Increasing B2O3 Content Research Articles

Effect of B/Pb ion replacement in B2O3-PbO-SiO2 glasses: Structural, thermal, optical and electrical properties

Due to its easy manufacturing process and outstanding physical and chemical characteristics, boron lead silicate glass is widely used in electronic packaging, optical fields, and sensor technology. Herein, new glass samples with different proportions of B2O3/PbO are prepared by a combined melting and annealing process. The glasses undergo structural and thermal characterization to investigate its composition, thermal behavior, optical properties, and dielectric properties. The results show that the glass structure changes gradually as [SiO4] and [PbO4] units were replaced by [BO3] units with increasing B2O3 content. This transformation has an impact on coefficient of thermal expansion and characteristic temperature of the glass. Additionally, it is observed that alterations in structure resulted in a decrease in both optical band gap as well as dielectric constant and loss. These findings provide insights into how variations in the B2O3/PbO ratio influence structural evolution and enhance properties for boron lead silicate glasses. This provides a theoretical basis for further advances to improve material properties and expand optical and electronic applications.

Structure and properties of aluminoborosilicate glasses for OLED display substrate

The effects of Al2O3/SiO2 and B2O3/SiO2 substitution on the network structure and properties of high aluminium and low boron alkali-free aluminoborosilicate glasses used as OLED display glass substrate were investigated. A more polymerized network within 3 mol.% substitution for Al2O3/SiO2 was obtained, represented by the decreasing value of NBO/T from 0.14 to 0.08, as well as the opposite result for B2O3/SiO2 substitution. Q3 and Q4 units held the vast majority of Si groups, and the tetrahedral [AlO4] occupied the majority among Al groups, while [AlO5] and [AlO6] was too low or even too tiny to be detected obviously in the investigated glass system. [BO4] concentration decreased from 59.04 % to 52.74 % with the increase of B2O3 content, and [BO3] increased accordingly, which indicated that [BO4] was not the preferential borate group in this glass system even if (RO-Al2O3)/B2O3 > 1. Higher [BO3] at lower (RO-Al2O3)/B2O3 value (>1) indicated the low conversion efficiency from [BO3] to [BO4] in the investigated glasses. The glass network between the bulk sample and glass melt was also investigated, and some differences in Al groups could be concluded from the test of the glass melt. Finally, samples with satisfied properties for OLED display substrate were acquired.

Effect of boron oxide on the structure and properties of Li2O‐Al2O3‐SiO2 transparent glass‐ceramics

AbstractTransparent lithium aluminum silicon glass‐ceramics are prepared via heat treatment and the effect of boron oxide (B2O3) content on the structure and properties of Li2O‐Al2O3‐SiO2 glass‐ceramics is investigated. The X‐ray photoelectron spectroscopy results reveal that the parent glass containing B2O3 exhibits a higher concentration of bridging oxygen (BO). With an increase in B2O3 content, the relative amount of BO changes from 76.64% to 79.86% and then to 79.52%. Simultaneously, the second crystallization peak temperature TP2 of the samples increases from 715°C to 720°C and then to 724°C by differential scanning calorimeter analysis. The X‐ray diffractometer and scanning electron microscope results indicate that the addition of B2O3 facilitates grain growth, while an increase in B2O3 substitution for Al2O3 hinders the precipitation of LiAlSi4O10 but promotes quartz formation. The glass containing 2 wt% B2O3 with the heat treatment of 560°C/ 4 h+ 680°C/2 h shows a Vickers Hardness value of approximately 7.75 GPa, and a transmittance at 550 nm reaching ∼85%.

