Increasing TiO2 Content Research Articles

Optimization of Hydrogen Utilization and Process Efficiency in the Direct Reduction of Iron Oxide Pellets: A Comprehensive Analysis of Processing Parameters and Pellet Composition

The article deals with the H2 consumption for different processing conditions and the composition of the processed pellets during the direct reduction process. The experiments are carried out at 600–1300 °C, with gas pressures of 1–5 bar, gas flow rates of 1–5 L min−1, and basicity indices of 0 to 2.15. Pellets with different compositions of TiO2, Al2O3, CaO, and SiO2 are analyzed. The gas flow rate is crucial, with 0–10 L min−1 leading to an H2 consumption of 0–5.1 kg H2/kg pellet. The gas pressure (0–10 bar) increases the H2 consumption from 0 to 5.1 kg H2/kg pellet. Higher temperatures (600–1300 °C) reduce H2 consumption from 5.1 to 0 kg H2/kg pellet, most efficiently at 950–1050 °C, where it decreases from 0.22 to 0.10 kg H2/kg pellet. An increase in TiO2 content from 0% to 0.92% lowers H2 consumption from 0.22 to 0.10 kg H2/kg pellet, while a higher Fe content (61–67.5%) also reduces it. An increase in SiO2 content from 0% to 3% increases H2 consumption from 0 to 5.1 kg H2/kg pellet. Porosity structure influences H2 consumption, with the average pore size decreasing from 2.83 to 0.436 mm with increasing TiO2 content, suggesting that micropores increase H2 consumption and macropores decrease it.

Synthesis of composite coatings based on Mg and Ti oxides by PEO for modulation of Mg corrosion resistance

In this study, the application of Plasma Electrolytic Oxidation (PEO) technique was investigated for fabricating composite coatings on magnesium (Mg) substrates aimed at modulating their corrosion resistance, an important characteristic for biodegradable orthopedic implants. The coatings were manufactured using an electrolytic solution containing MgO and TiO2 oxides, varying mass ratios, at currents of 30 mA and 200 mA. X-ray diffraction patterns confirmed the presence of TiO2 and MgO phases in the coatings, demonstrating the PEO capability to modulate the chemical composition by adjusting the mass ratio of oxides in the electrolytic solution. Microstructural analysis revealed decreased surface roughness with increasing TiO2 concentration. Corrosion tests indicated a significant improvement in corrosion resistance for all coatings compared to uncoated Mg substrate. In particularly, coatings with higher TiO2 concentrations, and those applied at a current density of 30 mA exhibited, enhanced corrosion resistance.

Preparation and structure of titanium‐containing pyrophosphate glasses prepared using the liquid‐phase method

AbstractPhosphate invert glasses (PIGs) exhibit excellent biocompatibility because of their high chemical durability and controlled ion releasability. PIGs are composed of short phosphate units such as ortho‐ and pyrophosphate. This structure makes it difficult to obtain clear glass using the melt‐quenching method. Our previous work reported that intermediate oxides (such as TiO2 and Nb2O5)‐containing PIGs exhibit good glass‐forming ability and ion dissolution controllability. This work used a liquid‐phase method to prepare PIGs at room temperature and pressure. Furthermore, TiO2 was used to control ion releasability for biomedical applications. Titanium‐containing PIGs were successfully prepared using a liquid‐phase method. Pyrophosphate and titania formed P‐O‐Ti bonds with an increasing TiO2 content in the glass, forming chain‐like structural units such as (‐O‐P‐O‐P‐O‐Ti‐O‐)n. The number of chain‐like structures increased with an increasing TiO2 content in the glass, improving the chemical durability. Hence, the ion releasability of titanium‐containing PIGs prepared using the liquid‐phase method can be controlled by the glass structure. Additionally, the PIGs exhibited good cell viability. Therefore, the PIGs are candidates for carriers of therapeutic inorganic ions for biomedical applications.

