Effect Of TiO2 Addition Research Articles

Effect of TiO₂ Addition on Elastic Moduli, Optical Bandgap, and Electrical Conductivity of xTiO₂-(0.30-x)Bi₂O₃-0.10ZnO-0.60TeO₂ Glassy Systems with Improved Thermal Stability

Glassy systems with the chemical composition xTiO2-(0.30-x)Bi2O3-0.10ZnO-0.60TeO2 (x = 0.05,0.10,0.15,0.20) have been synthesized using the melt quench approach. Numerous physical, electrical, optical, and other features of elastic moduli have been evaluated as titanium oxide concentration rises. The amorphous properties of the materials under inspection are displayed in the XRD pattern. As the concentration of arsenic rises, the glasses' density falls from 4.18 to 3.96 g/cm3, while their molar volume rises from 48.21 to 53.06 cm3mol-1. The elastic properties of the synthesized glasses, such as the shear (S) and longitudinal (L) stresses, bulk modulus (K), Young's modulus (Y), and Poisson's ratio (Pr), have all been measured using the measured values of the ultrasonic velocities. The increase in elastic moduli values showed that the materials' elastic qualities have been improved. The results are explained in terms of a significant structural alteration caused by molecular rearrangement, which controls the physical properties of the glass. The addition of titanium oxide is shown to cause a decrease in Urbach energies from 0.96 to 0.67 eV, which results in an increase in the optical band gap energies from 2.96 to 3.33 eV. DSC thermogram measurements reveal mechanically enhanced and thermally stable materials with potential for use in semiconducting devices.

Effect of TiO2 Addition in Ladle Slag on Evolution of Nonmetallic Inclusions in Ti-Bearing Al-Killed Steel

Effect of TiO2 Addition in Ladle Slag on Evolution of Nonmetallic Inclusions in Ti-Bearing Al-Killed Steel

Effect of TiO2 addition on microstructures and properties of MgO–CaO refractory aggregates

Effect of TiO2 addition on microstructures and properties of MgO–CaO refractory aggregates

The Effect of TiO2 Addition on Low-temperature Sintering Behaviors in a SnO2-CoO-CuO System

Pure SnO2 has proven very difficult to densify. This poor densification can be useful for the fabrication of SnO2 with a porous microstructure, which is used in electronic devices such as gas sensors. Most electronic devices based on SnO2 have a porous microstructure, with a porosity of > 40%. In pure SnO2, a high sintering temperature of approximately 1300C is required to obtain > 40% porosity. In an attempt to reduce the required sintering temperature, the present study investigated the low-temperature sinterability of a current system. With the addition of TiO2, the compositions of the samples were Sn1-xTixO2-CoO(0.3wt%)-CuO(2wt%) in the range of x ≤ 0.04. Compared to the samples without added TiO2, densification was shown to be improved when the samples were sintered at 950C. The dominant mass transport mechanism appears to be grain-boundary diffusion during heat treatment at 950C.

Effect of TiO2 Addition on the Viscosity of Ladle Refining Slags

Effect of TiO2 Addition on the Viscosity of Ladle Refining Slags

The effect of post heat treatment and TiO2 addition on tribological and electrochemical performances of thermally sprayed alumina

ABSTRACT The heat treatment of alumina ceramics is a fundamental process for controlling the physical, mechanical and thermal properties of these components during industrial operations. The problem statement in this case is about the effects of TiO2 addition and post heat-treatment on the expansion behaviour of alumina coating. For that alumina (Al-99) and alumina-titania coatings 5% wt. TiO2 (AT-5) and 15% wt. TiO2 (AT-15) were formed onto E335 substrate steel via the flame spraying technique. The samples were heat-treated (1000°C for 2 h in Air) and their wear and electrochemical behaviour was compared with the as-sprayed samples. The X-ray diffraction (XRD) patterns reveal a change in the phase composition of the heat-treated coatings compared to the as-sprayed coatings, as alpha alumina matrix but with different ratio. The heat-treated coatings exhibit higher values to as-sprayed coating. At the same time, the addition of TiO2 present hardness twice than pure alumina coating (Al-99). The tribological properties show that the deposits after heat treatment have low wear values compared to the as-sprayed coatings, the lowest specific wear rate was obtained for the heat-treated AT-5 composite coatings. The heat treatment had a positive effect on the corrosion resistance.

