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Diseases or complications that are caused by bone tissue damage affect millions of patients every year. Orthopedic and dental implants have become important treatment options for replacing and repairing missing or damaged parts of bones and teeth. In order to use a material in the manufacture of implants, the material must meet several requirements, such as mechanical stability, elasticity, biocompatibility, hydrophilicity, corrosion resistance, and non-toxicity. In the 1970s, a biocompatible glassy material called bioactive glass was discovered. At a later time, several glass materials with similar properties were developed. This material has a big potential to be used in formulating medical devices, but its fragility is an important disadvantage. The use of bioactive glasses in the form of coatings on metal substrates allows the combination of the mechanical hardness of the metal and the biocompatibility of the bioactive glass. In this review, an extensive study of the literature was conducted regarding the preparation methods of bioactive glass and the different techniques of coating on various substrates, such as stainless steel, titanium, and their alloys. Furthermore, the main doping agents that can be used to impart special properties to the bioactive glass coatings are described.

Sol‐gel technology has long been recognized as a promising stabilization treatment for glass. However, the acidity of its formulations may pose challenges, particularly due to the potential for corrosive effects, making its application on ancient and artistic glass more complex and requiring a delicate balance between safeguarding its structural integrity and preserving its visual and historical significance. This study investigates the incorporation of silica nanoparticles into silica‐based coatings to reduce the synthesis acidity and enhance anticorrosion protection. The sol‐gel formulations, tailored to minimize their acidity (from ̴pH 1–2 to pH 4) and ensure optimal compatibility with glass surfaces, are combined with 50nm and 200nm silica nanoparticles and applied using dip‐coating. Comprehensive analyses, including optical characterization, water contact angle measurements, and nanoindentation tests, reveals that composite coatings with 50nm nanoparticles, applied through a double‐dipping process, significantly improves resistance to alteration. These coatings demonstrates superior protective performance compare to both pure silica coatings and composite compositions containing 200nm nanoparticles. Surface analyses further highlighted that incorporating nanoparticles allowed for precise control over the formation of alteration structures on glass surfaces. This approach effectively manage the development of alteration patina, offering a promising solution for mitigating ancient glass alteration while maintaining its aesthetic integrity. This study presents a novel silica‐based sol‐gel coating enhance with silica nanoparticles to protect glass surfaces. By reducing formulation acidity and improving resistance to environmental alteration—especially with 50 nm particles and double‐dip application—the method creates a gentle yet effective protective barrier. It preserves the structural and visual integrity of aged glass, offering a promising approach for long‐term conservation.

Silicate (13-93) and borate (13-93-B3) bioactive glass coatings were successfully deposited on titanium using the nanosecond Pulsed Laser Deposition technique. The coatings’ microstructural characteristics, compositions and morphologies were examined by a number of physico-chemical techniques. The deposited coatings retain the same functional groups of the targets, are a few microns thick, amorphous, compact and crack free. Their surface is characterized by the presence of micrometric and nanometric particles. The surface topography, investigated by Atomic Force Microscopy, is characterized by spherical or ellipsoidal particles of the 0.2–3 μm size range for the 13-93 silicate bioactive glass film and of the 0.1–1 µm range for the 13-93-B3 borate bioactive glass coating. Equine adipose tissue-derived mesenchymal stem cells (ADMSCs) were applied for biological tests and the osteogenic differentiation activity of cells on the deposited coatings was studied after ADMSCs growth in osteogenic medium and staining with Alizarin Red. Cytocompatibility and osteogenic differentiation tests have shown that thin films retain the biocompatibility properties of the target silicate and borate glass, respectively. On the other hand, no antibacterial activity of the borate glass films was observed, suggesting that ion doping is advisable to inhibit bacterial growth on the surface of borate glass thin films.

