Coatings, Volume 14, Issue 3 (March 2024) – 129 articles

Al-Cu-Fe-Ce quasicrystalline-reinforced 6061 aluminum matrix composites were prepared through hot press sintering and treated with a solid solution and aging treatments. The influence of the solid solution and aging treatments on the microstructure and mechanical properties of the composites was investigated by XRD, EDS, SEM, and TEM. The results show that using Al-Cu-Fe-Ce quasicrystalline intermediate alloy as the reinforcing phase increases the interfacial areas of the composites and enhances the grain boundary strengthening effect, which is conducive to the improvement of the mechanical properties of the composites. And through the solid solution and aging treatment, the β phase and the Al₂CuMg phase belonging to the orthorhombic crystal system, as well as the β″ phase and a small amount of the β′ precipitated phase, were formed in aluminum matrix composites, and these precipitated phases all existed in the composites in a fine and uniform distribution, which ensured the consistency of the mechanical properties of the materials and improved the mechanical properties of the composites. Meanwhile, the deficiency of quasicrystalline particle-reinforced 6061 aluminum matrix composites in age-hardening was solved and the age-hardening capability of the composites was further developed. This method provides a feasible process route for the preparation of high-performance aluminum matrix composites. The application of this process is expected to improve the mechanical properties and durability of this composite and offer a more reliable option for the application of aluminum matrix composites in aerospace, transportation, and other fields. Full article

In order to improve the hydrophobicity of the composite film on the wood surface, the wettability of the wood surface and its morphology, chemical structure, roughness and free energy changes were investigated in this paper after modification treatments with different volume fractions of octadecyltrichlorosilane (OTS) and polydimethylsiloxane (PDMS). It can be found that the water contact angle and surface roughness of the hydrophobically modified wood increased with the increase in volume fraction, but the overall effect of OTS hydrophobic modification was better than that of PDMS, and a maximum water contact angle of up to 140.8° could be obtained at a volume fraction of 2% of OTS. In addition, the intensity of the stretching vibration peak of -OH was weakened after the modification, while the intensity of the stretching vibration peak of -CH₂- was enhanced, resulting in an increase in hydrophobicity. At the same time, it can be found that the surface free energy of the modified wood specimens was reduced, which shows that OTS and PDMS improve the surface hydrophobicity of the wood by increasing the surface roughness and decreasing the surface free energy together. Finally, the hydrophobically modified Bi₂O₃-doped silica–titanium composite film still possessed high photocatalytic degradation activity for rhodamine B and gas formaldehyde, and the degradation rate could reach more than 90%. Full article

In the hydrogen separation membrane, a dense TaTiNbZr amorphous layer was prepared between Pd and Ta to form a Pd/TaTiNbZr/Ta membrane system to prevent the reaction between Pd and Ta at high temperatures. The structural and chemical stability of the Pd/TaTiNbZr/Ta film system at high temperatures were investigated by annealing at 600 °C for 24 h. The high-temperature hydrogen permeation properties of the Pd/TaTiNbZr/Ta film systems were investigated by hydrogen permeation experiments at 600 °C after heat treatment for 6 h. The TaTiNbZr layer was significantly hydrogen-permeable. With the increase in the thickness of the barrier layer, the hydrogen permeability of Pd/TaTiNbZr/Ta decreased, but its hydrogen permeation flux was smaller than that of the highest value of Pd/Ta when it reached the steady state. The presence of the TaTiNbZr layer effectively blocks the interdiffusion between Pd and Ta to form TaPd₃, improving the sustained working ability of the Pd/TaTiNbZr/Ta membrane system. The results show that TaTiNbZr is a candidate material for the intermediate layer to improve the high-temperature stability of metal-composite hydrogen separation membranes. Full article

