predictive modeling and novel diagnostic tools, focusing on multiscale approaches for assessing bone fragility. We critically evaluate the translational potential of these tools for the early detection of fragility fractures and their clinical application in mitigating fracture risk. Moreover, this study discusses the integration of multiscale predictive methodologies, which promise to enhance early-stage bone fragility detection and potentially prevent severe fractures through timely intervention. Finally, the study reflects on current research limitations, addressing the challenges associated with multiscale predictive modeling of bone fragility, and proposes future directions to refine these tools to improve the accuracy and utility of fragility fracture prediction and prevention strategies. Full article

(This article belongs to the Special Issue Modelling of Deformation Characteristics of Materials or Structures)

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14 pages, 2932 KB

Open AccessArticle

Correlation Model of Damage Class and Deformation for Reinforced Concrete Beams Damaged by Earthquakes

by Chunri Quan, Ho Choi and Kiwoong Jin

Materials 2025, 18(19), 4638; https://doi.org/10.3390/ma18194638 - 9 Oct 2025

Viewed by 332

Abstract

The objective of this study was to propose a correlation model of the damage class and deformation of reinforced concrete (RC) beams damaged by earthquakes with a focus on columns and walls. For this purpose, a series of full-scale RC beam specimens with [...] Read more.

The objective of this study was to propose a correlation model of the damage class and deformation of reinforced concrete (RC) beams damaged by earthquakes with a focus on columns and walls. For this purpose, a series of full-scale RC beam specimens with different shear strength margins were tested under cyclic lateral loading to examine their deformation performance and damage states. Then, the damage class and seismic capacity reduction factor of RC beams were evaluated based on the test results. The results showed that the tendency of shear failure, such as shear crack pattern and shear deformation component, of specimens with small shear strength margins was more remarkable, and its maximum residual crack widths tended to be slightly larger and dominated by shear cracks. The results also indicated that the effect of the shear strength margin on the seismic capacity reduction factor which represents the residual seismic performance of RC beams was limited, whereas the specimen with a smaller shear strength margin exhibited lower ultimate deformation capacity. In addition, there was a difference in the boundary value of the lateral drift angle which classifies the damage class of specimens with different shear strength margins. Finally, correlation models between the damage class and deformation of RC beams with different deformation capacities were proposed. Full article

(This article belongs to the Section Construction and Building Materials)

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12 pages, 1464 KB

Open AccessArticle

Carbon Micro-Alloying Promotes Creep Flow via Enhanced Structural Heterogeneity in Fe-Based Amorphous Alloys

by Deyu Cao, Sishi Teng, Jiajie Lv, Xin Su, Yu Tong, Mingliang Xiang, Lijian Song, Meng Gao, Yan Zhang, Juntao Huo and Junqiang Wang

Materials 2025, 18(19), 4637; https://doi.org/10.3390/ma18194637 - 9 Oct 2025

Viewed by 477

Abstract

Tuning structural heterogeneity in metallic glasses is key to improving their mechanical performance. Here we examine how carbon micro-alloying modulates the relaxation dynamics and creep of Fe-based amorphous ribbons. Increasing carbon content lowers the crystallization temperature, amplifies β-relaxation, and reduces hardness, consistent [...] Read more.

Tuning structural heterogeneity in metallic glasses is key to improving their mechanical performance. Here we examine how carbon micro-alloying modulates the relaxation dynamics and creep of Fe-based amorphous ribbons. Increasing carbon content lowers the crystallization temperature, amplifies β-relaxation, and reduces hardness, consistent with enhanced atomic mobility. Nanoindentation creep, fitted with a stretched-exponential model, shows a decreasing exponent with carbon addition, indicating broader relaxation–time distributions and stronger dynamic heterogeneity. Nanoscale force-mapping further reveals a larger fraction of liquid-like regions and pronounced viscoelastic heterogeneity in carbon-rich samples. These changes facilitate the activation of shear-transformation zones and promote room-temperature creep flow. Together, the results establish a direct link between structural heterogeneity, relaxation processes, and mechanical response, providing guidance for the design of ductile metallic glasses. Full article

(This article belongs to the Special Issue Characterization, Properties, and Applications of New Metallic Alloys)

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22 pages, 6982 KB

Open AccessArticle

Design of Semi-Rigid Composite Highway Pavements Using Cementitious Grouting and Porous Asphalt

by Sevil Kofteci, Mansor Nazary, Ahmad Khaled Masbah and Halil Ibrahim Burgan

Materials 2025, 18(19), 4636; https://doi.org/10.3390/ma18194636 - 9 Oct 2025

Viewed by 489

Abstract

Due to the increasing volume of traffic on the world’s highways, researchers have been searching for new composite techniques and methods to develop durable and cost-effective pavement structures. The semi-rigid pavement is a composite pavement consisting of a porous asphalt mix with air [...] Read more.

Due to the increasing volume of traffic on the world’s highways, researchers have been searching for new composite techniques and methods to develop durable and cost-effective pavement structures. The semi-rigid pavement is a composite pavement consisting of a porous asphalt mix with air voids between 25 and 30% and a high-fluidity cementitious grout. In this study, different cementitious grout mixes were prepared. Then a porous asphalt mix with almost 30% air void content was designed. After evaluating the workability, mechanical strength, and volume stability of the prepared grout mixes, the most suitable mix is proposed to fill the voids in the porous asphalt mix. Finally, the prepared semi-rigid pavement specimens were subjected to various tests to evaluate the performance characteristics of the designed pavement. The research concludes that the grout mixture ratio proposed in this study has good grouting ability and the semi-rigid pavement has superior performance characteristics. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Green and Sustainable Materials in the Construction Industry)

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15 pages, 3884 KB

Open AccessArticle

Effect of B/N Doping on Enhanced Hydrogen Storage in Transition Metal-Modified Graphene: A First-Principles DFT Study

by Qian Nie, Lei Wang, Ye Chen and Zhengwei Nie

Materials 2025, 18(19), 4635; https://doi.org/10.3390/ma18194635 - 8 Oct 2025

Viewed by 333

Abstract

Hydrogen energy is viewed as a promising green energy source because of its high energy density, abundant availability, and clean combustion results. Hydrogen storage is the critical link in a hydrogen economy. Using first-principles density functional theory calculations, this work explored the role [...] Read more.

