Low-melting Glass Research Articles

Microstructure and properties of YIG/YIG magnetic homogenization joint fabricated by a novel Bi2O3–B2O3–NiO–Fe2O3 magnetic glass

Aiming at mechanical and electromagnetic demands for yttrium iron garnet ferrite (YIG) integrated structure, a novel Bi2O3–B2O3–NiO–Fe2O3 (BBNF) low-melting magnetic glass braze was designed. Nearly magnetic homogenization YIG/YIG joints were fabricated successfully. In-situ magnetic microcrystalline phases NiFe2O4 and Ni2FeO4 with good mechanical property precipitated in the brazing seam. The magnetization performance of YIG/YIG joints was significantly promoted. Merely 10 % difference of the magnetization strength per unit mass of the joints to YIG base materials was achieved. The joint shear strength reached its maximum of 79 MPa due to the enhancement of the microcrystalline phases. It is significant for improving both structural stability and functional reliability of the microwave devices for long-term service.

Corrosion behavior of low melting glass modified potassium silicate coating under the synergy of solid NaCl deposit and water vapor at 700 °C

The effects of LMG (SiO2–BaO–Al2O3–TiO2–Na2O–K2O–ZnO) modification on the performance of potassium silicate coatings on Ti–6Al–4V alloy during tests of either H2O/O2- or NaCl/H2O/O2- corrosion were investigated at 700 °C for 500 h using thermogravimetric, SEM, EPMA, and XRD. Adding 10-30 wt% LMG particles into the potassium silicate solution did not impair the intact and the surface roughness of the coatings and improved the resistance of the coatings against humid oxygen corrosion and NaCl/H2O/O2-induced corrosion. For the humid oxygen corrosion, the improvement was enhanced when the amounts of LMG was increased. However, the LMG10 coating with 30 vol% LMG had the most excellent corrosion resistance, the formation of titanate was prohibited; the coatings with more LMG additions were less protective than LMG10 though better than the coating without LMG.

Structural, optical properties, and laser spectroscopy of erbium-doped low-melting borate glasses

Glasses that contain Erbium oxide as a dopant exhibit garnered considerable interest for its use in photonic applications, primarily because of the intra-4f sublevel transitions of Erbium ions, which enable emission in the technologically significant 1.5 μm communications window. In this work, a series of Erbium oxide doped sodium lithium borate glasses were synthesized via melt quenching with compositions xEr2O3-(55-x)B2O3–25Li2O–10Na2O–5CaO–3SrO–2Al2O3 (x = 0, 1, 2, 3, and 5 mol%). An investigation was conducted to examine the consequences of Er3+ on the crystal structure and laser spectroscopy. Furthermore, the optical properties of the samples that were created. XRD analysis showed degradation of the glass network with increasing Er2O3 content due to disruption of boroxol rings. FTIR spectra indicated variations in BO3/BO4 ratios and Er–O vibrations with doping. Absorption spectra revealed characteristic Er3+ f-f transitions and a redshift in the UV edge. The bright field imaging proved the effect of Er3+ on the homogeneity of the surfaces. Meanwhile, 3D laser Raman mapping chemically proves the good distribution of Er2O3 on the glass surface. With an excitation under 980 nm, visible emissions at 550 and 660 nm, along with NIR emission at 1550 nm arising from Er3+ 4f levels, were observed. The results demonstrate that Er3+ doping effectively modifies the glass structure and optical properties. The borate glass host provides an excellent platform for customized erbium-doped photonic devices operating in the telecom C-band.