In this study, the combination of ordinary cement concrete (OCC) and shrinkage-compensating concrete (SCC) was utilized to pour super-long mass concrete. The temperature and strain of the concrete were continuously monitored and managed actively after pouring. The investigation focused on the temporal and spatial distribution patterns of the temperature field, the temperature difference between the core and surface, and the strain evolution. Based on the constructed hydration exothermic model of layered poured concrete, the effects of the SCC, molding temperature, and surface heat transfer coefficient on the temperature field were analyzed. The results show that the temperature of super-long mass concrete rises quickly but falls slowly. SCC exhibits higher total hydration heat than OCC. The temperature field is symmetric along the length but asymmetric along the thickness due to varying efficiency of heat dissipation between the upper and lower parts of the concrete. After final setting of the concrete, the strain varies opposite to the temperature and peaks at −278 με. A few short cracks are observed on the end of the upper surface. Moreover, the numerical simulation results are in good agreement with the measured results. Increasing the molding temperature and surface wind speed increases the temperature difference between the core and surface. Conversely, increasing the thickness of the insulation layer is an effective way to curtail this difference. Thermal stress analysis is carried out and shows that lowering the molding temperature of SCC and increasing the thickness of insulation material can effectively reduce thermal stress. Full article

Ship painting, as one of the three pillars of the shipping industry, runs through the whole process of ship construction. However, there are low scheduling efficiency and excessive carbon emissions in the segmental painting process, and optimizing the scheduling method is an important means to achieve the sustainable development of the ship manufacturing industry. To this end, firstly, a low-carbon scheduling mathematical model for the segmented painting workshop is proposed, aiming to reduce carbon emissions and improve the painting efficiency of the segmented painting workshop. Second, an artificial bee colony algorithm designed based on a decomposition strategy (MD/ABC) is proposed to solve the model. In the first stage, five neighborhood switching methods are designed to achieve the global search employed for each solution. In the second stage, the Technique of Ordering the Ideal Solutions (TOPSIS) improves the competition mechanism through the co-evolution between neighboring subproblems and designs the angle to define the relationship between neighboring subproblems to enhance the localized search and improve population quality. The solution exchange strategy is used in the third stage to improve the efficiency of the algorithm. In addition, a two-stage coding method is designed according to the characteristics of the scheduling problem. Finally, the algorithm before and after the improvement and with other algorithms is analyzed using comparative numerical experiments. The experimental results show the effectiveness of the algorithm in solving the low-carbon scheduling problem of ship segmental painting and can provide reliable guidance for the scheduling program of segmented painting workshops in shipyards. Full article

CrWN/MoN nano-multilayer coatings were deposited in pure N₂ by multi-arc ion plating using CrW and Mo targets, with the cathode co-controlled by a permanent magnet combined with an electromagnet. The effects of the thickness modulation period on the microstructure and mechanical and tribological performance were systematically analyzed by grazing-incident X-ray diffraction (GIXRD), transmission electron microscopy (TEM), Nanoindentation, scanning electron microscope (SEM) and profilometry using a Talysurf profilometer. The local coherent interfaces and nanoscale modulation period were confirmed by TEM, while the coatings were confirmed to be composed of fcc-CrWN and hexagonal δ-MoN by GIXRD. With the increase in the modulation period, the hardness of the CrWN/MoN nano-multilayer coatings decreased, and the values of the H/E ratio and friction coefficient showed the same variation trend. At an 8.0 nm modulation period, the CrWN/MoN nano-multilayer coating showed the maximum hardness (30.2 GPa), the lowest H/E value (0.082) and an H³/E*² value of 0.16. With the decrease in the modulation period, the average friction coefficient of the CrWN/MoN nano-multilayer coatings gradually decreased from 0.45 to 0.29, while the wear rate decreased from 4.2 × 10⁻⁷ mm³/Nm to 3.3 × 10⁻⁷ mm³/Nm. Full article

Fossil fuels play a powerful role in the global economy and are therefore referred to as strategic raw materials. However, their massive use around the world is associated with concerns about the sufficiency of energy sources for future generations. Currently, fossil fuel resources are heavily depleted, with limited supplies. According to forecasts, the demand for energy will constantly increase, so it is necessary to find a solution that reconciles the ever-increasing demand for energy with the need to protect the environment. The main solution to this problem is to acquire energy from renewable resources, especially in the direction of obtaining alternative substitutes for transportation fuels. One of the main alternative fuels that can replace existing fossil fuels is hydrogen. An efficient way to obtain this compound is through the use of modern photocatalysts. Hence, the purpose of this paper is to review the recent literature on the effective use of catalysts in photocatalytic processes (e.g., glycerol conversion) that enable the synthesis of hydrogen. Full article