Hydrogen energy is viewed as a promising green energy source because of its high energy density, abundant availability, and clean combustion results. Hydrogen storage is the critical link in a hydrogen economy. Using first-principles density functional theory calculations, this work explored the role of B and N in modulating the binding properties of transition metal-modified graphene. The hydrogen storage performance of Sc-, Ti-, and V-modified B-doped graphene was evaluated. Boron doping induces an electron-deficient state, enhancing interactions between transition metals and graphene. Sc, Ti, and V preferentially adsorbed at the carbon ring’s hollow site in B-doped graphene, with their binding energies being 1.87, 1.74, and 1.69 eV higher than those in pure graphene, respectively. These systems can stably adsorb up to 5, 4, and 4 H₂ molecules, with average adsorption energies of −0.528, −0.645, and −0.620 eV/H₂, respectively. The hydrogen adsorption mechanism was dominated by orbital interactions and polarization effects. Among the systems studied, Sc-modified B-doped graphene exhibited superior hydrogen storage characteristics, making it a promising candidate for reversible applications. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Gaseous Storage)

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18 pages, 2806 KB

Open AccessArticle

Polylactide (PLA) Composites Reinforced with Natural Fibrous Filler Recovered from the Biomass of Sorghum Leaves or Stems

by Ryszard Gąsiorowski, Danuta Matykiewicz and Dominika Janiszewska-Latterini

Materials 2025, 18(19), 4634; https://doi.org/10.3390/ma18194634 - 8 Oct 2025

Viewed by 342

Abstract

In response to environmental pressures and the growing demand for sustainable materials, this study investigates the use of lignocellulosic fillers derived from sorghum (Sorghum bicolor L. Moench) biomass, specifically stems and leaves, as reinforcements in biodegradable polylactic acid (PLA) composites. The aim [...] Read more.

In response to environmental pressures and the growing demand for sustainable materials, this study investigates the use of lignocellulosic fillers derived from sorghum (Sorghum bicolor L. Moench) biomass, specifically stems and leaves, as reinforcements in biodegradable polylactic acid (PLA) composites. The aim was to assess the effect of filler type and content (5, 10, and 15 wt.%) on the physicochemical properties of the composites. Sorghum was manually harvested in Greater Poland, separated, dried, milled, and fractionated to particles <0.25 mm. Composites were produced via extrusion and injection molding, followed by characterization using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), tensile and impact testing, density measurements, optical microscopy, and scanning electron microscopy (SEM). Results showed that stem-based fillers provided a better balance between stiffness and ductility, along with improved dispersion and interfacial adhesion. In contrast, leaf-based fillers led to higher stiffness but greater brittleness and agglomeration. All composites exhibited decreased impact strength and thermal stability compared to neat PLA, with the extent of these decreases depending on the filler type and loading. The study highlights the potential of sorghum stems as a viable, renewable reinforcement in biopolymer composites, aligning with circular economy and bioeconomy strategies. Full article

(This article belongs to the Special Issue Manufacturing and Recycling of Natural Fiber-Reinforced Composites)

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17 pages, 5705 KB

Open AccessArticle

Self-Assembled Monolayers of Various Alkyl-Phosphonic Acids on Bioactive FHA Coating for Improving Surface Stability and Corrosion Resistance of Biodegradable AZ91D Mg Alloy

by Chung-Wei Yang and Peng-Hsiu Li

Materials 2025, 18(19), 4633; https://doi.org/10.3390/ma18194633 - 8 Oct 2025

Viewed by 373

Abstract

The aim of present study is to deposit protective coatings with various surface chemical states on AZ91D Mg alloy. Hydrothermal bioactive ceramic coatings are performed with a surface modification by the chemical bonding of self-assembled monolayers (SAM). The electrochemical corrosion behaviors of various [...] Read more.

The aim of present study is to deposit protective coatings with various surface chemical states on AZ91D Mg alloy. Hydrothermal bioactive ceramic coatings are performed with a surface modification by the chemical bonding of self-assembled monolayers (SAM). The electrochemical corrosion behaviors of various surface-coated AZ91D alloy within DMEM cell culture medium related to their surface chemical states are evaluated through microstructure observations, XPS surface chemical bonding analysis, static contact angles measurements, potentiodynamic polarization curves, and immersion tests. XRD and high resolution XPS of F 1s analysis results show that the hydrothermal FHA coating with a phase composition of Ca₁₀(PO₄)₆(OH)F can be effectively and uniformly deposited on the AZ91D alloy. FHA-coated AZ91D displays better anti-corrosion performances and lower degradation rates than those of uncoated AZ91D alloy in the DMEM solution. Through the high resolution XPS analysis of O 1s and P 2p spectra, it is demonstrated that 1-butylphosphonic acid (BP), 1 octylphosphonic acid (OP), and dodecylphosphonic acid (DP) molecules can be effectively bonded on the FHA surface by a covalent bond to form SAM. BP/OP/DP-SAM specimens display increased static contact angles to show a hydrophobic surface. It demonstrates that the SAM surface treatment can further enhance the corrosion resistance of FHA-coated AZ91D in the DMEM solution. After 2–16 days in vitro immersion tests in the DMEM, the surface SAM-bonded hydrophobic BP/OP/DP-SAM layers can effectively inhibit and reduce the penetration of DMEM into FHA coating. Long alkyl chains of the dodecylphosphonic acid (DP) SAM represents superior enhancing effects on the reduction of corrosion properties and weight loss. Full article

(This article belongs to the Special Issue Corrosion Resistance and Protection of Metal Alloys)

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23 pages, 4283 KB

Open AccessArticle

Synergistic Regulation of δ-MnO₂ Cathode via Crystal Engineering and pH Buffering for Long-Cycle Aqueous Zinc-Ion Batteries

by Fan Zhang, Haotian Yu, Qiongyue Zhang, Yahao Wang, Haodong Ren, Huirong Liang, Jinrui Li, Yuanyuan Feng, Bin Zhao and Xiaogang Han

Materials 2025, 18(19), 4632; https://doi.org/10.3390/ma18194632 - 8 Oct 2025

Viewed by 472

Abstract

Aqueous zinc-ion batteries (ZIBs) have emerged as a promising candidate for large-scale energy storage due to their inherent safety, low cost, and environmental friendliness. However, manganese dioxide (MnO₂)-based cathodes, which are widely studied for ZIBs owing to their high theoretical capacity [...] Read more.