Effects of B2O3 on melting characteristic temperature and evaporation of CaF2-CaO-Al2O3 based ESR slag

The evaporation behaviors of ESR slag (CaF2-CaO-Al2O3-MgO-(B2O3)) for B-containing rack steel was laboratorially investigated to improve the stability of ESR process and the quality of ESR ingots. The thermogravimetric measurement, FactSage 8.3, kinetic analysis and molecular dynamics simulation methods were applied in this study. Additionally, the melting characteristic temperatures of the slag was tested by the hemisphere method. The results showed that B2O3 reduced the melting characteristic temperatures and mass loss of slag. Increasing the B2O3 content increased the vapor pressure of AlF3, OBF, and BF3, consequently promoting their evaporation. The main evaporating product in the slag was found to be CaF2, followed by minor amounts of MgF2, AlF3, OBF, AlOF, and BF3. Notably, the apparent activation energy for fluoride evaporation was calculated to fall within the range of 189.43–388.24 kJ mol−1, with the evaporation process following a nucleation and growth mechanism. The order of the self-diffusion coefficients of ions in the slag was determined to be F− > Mg2+>Ca2+>O2− ≈ B3+>Al3+. With the increase of B2O3 content in the slag, the self-diffusion coefficient of each ion underwent an initial decrease followed by a significant increase, illustrating that diffusion did not serve as the controlling step of the evaporation reaction.

Microstructure and mechanical properties of freeze-casted in-situ ABOw@Al2O3/AZ91 composites

In this work, the A18B4O33w (ABOw) was in-situ generated on the surface of Al2O3 through the reaction of B2O3 and Al2O3, resulting in the thorn structure. Then, the ABOw@Al2O3/AZ91 composites were fabricated through a combination of freeze casting and pressure casting. The influence of the initial content of B2O3 on the microstructure and mechanical properties of ABOw@Al2O3/AZ91 composites was investigated. The results show that the lamellar structure of ABOw@Al2O3/AZ91 composites were weakened, which gradually changed to dendritic structure with the increasing B2O3 content. The in-situ formation of ABOw on the surface of Al2O3 was favorable to improve the compressive strength of both ABOw@Al2O3 ceramic scaffold and ABOw@Al2O3/AZ91 composites, while also reducing the anisotropy of the composites. Furthermore, the in-situ generated ABOw within the ceramic layer could effectively relieve stress concentration and delay crack initiation and propagation, which led to the enhancement of the load-bearing capacity of ABOw@Al2O3/AZ91 composites. The ABOw@Al2O3/AZ91 composite exhibited the outstanding mechanical properties with the compressive strength of ∼685 MPa, when the B2O3's content is 5 wt%.

Thermodynamic modeling of interphase distribution of chromium and boron in slags of AOD reduction period

The paper presents the results of a thermodynamic modeling of the chromium and boron reduction from slags of reduction period of argon-oxygen decarburization (AOD) by a complex reducing agent containing silicon and aluminum. Using the simplex lattice method, an experiment planning matrix is constructed containing 16 compositions of the oxide system СаО – SiO2 – (3 – 6 %) В2О3 – 12 % Cr2O3 – 3 % Al2O3 – 8 % MgO of variable basicity 1.0 – 2.5. The results of thermodynamic modeling are graphically presented in form of dependence of equilibrium distribution of chromium and boron on the slag composition at temperatures of 1600 and 1700 °C. The constructed diagrams make it possible to quantify the influence of the temperature, basicity and B2O3 in the slag on equilibrium interphase distribution of chromium and boron. It is established that increasing the slag basicity from 1.0 to 2.5 improves the process of chromium reduction, but restores the boron stability. With an increase in B2O3 content in the slag, a slight deterioration of chromium reduction process occurs, while the boron content in the metal increases. With a simultaneous increase in basicity up to 2.5 and a decrease in boron oxide in the slag from 5 to 3 %, the interphase distribution coefficient of chromium is reduced to 1.5·10–3. Changing the process temperature from 1600 to 1700 °C does not have a negative effect on the process of chromium reduction, but worsens the boron reduction conditions. Based on analysis of the formed slag phases and thermodynamics of the reactions of their formation, it is established that chromium is mainly reduced by aliminum with only partial development of silicothermy. The residual silicon content reduces boron, thereby limiting its concentration in the metal. The results of high-temperature experiments showed high correspondence with the results of thermodynamic studies.