Fluorocarbon polyurethane amino baking paint for graffiti-resistant whiteboards was designed and prepared. Firstly, perfluorohexylethyl alcohol (TEOH6) and hexamethylene diisocyanate (HDI) were reacted under certain conditions to obtain fluorocarbon mono-isocyanate, then fluorocarbon diols were obtained by reacting with trimethylolpropane, and finally fluorocarbon polyurethane hydroxy resin was formed by reacting with hexamethylene diisocyanate (HDI) and polyester diols. The synthesized hydroxyl resin was used as the basis to configure fluorocarbon polyurethane amino baking paint for graffiti-resistant whiteboards and was upgraded by adding hydroxyl silicone oil. Secondly, a series of performance tests, such as hardness, adhesion, flexibility, and corrosion resistance, were conducted to verify that the baking paint possessed excellent properties for use on writing whiteboards. The graffiti resistance of each paint film was evaluated by different methods, and it was found that the graffiti resistance was mainly due to the excellent hydrophobicity and oleophobicity of the paint films after the enrichment of fluorocarbon chains on their surfaces, and the combined effect of low surface energy caused by hydroxyl silicone oil crosslinked with amino resin. This study provides a theoretical basis and technical support for the preparation of fluorocarbon polyurethane baking paint for graffiti-resistant whiteboards. Full article

Enhancing paper hydrophobicity is of key importance for many paper-based applications. Fatty acids or vegetable oils and their derivatives replace environmentally harmful conventional coating materials but still require challenging chemical reactions for covalent attachment onto paper. Here, we show that simple storage of olive oil-coated cotton linter paper at 70 °C and subsequent Soxhlet extraction is able to endow paper with hydrophobic properties, reaching water contact angles above 130°. In-depth chemical and morphological analytics show the relevance of temperature and air accessibility during the aging process compared with aging at ambient temperature and under the exclusion of oxygen, underlining the importance of assessing a coating’s long-term performance and stability under diverse storage conditions. Simple storage of vegetable oil-coated paper at elevated temperatures followed by extraction proves to be an easy way to produce stable covalently attached hydrophobic paper coatings with exceptionally low coating amounts. Full article

Often, bacterial infections delay the rate of healing of traumatic wounds, making it critical to improve antimicrobial efficiency. In this paper, titanium nanotubes (TNT) with good antimicrobial and synergistic photothermal properties were used as the core, and mesoporous polydopamine (MPDA) thin films were constructed on their surface. Gold nanoparticles (AuNPs) with excellent photothermal conversion efficiencies (PCE) were incorporated. Finally, a large number of composite nanoparticles were added to polyvinyl alcohol (PVA) and polyethylene glycol (PEG) with wound-restoring ability, and an injectable antimicrobial hydrogel was successfully prepared by a one-pot synthesis. The antimicrobial effect of TNT@MPDA@Au nanoparticles with different concentrations was assessed by in vitro antimicrobial experiments on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The higher the concentration of nanoparticles under near-infrared light irradiation (NIR), the stronger the antimicrobial effect. The in vitro cytotoxicity of TNT@MPDA and TNT@MPDA@Au nanoparticles on 293T normal cells was tested through CCK-8 assay. The results show that both nanoparticles have favourable biocompatibility. In this paper, a three-component synergistic photothermal antimicrobial nano-antimicrobial platform was constituted by incorporating MPDA, a photothermal agent with excellent biocompatibility and photothermal properties, and AuNPs with good photothermal properties on TNT with excellent photocatalytic properties. Full article

Strength assessment for thermal barrier coatings (TBCs) is vital in the safety design of hot-section components in engines. However, several crucial factors, including thermally grown oxide (TGO) growth and creep–plasticity interaction, have been less considered in thermo-mechanical analyses for TBCs near air holes. In this study, a unified viscoplastic constitutive model incorporating TGO growth is developed and integrated into a finite element framework. The model considers multiple factors, including TGO growth, creep–plasticity interaction, interface undulation, and temperature gradient. Additionally, an analytical solution for the non-uniform temperature field of a TBC is derived. The model is then applied to calculate interfacial stresses and accumulated strain energies in the TBC near an air hole, which promote interface debonding. The obtained results can be utilized to investigate the mechanisms of hole edge delamination in TBCs, considering the combined effects of multiple complex factors. A competition for the potential failure initiation location is revealed between the first oxide layer and the evolving TGO/bond coat interface. The developed viscoplasticity model demonstrates effective capability in modelling a range of dynamic behaviors that collectively contribute to hole edge delamination failure. Full article