Aqueous zinc-ion batteries (ZIBs) have emerged as a promising candidate for large-scale energy storage due to their inherent safety, low cost, and environmental friendliness. However, manganese dioxide (MnO₂)-based cathodes, which are widely studied for ZIBs owing to their high theoretical capacity and low cost, face severe capacity fading issues that hinder the commercialization of ZIBs. This performance degradation mainly stems from the weak van der Waals forces between MnO₂ layers leading to structural collapse during repeated Zn²⁺ insertion and extraction; it is also exacerbated by irreversible Mn dissolution via Mn³⁺ disproportionation that depletes active materials, and further aggravated by dynamic electrolyte pH fluctuations promoting insulating zinc hydroxide sulfate (ZHS) formation to block ion diffusion channels. To address these interconnected challenges, in this study, a synergistic strategy was developed combining crystal engineering and pH buffer regulation. We synthesized three MnO₂ polymorphs (α-, δ-, γ-MnO₂), identified δ-MnO₂ with flower-like microspheres as optimal, and introduced sodium dihydrogen phosphate (NaH₂PO₄) as a pH buffer (stabilizing pH at 2.8 ± 0.2). The modified electrolyte improved δ-MnO₂ wettability (contact angle of 17.8° in NaH₂PO₄-modified electrolyte vs. 26.1° in base electrolyte) and reduced charge transfer resistance (Rct = 78.17 Ω), enabling the optimized cathode to retain 117.25 mAh g⁻¹ (82.16% retention) after 2500 cycles at 1 A g⁻¹. This work provides an effective strategy for stable MnO₂-based ZIBs, promoting their application in renewable energy storage. Full article

(This article belongs to the Section Energy Materials)

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27 pages, 4835 KB

Open AccessArticle

Real-Time Carbon Content Prediction Model for the Reblowing Stage of Converter Based on PI-LSTM

by Yuanzheng Guo, Dongfeng He, Xiaolong Li and Kai Feng

Materials 2025, 18(19), 4631; https://doi.org/10.3390/ma18194631 - 8 Oct 2025

Viewed by 345

Abstract

Precise forecasting of carbon content in the converter’s reblowing phase is pivotal to boosting steel production efficiency and ensuring effective control over molten steel quality. However, existing mechanistic models based on material balance and decarbonization kinetics suffer from insufficient accuracy due to simplifying [...] Read more.

Precise forecasting of carbon content in the converter’s reblowing phase is pivotal to boosting steel production efficiency and ensuring effective control over molten steel quality. However, existing mechanistic models based on material balance and decarbonization kinetics suffer from insufficient accuracy due to simplifying assumptions. In contrast, data-driven models rely on data quality, lack generalization capability, and lack physical interpretability. Additionally, integral models based on flue gas analysis suffer from data latency issues. To overcome these limitations, this study proposed a real-time carbon content prediction model for the converter’s reblowing phase, leveraging a physics-informed long short-term memory (PI-LSTM) network. First, flue gas data was processed using a carbon integration model to generate a carbon content change curve during the reblowing stage as a reference for actual values; second, a dual-branch network structure was designed, where the LSTM branch simultaneously predicts carbon content and key unmeasurable parameters in the decarbonization kinetics, while the mechanism branch combined these parameters with the decarbonization formula to calculate carbon content under mechanism constraints; finally, a joint loss function (combining data-driven loss and mechanism constraint loss) was used to train the model, and the gray wolf optimization (GWO) algorithm was employed to optimize hyperparameters. Experimental results show that compared to the mechanism model (MM) and LSTM model, the PI-LSTM model achieves an average absolute error (MAE) of 0.0077, a root mean square error (RMSE) of 0.0112, and endpoint carbon content hit rates within ±0.005%, ±0.01%, ±0.015% error ranges, achieving 53.71%, 82.23%, and 95.45%, respectively, significantly improving prediction accuracy and physical plausibility. This model lays a robust groundwork for dynamic closed-loop real-time control of carbon levels in the converter’s reblowing stage. Full article

(This article belongs to the Section Materials Simulation and Design)

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13 pages, 2155 KB

Open AccessArticle

Analysis of Stator Material Influence on BLDC Motor Performance

by Daniel Ziemiański, Gabriela Chwalik-Pilszyk and Grzegorz Dudzik

Materials 2025, 18(19), 4630; https://doi.org/10.3390/ma18194630 - 7 Oct 2025

Viewed by 314

Abstract

Brushless DC (BLDC) motors are increasingly used in industrial applications due to their high efficiency, reliability, and low weight. However, their performance strongly depends on the electromagnetic properties of stator and rotor core materials. This study evaluates six BLDC motor configurations, employing materials [...] Read more.

Brushless DC (BLDC) motors are increasingly used in industrial applications due to their high efficiency, reliability, and low weight. However, their performance strongly depends on the electromagnetic properties of stator and rotor core materials. This study evaluates six BLDC motor configurations, employing materials such as M19 electrical steel, 1010 low-carbon steel, magnetic PLA, and ABS, and analyzes their impact using FEMM 4.2 finite element simulations. Key electromagnetic characteristics—including flux linkage, Back-EMF, torque, and torque ripple—were compared across configurations. The reference motor with M19 steel stator and 1010 steel rotor achieved ~7 mWb flux linkage, ~39 V pk–pk Back-EMF, and 1.44 Nm torque with ~49% ripple, confirming the suitability of laminated steels for high-power-density designs. Substituting M19 with 1010 steel in the stator reduced torque by less than 10%, indicating material interchangeability with minimal performance loss. By contrast, polymer-based designs exhibited drastic degradation: magnetic PLA yielded only 3.5% of the baseline torque with sixfold ripple increase, while ABS delivered nearly zero torque and >700% ripple. Hybrid configurations improved PLA-based results by 15–20%, though they remained far below ferromagnetic cores. Overall, results demonstrate a nearly linear relationship between material permeability and both flux linkage and Back-EMF, alongside a sharp rise in torque ripple at low permeability. The findings highlight the advantages of ferromagnetic and laminated steel cores for efficiency and stability, while polymer and hybrid cores are limited to lightweight demonstrator applications. Full article