Effect of TiO2 content on the thermal control properties of Al2O3-xTiO2 composite coatings prepared by supersonic plasma spraying technology

The main challenge faced by spacecraft is the large temperature difference in its operating environment. Thermal control coatings prepared on spacecraft and instrument surfaces are currently the most efficient ways for heat dissipation and control. In this work, Al2O3-xTiO2 composite coatings with different TiO2 contents were prepared on 7075-Al alloy substrate by supersonic plasma spraying technology. The microstructure, phase composition, mechanical properties, thermal control properties, and corrosion resistances of the coatings were investigated. The raw stock feeds were mainly composed of α-Al2O3 and anatase TiO2, but the coatings were mainly γ-Al2O3 and rutile TiO2. The average Vickers microhardness of the coatings decreased from 1198.9 to 810.4 HV0.2 with the increase of TiO2 contents, but the elastic modulus increased from 158.5 to 244.3 GPa. The thermal control properties of the coatings were promoted with the growth of TiO2 contents, and the absorptance increased from 27.1 to 89.2% with the emittance from 83.7 to 86.5%. The corrosion potential and corrosion resistance of the coating gradually increased with TiO2 content due to its gradually improved hydrophobicity. This work broadens the application boundary of Al2O3-xTiO2 composite coating and provides an innovative idea for material selection of thermal control coatings.

The effect of dissolved oxygen and Shewanella algae on the corrosion mechanism of titanium in a simulated marine environment

The influence of dissolved oxygen (DO) and Shewanella algae on the corrosion behavior of pure titanium were systematically studied in this work. The formation of S. algae biofilms on titanium surface was facilitated by the anaerobic environment, which accelerated titanium corrosion. Upon the breakdown of passive film, S. algae acquired electrons from the titanium base substrate through extracellular electron transfer (EET) processes. Various EET-related genes were overexpressed by the low DO condition, leading to enhanced EET kinetics. High concentration DO increased TiO2 content and the thickness of passive film, which enhanced the protective effect and mitigated microbiologically influenced corrosion.

Design and characterization of borosilicate glass modified with TiO2 for enhanced optical and radiation shielding applications

This work investigates the potential of borosilicate glass doped with titanium dioxide (TiO2) for radiation shielding applications. The study explored the impact of varying TiO2 concentrations on the glass structure, optical properties, and radiation shielding effectiveness. X-ray diffraction (XRD) and Raman spectroscopy confirmed the amorphous nature of the glasses. The addition of TiO2 affected the glass network structure, as evidenced by changes in the Raman spectra and density measurements. UV–Vis spectroscopy revealed a red shift in the absorption edge (416–481 nm) and a decrease in the indirect optical band gap (2.91–2.70 eV) with increasing TiO2 content. The refractive index also increased from 2.54 to 3.54 with TiO2 concentration. The mass attenuation coefficient (MAC) and linear attenuation coefficient (LAC) increased significantly with TiO2 addition, indicating enhanced radiation attenuation capability. The inclusion of TiO2 reduced the half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP), while increasing the effective atomic number (Zeff). The effective electron density (Neff) and effective conductivity (Ceff) showed a slight increase with TiO2 content. Energy build-up factors (EBF and EABF) indicated a higher rate of radiation intensity increase and energy absorption within the glass due to the presence of TiO2. Finally, the incorporation of TiO2 into borosilicate glass offered a promising approach to developing improved optical and radiation shielding glasses.

Pd Catalysts Supported on Mixed Iron and Titanium Oxides in Phenylacetylene Hydrogenation: Effect of TiO2 Content in Magnetic Support Material.