This study compared the fatigue resistance and elemental composition of two blue heat-treated nickel–titanium (NiTi) files used in root canal preparation as follows: Tia Tornado Blue (TTB) and Race Evo (RE) file systems. For cyclic fatigue testing, the two systems were tested where each file was rotated inside an artificial metal canal submerged in either sodium hypochlorite or saline solution until fracture. Time to fracture was recorded. For torsional fatigue testing, the file tip was secured while the file was allowed to rotate at a fixed rate until fracture. Torque at failure was recorded. The two experiments were performed at simulated body temperature and the length of fractured segments was measured. Statistical analysis was carried out with a significance level (p-value) set at 5%. The mean cycles to fracture for RE were superior to that of TTB irrespective of the solution used (p < 0.05). TTB’s cyclic fatigue resistance decreased in NaOCl (p < 0.0001). RE demonstrated lower torque at failure (p = 0.002). All files were fractured at comparable lengths (p = 0.218). Although RE is considered more resistant to cyclic fatigue, it showed inferior torsional resistance compared with TTB. The NaOCl negatively affected the TTB’s cyclic fatigue resistance. Full article

Dry lubricants used in highly loaded rolling bearings are in the focus of current research. In previous studies, graphene platelets applied as dry lubricants on the surfaces of angular contact ball bearings demonstrated superior properties. These specific bearings, experiencing both rolling and spinning motion, create more severe conditions for dry lubricants. To gain deeper insights into the lubrication effects, micro-tribological studies were carried out on the respective film formation and running behavior effects. In the tests, a fixed steel ball slid against an oscillating counterpart under a defined load. During the measurements, the applied load and tangential forces on the ball were recorded to calculate the friction. Comparative investigations included nano-graphite particles and fullerene as dry lubricants, in addition to graphene platelets of various staple thicknesses. To increase the adhesion of the films to the surfaces, a pre-rolling process was implemented. Afterwards, the friction on the compressed films was measured. The results indicate that the pre-rolling process effectively reduces the friction of the system. After testing, the surfaces underwent analysis using laser scanning microscopy to assess the formed films, wear, and material transfer. It has been demonstrated that the pre-rolling process leads to the formation of a very thin compacted film with surface protective properties. With the ball as a counterpart, the graphene platelets generate a transfer film on the contacting surface. Full article

A large amount of multi-layer ceramic capacitor (MLCC) is mounted inside a printed circuit board (PCB) constituting electronic components. The use of MLCC in electric vehicles and the latest mobile phones is rapidly increasing with the latest technology. Environments in which electronic components are used are becoming more diverse and conformal coatings are being applied to protect mounted components from these environments. In particular, MLCCs in electronic components mainly have voltage applied. They might be used in environments where humidity exists for various reasons. In a humid environment, electrochemical migration (ECM) will occur, with the cathode and anode on the surface of the MLCC encountering each other. This can result in product damage due to a short circuit. In this study, the effects of voltage, NaCl concentration, and distance between electrodes on a non-mount MLCC, surface mount MLCC, and solder pad pattern were evaluated using a water drop test (WDT). Based on the analysis of the effects of the presence of conformal coating, applied voltage, concentration of NaCl, and the distance between electrodes, a mechanism model for ECM behavior in MLCCs was proposed. Full article

This paper presents research on the application of ultrasonic-guided wave technology in corrosion defect identification, expounds the relevant ultrasonic-guided wave theories and the principle of ultrasonic-guided wave non-destructive testing of pipelines, and discusses the Lamb wave and shear horizontal wave mode selection that is commonly used in ultrasonic-guided wave corrosion detection. Furthermore, research progress in the field of ultrasonic-guided wave non-destructive testing (NDT) technology, i.e., regarding transducers, structural health monitoring, convolutional neural networks, machine learning, and other fields, is reviewed. Finally, the future prospects of ultrasonic-guided wave NDT technology are discussed. Full article