(This article belongs to the Special Issue Optimization and Simulation in Alloy Cutting Processes (Third Edition))

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33 pages, 3993 KB

Open AccessArticle

Free Vibration Analysis of Thin Functionally Graded Plate Bands with Microstructure as a Function of Material Inhomogeneity Distribution and Boundary Conditions

by Jarosław Jędrysiak and Magda Kaźmierczak-Sobińska

Materials 2025, 18(19), 4629; https://doi.org/10.3390/ma18194629 - 7 Oct 2025

Viewed by 293

Abstract

An analysis of free vibrations for thin functionally graded plate bands is presented in this work. On the microlevel these plate bands have a tolerance-periodic microstructure in planes parallel to the mid-plane. Partial differential equations with tolerance-periodic, highly oscillating, non-continuous coefficients describe the [...] Read more.

An analysis of free vibrations for thin functionally graded plate bands is presented in this work. On the microlevel these plate bands have a tolerance-periodic microstructure in planes parallel to the mid-plane. Partial differential equations with tolerance-periodic, highly oscillating, non-continuous coefficients describe the vibrations of such plates. Here, the influence of microstructure inhomogeneity is shown on free vibration frequencies of these plate bands with different boundary conditions. This analysis was carried out within the framework of two models of these plates. The models are represented by equations with smooth, slowly varying coefficients. One of these models, called the tolerance model, takes into account the effect of the microstructure size. Hence, it leads not only to formulas of fundamental lower-order vibration frequencies, but also to formulas of higher-order vibration frequencies, which are related to the microstructure. The analyses of free vibration frequencies for thin functionally graded plate bands with different boundary conditions are presented. The formulas of frequencies are obtained using the Ritz method. A comparison of some calculated results to the results obtained by the FEM is also shown. Full article

(This article belongs to the Section Construction and Building Materials)

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13 pages, 1889 KB

Open AccessArticle

Dimension Tailoring of Quasi-2D Perovskite Films Based on Atmosphere Control Toward Enhanced Amplified Spontaneous Emission

by Zijia Wang, Xuexuan Huang, Zixuan Song, Chiyu Guo, Liang Tao, Shibo Wei, Ke Ren, Yuze Wu, Xuejiao Sun and Chenghao Bi

Materials 2025, 18(19), 4628; https://doi.org/10.3390/ma18194628 - 7 Oct 2025

Viewed by 332

Abstract

Quasi-two-dimensional (Q2D) perovskite films have garnered significant attention as novel gain media for lasers due to their tunable bandgap, narrow linewidth, and solution processability. Q2D perovskites endowed with intrinsic quantum well structures demonstrate remarkable potential as gain media for cost-effective miniaturized lasers, owing [...] Read more.

Quasi-two-dimensional (Q2D) perovskite films have garnered significant attention as novel gain media for lasers due to their tunable bandgap, narrow linewidth, and solution processability. Q2D perovskites endowed with intrinsic quantum well structures demonstrate remarkable potential as gain media for cost-effective miniaturized lasers, owing to their superior ambient stability and enhanced photon confinement capabilities. However, the mixed-phase distribution within Q2D films constitutes a critical determinant of their optical properties, exhibiting pronounced sensitivity to specific fabrication protocols and processing parameters, including annealing temperature, duration, antisolvent volume, injection timing, and dosing rate. These factors frequently lead to broad phase distribution in Q2D perovskite films, thereby inducing incomplete exciton energy transfer and multiple emission peaks, while simultaneously making the fabrication processes intricate and reducing reproducibility. Here, we report a novel annealing-free and antisolvent-free method for the preparation of Q2D perovskite films fabricated in ambient atmosphere. By constructing a tailored mixed-solvent vapor atmosphere and systematically investigating its regulatory effects on the nucleation and growth processes of film via in situ photoluminescence spectra, we successfully achieved the fabrication of Q2D perovskite films with large n narrow phase distribution characteristics. Due to the reduced content of small n domains, the incomplete energy transfer from small n to large n phases and the carriers’ accumulation in small n can be greatly suppressed, thereby suppressing the trap-assistant nonradiative recombination and Auger recombination. Ultimately, the Q2D perovskite film showed a single emission peak at 519 nm with the narrow full width at half maximum (FWHM) of 21.5 nm and high photoluminescence quantum yield (PLQY) of 83%. And based on the optimized Q2D film, we achieved an amplified spontaneous emission (ASE) with a low threshold of 29 μJ·cm⁻², which was approximately 60% lower than the 69 μJ·cm⁻² of the control film. Full article

(This article belongs to the Special Issue Surface Modulation of Semiconductor Quantum Dots for Advanced Optoelectronic Applications)

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26 pages, 7645 KB

Open AccessArticle

Investigation on Drying Shrinkage of Basalt Fiber-Reinforced Concrete with Coal Gangue Ceramsite as Coarse Aggregates

by Shi Liu, Xiaojian Rong, Shuchao Wei and Dong Li

Materials 2025, 18(19), 4627; https://doi.org/10.3390/ma18194627 - 7 Oct 2025

Viewed by 487

Abstract

In order to investigate the basalt fiber influences on drying shrinkage of coal gangue ceramsite concrete, specimens with varying fiber dosages and matrix strength were prepared. The drying shrinkage (DS) was compared. To elucidate the characteristics of the DS, the internal humidity (IH) [...] Read more.