Recently, Pd catalysts supported on magnetic nanoparticles (MNPs) have attracted a great attention due to their ability of easy separation with an external magnet. Modification of MNPs is successfully used to obtain Pd magnetic catalysts with enhanced catalytic activity. In this work, we discussed the effect of titania content in TiO2/MNPs support materials on catalytic properties of Pd@TiO2/MNPs catalysts in phenylacetylene hydrogenation. TiO2/MNPs composites were prepared by simple ultrasound-assisted mixing of TiO2 and MNPs, synthesized by co-precipitation method. This was followed by deposition of palladium ions on the mixed metal oxides using NaOH as precipitant. The supports and catalysts were characterized using XRD, BET, STEM, EDX, XPS, and a SQUID magnetometer. Pd nanoparticles (5-6 nm) formed were found to be homogeneously distributed on support materials representing the well-mixed metal oxides with TiO2 content of 10, 30, 50, or 70%wt. Testing of the catalysts in phenylacetylene hydrogenation showed that their activity increased with increasing TiO2 content, and the process was faster in alkali medium (pH = 10). The hydrogenation rates of triple and double C-C bonds on Pd@70TiO2/MNPs achieved 9.3 × 10-6 mol/s and 23.1 × 10-6 mol/s, respectively, and selectivity to styrene was 96%. The catalyst can be easily recovered with an external magnet and reused for 12 runs without significant degradation in the catalytic activity. The improved catalytic properties of Pd@70TiO2/MNPs can be explained by the fact that the surface of the support is mainly composed of TiO2 particles, affecting the state and size of Pd species.

Photoactivated rose bengal-doped TiO2 nanoparticles modified fifth-generation adhesive on the survival rate of Streptococcus mutants and mechanical properties of tooth-colored restorative material to carious dentin.

Assessment of the antimicrobial, micro tensile bond strength (μTBS), and degree of conversion (DC) of fifth-generation adhesive modified using photoactivated 0.5% rose bengal (RB) and photoactivated RB-doped titanium dioxide nanoparticles (TiO2NPs) in different concentrations (2% and 5%) as compared with the unmodified adhesive bonded to the carious affected dentin (CAD). Forty mandibular molars with caries progression up to the middle third of the dentin, as per the International Caries Detection and Assessment System (ICDAS) score of 4 and 5 were included. Specimens were divided into four groups based on etch and rinse adhesive (ERA) modification group 1: unmodified ERA, group 2: photoactivated 0.5% RB photosensitizer (PS) modified ERA, group 3: photoactivated RB-doped 2 wt% TiO2NPs adhesive, group 4: photoactivated RB-doped 5 wt% TiO2NPs adhesive. Followed by adhesive and composite restoration on the CAD surface. All the specimens were thermocycled and an assessment of μTBS and failure pattern analysis was performed. The antibacterial potency of RB and RB-doped TiO2NPs (2% and 5%) followed by their activation using visible light against Streptococcus mutans (S.mutans) were tested. The survival rate of S.mutans was assessed using the Kruskal-Wallis test. The analysis of μTBS involved the use of ANOVA, followed by a post-hoc Tukey honestly significant difference (HSD) multiple comparisons test. Group 1 (Unmodified ERA) (0.52 ± 0.31 CFU/mL) treated samples unveiled the highest means of bacterial survival and lowest μTBS (11.32 ± 0.63 MPa). Nevertheless, group 4: photoactivated RB-doped 5 wt% TiO2NPs adhesive displayed the lowest outcomes of S.mutans survival (0.11 ± 0.02 CFU/mL) and highest bond strength (18.76 ± 1.45 MPa). The photoactivated RB-doped 2 wt% TiO2NPs in adhesive demonstrated promising enhancements in both μTBS and antibacterial efficacy against S.mutans. However, it is noteworthy that this modification led to a decrease in the DC of the adhesive. RESEARCH HIGHLIGHTS: Unmodified ERA-treated samples unveiled the highest bacterial survival and the lowest μTBS. Photoactivated RB-doped 5 wt% TiO2NPs adhesive displayed the lowest S.mutans survival rate and highest bond strength. DC decreased with an increase in concentration of TiO2.

Photocatalytic removals of imidacloprid insecticide in TiO2- and Fe2O3-immobilized porous geopolymer granules