Unveiling the effect of phase separation on crystallization of calcium borosilicate glass-ceramics

The CaO–B2O3–SiO2(CBS) glass-ceramics with low sintering temperature and good microwave dielectric properties have been applied on the famous commercial low temperature co-fired ceramics (LTCC) Tape for passivation substrate materials for 5G/6G technology. However, the phase separation and its relationship with the crystallization is rarely studied but extremely important for understanding and designing the high-performance CBS glass-ceramics. Herein, we find that the phase separation type of CBS glass-ceramics changes from metastable immiscibility to stable immiscibility with the increase of B2O3 content. In the metastable immiscible glass-ceramics, three phases are observed, including continuous borate-rich and silicate-rich phases as well as spherical silicate-rich phases. In the stable immiscible glass-ceramics, the silicate-rich phases transform into petal-liked shapes. β-CaSiO3 nuclei are formed in fractions with BO3/SiO4 equaling to 0.56. Notably the β-CaSiO3 nucleus do not grow after heat treatment at 850 °C, but grow at higher temperatures. Phase separation hinders the precipitation of β-CaSiO3 and promoted the formation of CaB2O4 and SiO2. In addition, interfacial defects caused by phase separation alter the crystal barrier and promote the formation of α-CaSiO3. However, α-CaSiO3 dissolves at 1000 °C and may provide Ca2+ cations together with the borate-rich phase for the regrowth of β-CaSiO3. Our work provides another perspective for understanding the effects of phase separation on crystallization in CBS glass-ceramics, contributing to improving the microwave dielectric performance by structural design.

Rheological behaviour of CaO–MgO–SiO2–Al2O3–B2O3 system with varying B2O3 content up to 30 wt% at basicity of 0.4

A comprehensive theoretical and experimental study describing the effect of B2O3 (0–30 wt%) on softening, liquidus, and crystallization temperatures, flow behaviour, and dynamic viscosity of the glass-based oxide system SiO2(64.64–43.21 wt%)-MgO(10 wt%)-CaO(15.86–7.29 wt%)-Al2O3(9.50 wt%)-B2O3 with a constant basicity of 0.4 was carried out. The experimental data was obtained up to 1550 °C using a high-temperature rheometer and were supported by the study of the internal structure by means of scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray powder diffraction analysis, and Fourier transform infrared spectroscopy. The increasing addition of boron oxide caused a decrease in the start and end softening and liquidus temperatures. At 1550 °C, the systems exhibited Newtonian behaviour, with a dynamic viscosity increasing exponentially with a decreasing temperature and decreasing with increasing B2O3 content. The amorphous character of the samples and the formation of structural units [BO2O−] and [BO3] and [BO4], confirmed by complementary analyses, led to a decrease in the degree of polymerization of the silicate structure. The theoretical insight into the dependence of dynamic viscosity on the temperature and composition was realized based on molecular dynamics. Furthermore, the prediction of viscosity as a function of temperature (1230–1550 °C) and the change in chemical composition (0–30 wt% B2O3) was performed using artificial neural networks.

Effect of B2O3 substitution for P2O5 on the refractive index and optical absorption in pyro SnO−P2O5−B2O3 glasses

We investigated the impact of substituting B2O3 for P2O5 on a refractive index and optical absorption of pyro SnO−P2O5−B2O3 glasses. To date, we have reported that thermal properties and glass structure have a characteristic composition dependence when B2O3 replaces P2O5. In this paper, we report that optical properties such as optical absorption and refractive index also have a characteristic composition dependence. We observed a consistent increase in the refractive index with increasing B2O3 substitution, categorized into three regions, which is consistent with the trend in density. In addition, we observed that the optical absorption edge of the glass is shifted to a longer wavelength with increasing B2O3 concentration. To gain further insight into the optical properties of the glasses, we utilized Kramers–Kronig analysis to experimentally correlate the observed changes in refractive index and optical absorption. These changes in density and refractive index were predicted by elucidating the short-range structures of the glass, which were quantitatively provided by determining the proportions of phosphate and borate units. This information was then used to calculate the ion packing ratio.