In order to investigate the basalt fiber influences on drying shrinkage of coal gangue ceramsite concrete, specimens with varying fiber dosages and matrix strength were prepared. The drying shrinkage (DS) was compared. To elucidate the characteristics of the DS, the internal humidity (IH) and electrical resistivity (ER) were also tested. The properties of the variation in the DS, IH, and ER were verified. The correlation between the values of the DS, IH, and ES was systematically analyzed, and a prediction model of DS considering the influence of fiber dosage and coal gangue ceramsite was proposed. The results showed that the incorporation of basalt fiber can significantly reduce the DS, and the value of the DS decreased with the increment of fiber dosage. The value of the DS also decreased with the enhancement of the matrix strength. An inverse relationship existed between the variation in the IH and DS, whereas the variation in the ER demonstrated a direct proportionality with the variation in the DS. The prediction model for the basalt fiber-reinforced coal gangue ceramsite concrete was obtained by modifying the AFREM model. The values predicted by the improved AFREM model demonstrated excellent consistency with the test data. Full article

(This article belongs to the Topic Solid Waste Recycling in Civil Engineering Materials)

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13 pages, 3860 KB

Open AccessArticle

Mechanical Performance and Energy Absorption of Ti6Al4V I-WP Lattice Metamaterials Manufactured via Selective Laser Melting

by Le Yu, Xiong Xiao, Xianyong Zhu, Jiaan Liu, Guangzhi Sun, Yanheng Xu, Song Yang, Cheng Jiang and Dongni Geng

Materials 2025, 18(19), 4626; https://doi.org/10.3390/ma18194626 - 7 Oct 2025

Viewed by 394

Abstract

Metamaterial lattice structures based on a Triply Periodic Minimal Surface (TPMS) structure have attracted much attention due to their excellent mechanical properties and energy absorption capabilities. In this study, a novel TPMS lattice metamaterial structure (IWP-X) is designed to enhance the axial mechanical [...] Read more.

Metamaterial lattice structures based on a Triply Periodic Minimal Surface (TPMS) structure have attracted much attention due to their excellent mechanical properties and energy absorption capabilities. In this study, a novel TPMS lattice metamaterial structure (IWP-X) is designed to enhance the axial mechanical properties by fusing an X-shaped plate with an IWP surface structure. A selective laser melting (SLM) machine was utilized to print the designed lattice structures with Ti6Al4V powder. The thickness of the plate and the density of the IWP are varied to explore the responsivity of the mechanical and energy absorption properties with the volume ratio of IWP-X. The finite element simulation analysis is used to effectively predict the stress distribution and fracture site of each structure in the compression test. The results show that the IWP-X structure obtains the ultimate compressive strength of 122.06% improvement, and the energy absorption of 282.03% improvement. The specific energy absorption (SEA) reaches its maximum value in the plate-to-IWP volume ratio of 0.7 to 0.8. Full article

(This article belongs to the Special Issue Multiscale Mechanical Behaviors of Advanced Materials and Structures)

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14 pages, 4813 KB

Open AccessArticle

Microstructural Stability and Densification Behavior of Cantor-Type High-Entropy Alloy Processed by Spark Plasma Sintering

by Marcin Madej, Beata Leszczyńska-Madej, Anna Kopeć-Surzyn, Paweł Nieroda and Stanislav Rusz

Materials 2025, 18(19), 4625; https://doi.org/10.3390/ma18194625 - 7 Oct 2025

Viewed by 389

Abstract

High-entropy alloys (HEAs) of the Cantor type (CoCrFeMnNi) are widely recognized as model systems for studying the relationships between composition, microstructure, and functional performance. In this study, atomized Cantor alloy powders were consolidated using spark plasma sintering (SPS) under systematically varied process parameters [...] Read more.

High-entropy alloys (HEAs) of the Cantor type (CoCrFeMnNi) are widely recognized as model systems for studying the relationships between composition, microstructure, and functional performance. In this study, atomized Cantor alloy powders were consolidated using spark plasma sintering (SPS) under systematically varied process parameters (temperature and dwell time). The densification behavior, microstructural evolution, and mechanical response were investigated using Archimedes’ density measurements, Vickers hardness testing, compression tests, scanning electron microscopy, and EDS mapping. The results reveal a non-linear relationship between sintering temperature and densification, with maximum relative densities obtained at 1050 °C and 1100 °C for short dwell times. Despite the ultrafast nature of SPS, grain growth was observed, particularly at elevated temperatures and extended dwell times, challenging the assumption that SPS inherently limits grain coarsening. All sintered samples retained a single-phase FCC structure with homogeneous elemental distribution, and no phase segregation or secondary precipitates were detected. Compression testing showed that samples sintered at 1050 °C and 1070 °C exhibited the highest strength, demonstrating the strong interplay between sintering kinetics and grain cohesion. Full article

(This article belongs to the Collection Spark-Plasma Sintering and Related Field-Assisted Powder Consolidation Technologies)

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13 pages, 4227 KB

Open AccessArticle

Wear Measurements in Cylindrical Telescopic Crowns Using an Active Piezoresistive Cantilever with an Integrated Gold Microsphere Probe

by Tomasz Dąbrowa, Dominik Badura, Bartosz Pruchnik, Władysław Kopczyński, Ivo W. Rangelow, Edward Kijak and Teodor Gotszalk

Materials 2025, 18(19), 4624; https://doi.org/10.3390/ma18194624 - 7 Oct 2025

Viewed by 326

Abstract

In this paper, we report a novel application of atomic force microscopy (AFM) for measurement of wear of prosthetic materials. In contrast to previously employed methods, we introduce AFM-based wear induction. In this way, we utilize AFM as both measurement technique and the [...] Read more.