Craniofacial bone defects are usually secondary to accident trauma, resection of tumor, sever inflammation, and congenital disease. The defects of craniofacial bones impact esthetic appearance and functionality such as mastication, pronunciation, and facial features. During the craniofacial bone regeneration process, different osteogenic cells are introduced, including primary osteoblasts or pluripotent stem cells. However, the defect area is initially avascular, resulting in the death of the introduced cells and failed regeneration. Thus, it is vital to establish vascularization strategies to build a timely and abundant blood vessel supply network. This review paper therefore focuses on the reconstruction of both osteogenesis and vasculogenesis. The current challenges, various strategies, and latest efforts applied to enhance vascularization in craniofacial bone regeneration are discussed. These involve the application of angiogenic growth factors and cell-based vascularization strategies. In addition, surface morphology, porous characters, and the angiogenic release property of scaffolds also have a fundamental effect on vasculogenesis via cell behavior and are further discussed. Full article

This work is devoted to the study of nanosized polymer polyvinylidene fluoride (PVDF) thin ferroelectric films (two-dimensional ferroelectrics) and their composites with graphene layers, using molecular dynamics methods to (1) study and calculate the polarization switching time depending on the electric field and film thickness, (2) study and calculate the polarization switching time depending on changes of the PVDF in PVDF-TrFE film, and (3) study the polarization switching time in PVDF under the influence of graphene layers. All calculations at each MD run step were carried out using the semi-empirical quantum method PM3. A comparison and analysis of the results of these calculations and the kinetics of polarization switching within the framework of the Landau–Ginzburg–Devonshire theory for homogeneous switching in ferroelectric polymer films is carried out. The study of the composite heterostructures of the “graphene-PVDF” type, and calculations of their polarization switching times, are presented. It is shown that replacing PVDF with PVDF-TrFE significantly changes the polarization switching times in these thin polymer films, and that introducing various graphene layers into the PVDF layered structure leads to both an increase and a decrease in the polarization switching time. It is shown that everything here depends on the position and displacement of the coercive field depending on the damping parameters of the system. These phenomena are very important for various ferroelectric coatings. Full article

In the context of a main road area with significant traffic flow, posing challenges to constructing the freezing station on the ground, an innovative proposal suggests situating the freezing station at the station. This approach aims to facilitate construction at the same time for the connection aisle, tunneling, and track laying, thereby reducing the construction period; however, this will lead to a corresponding increase in the freezing pipeline distance. The theoretical analysis, numerical analysis, and integration with engineering practices were employed to examine the essential aspects and key technologies in the long-distance freezing design and construction, including the freezing hole construction, thermal insulation method of brine pipelines and tunnel segments, and technique program to retain the brine pressure and flow discharge, as well as the method to reduce the interplay of cross-construction. The validity of the construction program for the long-distance frozen excavation was finally evaluated based on onsite monitoring and theoretical analysis. The results show that the temperature of the brine in both the delivery and return pipelines first decreases linearly and then stabilizes gradually with freezing time, and the temperature difference is between 1 °C and 1.5 °C at the later freezing period. The temperature variation of the frozen wall is similar to that of brine in the delivery and return pipelines, and there is a good correlation between them. After the frozen wall encloses, the internal pressure of the frozen wall increases quickly, which can be effectively reduced to prevent wall cracking and breakage by regulating the pressure relief holes. The above theoretical analysis result shows that the average temperature of the frozen wall should be less than −9.7 °C when the designed thickness of the frozen wall is 2.2 m. The monitoring data indicates that the average temperature of the frozen wall reaches −13.9 °C, which satisfies the design requirement. The design and construction technology of long-distance freezing enhance the construction of the subway connection aisle. The novel method deviates from the conventional practice of establishing freezing stations within tunnels and offers valuable insight and guidance for comparable projects. Full article

The mechanical response of a quasicrystal thin film is strongly affected by an adhesive layer along the interface. In this paper, a theoretical model is proposed to study a thin two-dimensional hexagonal quasicrystal film attached to a half-plane substrate with an adhesive layer, which undergoes a thermally induced deformation. A perfect non-slipping contact condition is assumed at the interface by adopting the membrane assumption. An analytical solution to the problem is obtained by constructing governing integral–differential equations for both single and multiple films in terms of interfacial shear stresses that are reduced to a linear algebraic system via the series expansion of Chebyshev polynomials. The solution is compared to that without adhesive layers, and the effects of the aspect ratio of films, material mismatch, and the adhesive layer, as well as the interaction between films, are discussed in detail. It is found that the adhesive layer can soften the localized stress concentration. This study is instructive to the accurate safety assessment and functional design of a quasicrystal film system. Full article