Influence of B2O3 on the thermophysical properties of molten blast furnace slag

The thermophysical characteristics of blast furnace molten slags have crucial implications for their smelting process and the subsequent utilization of resources. To efficiently recover molten slag waste heat resources, the thermodynamic properties and viscous flow characteristics of molten blast furnace slag systems with various B2O3 contents were investigated. The stability of the slag at high temperatures was evaluated by calculating its heat capacity and critical heat release. The structural evolution of the melt under varying B2O3 contents was comprehensively studied using Raman spectroscopy and Nuclear Magnetic Resonance. From the perspective of viscous flow characteristics, the impact of B2O3 resulted in a reduction in viscosity of the slag, while the electrical conductivity of the slag increased. Concerning the thermodynamic properties, the break temperature decreased from 1377 °C to 1280 °C with an increase in B2O3 content in the range of 0 to 6 wt.%, while heat capacity and critical heat release of the slag both increased. The introduction of B2O3 facilitated smoother the blast furnace smelting conditions while enhancing the superiority of the granulated product and the efficiency of heat recovery. Adding B2O3 to the molten slag disrupted part of chain structure (Si-O-Si) to create a more flowable cyclic borosilicate structure (Si-O-B).

Effect of B2O3 on luminescence and scintillation properties of Ce3+-doped gadolinium aluminium–silicate glass

Different B2O3 content was added to Ce3+–doped Gd2O3–Al2O3–SiO2 (xBGAS:1.1Ce3+, x = 0, 5, 10, 15) glasses to improve the photoluminescence (PL) and scintillation properties. The transmittance of 15BGAS:1.1Ce3+ glass is over 80%. The X–ray absorption near edge spectroscopy (XANES) spectra imply that Ce4+ can be effectively reduced to Ce3+ in the glasses by adding Si3N4. The excitation and emission spectra show a blue shift with increase of B2O3 content. The photoluminescence quantum yield (PL QY) increases with the increase of B2O3 content, reached the maximum of 59.55% when x = 15. The PL decay time of the glasses exhibits typical values (44–50 ns) due to 5d→4f transition of Ce3+ ions. The PL thermal activation energy become larger, indicating that xBGAS:1.1Ce3+ glasses have better luminescent thermal stability. The integral X–ray excited luminescence (XEL) intensity of the 15BGAS:1.1Ce3+ glass is 37.38% of Bi4Ge3O12 (BGO) crystal, and the light yield is 1267 ph/MeV with an energy resolution of 23.22% at 662 keV when exposed to γ–rays. With the increase of B2O3 content, the fast component of scintillation decay time gradually becomes shorter and the slow component becomes longer. The thermally stimulated luminescence (TSL) curves were measured to investigate the trap depth and density of defects in xBGAS:1.1Ce3+ glasses.

Effect of B<sub>2</sub>O<sub>3</sub> Content on Structure and Properties in High Refractive Index BaO-ZnO-TiO<sub>2</sub>-SiO<sub>2</sub> Glass System

In this paper, BaO-ZnO-TiO2-SiO2 is used as the research system of high refractive index glass, and IR, XRD and DTA are used to study the structure, thermal behavior, crystallization and chemical stability of different glasses when B2O3 gradually replaces SiO2. The results show that when B2O3 replaces SiO2, glass still has an amorphous structure, and the density of glass shows a decreasing trend with the increase of B2O3 content. With the increase of B2O3 content, the boron-oxygen tetrahedron gradually transforms into the boron-oxygen triangle, which makes the overall crystallization of the glass structure weaken. The results show that the density, refractive index and water resistance of glass beads without B2O3 are the best. With the increase of B2O3 content, the activation energy of crystallization decreases, the potential barrier to be overcome for crystallization decreases, as the same time the phenomenon of glass crystallization is obvious. Keywords:High refractive index glass; BaO-ZnO-TiO2-SiO2; Crystallization; Chemical stability

Structural, thermal, and DC conductivity properties of WO3–P2O5 glasses doped with B2O3

AbstractIn this study, glasses in composition 70WO3–(30 − х)P2O5–хB2O3 (0 ≤ х ≤ 20 mol%) were prepared by melt quenching method. The glass formation, structure, and thermal and electrical properties are discussed. Homogeneous glasses were obtained at x = 0–10 mol% B2O3, whereas glasses with x = 15 and 20 contain microinclusions of WO3. The glass transition temperature decreases from 709 to 531.6°C with increasing B2O3 content, as well as the crystallization temperature and the thermal stability. The structure of the glasses was studied by Raman spectroscopy and infrared spectroscopy. The Raman spectra are characterized by a band near 995 cm−1, a broad band at 788–800 cm−1, and a band near 675 cm−1 ascribed to vibrations of W–O–P, W–O–W, and P–O–B bonds, respectively. The Fourier‐transform infrared spectra show vibrational bands due to characteristic phosphate and borate groups. Tetrahedral BO4 units prevail in the structural network. The electrical conductivity of the glasses decreased with x content due to the growth of WO3‐deficient regions.