In this paper, we report a novel application of atomic force microscopy (AFM) for measurement of wear of prosthetic materials. In contrast to previously employed methods, we introduce AFM-based wear induction. In this way, we utilize AFM as both measurement technique and the mean for surface wear. We describe the methodology along with the metrological advantages of the approach regarding the supreme resolution of volume measurement (down to 1 μm³). We investigate wear between prosthetic gold alloy (Degulor M) and FGP polymeric material from Bredent in nanoscale. For that purpose, we modify active piezoresistive cantilever, replacing the original tip with Degulor M microsphere. We elaborate on the process of modification and present how the mass volume and topology of the tip is controlled throughout the process. Wear process was performed in reciprocal motion over the length of 5 μm in 35,000 repetitions to mimic the actual conditions occurring in human mouth cavity. We present how this method, by focusing on a small area of investigated materials, leads to shortening the overall time of wear measurements from tong term observations down to several minutes. AFM-measured data present consistent relation between wear energy and wear volume. Exemplary results seem to confirm durability of the FGP-Degulor M mechanical contact and occurring strengthening of the mechanical contact with roughening of the polymeric surface. Full article

(This article belongs to the Special Issue Materials for Dentistry: Biofunctional Properties and Their Improvement)

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28 pages, 3028 KB

Open AccessArticle

Performance Research of Ultra-High Performance Concrete Incorporating Municipal Solid Waste Incineration Fly Ash

by Fengli Liu, Yize He, Junhua Liu, Feiyang Zhang, Xiaofei Hao and Chang Liu

Materials 2025, 18(19), 4623; https://doi.org/10.3390/ma18194623 - 7 Oct 2025

Viewed by 399

Abstract

Waste management poses escalating threats to environmental sustainability, particularly with municipal solid waste (MSW) growth. Incineration, a widely adopted method for reducing waste volume, produces millions of tons of municipal solid waste incineration fly ash (MSWIFA) each year. Despite its high toxicity and [...] Read more.

Waste management poses escalating threats to environmental sustainability, particularly with municipal solid waste (MSW) growth. Incineration, a widely adopted method for reducing waste volume, produces millions of tons of municipal solid waste incineration fly ash (MSWIFA) each year. Despite its high toxicity and classification as a hazardous solid waste, its ultrafine particle size and pozzolanic activity offer potential for its use in construction materials. In this study, MSWIFA was used to replace 6%, 12%, 18% and 24% of cementitious materials, and the effect of MSWIFA substitution rate on the workability, mechanical properties, microstructure, and durability of UHPC was studied. Furthermore, the study assessed the solidification capacity of the UHPC for heavy metal ions and quantitatively analyzed its eco-economic benefits. The results show that, under standard curing conditions, substituting 12% of cementitious materials with MSWIFA significantly modified UHPC hydration, shortened setting time, reduced fluidity, and increased wet packing density. The 28-day compressive strength reached 134.63 MPa, comparable to the control group. Concurrently, fluidity, durability, and heavy metal leaching all met the required standards, with energy consumption reduced by 14.86%, carbon emissions lowered by 12.76%, and economic costs decreased by 6.41%. This study provides a feasible solution for recycling MSWIFA into non-hazardous concrete, facilitating sustainable hazardous waste management and mitigating heavy metal-related environmental pollution. Full article

(This article belongs to the Special Issue Transforming Industrial Waste into Sustainable Construction Materials (2nd Edition))

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18 pages, 3170 KB

Open AccessArticle

Synthesis and Characterisation of Metal–Glass Composite Materials Fabricated by Liquid Phase Sintering

by Vladimir Pavkov, Gordana Bakić, Vesna Maksimović and Srećko Stopić

Materials 2025, 18(19), 4622; https://doi.org/10.3390/ma18194622 - 7 Oct 2025

Viewed by 483

Abstract

In recent years, there has been a global increase in environmental awareness, which has driven the application of natural materials or the synthesis of novel, environmentally compatible materials. Composite materials hold a prominent position among modern materials and are typically developed to achieve [...] Read more.

In recent years, there has been a global increase in environmental awareness, which has driven the application of natural materials or the synthesis of novel, environmentally compatible materials. Composite materials hold a prominent position among modern materials and are typically developed to achieve resistance to various damage mechanisms, thereby extending the service life of structures. This study presents the synthesis and characterisation of high-density metal–glass composite materials. The commercially available 316L stainless steel powder was used as the matrix material, while andesite basalt powder was used as the reinforcement phase. Andesite basalt aggregate, ground into powder, is a cost-effective, widely available, and environmentally friendly natural raw material. Powder metallurgy was employed to produce the composite materials. Sintering was performed at 1250 °C for 30 min in a vacuum. The density of the sintered composite samples was analysed as a function of andesite basalt content, with sintering conducted in the presence of a liquid phase. Composite materials were characterised using optical and scanning electron microscopy, X-ray structural analysis, and hardness testing. This study confirmed that the optimal combination of properties was achieved in the composite with 20 wt.% andesite basalt, present as a glass phase within the 316L steel matrix. Full article

(This article belongs to the Special Issue Synthesis, Sintering, and Characterization of Composites)

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12 pages, 3068 KB

Open AccessArticle

Research on the Synthesis and Conductivity of Titanium Oxycarbide

by Shaolong Li, Fan Yang, Peizhu Mao, Tianzhu Mu, Fuxing Zhu and Shengwei Li

Materials 2025, 18(19), 4621; https://doi.org/10.3390/ma18194621 - 6 Oct 2025

Viewed by 278

Abstract

In this study, TiC_xO_y was produced by sintering in an argon atmosphere using carbon–thermal reduction with TiO₂ and graphite powder as the initial materials. The sintered TiC_xO_y was analyzed using X-ray diffraction, scanning electron microscopy, and [...] Read more.

In this study, TiC_xO_y was produced by sintering in an argon atmosphere using carbon–thermal reduction with TiO₂ and graphite powder as the initial materials. The sintered TiC_xO_y was analyzed using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. As the oxygen content increased, the grain color of the sintered TiC_xO_y gradually shifted from gray to reddish-brown. The structure of TiC_xO_y resembles that of a coral, with a uniform distribution of Ti, C, and O throughout the sample. Analysis using X-ray photoelectron spectroscopy reveals the presence of bivalent, trivalent, and tetravalent titanium. Utilizing General Structure Analysis System software (GSAS-II), the X-ray Diffraction data obtained were refined, revealing a gradual decrease in lattice parameters as the oxygen atom content increased. Furthermore, the conductivity and density of the single phase, determined through the four-probe method and the Archimedes method, respectively, exhibited an increase in tandem with the rise in C content. Full article

(This article belongs to the Section Advanced Materials Characterization)

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17 pages, 14162 KB

Open AccessArticle

Structure and Phase Composition of the Products Derived from Vacuum–Thermal Treatment of a Tellurium-Containing Middling

by Alina Nitsenko, Xeniya Linnik, Valeriy Volodin, Sergey Trebukhov, Bulat Sukurov, Farkhad Tuleutay and Tolebi Dzhienalyev

Materials 2025, 18(19), 4620; https://doi.org/10.3390/ma18194620 - 6 Oct 2025

Viewed by 342

Abstract

In this paper, the results from a study of the products obtained by vacuum–thermal processing of industrial copper telluride in an inert atmosphere at a pressure of 66 Pa and a temperature of 1100 °C are presented. The residue obtained mainly consisted of [...] Read more.

