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Abstract A new Pb-free Ag paste containing a Bi 2 O 3 -B 2 O 3 -ZnO glass frit was developed for Al 2 O 3 substrate metallization. First, Bi 2 O 3 -B 2 O 3 -ZnO glass frits with various compositions and glass transition temperatures (T g) of 322 °C–440 °C were synthesized by using a traditional melt-quenching method. Then, silver pastes containing different contents of the glass frit were sintered on an Al 2 O 3 substrate at temperatures ranging from 450 °C to 600 °C. The glass frit content and the sintering temperature had significant impacts on the electrical resistivity and shear strength of the product. The experimental results indicated that the silver film formed from the paste containing 7 wt.% glass frit and sintered at 600 °C for 15 min had a low electrical resistivity of 2.5 μΩ cm and a high strength of 28.5 MPa. These properties resulted from the formation of a stable glass network that supported the Ag network. Furthermore, ZnAl 2 O 4 was observed to form close to the interface of the Al 2 O 3 substrate, which could improve the shear strength. Moreover, the Bi-based glass frit could be a suitable substitute for Pb-based glass frits in the preparation of environmentally friendly silver pastes for forming thick Ag films on Al 2 O 3 substrates. [ABSTRACT FROM AUTHOR]

Abstract: The large amount of generated waste determines the importance of their valorization. Red mud is the residue of the Bayer process, which stored cumulative value raises 2.7 Bt. This paper describes an easy way to produce a ferrimagnetic glass‐ceramic frit, using bauxite residue, fly ash and glass cullet as raw materials. The synthesized frit consists of faceted and dendritic agglomerated crystals of magnetite and titanomagnetite embedded in a glass matrix, which exhibits a saturation magnetization (MS) of 6.3 emu/g, a remanent magnetization (MR) of 2.7 emu/g and a coercive field (HC) of 347 Oe. Furthermore, it presents Vickers hardness value of HV = 5.55 ± 0.16 GPa and fracture toughness value of KIC = 1.64 ± 0.34 MPa·m1/2. [ABSTRACT FROM AUTHOR]

Glass frit encapsulation for laser-base sealing of the complex interiors results challenges for the electronics manufacturing process. The conventional frit packaging method relies on elevating thermal process by furnace where the package is heated to required temperature, hence limiting the use of temperature-sensitive materials and also creating problems in different packaging processes or multi-stage sealing products. In this paper, the benefits of combining novel laser-assist hermetical sealing and low temperature glass frit packaging are demonstrated and the technique offers a suitable and feasible solution. This frit of absorbent at specific laser wavelength is selected and applied as excellent contact with both large CTE range substrates. Glass frit composites consisting of a PbTiO ceramic and the rare earth NdO are evaluated for thermal properties and electrical characteristics. This developed glass frit hermetical sealing method achieves moisture durability, satisfying the enculturation of electronics-level. In this paper, we demonstrate successfully using laser to seal organic light emitting diode (OLED) via low melting temperature glass frit. [ABSTRACT FROM AUTHOR]

The influence of particle size on the dissolution of several materials has been widely studied. In regard to ceramic frits, no studies on this influence have been found, despite the importance of knowing the optimum particle size which allows stable suspensions to be obtained while avoiding the solubility of the cations. In this work, the influence of the particle size in the dissolution process of a zirconium white frit has been studied using five particle size distributions. The evolution of the dissolution of Ca(II), Mg(II), Zn(II), Si(IV) and B(III) has been determined. The concentration profiles obtained have been fitted to a kinetic model considering that the whole dissolution process is controlled by diffusion except at the initial instant when it is controlled by chemical reaction. The kinetic model proposed can be used to predict the frit behaviour in aqueous suspension by controlling the particle size in the milling process during industrial glaze preparation. [ABSTRACT FROM AUTHOR]

In this paper, the electrospray technology is used to easily deposit the glass frit into patterns at a micro-scale level. First, far-field electrospray process was carried out with a mixture of glass frit in the presence of ethanol. A uniform, smooth, and dense glass frit film was obtained, verifying that the electrospray technology was feasible. Then, the distance between the nozzle and the substrate was reduced to 2 mm to carry out near-field electrospray. The experimental process was improved by setting the range of the feed rate of the substrate to match both the concentration and the flow rate of the solution. Spray diameter could be less at the voltage of 2 kV, in which the glass frit film was expected to reach the minimum line width. A uniform glass frit film with a line width within the range of 400-500 µm was prepared when the speed of the substrate was 25 mm/s. It indicates that electrospray is an efficient technique for the patterned deposition of glass frit in wafer-level hermetic encapsulation. [ABSTRACT FROM AUTHOR]