In this study, geopolymer catalysts were synthesized by incorporating different TiO2 (0, 7, and 14 wt%) and Fe2O3 content (0, 7, 14, and 20 wt%) into porous metakaolin-based geopolymer granules. TiO2- and Fe2O3-immobilized geopolymer granules were applied for photocatalytic removals of imidacloprid under UV-C irradiation. The analysis of the surface morphology of the Fe2O3 catalyst revealed its larger surface area predominated with meso- and macro-pores thus providing a larger area for photocatalysis. Meanwhile, the TiO2 catalyst had TiO2 nanoparticles filled up those mesopores and macropores in geopolymer resulting in its denser structure therefore limiting access of imidacloprid to the reactive sites. To maximize its photocatalytic activities, Fe2O3 and TiO2 could be immobilized into porous geopolymer matrix up to 20 and 14 wt%, respectively. The developed porous geopolymer had relatively stable imidacloprid adsorption capacities regardless of the TiO2 and Fe2O3 contents in their texture. After UV irradiation, their removal efficiencies were 94.85–100% and the photocatalytic degradation increased with the increase in TiO2 content (from 0 to 14 wt%) and Fe2O3 content (from 14 to 20 wt%). Nevertheless, Fe2O3-immobilized geopolymer granules posed a significantly higher kinetic rate (1.966 h−1) compared to that of TiO2 (0.154 h−1) at the same catalyst content (14 wt%). The newly developed Fe2O3-immobilized porous geopolymer catalysts could be effectively reused over 10 successive cycles during which the imidacloprid could be completely removed.

Thermophysical properties, crystallization behavior and structure of CaO–SiO2–MgO–Al2O3–TiO2–FeO slag with varying TiO2 contents

This study investigated the effect of TiO2 content on the viscosity, free running temperature, electrical conductivity, crystallization behavior, and structure of high-titanium CaO–SiO2-10 wt% MgO-13 wt%Al2O3–TiO2-4 wt.% FeO slag by experiments and molecular dynamics simulations. The results revealed that increasing TiO2 weakened the overall bonding energy and simplified the slag structure, leading to a decrease in viscosity and an increase in electrical conductivity. Thermodynamic calculations revealed a continuous enrichment of the slag towards the pseudobrookite region with increasing TiO2 content. The precipitation of pseudobrookite phase during cooling resulted in short-slag characteristics and a rising free running temperature. Additionally, the peak intensity of pseudobrookite phase gradually enhanced and its morphology changed from elongated strips to plates with higher TiO2 concentration. Structural analysis demonstrated that the poorly stabilized [TiO6] octahedron was the major form of Ti atoms in the slag, and its proportion progressively increased with increasing TiO2 content.

Effect of TiO2 on the structural properties and viscosity of CaO-SiO2-8.25 %MgO-15 %Al2O3-TiO2 slags

As a raw material for ironmaking, vanadium-bearing titanomagnetite will leads to an increase in the TiO2 content of blast-furnace slag and deteriorates the metallurgical properties of the slag. In this study, the effect of TiO2 content on the viscosity of CaO-SiO2–8.25 %MgO-15 %Al2O3-TiO2 slag system at fixed w(CaO)/w(SiO2) ratio of 1.2 was investigated, and Raman spectroscopy focusing on the relationship between the structure of high TiO2-bearing blast furnace slag and viscosity was performed. The findings showed that under the experimental condition, the viscosity of slag decreases with the increase of TiO2 content over a range of 20 to 35 %. The melting temperature of slag increases first and then decreases after w(TiO2) is higher than 30 %. The viscous-flow activation energy of slag decreases with the increase of TiO2 content, which has a concomitant variation corresponding with the results of the effect of TiO2 on viscosity. The analysis of Raman spectroscopy results reveals that the blast-furnace slag system is dominated by [SiO4]4- network structure. As the TiO2 content increases, more and more Ti4+ enters the silica-oxygen tetrahedral network structure, disrupting the Si-O-Si bond to form the [TiO4]4- structural unit and a small portion of the [TiO6]8- structural unit. The NBO/Si value of the Si4+ in the tetrahedron unit as an index for the degree of depolymerization of slags increased from 1.62 to 2.60 as the TiO2 content increased, the slag structure was gradually simplified and the slag viscosity was gradually decreased.