Structure-Property Correlation in Sodium Borophosphate Glasses Modified with Niobium Oxide

Bulk glasses of the series (100−x)[0.4Na2O-0.2Nb2O5-0.4P2O5]-xB2O3 with x = 0–48 mol% B2O3 were prepared by slow cooling in air. Their glass transition temperature increases within the range of 0–16 mol% B2O3, but further additions of B2O3 result in its decrease. Their structure was investigated by Raman, 11B, and 31P MAS NMR spectroscopy. The relative number of BO4 units decreases with increasing B2O3 content, while the number of BO3 units increases up to 59 % at x = 48. The upfield shift of a broad resonance peak in the 31P MAS NMR spectra is ascribed to an increasing connectedness of the structural network with increasing B2O3 content. Strong Raman band at 916–929 cm−1 shows on the presence of NbO6 octahedra in the structural network of these glasses. With the B2O3 addition, a decrease in DC conductivity is observed, which is attributed to the decrease in the concentration of Na+ ions.

Compositional dependence of crystallization and chemical durability in alkali aluminoborosilicate glasses

This study aims to understand the impact of composition on crystallization and chemical durability in alkali aluminoborosilicate based model nuclear waste glasses designed in the peralkaline, metaluminous and peraluminous regimes. The glasses have been thermally treated using the canister centerline cooling (CCC) schedule. The chemical durability of both parent and CCC-treated glasses has been assessed by product consistency test (PCT-B) for 120 days. The peraluminous glasses exhibit the highest dissolution rates, followed by peralkaline and metaluminous glasses. In general, increasing B2O3 content in glasses tends to suppress nepheline formation, thus, decreasing the negative impact of nepheline on durability of the final waste form. However, higher B2O3 content itself may result in detrimental impact on the durability of the final waste form. The thermal history has been shown to have a significant impact on the durability of the glasses.

Role of CuO in Al2O3-B2O3 Composites: In Situ Phases, Density, Hardness, and Wear Resistance

Abstract The aim of this study was to develop a novel set of Al2O3-B2O3-CuO composites and evaluate their tribological performance at varying humidity (10–95% relative humidity) levels. First, the Al2O3-B2O3 composites were prepared using cold press sintering by varying the amount of B2O3 (5–20 wt%). The results revealed that an increase in B2O3 content in the composites increased the amount of aluminum borate in situ phase during sintering. The presence of the aluminum borate phase in the composite enhanced the hardness and wear resistance, whereas the humidity-sensitive alumina phase reduced friction at higher humidity levels. Next, CuO (5 wt%) was added to the Al2O3-B2O3 composites to form Al2O3-B2O3-CuO composites. These composites showed an increase in the percentage relative density by 16–37% and hardness by 1.2–1.9 times. Subsequently, the tribological performance was improved significantly. The underlying mechanism for improved wear resistance was discussed using the crystal-chemical approach and polarization theory to guide the design of these novel Al2O3-B2O3-CuO composites.

Evaluation of the dynamic behavior, elastic properties, and in vitro bioactivity of some borophosphosilicate glasses for orthopedic applications

The present work employed the finite element model (FEM) to predict the influence of successive increases in borate (B2O3) contents, from 0 to 25 mol%, on mechanical properties and dynamic behavior. By feeding the isotropic elasticity characteristics of the phosphosilicate glass to the model, such as Young's modulus, density, and maximum compressive stress of the produced glass samples to fit the aim of their clinical use. The effect of successive addition of B2O3 on the in vitro bioactivity of the examined glasses in addition to examined after being dipped in simulated body fluid (SBF) at different times. Moreover, tracking the formation of hydroxyapatite (HA)-like layers on their surfaces using X-ray diffraction technique (XRD) technique and scanning electron microscopy (SEM). The results obtained indicated that increasing B2O3 content to 25% was responsible for improving the deflect resistance by 39%.On the other hand, neither shear stress nor principles stress was affected by this increase in B2O3 content. Moreover, the gradual increases in B2O3 contents were very helpful in improving the bioactivity of the samples. The prepared glasses can be successfully used in bone replacement applications from these promising results.