High-emissivity coatings constitute an essential component of reusable thermal protection systems, determining the success or failure of hypersonic spacecraft. Reaction-cured glass coating is the basis for all current high-emissivity coatings, and the study of its sintering behavior is of great scientific significance for the development and performance enhancement of the coating. Microstructures and phase compositions of the samples before and after the sintering process were determined using SEM, XRD, and EDS. The sintering temperature, inserting temperature, and heating rate were systematically investigated. The results show that the effects of the sintering temperature, inserting temperature, and heating rate on the coating occur in decreasing order. The optimum condition for coating sintering in this study is an insertion temperature of 1100 °C, a heating rate of 10 °C/min, and a sintering temperature of 1200 °C, and a crack-free and containing SiB4 borosilicate glass coating was successfully prepared.

In this study, bioactive glass material containing sodium alginate was coated on the surface of Ti6Al4V alloy by the sol–gel method, and its bioactive property was investigated. The aim of the study is to make the surface of Ti6Al4V alloy bioactive with the help of the coating layer. For this purpose, polymeric coating functional new material with bioactive glass layer was formed. Combination of triethyl phosphate tetraethoxysilane, and calcium nitrate was used as phosphate, silica, and calcium sources to form the sol structure. Also, by adding polyvinylpyrrolidone to the bioactive glass coating solution, the rheological properties of the solution were optimized, which is an important factor in the formation of a homogeneous coating surface. Bioactive glasses were coated on the Ti6Al4V surface and then heat treatment was applied to the samples at the optimum temperature of 200 °C for half an hour. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) devices were used to identify the phases formed and detect the functional groups. The energy-dispersive X-ray spectroscopy, XRD, and FTIR analysis methods were used to determine the in vitro bioactive property of the heat-treated samples at 200 °C before and after contact with simulated body fluid. The transmission electron microscope, differential scanning calorimetry, and simultaneous thermal analysis methods were also used to characterize the coating materials. Providing the desired bioactivity together with the lower heat treatment temperature has added superiority to the formed original coatings.

The present paper reports on the development of a vitreous material with high near-infrared (NIR) emissivity. Silica-based glasses (SiO 2 , Na 2 O, Al 2 O 3 , K 2 O) with different Fe 2 O 3 (hematite) contents are deposited on ceramic tiles as coatings and annealed at 1250 °C. Using the indirect radiometric measurement method, the emissivity of the materials was determined at room temperature, where the spectral directional reflectance of the coatings was measured. The samples possessing high emissivity values of 0.78–0.80 in the near-infrared are those with the highest Fe 2 O 3 contents. Colorimetric test ( L * a * b *), has revealed that the glass coating goes darker red by adding more amount of Fe 2 O 3 . XRD analysis has shown the magnetite, hematite, and nepheline crystallization phases in the glasses with Fe 2 O 3 contents above 30 wt%. Readable aspects of FTIR absorbance spectra were found, which gave information about the structure variations of these glasses as a function of Fe 2 O 3 content, also, SEM photographs displayed morphology of the prepared glass coatings.

Two compositions of 58S (60 mol% SiO2, 36 mol% CaO, 4 mol% P2O5) glass coatings were made by sol-gel and applied by dip coating onto two commercial magnesium alloys (AZ31 and AZ91) as a strategy to retard the hydrogen evolution and accelerate the deposition of a hydroxyapatite layer to enhance bioactivity. Surface studies with x-ray photoelectron spectroscopy, Raman spectroscopy, and scanning electronic microscopy techniques are presented after coating deposition and after immersion in Hanks’ balanced salt solution (HBSS) at 37°C. Electrochemical tests were also conducted to evaluate the evolution of the coating with immersion. It is observed that even though the coating presents defects, it is able to retard substrate degradation, and this effect is more pronounced for AZ91 as substrate. Coating performance is mainly governed by the substrate because of defective nature of the film.