Study of the Properties of Low-Melting Borosilicate Glasses Developed for a Removable Small-Sized Melter Designed by Mayak Production Association Using the Simplex Planning Method

Study of the Properties of Low-Melting Borosilicate Glasses Developed for a Removable Small-Sized Melter Designed by Mayak Production Association Using the Simplex Planning Method

Thermoviscosimetric characteristics of borosilicate glasses with regard to the promising area of low-melting compositions currently being developed for the removable small-scale melter designed by Mayak Production Association

Relevance. The need to obtain experimental data on dependence of thermoviscosimetric properties of the examined borosilicate glasses on temperature, in order to solve the problem of developing a low-melting composition of borosilicate glass for a small-scale melter designed by Mayak Production Association. Aim. To get the most complete characterization of the glasses under study using thermoviscometric measurements. Methods. Mathematical modelling, simplex-lattice design. Results and conclusions. One of the most effective methods of experiment planning, which allows, with a relatively small number of experiments, obtaining a mathematical model reflecting the dependence of the studied property of the mixture on the content of components in it, is the simplex experiment planning method. To simplify the solution of such a task, a group or groups of components are usually distinguished, in which the ratio of the mass fraction of the components does not change. In this article, three groups of components are taken – simulators of high-level radioactive waste, sodium and boron oxides, and glass frit. The authors have identified the most promising area, where the mass fraction of glass frit is from 67.5 to 75%, the mass fraction of sodium and boron is from 25 to 32.5% and the mass fraction of high-level waste components is from 0 to 20%. The paper presents the results of thermoviscometric measurements of 15 melts of low-melting borosilicate glasses of different compositions at temperatures ranging from 700 to 1,200°C. Using simplex-based mathematical models of experiment planning, domains of dependence of thermoviscosimetric characteristics of glass melts on their compositions were created. The authors identified the compositions of glass melts that are found within the viscosity limits determined as allowable for glass melt discharge during operation of the removable small-scale melter of Mayak Production Association design.

Corrosion testing of prospective chrome refractory materials in borosilicate glass melts

Justification is provided of significant practical relevance of the issue of corrosion and erosion resistance of refractory materials in furnaces with direct electric heating that are used for vitrification of high-level waste. Main promising materials are listed, and an algorithm is given for assessing their resistance to attack of borosilicate glass melts under operating conditions of electric furnaces. Corrosion testing of chrome refractory materials of joint Chinese and Belgian origin has been carried out under static and dynamic conditions in a low-melting borosilicate glass melt and in a borosilicate glass melt containing simulated liquid high-level waste (HLW). A search has been conducted among chrome refractory materials of Chinese and Belgian origin for ones demonstrating the highest glass melt attack resistance with regard to the conditions of HLW solidification. The results of these tests will be considered in the design of removable and small-scale melters when selecting the material for melter lining.

The Study on the Decolorization and Properties of Bismuth Glass

PbO glass has an adverse effect on the environment; the bismuth glass has a high refractive index, low melting temperature, softening temperature, and glass transition temperature (Tg), so that it can be used as a lead-free glass, used in optoelectronics, electronics, optics, and other components, which bismuth glass has been proved to be an important replacement material. Due to the higher melting temperature, Bi3+ ions tend to partially reduce to the low valence state of Bi0, which in turn causes coloration of the glass. In this experiment, the absorption peaks of glass oxidized brown color were observed at about 470 nm at 1,100°C (Bi2O3 = 40, 45 mol%) and 1,000°C (Bi2O3 = 40 mol%) for these three curves. The bismuth glass produced by high-temperature melting is not suitable for optical applications; by adding an oxidant (Sb2O3), which inhibits the reduction reaction of bismuth ions and maintains the ions in the state of Bi3+, the glass becomes more transparent in appearance and the transmittance is also improved and raised to approximately 75%–80%, which proves that appropriate additives are sufficient to greatly improve the application of bismuth glass for optical components. In the research process, the density and molar volume were measured by Archimedes method, Raman analysis was used to explore the influence of its structural changes, UV/Vis spectroscopy was used to measure the transmittance and absorption spectra for analysis and discussion, and TMA was used to observe the thermal properties, in the hope of developing a good optical properties of the glass, and the present experiments have confirmed that the addition of a small amount of Sb2O3 changes the color of the glass from black to a light yellow, which can be better used in the optical glass.