Insight into the TiO2 on transport behavior and heat transfer of the CaO–SiO2–FeO–MgO system at different basicities: Molecular dynamics simulation and thermodynamics

In order to promote the resource utilization of Ti-containing converter slag and reduce the loss of metallic Ti, it is necessary to clarify the relationship between the oxygen network structure and thermophysical properties of the slag. The present work uses classical molecular dynamics (CMD) simulation to study the effects of basicity (1.0–3.0) and TiO2 content (0%–10 %) on the local structural properties, viscosity, and thermal conductivity of the CaO–SiO2–FeO–MgO–TiO2 (CSFMT) system at 1873 K. The M − O (M = Ca, Si, Fe, Mg, and Ti) bond length calculated based on CMD is consistent with the experimental results, and the [SiO4] tetrahedron and [TiO6] octahedron are the basic structural units of the CSFMT system. The increase in basicity promotes the break of bridging oxygen (BO) Si–O–Si and the formation of non-bridging oxygen Si–O-M. The increase in TiO2 content promotes the formation of Ti–O–Si in the system. The basicity and TiO2 content affect the thermophysical properties of the CSFMT system by promoting and inhibiting the depolymerization of the oxygen network structure, respectively. The diffusion abilities of different atoms in the CSFMT system are in descending order of Fe > Mg > Ca > O > Si > Ti. The viscosity of the CSFMT system decreases with increasing basicity and increases with increasing TiO2 content. Increasing the proportion of BOs can weaken the anharmonicity in the polyhedral structural units and reduce phonon scattering. With increasing basicity and TiO2 content, the effective phonon mean free path decreases and increases, respectively, resulting in a decrease and an increase in the thermal conductivity of the CSFMT system. The changes in the microstructure properties of the CSFMT system can be reasonably explained by the changes in its thermodynamic properties such as enthalpy. It is worth noting that the basicity has a greater effect on the viscosity, while the TiO2 content has a more significant impact on the thermal conductivity of the CSFMT system.

Experimental evaluation of radiation shielding characteristics of borate-based-glass system reinforced with titanium oxide

In this work, the attenuation capability of new Borate-based-glass system reinforced with titanium oxide containing PbO, CaO, TiO2 and B2O3 with different percentages was determined. Four different glass samples were synthesized by experimental technique using high pure germanium detector at different gamma ray sources using narrow beam method. The experimental method was verified by XCOM software. The values of the two methods were close and the relative deviation was satisfactory (less than 5 %) for all gamma energies (0.060, 0.662, 1.173 and 1.333 MeV). The highest linear attenuation coefficient (LAC) values achieved at low radiation energy of 0.0595 MeV. The Highest LAC values were 13.64, 13.97, 14.32 and 14.67 cm−1 for samples PCBT-1, PCBT-2, PCBT-3 and PCBT-4 in the same order, respectively. Conversely, the lowest LAC values in the examined energy range were found at 1.333 MeV. The lowest LAC values were 0.259, 0.266, 0.272 and 0.279 cm−1 for the aforementioned glasses, respectively. At 0.662 MeV, the transmission factor (TF) values decreases as 64.18, 63.54, 62.88 and 62.19 % as TiO2 content increases as 5, 10, 15 and 20 mol % in the same order, respectively. The decreases in TF values was linked to an observable increase in the radiation protection efficiency (RPE). The increase in RPE with the increase of TiO2 content confirms that the addition of TiO2 leads to an improvement in the radiation shielding performance for the prepared glasses.

Optical properties of germania and titania at 1064 nm and at 1550 nm

One of the main noise sources in current gravitational-wave detectors is the thermal noise of the high-reflectivity coatings on the main interferometer optics. Coating thermal noise is dominated by the mechanical loss of the high-refractive index material within the coating stacks, Ta2O5 mixed with TiO2 . For upgrades to room-temperature detectors, a mixture of GeO2 and TiO2 is an interesting alternative candidate coating material. While the rather low refractive index of GeO2 increases with increasing TiO2 content, a higher TiO2 content results in a lower threshold temperature before heat treatment leads to crystallisation, and potentially to a degradation of optical properties. For future cryogenic detectors, on the other hand, a higher TiO2 content is beneficial as the TiO2 suppresses the low-temperature mechanical loss peak of GeO2. In this paper, we present the optical properties of coatings—produced by plasma-assisted ion-beam evaporation—with high TiO2 content at 1550 nm, a laser wavelength considered for cryogenic gravitational-wave detectors, as a function of heat-treatment temperature. For comparison, the absorption of pure GeO2 was also measured. Furthermore, results at the currently-used wavelength of 1064 nm are presented.