In this paper, the results from a study of the products obtained by vacuum–thermal processing of industrial copper telluride in an inert atmosphere at a pressure of 66 Pa and a temperature of 1100 °C are presented. The residue obtained mainly consisted of the copper(I) oxide phase. The condensate was represented by the phases CuTe₂O₅, CuO·CuTeO₃, TeO₂, SiO₂, and CuTe₂Cl. The vapor phase condensed in four temperature zones, each represented by a different phase composition. A monophase of tellurium oxide was identified in the condensate at temperatures of 150 to 270 °C. The obtained data contribute to expanding scientific knowledge and form the basis for developing a new, environmentally safe method of processing tellurium-containing middling. The creation of new technologies promotes increased efficiency of tellurium recovery and reduces environmental risks. Full article

(This article belongs to the Section Metals and Alloys)

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14 pages, 1118 KB

Open AccessArticle

Increased Heat Absorption by the Walls of Exchangers Sprayed with Coatings Exhibiting High Heat Absorption and Conductivity

by Sławomir Morel and Monika Górska

Materials 2025, 18(19), 4619; https://doi.org/10.3390/ma18194619 - 6 Oct 2025

Viewed by 434

Abstract

The article presents a method for selecting spray coating systems for furnace walls and heat exchangers, aimed at protecting them and intensifying heat exchange processes. Calculations were made of the effect of the mutual emissivity coefficient between the heating medium (exhaust gases) and [...] Read more.

The article presents a method for selecting spray coating systems for furnace walls and heat exchangers, aimed at protecting them and intensifying heat exchange processes. Calculations were made of the effect of the mutual emissivity coefficient between the heating medium (exhaust gases) and the surface of the exchanger—both uncoated and coated—on the heat flux value. Selected coating systems were applied in laboratory conditions by spraying them onto the boiler surfaces and then measuring their heat exchange efficiency with the cooling medium (water) flowing through the piping system. The results of the laboratory tests were verified under industrial conditions in metallurgical installations, confirming the accuracy of the calculations and the validity of using spray coatings to increase thermal efficiency. The use of appropriately selected coating systems increases heat absorption, extends the service life of exchangers, reduces the risk of cooling system failure, and lowers the cost of heating equipment repairs. Full article

(This article belongs to the Special Issue Advanced Functional Coatings for Surface Engineering: Deposition, Properties and Applications)

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22 pages, 3798 KB

Open AccessArticle

Range-Aware Two-Stage Modeling for Feed Ratio Optimization in Fluoroelastomers: Mechanistic Pathways from NMR Structural Features to Macroscopic Properties

by Yaxian Liu, Yadong Wu, Zhoujun Lin, Lijuan Peng and Hongwei Fu

Materials 2025, 18(19), 4618; https://doi.org/10.3390/ma18194618 - 6 Oct 2025

Viewed by 397

Abstract

This study developed the RATS (Range-Aware Two-Stage) modeling approach to establish mechanistic foundations for feed ratio optimization in fluoroelastomers. Using ¹⁹F NMR spectroscopic analysis, the approach decomposes complex composition–property relationships into sequential processes: monomer feed ratios to NMR-derived structural features, and structural [...] Read more.

This study developed the RATS (Range-Aware Two-Stage) modeling approach to establish mechanistic foundations for feed ratio optimization in fluoroelastomers. Using ¹⁹F NMR spectroscopic analysis, the approach decomposes complex composition–property relationships into sequential processes: monomer feed ratios to NMR-derived structural features, and structural features to properties, enabling mechanistic pathway analysis through quantifiable structural intermediates. Using 52 industrial datasets, RATS achieved an average R² of 0.90 across four property predictions, representing a 0.14 improvement over direct modeling and a 28% reduction in prediction error. The approach identified 72 systematic transmission pathways, including promoting effects of PMVE-series structures (+0.220 influence strength) and inhibitory effects of VDF monomers (−0.219 influence strength), through quantified model parameter analysis. This methodology provides a practical analytical tool for mechanism-driven feed ratio optimization, facilitating the transition from empirical trial-and-error to systematic, data-guided fluoroelastomer formulation. Full article

(This article belongs to the Topic Advances in Rubbers, Elastomers and Resins for Leading Edge Technologies)

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18 pages, 6151 KB

Open AccessArticle

Impact of Cutting Parameters and Tool Type on Surface Finish in MQL Turning of Inconel 625

by Magdalena Machno, Wojciech Zębala and Emilia Franczyk

Materials 2025, 18(19), 4617; https://doi.org/10.3390/ma18194617 - 6 Oct 2025

Viewed by 407

Abstract

Inconel 625 is a nickel-based superalloy widely applied in aerospace and energy sectors due to its high strength and corrosion resistance. However, its poor machinability remains a significant challenge in precision manufacturing. This study investigates the influence of tool geometry and cutting parameters [...] Read more.