Effect of K2WO4 on structure and properties of low melting glasses in K2O–Fe2O3–P2O5 system as sealing materials

New phosphate glasses based on the K2O–Fe2O3–P2O5 system, with variable K2WO4 content in place of Fe2O3, are prepared through the melt quenching route. The thermal and structural characteristics and water resistance properties are studied for sealing applications by means of XRD, DSC, and FTIR spectroscopic and dilatometry measurements. The results showed an amorphous nature and a linear increase in the parameters of the glass density and molar volume with the addition of K2WO4. While the glass transition (Tg), crystallization (Tc) temperatures, the thermal stability (ΔT), and the relative criterion (H) values were decreased are decreased. Inversely, the ΔCp values were markedly increased with growing NBO bonds that led to markedly increase in the O/P ratio. Also, the coefficient of thermal expansion (CTE) is increased (from 124 to 211 × 10−7/oC). The glass with high K2WO4 content is a suitable sample for excellent sealing properties with a low transition temperature (Tg < 300 °C), a very low melting point, and a high thermal expansion value (211 × 10−7/oC). As well, the durability values of the examined samples decreased, but they were in the range of those for commercial sealing glass. The study offers fresh suggestions for the development of sealant materials that are both low-temperature and environmentally safe.

Physical, Structural, and Optical Characteristics of Manganese Ion-Containing Low-Melting Borate Glasses

Physical, Structural, and Optical Characteristics of Manganese Ion-Containing Low-Melting Borate Glasses

Glass with a low-melting temperature belonging to the P2O5–CaO–Na2O system, applied as a coating on technical ceramics (alumina, zirconia) and traditional ceramics (porcelain stoneware)

This article investigates the development and potential applications of low-melting point lead-free glasses. Their importance is due to strong market demands to comply with the strict international regulations against the use of lead. In this work, a preliminary study of the existing interactions of a low-melting-temperature glass belonging to the P2O5–CaO–Na2O system when it is deposited on different ceramic substrates, both traditional (porcelain stoneware) and technical (alumina and zirconia), has been carried out. The ionic diffusion through the studied interfaces, the phases present, the composition of the glassy phase and the surface morphology of the coating have been studied by Field Emission Scanning Electron Microscopy (FESEM), with coupled EDX microanalysis. The chemical resistance of the different glassy coatings obtained is also evaluated. The results showed that these new lead-free low-melting-temperature glassy coatings are chemically and mechanically compatible, and promising candidates for applications and markets in a broad range of fields.

Data analysis of compositional distribution and glass transition temperature of low-melting phosphate glass using big data

Data analysis of compositional distribution and glass transition temperature of low-melting phosphate glass using big data

B2O3-ZnO-SiO2 low-melting glass and its application in high reflective white glass ink

Glass of B2O3-ZnO-SiO2 (BZS) is used for the first time to prepare high reflective white glass ink for photovoltaic glass backplanes. White glass inks with specific compositions have successfully produced. The effects of B2O3/ZnO (B/Zn) ratio and B2O3/SiO2 (B/Si) ratio on the properties of low-melting glass (LMG) and white glass ink were studied. It is found that [SiO4] and [ZnO4] structures can improve the reflectivity of glass ink, while [BO3] structures can reduce the reflectivity of glass ink. Furthermore, the effect of the surface morphology of the glass inks heat-treated on the glass brightness is investigated by varying the sample heat-treated temperature. Our research and findings have provided an important reference point for future development of high reflective and low-cost white glass inks for photovoltaic glass backplanes.

Investigation and Evaluation of High-Temperature Encapsulation Materials for Power Module Applications