Effect of TiO2 addition on the microstructure and electrical properties of Al2O3 ceramics

The resistivity of the dielectric layer material of a Johnsen–Rahbek (J–R) electrostatic chuck is generally between E8 and E12 Ω⋅cm, while that of pure alumina ceramic is more than E15 Ω⋅cm. Therefore, it is necessary to regulate the resistivity of the alumina ceramic for use as a dielectric layer material for a J–R-type electrostatic chuck. An electrostatic chuck requires a uniform and controllable surface temperature on the silicon wafer. Therefore, there is a certain requirement for the thermal conductivity of the dielectric layer.In this experiment, Al2O3 ceramics with different TiO2 contents (ranging from 0.08 to 3.6 wt%) were used as the research system and sintered at 1550 °C in a reducing sintering atmosphere. The obtained samples showed electrical resistivity from E9 to E14 Ω⋅cm and thermal conductivity from 26 to 37 W/m·K. The effects of Al2O3 ceramics with TiO2 on the phase composition, microstructure, relative density, electrical conductivity, and thermal conductivity were systematically studied, along with the relationship between the temperature and electrostatic adsorption force J–R and the resistivity of the sample. The addition of 1.2 wt% TiO2 gave the Al2O3 sample better overall performance; its relative density was up to 97.88 %, resistivity was reduced to 7.09 × 109 Ω cm, thermal conductivity was 27.211 W/m·K, and the electrostatic adsorption forces at 300 and 500 V/mm were up to 119 and 331 gf/cm2, respectively. The samples were primarily used as dielectric layers of the electrostatic chuck. By simulating the electrostatic adsorption between the dielectric layer and silicon wafer under an external voltage, the J–R force of stable adsorption between the electrostatic chuck and the silicon wafer was realised.

Effect of TiO2 Additions on the Properties of Bioactive Granulated Materials of the TiO2–SiO2–P2O5/СаO(ZnO) System

Effect of TiO2 Additions on the Properties of Bioactive Granulated Materials of the TiO2–SiO2–P2O5/СаO(ZnO) System

Effects of TiO2 addition on phase, mechanical properties, and microstructure of Cr2O3–Al2O3 ceramic composite

TiO2 is a sintering additive that can significantly improve the sintering and mechanical properties of Cr2O3–Al2O3 refractory materials with high Cr2O3 contents. In this study, TiO2-reinforced Cr2O3–Al2O3 composite refractories were prepared using a reaction-sintering process. The microstructure, phase composition, mechanical properties, and strengthening mechanism of the TiO2-reinforced Cr2O3–Al2O3 composite refractories were investigated. The results indicated that the Al2O3–Cr2O3–TiO2 composite refractory with a TiO2 content of 3.0–4.5 wt% had good compactness (porosity of 5.89%), hardness (17.21 GPa), wear resistance (wear rate of 0.4 mm3/Nm), flexural strength (101.10 MPa), and compressive strength (420.90 MPa). This is mainly because when the added amount of TiO2 was <3.0 wt%, TiO2 was solidly soluble in the matrix, forming a Ti3+-doped (Cr, Al)2O3 solid solution, inhibiting abnormal grain growth, rapidly increasing the sintering shrinkage of the sample, rapidly increasing the bulk density, rapidly decreasing the apparent porosity, and improving the sintering and mechanical properties of the composite resistant material. When the TiO2 addition exceeded 4.5 wt%, a large amount of (Cr, Al)2TiO5 phase was distributed between the grain boundaries of the solid solution, and its bulk density started to decrease. The sintering shrinkage and apparent porosity did not change significantly, and the bonding between the solid solution was not improved. Thus, the sintering and mechanical properties of the composite resistant material deteriorated. Taking into account the slag resistance and mechanical properties of the material, Al2O3–Cr2O3–TiO2 with a TiO2 content of 3.0–4.5 wt% can meet the service requirements for mechanical properties of the lining of smelting reduction ironmaking furnaces.