Effect of titanium dioxide as nanomaterials on mechanical and durability properties of rubberised concrete by applying RSM modelling and optimizations

The use of rubber aggregates derived from discarded rubber tyres in concrete is a pioneering approach to replacing natural aggregate (NA) and promoting sustainable building practices. Recycled aggregate in concrete serves the dual purpose of alleviating the accumulation of discarded rubber tyres on the planet and providing a more sustainable alternative to decreasing natural aggregate. Due to fact that the crumb rubber (CR) decreases the strength when used in concrete, incorporating titanium dioxide (TiO2) as a nanomaterial to counteract the decrease in strength of crumb rubber concrete is a potential solution. Response Surface Methodology was developed to generate sixteen RUNs which contains different mix design by providing two input parameters like TiO2 at 1%, 1.5%, and 2% by cement weight and CR at 10%, 20%, and 30% as substitutions for volume of sand. These mixtures underwent testing for 28 days to evaluate their mechanical, deformation, and durability properties. Moreover, the compressive strength, tensile strength, flexural strength and elastic modulus were recorded by 51.40 MPa, 4.47 MPa, 5.91 MPa, and 40.15 GPa when 1.5% TiO2 and 10% CR were added in rubberised concrete after 28 days respectively. Furthermore, the incorporation of TiO2 led to reduced drying shrinkage and sorptivity in rubberized concrete, especially with increased TiO2 content. The study highlights that TiO2 inclusion refines pore size and densifies the interface between cement matrix and aggregate in hardened rubberized concrete. This transformative effect results in rubberized concrete demonstrating a commendable compressive strength comparable to normal concrete.

Study on structure and properties of La2O3–TiO2–B2O3 system glass

High refractive index La2O3–TiO2–B2O3 (LTB) system glasses have been successfully prepared by traditional melt-quenching method. Based on XPS results, we acquire details regarding the Ti oxidation state, coordination environments of boron and titanium, and the ratio of bridging to non-bridging oxygens within the glass. The predominant structural units identified in the glass matrix include [BO4], [BO3] and [TiO5] polyhedra, alongside a fraction of [TiO4] and [TiO6] polyhedra. The incorporation of TiO2 results in a reduction of the [BO4] tetrahedral groups and an increase of bridging oxygens and non-bridging oxygens bonds with Ti within the glass structure. 20 % of Ti(Ⅳ) ions in the glass are reduced to Ti(Ⅲ) ions. The addition of TiO2 content leads to an increase in Vickers hardness and refractive index of the glass, with [TiO5] polyhedra notably enhancing the refractive index. However, the increase in TiO2 content correspondingly decreases glass transmittance due to the charge transfer between Ti4+ or Ti3+and O2−.

Influence of TiO2 addition on the Mg4Nb2O9 ceramic phase and its application in the radiofrequency region

In this work, the dielectric properties of (1-x) Mg4Nb2O9 – (x) TiO2 composite ceramics in radiofrequency and the microwave region were evaluated. X-ray diffraction demonstrated that Mg4Nb2O9 (MNO) reacted with TiO2 resulting in the formation of new crystalline phase Mg5(Nb0.625Ti0.375)4O15. Complex Impedance Spectroscopy (CIS) analysis was realized to analysis the electrical properties of materials, whereas was observed that activation energy (Ea) decrease from 1.64 to 1.37 eV with an increase in TiO2 concentration. Temperature capacitance coefficient (TCC) was obtained and showed that at different frequencies all materials could be used as Class 1 ceramic capacitors according to EIA RS-198. In the Microwave region, MNO – TiO2 demonstrated ε’r between 12.07 (MNO) and 14.08 (MNO18T), tan δ values varying of 2.64 × 10-4 (MNO) up to 5.92 × 10−4 (MNOT14). Regarding the temperature coefficient of resonant frequency (τf) was observed that the values decreased with the increase in TiO2, with the value closest to zero being that of pure MNO (τf = −27 ppm.°C−1). The results presented show that materials evaluated could be utilized in devices that can be act in radio frequency (RF) and microwave (MW) regions.