This study investigated the impact of NaAlO₂ concentration in electrolytic solutions on micro-arc oxidation (MAO) coatings, focusing on their surface quality enhancement and corrosion resistance improvement. The surface morphology and microstructure of these coatings were assessed using scanning electron microscopy. Mechanical properties, such as hardness and wear resistance of MAO coatings, were tested. The hardness of the 6 g/L group was 411.2 HV. X-ray photoelectron spectroscopy examinations showed that MgAl₂O₄, CaMgP₂O₇, and MgSiO₄ were the phases in the MAO coating. Antibacterial assessments were performed to evaluate the influence of NaAlO₂ concentration, and the antibacterial rate of the 6 g/L group reached 97.08%. The hydrophilicity of the coatings was determined using water contact angle measurements, wherein the water contact angle of the 6 g/L was the lowest, at 58.25°. Corrosion resistance was evaluated with an electrochemical workstation. The findings revealed that the MAO coatings prepared with a NaAlO₂ concentration of 6 g/L exhibited superior uniformity with fewer defects, enhanced corrosion resistance, and increased adhesive strength compared to other concentration groups. The 6 g/L NaAlO₂ concentration MAO coating demonstrated the highest fitting coating resistance R₃ (8.14 × 10⁴ Ω∙cm²), signifying better corrosion resistance. Full article

The efficacy of electrodes that are chronically implanted and used in the context of deep brain stimulation (DBS) for the treatment of neurological disorders critically depends on stable impedance. Platinum–iridium electrodes were coated with laser-generated platinum nanoparticle colloids (PtNPs) via electrophoretic deposition using pulsed direct currents (DC-EPD). Uncoated electrodes were used as controls. In vitro, electrodes were stimulated for four weeks in a 0.9% NaCl solution. For the in vivo (rats) study, coated electrodes were implanted in the left and uncoated control electrodes in the right subthalamic nucleus (STN). After two weeks of recovery, electrodes were stimulated for four weeks. Impedance measurements were conducted after each week of stimulation, both in vivo and in vitro. NP-coating resulted in a significant and long-lasting reduction in electrode impedance (p < 0.05) over four weeks of in vitro stimulation. Despite an initial increase in impedance after intracranial implantation, the impedance of the NP-coated electrodes was also reduced during in vivo stimulation over four weeks. NP-coated electrodes had a lower fluctuation of impedance during stimulation compared to uncoated electrodes both in vitro and in vivo (p < 0.05). Laser-generated PtNPs applied to electrodes by pulsed DC-EPD lead to lower and more stable electrode impedance during chronic stimulation, with the potential to enhance the performance of DBS systems during chronic use. Full article

The failure of premature thermal cycling spalling off is the bottleneck problem currently faced by yttrium oxide partially stabilized zirconia (YSZ) ceramic-based sealing coatings. Studies on the thermal cycling performance of coatings with “brick-mud” structures were carried out by experimental and simulation methods in this paper. The results showed that, as the thickness of “mud” layer increased, the bonding strength of the “brick-mud” structure coatings gradually decreased. When the thickness of the “mud” layer was about 3 μm and 10 μm, the thermal cycling lives of the T1 and T2 coatings were improved by 90.0% and 135.7%, respectively, compared with conventional coating (T0 coating), while that of the T3 coating (containing thick “mud” layers of about 20 μm) was decreased by 81.4%. The stress field of M2 “mud” layers with different thicknesses was subjected to a comprehensive effect by thermal mismatch stress and pores in “brick” layer. Compared with the medium and thick “mud” layers, the thin “mud” layer sustained obvious larger ${\sigma }_{22 max}$ and ${\sigma }_{12 max}$, indicating its potential for the preferential initiation of transverse microcracks. In addition, the thin “mud” layer withstood the largest ${\sigma }_{11 max}$ and had the strongest potential for longitudinal crack growth. Both transverse and longitudinal cracking could consume energy during thermal cycling and reduce the stress concentration at the top coating/bond coating interface. These were the main reasons for the improvements in the thermal cycling performances of the T1 and T2 coatings. The degree of crack deflection and the capacity of energy dissipation in the “mud” layer increased significantly with its thickness. However, the propagation length of transverse cracks also gradually increased in the meantime. Especially when the “mud” layer was 20 μm, the length of the transverse cracks increased rapidly. Thus, early interlayer delamination failure occurred in the T3 coating during thermal cycling. Full article