With the advent of ultra-wide bandgap semiconductor materials, such as gallium oxide (Ga2O3) and aluminum nitride (AlN), higher temperature and higher voltage operation of power devices are becoming realizable. However, conventional polymeric and organic encapsulant materials are typically limited to operating temperatures of 200 degrees C and below. In this work, six materials were identified and evaluated as candidates for use as encapsulants for operation and high-voltage insulation at and above 250 degrees C. High-temperature silicone gel was used as a reference material and was compared with five novel encapsulants including an epoxy resin, a hydro-set cement, two low-melting point glass compounds, and a ceramic potting compound. Gas pycnometry was utilized to evaluate the voiding concentration to avoid partial discharge. Each material was then processed onto a direct-bonded-aluminum substrate test coupon to evaluate compatibility with a commonly used metal-ceramic substrate and processability for use in a power module. The insulation capability of each material was evaluated by testing the partial discharge inception voltage (PDIV) across a 1-mm gap etched in the substrate. The dielectric stability was then tested by soaking the materials in air at 250 degrees C for various intervals and observing the degradation of their PDIVs and appearances. The results of each test were compared, and conclusions were drawn about each material’s feasibility for use as a dielectric encapsulation material for a power module operating at temperatures exceeding 200 degrees C.

Corrosion testing of domestically produced baddeleyitecorundum and chromium-containing materials in borosilicate glass melts

Practical importance of corrosion and erosion resistance of refractories was justified for the design of furnaces with direct electric heating that are used for vitrification of high-level waste (HLW). The main promising materials are listed, and the algorithm of assessment of their resistance to the effects of borosilicate melts is given for the operating conditions of electric furnaces. Corrosion testing of refractories was carried out under static and dynamic conditions in a low-melting borosilicate glass melt and in a borosilicate glass melt containing simulated liquid HLW. Refractory materials were selected that have the highest resistance in a glass melt under conditions of HLW immobilization. The testing results will be used for choosing lining material in the design of removable and small-scale melters. Ill. 5. Ref. 11. Tab. 3.

Lead-Free Ternary Glass for Radiation Protection: Composition and Performance Evaluation for Solar Cell Coverage.

Solar cells in superstrate arrangement need a protective cover glass as one of its main components. The effectiveness of these cells is determined by the cover glass's low weight, radiation resistance, optical clarity, and structural integrity. Damage to the cell covers brought on by exposure to UV irradiation and energetic radiation is thought to be the root cause of the ongoing issue of a reduction in the amount of electricity that can be generated by solar panels installed on spacecraft. Lead-free glasses made of xBi2O3-(40 - x)CaO-60P2O5 (x = 5, 10, 15, 20, 25, and 30 mol%) were created using the usual approach of melting at a high temperature. The amorphous nature of the glass samples was confirmed using X-ray diffraction. At energies of 81, 238, 356, 662, 911, 1173, 1332, and 2614 keV, the impact of various chemical compositions on gamma shielding in a phospho-bismuth glass structure was measured. The evaluation of gamma shielding revealed that the results of the mass attenuation coefficient of glasses increase as the Bi2O3 content increases but decrease as the photon energy increases. As a result of the study conducted on the radiation-deflecting properties of ternary glass, a lead-free low-melting phosphate glass that exhibited outstanding overall performance was developed, and the optimal composition of a glass sample was identified. The 60P2O5-30Bi2O3-10CaO glass combination is a viable option for use in radiation shielding that does not include lead.

Composite structures “ferroelectric/glass/dielectric matrix”

Meta-structures based on periodic ferroelectric inhomogeneities in a dielectric matrix were implemented, which demonstrated tunability at a relatively low effective dielectric permittivity and low microwave losses. Glass-ceramic composite consisting of low melting glass and barium-strontium titanate was successfully incorporated into the periodic holes of dielectric matrix to form tunable metamaterial structure. The studied composite samples showed a relative dielectric permittivity of 18 with a dielectric loss level of 0.02 at a frequency of 2 GHz. The tunability of the entire structure under the applied electric field of 2 V/μm was 4%, which is a promising result for microwave tunable applications.