Experimental studies on mechanical properties of Al-7075/TiO2 metal matrix composite and its tribological behaviour

This study explores the fabrication and characterization of an Al-7075/TiO2 metal matrix composites (MMCs) through stir casting, varying TiO2 contents from 2% to 10%. Various tests, including tensile, hardness, and elastic indentation modulus testing, dynamic mechanical analysis, microstructural evaluation, and XRD, were conducted. Tribological analysis involved tribo-pairs of an EN31 disc and a smooth MMCs pin, using a high-temperature Pin-on-disc setup. Microstructural analysis of Al-7075/TiO2 MMCs revealed uniform TiO2 distribution, grain refinement, and enhanced mechanical properties, with XRD confirming structural changes. Tensile tests showed improved ultimate force and stress with increasing TiO2 content, indicating potential for high-strength applications. Hardness assessments demonstrated progressive improvements in Martens, Elastic Indentation, and Vickers Hardness, highlighting the material's suitability for critical wear and tribology applications. The composites exhibited enhanced damping flexural characteristics, especially with 8% TiO2. Maximum and minimum modulus values are reported as 98.9 GPa at 25 °C and 77.3 GPa at 350 °C for 8% TiO2 mix MMC. Tribological performance was improved with lower COF values and wear rates. At elevated temperatures, the wear behavior varied with TiO2 content, influenced by factors such as heat generation and localized welding.

Thermophysical Properties of CaO–SiO2–Al2O3–MgO–TiO2–FeOx–V2O3 Slag with CaO/SiO2 = 1.13 with Different TiO2 and V2O3 Additions

The thermophysical properties of an industrial blast furnace slag with varying TiO2, V2O3, and FeOx content are investigated using a rotating viscometer and maximum bubble pressure method at low oxygen partial pressure. The obtained experimental results are supported by thermodynamic calculations using FactSage 7.2 software and by scanning electron microscope analysis. The measurement outcomes clearly indicate that an increase in V2O3 and TiO2 content up to 10 wt% at 5 wt% FeOx leads to a decrease in the viscosity of all studied slags; however, with 15 wt% of V2O3 and TiO2, the viscosity changes insignificant. The presence of 10 wt% FeOx alters the behavior of the slags in the liquid‐dominant region. These changes in the break point temperature are consistent with the behavior of melilite and perovskite phases. Moreover, an increase in the FeOx, V2O3, and TiO2 increases the density of all studied slags within the temperature range of 1450–1650 °C. Additionally, introducing pure oxides to the slag reduces the surface tension of all the studied slags, confirming their role as a surfactant.

Thulium-doped titanate-germanate glasses for infrared photonics

In this paper, we performed a comparative spectroscopic analysis of Tm3+-doped glasses based on GeO2-BaO-Ga2O3 (GBG) and TiO2-GeO2-BaO-Ga2O3 (TGBG) to achieve broadband luminescence at 1.8 μm. Glasses were prepared at different doping concentrations (0.05 mol% and 1mol%) in order to investigate the effect of Tm3+ ions as well as host composition (GeO2:TiO2 molar ratios) on near-IR luminescence properties. We report on the hypersensitivity of the transition 3H6 → 3F4 of Tm3+ in a series of titanate-germanate glasses, which was shifted to longer wavelengths with increasing TiO2 concentration. The relative intensity of the main near-IR emission band corresponding to the 3F4 → 3H6 (1.8 μm) transition of Tm3+ was 4.8-fold enhanced for glass with molar ratio GeO2:TiO2 = 1:5 compared to GBG glass system. We observed the luminescence quenching phenomena for samples containing more than 0.5 mol% of Tm3+ ions. The calculated spectroscopic parameters, such as measured luminescence lifetime (τm) and the quantum efficiency (η), were discussed and compared to the different laser glasses. Importantly, luminescence decay curves have been examined using the Inokuti-Hirayama model. Additionally, the correlation between optical properties and local structure in glasses was well evidenced by Raman spectroscopy. The proposed strategy, in combination with various chemical composition of glass host activated by various Tm2O3 concentration, might be beneficial for modern near-infrared photonics.