Zinc and its alloys have garnered significant attention in the field of biological implantation due to their biodegradable, osteogenic, and mechanical properties. However, the degradation of zinc and its alloys always lead to an increase in local ion concentration, and the bare metal surfaces lack biocompatibility for implantation. To address these issues, a layer of calcium–phosphorus (CaP) coating was prepared on the surface of a Zn-0.5Li alloy. The micro-structure of the coating was observed with scanning electron microscopy (SEM) and a white light interferometry microscope. The phases of the coatings were characterized through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The bonding strength between the coating and substrate was investigated using a scratch tester with a diamond stylus, and the corrosion properties were assessed using an electrochemical method. For the evaluation of biocompatibility and osteogenic properties, MC3T3-E1 cells were cultured on the coating. Live/dead staining and proliferation tests were performed to assess cell viability and growth. Cell adhesion morphology was observed with SEM, and the level of alkaline phosphatase (ALP) in the MC3T3-E1 cells cultured on the material surface was evaluated by ALP staining and activity measurement. The CaP coating on the zinc alloy surface improved the alloy’s biocompatibility and osteogenic property, and could be a promising surface modification option for a biodegradable zinc alloy. Full article

Steel pipes are commonly used to strengthen the concrete’s load-bearing capacity. However, they are prone to corrosion in salt erosion environments. In this study, the influence of Na₂MoO₄ and benzotriazole on concrete-filled steel tubes’ corrosion performance is investigated. The steel pipes’ mass loss rates (MRs), ultrasonic velocity, electrical resistance, and the AC impedance spectrum and Tafel curves of concrete-filled steel tubes were used to characterize the degree of corrosion in the steel pipes. Scanning electron microscopy–energy-dispersive spectrometry and X-ray diffraction were used for studying the composition of steel pipe rust. The research results revealed that the NaCl freeze–thaw cycles (F-C) and NaCl dry–wet alternation (D-A) actions had a reducing effect on the mass and ultrasonic velocity of the concrete-filled steel tubes. After 300 NaCl F-C and 30 NaCl D-A, the MRs were 0%~0.00470% and 0%~0.00666%. The corresponding ultrasonic velocities were 0%~21.1% and 0%~23.6%. When a rust inhibitor was added, the results were the opposite. The MRs decreased by 0%~80.3% and 0%~81.6% with the added Na₂MoO₄ and benzotriazole. Meanwhile, the corresponding ultrasonic velocities were 0%~8.1% and 0%~8.3%. The steel tubes were corroded after 300 NaCl F-C and 30 NaCl D-A. The addition of rust inhibitors improved the corrosion resistance of the concrete-filled steel tubes by increasing the electrical resistance before NaCl erosion. The corrosion area rate decreased by using the rust inhibitors. The corrosion resistance effect of benzotriazole was higher than that of Na₂MoO₄. The concrete-filled steel tube with an assembly unit comprising 5 kg/m³ of Na₂MoO₄ and 15 kg/m³ of benzotriazole had the best corrosion resistance under the erosion induced by NaCl F-C and D-A. Rust inhibitors reduced the content of iron-containing crystals and iron elements. The specimens with 5 kg/m³ Na₂MoO₄ and 15 kg/m³ benzotriazole had the lowest concentration of iron-containing crystals and iron elements. Full article