The effects of TiO2 addition on the anticorrosion performance of ECTFE coating under lighting

In this study, TiO2 particles were dispersed into ethylene-chlorotrifluoroethylene copolymers (ECTFE), and TiO2/ECTFE composite coating was prepared with the TiO2/ECTFE mixture via electrostatic spraying and low temperature thermal processing. The prepared coating was soaked in 3.5 wt% NaCl solution under lighting or dark for anticorrosion performance study. The microstructure of the treated coating was characterized with XRD, Raman, FT-IR and SEM. The results indicate that the low frequency impedance (|Z| 0.01 Hz) of the TiO2/ECTFE coating maintained above the 109 orders of magnitude after 90-day soaking. It is evident that the addition of TiO2 enhances the protective performance of the coating on steel, while simultaneously compromising its own integrity. With increasing soaking time, C-H groups in ECTFE coating would be exposed gradually and lighting would speed this process, making the surface roughness of coating reduced. This is because halogens in the polymer chain of ECTFE would be stretched gradually. TiO2 would also change the bond length of C-H groups and make the C-H groups oxidized under lighting. The strengthening effect of TiO2 can be ascribed to the filler and barrier effects of TiO2 particles together with the prior consumption of dissolved oxygen by photo-generated electrons. However, the fast degradation of TiO2/ECTFE coating under lighting is the result of local agglomeration of TiO2 particles, and oxidation of the C-H groups by photo-generated holes.

Effect of TiO2 addition on sintering, microstructure and properties of anorthite-based ceramics derived from reduced copper slag

Reduced copper slag is a promising substitute constituent in anorthite-based ceramics. To reduce the sintering temperature of this type of slag-derived ceramics, the role of TiO2 addition in the sintering, microstructure, physical and mechanical properties, and environmental and appearance performance was studied by experimental and theoretical methods. The results show that the Ti element was dissolved in the glassy phases and anorthite crystals instead of producing new phases. This behavior allows the liquid appearance at earlier temperatures and accelerates the ion diffusion, thus significantly enhancing the sintering and contributing to a dense microstructure with fine closed pores. Besides, this improvement is achieved at a relatively slight sacrifice of anorthite grains. The addition of 4 wt% TiO2 results in a decrease in the vitrification temperature by 100 oC and an enhancement of flexural strength by 50%. Moreover, the slag-derived ceramics show extremely low leaching toxicity and a relatively higher whiteness, ensuring the cleanliness and quality of anorthite-based ceramics. However, the ceramics show lower bulk density and obvious surface defects with the TiO2 content up to 6 wt%.

Tribology and in-vitro biological characterization of TiO2 addition on ceria stabilized zirconia-toughened alumina (CSZTA) composite

ABSTRACT The effect of TiO2 addition on tribology and in-vitro biological characteristics of ceria-stabilized zirconia-toughened alumina (CSZTA-TiO2) ceramic composites were examined and presented in this study. Through the powder metallurgy route, the TiO2 added to CSZTA samples were synthesized and sintered (air environment). Additionally, the pin on the disc machine was used to examine the wear characteristics of sintered samples. Adding TiO2 to CSZTA enhances the tribological properties compared to pure ceria-stabilized zirconia-toughened alumina (CSZTA). In addition, the samples (CSZTA and CSZTA-TiO2) were subjected to aging. There is no monoclinic-phase transformation (no degradation) in the CSZTA-TiO2 sample after 100 h of testing, confirming its great resistance to LTD. The bioactivity of developed CSZTA and CSZTA-TiO2 samples was studied using simulated body fluid (SBF). After chemical treatment, it was shown that the composite would create an apatite layer that resembled bone when soaked in a simulated body fluid with ion concentrations equal to human blood plasma. These results suggest that it may generate apatite within a live organism and connect to the bone via the apatite layer.

Effect of TiO2 addition on the structural and electrical properties of La0.67Ca0.33MnO3

Numerous studies have been conducted on perovskite manganites to enhance the low field magnetoresistance (LFMR). One effective approach is adding an insulating oxide as the artificial boundary layer outside the manganite grain. This research aims to determine the structural and electrical properties of La0.67Ca0.33MnO3 (LCMO) when added with different contents of TiO2. LCMO powder was prepared via sol–gel route before appended with TiO2 nanoparticle to form (1 − x) LCMO: x TiO2, x = 0.00, 0.005, 0.010, 0.030 and 0.050. The structural analysis by X-ray diffraction (XRD) revealed no significant changes in the lattice parameter, crystallite size, bond length and angle as the concentration of TiO2 increased. The TiO2 in LCMO caused an increase in resistivity and a decrease in metal–insulator transition (TMI). This indicates the double exchange (DE) has been suppressed by the TiO2 addition, which acts as disordered layers at LCMO grains surface. The electrical resistivity of the samples was fitted with theoretical models, and the conduction mechanism is explained by the grain/domain boundary effect and the small polaron hopping (SPH) model. The first fitting inferred that the grain/ domain boundary effect plays an inevitable role throughout the conduction in the metallic region. The latter supports the notion that the presence of TiO2 in the LCMO compound produces a more resistive grain boundary.