Inconel 625 is a nickel-based superalloy widely applied in aerospace and energy sectors due to its high strength and corrosion resistance. However, its poor machinability remains a significant challenge in precision manufacturing. This study investigates the influence of tool geometry and cutting parameters on surface roughness of Inconel 625 during turning operations under the minimum quantity lubrication (MQL) conditions. Experiments were carried out using three types of cutting inserts with distinct chip breaker geometries while systematically varying the cutting speed, feed rate, and depth of cut. The results were statistically analyzed using analysis of variance (ANOVA) to determine the significance of individual factors. The findings reveal that both the type of cutting insert and the process parameters have a considerable effect on surface roughness, which is the key output examined in this study. Cutting forces and chip type were examined to provide complementary insights and improve understanding of the observed relationships. Based on the results, an optimal set of cutting data was proposed to achieve a required surface roughness during the turning of Inconel 625 with MQL. Furthermore, a practical algorithm was developed to support the selection of cutting parameters in industrial applications. Analysis of the results showed that a cutting insert with a 0.4 mm corner radius achieved the required surface finish (Rz ≤ 0.4 µm). Furthermore, the analysis revealed a significant effect of the thermal properties of Inconel 625 on machining results and chip geometry. Full article

(This article belongs to the Special Issue Optimization and Simulation in Alloy Cutting Processes (Third Edition))

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19 pages, 4254 KB

Open AccessArticle

Microstructure and Mechanical and Corrosion Behavior of Novel High-Entropy CoCrFeNiSiV_x (x = 0.25; 0.5; 0.75; 1.0) Alloys

by Rafał Babilas, Monika Spilka, Katarzyna Młynarek-Żak, Adrian Radoń, Wojciech Łoński, Krzysztof Matus and Jakub Bicz

Materials 2025, 18(19), 4616; https://doi.org/10.3390/ma18194616 - 6 Oct 2025

Viewed by 376

Abstract

In this work, a series of novel high-entropy alloys CoCrFeNiSiV_x (x = 0.25; 0.5; 0.75; 1.0) with an intermetallic compound structure was proposed. The effect of vanadium addition on the structure, as well as selected mechanical and corrosion properties, was investigated. In [...] Read more.

In this work, a series of novel high-entropy alloys CoCrFeNiSiV_x (x = 0.25; 0.5; 0.75; 1.0) with an intermetallic compound structure was proposed. The effect of vanadium addition on the structure, as well as selected mechanical and corrosion properties, was investigated. In the case of the CoCrFeNiSiV_0.25 alloy, the structural analysis revealed the formation of a dual-phase structure consisting of Fe_1.812V_0.907Si_0.906-type and Fe₅Ni₃Si₂-type intermetallic phases. The increase in vanadium concentration results in the crystallization of one Fe_1.812V_0.907Si_0.906 intermetallic phase detected by the X-ray diffraction method. The increase in vanadium content had a beneficial influence on the corrosion resistance of CoCrFeNiSiV_x alloys in 3.5% NaCl. The CoCrFeNiSiV alloy exhibited the lowest corrosion current density of 0.17 μA/cm² and the highest corrosion potential of −0.228 V. The hardness of the alloys investigated increased with vanadium content, reaching 1006 HV for the equimolar alloy. In turn, the lowest friction coefficient of 0.63 ± 0.06 was obtained for the CoCrFeNiSiV_0.75 alloy. The abrasive, fatigue, and oxidative wear were identified as the main wear mechanisms. Full article

(This article belongs to the Section Metals and Alloys)

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19 pages, 9778 KB

Open AccessArticle

Low Noise Structure Design and Experimental Verification of Ship Based on Flexural Wave Band Gap Characteristics

by Yicheng Lu, Li Tang, Chuanlong Wang, Zilong Peng and Li Xiang

Materials 2025, 18(19), 4615; https://doi.org/10.3390/ma18194615 - 6 Oct 2025

Viewed by 399

Abstract

To address low-frequency vibration and noise issues in ship grating structures, this study proposes a novel acoustic optimization design method based on modulating flexural wave bandgap characteristics. By establishing an equivalent periodic spring-mass coupled beam model to predict bandgap properties, its effectiveness is [...] Read more.

To address low-frequency vibration and noise issues in ship grating structures, this study proposes a novel acoustic optimization design method based on modulating flexural wave bandgap characteristics. By establishing an equivalent periodic spring-mass coupled beam model to predict bandgap properties, its effectiveness is validated through numerical simulations and experimental testing. By selectively enhancing longitudinal stiffness while weakening transverse components, the bandgap characteristics are effectively tuned to target frequency bands. This approach achieves an 8.2 dB noise reduction at the 31.4 Hz natural frequency. The results demonstrate that bandgap-based design provides a numerically and experimentally validated solution for low-noise ship structures. Full article

(This article belongs to the Section Advanced Materials Characterization)

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13 pages, 9165 KB

Open AccessCommunication

Optimizing Volumetric Ratio and Supporting Electrolyte of Tiron-A/Tungstosilicic Acid Derived Redox Flow Battery

by Yong Jin Cho, Jun-Hee Jeong and Byeong Wan Kwon

Materials 2025, 18(19), 4614; https://doi.org/10.3390/ma18194614 - 5 Oct 2025

Viewed by 387

Abstract

Redox flow batteries (RFBs) are a promising technology for large-scale energy storage due to their safety, scalability, and design flexibility. This study investigated a tiron-A (4,5-dihydroxybenzene-1,3-disulfonic acid)/tungstosilicic acid (TSA) RFB system, focusing on optimizing the supporting electrolyte and the volumetric ratio of the [...] Read more.

Redox flow batteries (RFBs) are a promising technology for large-scale energy storage due to their safety, scalability, and design flexibility. This study investigated a tiron-A (4,5-dihydroxybenzene-1,3-disulfonic acid)/tungstosilicic acid (TSA) RFB system, focusing on optimizing the supporting electrolyte and the volumetric ratio of the catholyte (tiron-A) to anolyte (TSA). Electrochemical characteristics, confirmed by CV and EIS, showed that sulfuric acid was the most suitable supporting electrolyte due to its excellent cell potential and lower ohmic resistance compared to sodium chloride and sodium hydroxide electrolytes. To address the inherent electron capacity imbalance between tiron-A (two electrons) and TSA (four electrons), various volumetric ratios were evaluated. The cell with the 3:1 tiron-A:TSA ratio exhibited optimal performance, achieving the highest discharge capacity, excellent cycle stability, and consistent energy efficiency. The electrochemical impedance spectroscopy results revealed that the ohmic resistance was minimized at the 3:1 ratio. This stable, low-ohmic resistance, coupled with a significant reduction in charge transfer resistance after cycling, was confirmed as the dominant factor for the improved long-term performance. These findings demonstrate an effective strategy for developing a high-performance performance tiron-A/TSA RFB system. Full article

(This article belongs to the Section Electronic Materials)

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Materials, Volume 18, Issue 19 (October-1 2025) – 212 articles

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