Laser powder bed fusion can fabricate porous structures through lattices, but the preparation of micropores (<50 μm) with a specific pore distribution remains a challenge. Microporous 316L was fabricated by controlling the melting and solidification behavior of the particles using laser energy. The laser energy density was not a determining factor for the porosity and micropore formation, except for the single-factor condition. The high-speed scanning mode required a higher laser power to disorder the pore distribution, whereas low-speed scanning with a low laser impact on the stacking particles formed organized pores. The hatch distance significantly affected the pore distribution and pore size. The pore distribution in the XY plane was organized and homogenous, with channeled pores mainly interconnected along the laser scanning tracks, whereas in the Z direction, it showed a relatively disordered distribution, mainly linked along the layered direction. The microporous 316L displayed a mean pore size and median pore size of 10–50 μm with a high-percentage size distribution in 1–10 μm, a controllable porosity of 17.06%–45.33% and a good yield strength of 79.44–318.42 MPa, superior to the lattice porous 316L with 250.00 MPa at similar porosity. Full article

In recent years, there has been growing interest in pH-responsive polymers. Polymers with ionizable tertiary amine groups, which have the potential to be used in many critical application areas due to their pKa values, have an important place in pH-responsive polymers. In this study, poly(2-Diisopropyl aminoethyl methacrylate) (PDPAEMA) thin films were coated on various substrates such as glass, fabric, and silicon wafer using a one-step environmentally friendly plasma enhanced chemical vapor deposition (PECVD) method. The effects of typical PECVD plasma processing parameters such as substrate temperature, plasma power, and reactor pressure on the deposition rate were studied. The highest deposition rate was obtained at a substrate temperature of 40 °C, a reactor pressure of 300 mtorr, and a plasma power of 60 W. The apparent activation energy was found to be 17.56 kJ/mol. Based on the results of this study, uniform film thickness and surface roughness were observed in a large area. The PDPAEMA thin film was exposed to successive acid/base cycles. The results showed that the pH sensitivity of the thin film produced by the PECVD method is permanent and reversible. Full article

For decades, experts have paid considerable scientific and technological attention to the possibility of recycling waste that has reached nature as a result of mining activities related to natural stone, extracting metal or using foreign matter to recover natural environments. Several authors have shown that many of these types of waste can be vitrified or synthesised with an appropriately designed composition, not just to decrease their size but (as is more interesting from a financial point of view) to produce a wide range of glassy and/or ceramic materials that can have uses in industry and, crucially, in the construction sector (building and public works). In this paper, we conduct a comprehensive analysis of the state of the art, defining the different types of materials and their uses in order to decisively contribute to the circular economy and the zero-waste approach. We analyse the achievements accomplished in recent decades to be able to generate novel innovative ideas for collecting new eco-materials. Full article

Artifacts pertaining to Buddhist culture are often studied in relation to their circulation from India throughout the rest of Asia; however, many traveled to Europe during the last few centuries as trade commodities and pieces for the art market, losing any devotional purpose in favor of a specific aesthetic sensitivity that was typically adapted to Western taste to appeal to collectors. This article presents a technical study of seven polychrome wooden sculptures from the Museo d’Arte Orientale (MAO) in Turin, Italy. Originally from China, these objects are generally attributed to the late Ming–early Qing dynasties (16th–18th centuries) based merely on stylistic and iconographic considerations. Scientific analysis sought to expand the available knowledge on their constituting materials and fabrication techniques, to address questions on their authenticity, to assess their state of preservation, and to trace the history of transformations they have undergone while transitioning from devotional objects to private collection and museum artwork. By delving into the sculptures’ intricate paint stratigraphy, the results were also key to guiding treatment choices. The outcomes of this study were featured in the MAO exhibition “Buddha10. A Fragmented Display on Buddhist Visual Evolution” (October 2022–September 2023). Full article

It is well known that the mechanical properties of a steel plate depend on the anisotropy of the material and the rolling directions. This paper presents the results of the Charpy V-Notch (CVN) impact test for the ST, TL, TS, LS, LT, 45°, and SL directions in API 5L X52 pipelines with electric-resistance-welded (ERW) and seamless (SMLS) pipes. Charpy specimens were manufactured and tested according to the ASTM E23 standard in laboratory conditions. All possible directions in the pipe were tested. Three Charpy specimens were tested for each direction, for a total of 21 Charpy tests. Moreover, the microstructures, hardness, ductile and brittle areas, and fracture surfaces of the Charpy specimens are presented in this research. The results show that the Charpy energy values, hardness, and microstructures depend on the direction of the specimens. The Charpy values of the SMLS pipe are higher than those of the ERW pipe because of several metallurgical factors, such as grain size, non-metallic inclusions, delaminations, and microstructures. Full article