Microstructure and mechanical properties of (Zr,Ti)B2–SiC composites obtained by pressureless sintering of ZrB2–SiC–TiO2 powder mixtures

Multiphase ceramics have been highlighted due to the combination of different properties. This work proposes to obtain the multiphase composite of (Zr,Ti)B2–SiC based on the mixture of ZrB2, SiC, and TiO2 sintered without pressure. The effect of TiO2 addition on solid solution formation with ZrB2, densification, microstructure, and mechanical properties was investigated. For this, 2.0 wt% TiO2 was added to ZrB2–SiC composites with 10–30 vol% SiC and processed by reactive pressureless sintering at 2050 °C with a 2 h holding time. Sinterability, crystalline phases, microstructure, Vickers hardness, and indentation fracture toughness of these composites were analyzed and compared to the non-doped ZrB2–SiC samples. The XRD analysis and EDS elemental map images indicated the incorporation of Ti atoms into the ZrB2 crystalline structure with solid solution generation of (Zr,Ti)B2. The addition of TiO2 resulted in matrix grain size refinement and a predominant intergranular fracture mode. The relative densities were not significantly modified with the TiO2 addition, though a higher weight loss was detected after the sample sintering process. The composites doped with TiO2 showed an increase in fracture toughness but exhibited a slightly lower Vickers hardness compared to composites without TiO2 addition.

Promotion Effect of TiO2 on Ni/SiO2 Catalysts Prepared by Hydrothermal Method for CO2 Methanation

Herein, the effects of TiO2 addition and different preparation methods on catalyst structure and CO2 methanation activity of Ni/SiO2 catalysts are investigated. Compared with wetness impregnation and sol–gel method, hydrothermal method is demonstrated to be a more efficient means for preparing Ni/SiO2 catalysts with more suitable pore structure, more active sites on the catalyst surface, and better catalytic performance. Ni/SiO2 catalysts with different TiO2 concentrations are synthesized by hydrothermal method for comparison with those without TiO2 introduced. The results show that TiO2‐promoted Ni/SiO2‐HS‐xTi exhibits higher activity and CH4 selectivity. Among this group, the Ni/SiO2‐HS‐2Ti catalyst performs the best, achieving 53.2% CO2 conversion at 350 ºC, 0.1 MPa, and WHSV of 45 000 mL g−1 h−1. The conclusions of the characterization analysis indicate that TiO2 effectively promotes the Ni dispersion on the SiO2 surface while reducing Ni particle size. In addition, TiO2 increases the amount of weak basic sites on the SiO2 surface and the electron cloud density around the active metal Ni, which facilitates the CO2 adsorption and activation.

Effect of TiO2 addition on phase stability and sintering behavior of 1 mol%La2O3 -2 mol%Gd2O3-2 mol%Yb2O3-6 mol%Y2O3 co-doped ZrO2

In this study, 1 mol%La2O3-2 mol%Gd2O3-2 mol%Yb2O3-6 mol%Y2O3 co-doped ZrO2 (LGYYSZ) with 0 mol%, 5 mol% and 10 mol% TiO2 additions were synthesised by solid-state reactions. The effect of TiO2 addition on the phase stability of LGYYSZ and its sintering behaviour at 1500 °C were investigated using XRD, SEM and EDS. The results show that the eutectic temperature of LGYYSZ decreases with increasing TiO2 content. SEM, EDS and XRD results show that the TiO2 addition is reacted with the La2O3 in LGYYSZ to form a orthorhombic La2Ti2O7 phase. When held at 1500 °C, La2Ti2O7 is precipitated on the surface of the samples by evaporation-condensation mechanism. This resulted in the anti-sintering properties of LGYYSZ at 1500 °C decreasing with increasing TiO2 content.

Effect of TiO2 Additives on the Stabilization of h-YbFeO3 and Promotion of Photo-Fenton Activity of o-YbFeO3/h-YbFeO3/r-TiO2 Nanocomposites.