Effect of B2O3 addition on thermal and optical properties of TeO2–ZnO–Bi2O3–TiO2 glasses

New tellurite glasses with composition (in mol%): 60TeO2–(30-x)ZnO–5Bi2O3–5TiO2-xB2O3 (where x = 0, 2.5, 5.0, 7.5 and 10.0) were fabricated using conventional melt quenching method. Compositional dependence of the glasses on their density, thermal, refractive index and optical properties were investigated. X-Ray Diffraction analysis was carried out to confirm the nature of the thus formed glasses. Density, refractive index, and absorption spectra were measured at room temperature from which other glass characteristics such as polaron radius, oxygen packing density, field strength, B3+ interatomic distance, band gap energy, and Urbach tail were determined. Thermal characterisation to determine the change in glass transition temperature, glass crystallisation, melting point, and glass stability was carried out using Differential Scanning Calorimetry. A discussion was made in order to understand the results in terms of the ratio of bridging oxygen to non-bridging oxygen ions (BO/NBO). It was found that the addition of B2O3 results in increasing oxygen packing density, glass transition temperature, BO/NBO ratio and band gap energy, while decreasing density, refractive index, field strength, glass stability and Urbach tail energy. With increasing B2O3 concentration density changed from 5.879 to 5.646 g cm−3, refractive index 1.875 to 1.741, working temperature range (ΔT = 66 °C) and phonon energy within the range of 736–740 cm−1.

Microstructure and mechanical properties of diopside and anorthite glazes with high abrasion resistance

The paper presents the results of research on the influence of the chemical composition of frits on the microstructure and mechanical properties of ceramic glazes. Glaze sets are designed based on frits of different chemical composition and increasing B2O3 content. Thermal DSC analysis showed a high tendency to crystallize the designed glazes, and in the obtained glazes the main crystalline phases were diopside or anorthite, which was also confirmed by XRD analysis and SEM microscopic observations. In glazes not containing B2O3 and at a SiO2/Al2O3 molar ratio in the 5.3–5.6 range, mainly diopside crystallized, while a decrease in the SiO2/Al2O3 molar ratio to a value below 4.9 and an increase in B2O3 content contributed to an increase in the anorthite crystal phase content. The obtained glazes were characterized by a surface roughness of Ra in the range of 0.2–1.1 μm and a high abrasion resistance measured with a mass loss of less than 50 mg after 6000 abrasion cycles in accordance with the EN ISO 10545-7 standard. Such high abrasion resistance was achieved thanks to the high hardness of the glazes in the range of 6.4–8.0 GPa, which was confirmed by the Vickers hardness measurement.

Effects of B2O3 on the structure and properties of blast furnace slag by molecular dynamics simulation

B2O3 has the advantages of reducing the liquidus temperature and enhancing the fluidity of slag, while its influence mechanism in atomic scale has not yet been fully understood. Molecular dynamics simulation was conducted to investigate the influence of B2O3 on the structure and properties of SiO2CaO-Al2O3-B2O3 blast furnace slag system at 1773 K. Results showed that a large number of [SiO4]4−-[BO3]3− structures are generated in the system after B2O3 added, Si4+ ions mainly exist in the form of [SiO4]4- tetrahedrons and B3+ ions mainly exist in the form of [BO3]3− planar triangular structures and [BO4]5− tetrahedrons. With the increase of B2O3 content, the proportion of [BO3]3− planar triangular structures increase. In addition, the content of bridge oxygen in the microstructure of slag increases obviously, the content of non-bridge oxygen decreases, and the polymerization degree of the system increases somewhat. Through the analysis of microscopic mechanism and the modified NPL viscosity model, combined with experimental data, the truth that the slag viscosity decreases with the increase of B2O3 contents were known in the simulated concentration range.