This study reports the preparation of disposable microcolumns with welded metal frits for the first time. First, the bottom of glass-lined stainless-steel tubing of 30 cm length, 1.6 mm od, and 0.5 mm id was welded with a stainless-steel screen frit of 1.6 mm diameter. A micro-welding machine was used for this. Next, the column was connected to a slurry packer and packed with porous silica particles. Then, the inlet of the column was carefully welded with another frit. The column was tested for separation of a test mix composed of phenol, 2-nitrophenol, acetophenone, aceanilide, and benzamide. Another column of the same physical dimension was also prepared with frits that were not welded to the column. The chromatographic performances of the two groups of columns (welded frits versus non-welded frits) were examined. The columns of welded frits showed ca. 18% better separation efficiency (number of theoretical plates) than those of non-welded frits. [ABSTRACT FROM AUTHOR]

Zircon (ZrSiO 4 ) is widely used as a glaze opacifier in the ceramic industry. The crystallization mechanism of ZrSiO 4 from a CaO-riched zirconium-based frit glaze was studied by XRD, SEM, and DSC in this work. Isothermal and non-isothermal heat treatments were used to study the phase development and microstructural evolution during the firing process. It was found that t-ZrO 2 and Ca 2 ZrSi 4 O 12 were first crystallized at a relative low temperature and then converted to ZrSiO 4 with the increasing of temperature. ZrSiO 4 originating from t-ZrO 2 has an inward growth and an outward growth, while ZrSiO 4 transformed from Ca 2 ZrSi 4 O 12 only has an outward growth. SEM showed that ZrSiO 4 appeared to be a rod shape in fired samples. The calculated activation energy for ZrSiO 4 is 311.2 kJ/mol, and the Avrami index ( n ) is 0.35–0.39. This indicates the one-dimensional diffusion-controlled growth of ZrSiO 4 , which explains the formation of rod-shape ZrSiO 4 crystal. [ABSTRACT FROM AUTHOR]

The focus of this study was the development of a CAS glass-ceramic (14.0CaO·5.5Al2O3.80·5SiO2) for use in civil engineering as a decorative material. This glass-ceramic system was chosen because it can be used to produce plates with a similar appearance to those of marble and granite materials. Ceramic plates were produced by the Grain Glass Sintering process from frits with a coarse grain size (2.1mm average particle size). Powder frit samples (5.3-μm average particle size) were prepared and characterized. The results were compared with those obtained with coarse particles. Thermal treatment was performed in one stage, with the heating rate varying from 2 to 25°Cmin−1. Temperatures were defined by differential thermal analysis and heating microscopy. With these results, it was possible to establish correlations among the esthetic effects, the microstructure, and the heat treatment conditions (temperature, heating rate, and holding time). The relative density ranged from 0.92 to 0.96. The formation of wollastonite and pseudowollastonite was observed. An esthetic effect similar to that of natural marble was more apparent in those samples in which the microstructure presented a visual contrast between the bulk and the coarse frit. Lower heating rates intensified the visual contrast and reduced porosity near the surface regions. [ABSTRACT FROM AUTHOR]

Glasses in the Fe2O3-SiO2-CaO system are potential candidates for many technological applications due to their ferrimagnetic and semiconductive properties, which have been extensively studied; in this sense, the effect of adding different melting additives like Li2O, B2O3, in this glass system on frits and glazes with 30-40 mass-% of Fe2O3 was studied. Ceramic frits were melted at different temperatures with subsequent cooling in water. Samples were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis and thermogravimetry (DTA, TG) and by heating microscopy. Finally, frits were applied as glazes on ceramic tiles to evaluate their capacity to adapt to the tile productive process. The frits showed low to high homogeneity (depending on the fusion temperature) and oxidation phenomena. High temperature fusion led to the crystallization of magnetite during cooling. Glaze porosity was observed after heat treatment with the presence of anorthite and hematite as crystalline phases in glazes. [ABSTRACT FROM AUTHOR]

A technique for functionalizing glass frits is described for use in separating water and organic solvents. The frits are coated with a hydrophobic--oleophilic silicone elastomer, giving rise to a reusable device that allows non-polar solvents to pass through but not water. [ABSTRACT FROM AUTHOR]

Low-melting non-frit glazes with firing temperature 950 - 1000°C were obtained in the system datolite-perlite-cullet. The conditions under which high-quality coatings are formed were determined: pre-firing datolite and perlite, BO/AlO > 2.5 in the glaze and slip ultradispersity. [ABSTRACT FROM AUTHOR]

A simple electroless plating process was employed to prepare silver-coated glass frits for solar cells. The surface of the glass frits was modified with polyvinyl-pyrrolidone (PVP) before the electroless plating process. Infrared (IR) spectroscopy, field emission scanning electron microscopy (FESEM), and x-ray diffraction (XRD) were used to characterize the PVP modified glass frits and investigate the mechanism of the modification process. It was found that the PVP molecules adsorbed on the glass frit surface and reduced the silver ions to the silver nanoparticles. Through epitaxial growth, these nanoparticles were uniformly deposited onto the surface of the glass frit. Silicon solar cells with this novel silver coating exhibited a photoelectric conversion efficiency increase of 0.33%. Compared with the electroless plating processes, this method provides a simple route to prepare silver-coated glass frits without introducing impurity ions. [ABSTRACT FROM AUTHOR]