Nanostructured hexagonal rare-earth orthoferrites (h-RfeO3, R = Sc, Y, Tb-Lu) are well known as a highly effective base for visible-light-driven heterojunction photocatalysts. However, their application is limited by metastability, leading to difficulties in synthesis due to the irreversible transformation to a stable orthorhombic structure. In this work, we report on a simple route to the stabilization of h-YbFeO3 nanocrystals by the synthesis of multiphase nanocomposites with titania additives. The new I-type heterojunction nanocomposites of o-YbFeO3/h-YbFeO3/r-TiO2 were obtained by the glycine-nitrate solution combustion method with subsequent heat treatment of the products. An increase in the mole fraction of the h-YbFeO3 phase in nanocomposites was found with the titanium addition, indicating its stabilizing effect via limiting mass transfer over heat treatment. The complex physicochemical analysis shows multiple contacts of individual nanocrystals of o-YbFeO3 (44.4-50.6 nm), h-YbFeO3 (7.5-17.6 nm), and rutile r-TiO2 (~5 nm), confirming the presence of the heterojunction structure in the obtained nanocomposite. The photocatalytic activity of h-YbFeO3/o-YbFeO3/r-TiO2 nanocomposites was evaluated by the photo-Fenton degradation of the methyl violet under visible light (λ ≥ 400 nm). It was demonstrated that the addition of 5 mol.% of TiO2 stabilizes h-YbFeO3, which allowed us to achieve a 41.5 mol% fraction, followed by a three-time increase in the photodecomposition rate constant up to 0.0160 min-1.

Effect of TiO2 nano-ceramic particles on microstructure and mechanical properties of Al0.4CoCrFe2Ni2 high-entropy alloy

Al0.4CoCrFe2Ni2 high-entropy alloys with different additions of TiO2 nano-ceramic particles (0, 1.25vol.%, 2.5vol.%, 3.75vol.% and 5vol.%, respectively) were prepared by using the vacuum arc melting method. The effects of TiO2 addition on the crystal structure, microstructures and mechanical properties of the alloy were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile testing. The microstructure analysis shows that the TiO2 nano-ceramic particles added in the alloy are decomposed, and a small amount of Al2O3 and a great number of intermetallic compounds (γ′ phases) with simple cube structure are formed. The γ′ phases are enriched at inter-dendrite, which increases the resistance of dislocation movement during the deformation of the alloy, thus balancing the problem of high plasticity and low strength of the alloy. When the addition of TiO2 is 2.5vol.%, the strength of the high-entropy alloy reaches the maximum of 489 MPa, which is 11.1% higher than the matrix alloy composed of single FCC phase.

Effect of TiO2 addition on densification, microstructure, and mechanical properties of CSZTA

The effect of TiO2 addition on densification, microstructure, and mechanical behaviour of Ceria Stabilized Zirconia Toughened Alumina (CSZTA) was studied in the present work. CSZTA powders with various concentrations (0–10 wt%) of TiO2 were synthesized using the co-precipitation method. The powders were compacted into ϕ 10 mm pellets using a uniaxial hydraulic press and sintered in the presence of air at various sintering schedules. The TiO2 content and sintering schedule were optimized based on density, phases present, microstructure, and mechanical properties of the sintered sample. X-ray Diffraction (XRD) was used to identify the phases present, and the Rietveld refinement method was used to quantify phases from the XRD patterns. Microstructures of sintered samples were studied using Scanning Electron Microscope (SEM). The hardness and indentation fracture toughness was determined using a Vickers hardness tester. It was found that the addition of TiO2 to CSZTA improved sinterability and reduced the sintering temperature from 1600 °C to 1400 °C. The maximum Vickers hardness of up to 1591 HV10 with an optimum fracture toughness of 7.42 MPa.√m was observed for 4 wt%TiO2 - CSZTA sample sintered at 1400 °C for 3 h.

The effect of TiO2 addition on thermal resistance of geopolymer mortar based low alumina fly ash

The utilization of fly ash with low alumina has been carried out. The addition of TiO2 to the base material of fly ash and fly ash added with 20% metakaolin mixed with an alkaline solution has been characterized by heat resistance, compressive strength and porosity. These results indicate that the addition of TiO2 to both fly ash and fly ash with an additional 20% metakaolin shows a reduction in porosity reduction, an increase in the compressive strength value, and an increase in the thermal resistance of the sample. Despite an increase in the compressive strength value, however, the minimum requirement for a fire brick has not been achieved.