A novel high reflective glass-ceramic ink with Bi2Ti2O7 nanocrystals used for the photovoltaic glass backplane

Photovoltaic glass ink is a kind of ink used for the photovoltaic glass backplane to enhance the photoelectric conversion efficiency of solar cells. In this work, a novel kind of photovoltaic glass-ceramic ink, with Bi2Ti2O7 nanocrystals precipitated from the low-melting glass for the first time in the short sintering process, was successfully designed and prepared to further improve the reflectance of near-infrared light. Bi2Ti2O7 nanocrystals fill the gap between TiO2 color pigments to a certain extent, which reduce the diffraction of light and greatly improve the reflectivity of the photovoltaic glass backplane to near-infrared light. In the near-infrared wavelength range (780–2500 nm), the average reflectance of photovoltaic glass ink with Bi2Ti2O7 nanocrystals is 20.6% higher than that without Bi2Ti2O7 nanocrystals. The maximum reflectance of photovoltaic glass-ceramic ink is 86.18%. Our research and findings have provided an important reference point for future development of photovoltaic glass inks.

Composite Metamaterial: Ferrite Matrix with Ferroelectric Inclusions

A metamaterial based on periodic ferroelectric inhomogeneities in a magnetic ferrite matrix including a quantity of ferroelectric composite in a matrix, demonstrating relative low microwave losses and effective dielectric permittivity, was produced. Glass-ceramic composites, consisting of low-melting glass and barium-strontium titanate, were successfully synthesized and incorporated into the periodic holes of the ferrite matrix to build the meta-structure. Investigation of the structure showed dielectric permittivity, which increased with the volume of ferroelectric inclusions. The range of magnetically controlled interactions of the meta-structures with an electro-magnetic field was increased for the matrix with periodic holes filled by the ferroelectric composite in comparison with the basic ferrite matrix. The ferrite substrate completely determined the microwave losses of the sample and the ferroelectric inclusions increased the Q-factor of the meta-structure.

Investigation of the P2O5–Bi2O3–CaO system: Glass forming region, structure, properties

(80-x)P2O5-xBi2O3–20CaO (x = 5, 10, 15, 20 and 25mol%) and 60P2O5-(40-y)Bi2O3-yCaO (y = 5, 10, 15, 20 and 25 mol%) lead-free glasses were prepared by traditional high temperature melting method. The formation region of P2O5–Bi2O3–CaO glass system is determined. The X-Ray diffraction verified the amorphous of the glass samples in a certain composition range, and analyzed the crystal structure and crystal chemistry of BiPO4 and Bi2P4O13 in the crystallization glass. The effect of different chemical compositions on the vibration of Q elements in phosphobismuth glass structure was studied by Fourier Transform Infrared and Raman spectroscopy. It was found through chemical durability evaluation that the dissolution rate of glass in water continued to decrease with time, and the decreasing trend continued to be stable. Through the research on the structure and performance of P2O5–Bi2O3–CaO ternary glass, a lead-free low-melting phosphate glass with excellent comprehensive performance was obtained, and the best composition of glass sample was determined. The P2O5–Bi2O3–CaO glass system is a potential lead-free candidate for sealing material.

Structural, morphological and magnetic properties of low temperature sintered LiZnTiBi ferrites

Interest in enhancing magnetic performances of low-sintered ceramic materials by co-doping of oxide nanoparticle and low-melting glass has thrived. Usually this process includes performance enhancement of ceramic attributed to grain growth and deterioration caused by excess additives. Here, we study the grain growth and magnetic properties of Bi-substituted LiZnTi (LiZnTiBi) ferrites doped with various Al2O3-modified ZnO-B2O3-SiO2 (Al-ZBS) glass additives. XRD patterns indicate that the Al-ZBS glass has no effect on lattice constant of ferrite, which means that the Al-ZBS glasss is only existed in grain boundary. SEM results indicate that the LiZnTiBi ferrites has two changes due to the interaction between substituted of Bi2O3 and doping of Al-ZBS glasses. Firstly, grain growth of the ferrite is dominant and its relative density gradually increases when contents of Al-ZBS glass (x) is less than 0.10. Moreover, the grain growth of the ferrite is suppressed because of competition between the two additives when value of x more than 0.10. Finally, one kind of LiZnTiBi ferrite (x = 0.10) with large average grains size (∼8.11 µm) and good magnetic properties (4πMs =3747.3 Gs, Hc=165.7 A/m and Bs =324.9 mT) is obtained at ∼900 oC.