A FeCrMoNiCuBSiC metallic glass coating was designed and then deposited by the high-velocity oxygen fuel (HVOF) spraying technique. X-ray diffraction, a scanning electron microscope, and a microhardness tester were applied to characterize the phase, microstructure, and mechanical properties of the coating. The amorphous phase was the main phase in the coating, and crystal phases were almost undetectable in the XRD results. The coating had a dense structure (the porosity was 1.47 ± 0.32%) and high Vickers microhardness (848 ± 22 HV0.3). The wear behavior of the coatings sliding against WC-Co was studied with a pin-on-disc wear test system and was compared with that of 316L stainless steel. The coating improved the wear resistance of the steel by around 7–9 times at different sliding speeds. As the sliding speed was increased, the wear loss rate of the steel obviously increased, yet the loss rate of the coating decreased first and then increased. This happened because the contact flash temperature induced by friction increases with the sliding speed, which results in oxidative behavior and crystallization events in the coating. The dominating wear mechanism of the coating is fatigue wear combined with oxidative wear.

Silver electrodes are commonly used as a conductive layer for electromagnetic devices. It has the advantages of good conductivity, easy processing, and good bonding with a ceramic matrix. However, the low melting point (961 °C) results in a decrease in electrical conductivity and migration of silver ions under an electric field when it works at high temperatures. Using a dense coating layer on the silver surface is a feasible way to effectively prevent the performance fluctuation or failure of the electrodes without sacrificing its wave-transmitting performance. Calcium-magnesium-silicon glass-ceramic (CaMgSi2O6) is a diopside material that has been widely used in electronic packaging materials. However, CaMgSi2O6 glass-ceramics (CMS) are facing tough challenges, such as high sintering temperature and insufficient density after sintering, which significantly confine its applications. In this study, CaO, MgO, B2O3, and SiO2 were used as raw materials to manufacture a uniform glass coating on the silver and Al2O3 ceramics surface via 3D printing technology followed by high-temperature sintering. The dielectric and thermal properties of the glass/ceramic layer prepared with various CaO-MgO-B2O3-SiO2 components were studied, and the protective effect of the glass-ceramic coating on the silver substrate at high temperatures were evaluated. It was found that the viscosity of the paste and the surface density of the coating increase with the increase of solid contents. The 3D-printed coating shows well-bonded interfaces between the Ag layer, the CMS coating, and the Al2O3 substrate. The diffusion depth was 2.5 μm, and no obvious pores and cracks can be detected. According to the high density and well-bonded glass coating, the silver was well protected from the corrosion environment. Increasing the sintering temperature and extending the sintering time is beneficial to form the crystallinity and the densification effect. This study provides an effective method to manufacture a corrosive-resistant coating on an electrically conductive substrate with outstanding dielectric performances.

A SiO2-Al2O3-B2O3-CaO-MgO-Na2O glass-based protective lubricant coating was developed for Ti-6Al-4V alloy forging, featuring a fully non-toxic formulation. The coating consisted of a composite glass matrix formed by blending two phases with distinct softening temperatures, extending its operational window to 700–950 °C. The composite glass showed initial softening at 700 °C and complete melting at 800 °C, with contact angle measurements confirming superior wettability (θ < 90°) across the forging range (800~950 °C). With an increase in temperature, the surface tension of the composite glass melt decreased, and subsequently, the wettability of the composite glass melt was significantly improved. XRD revealed that the uncoated Ti-6Al-4V formed a 22 μm thick rutile TiO2 scale with a porous structure and interfacial cracks, while the coated sample retained an amorphous glass layer with no TiO2. Cross-sectional SEM showed a crack-free, poreless interface with strong metallurgical bonding, in contrast to the uncoated sample’s spalled oxide layer. EDS showed minimal oxygen diffusion of the glass coating into the substrate. Ring upsetting tests showed that the coating reduced friction from 0.5–0.7 to 0.3 (50–57% decrease). Collectively, the glass protective lubricant coating showed good performance in terms of protection and lubrication.