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Contemporary Methods of Protection and Restoration of Components
Published in E. S. Gevorkyan, M. Rucki, V. P. Nerubatskyi, W. Żurowski, Z. Siemiątkowski, D. Morozow, A. G. Kharatyan, Remanufacturing and Advanced Machining Processes for New Materials and Components, 2022
E. S. Gevorkyan, M. Rucki, V. P. Nerubatskyi, W. Żurowski, Z. Siemiątkowski, D. Morozow, A. G. Kharatyan
For glass processing, the starting material is a glass batch, which is formulated from a variety of materials, some mined from the earth and used with only a few preparatory steps, and some more refined, such as metal oxide powders (Francis, 2016). Materials in a glass batch perform different functions, either supply a metal oxide for glass composition or are additives that help produce a uniform melt. Glass powder or frit is considered a glass starting material and is prepared by quenching a uniform glass melt. A glass batch is heated in a furnace and converted into a homogeneous melt. Quenching a glass melt from a high temperature into water or between metal rollers results in thermal shock, so that glass is fractured into fragments, which further can be broken down using ball milling to create a frit of a desired particle size. When heated, a powdery glass batch is converted to a homogeneous glass melt (Francis, 2016).
Field-Flow Fractionation
Published in Grinberg Nelu, Rodriguez Sonia, Ewing’s Analytical Instrumentation Handbook, Fourth Edition, 2019
Any of the FFF subtechniques can be used to separate particles with d > 1 μm, but such applications are dominated by FlFFF (Wahlund and Zattoni, 2002; Williams et al., 1991) and SdFFF (Giddings and Williams, 1993). ThFFF and ElFFF can also separate micrometer-sized particles (Liu and Giddings, 1992), but most laboratories with ThFFF are focused on polymer analysis, whereas ElFFF is still under development. FlFFF can in principle be used without a membrane at the accumulation wall (Melucci et al., 2002; Reschiglian et al., 2000) because the underlying porous frit, which supports the membrane, has a pore size <1 μm. However, care must be taken that colloidal impurities are not present because they can eventually plug the frit, requiring an expensive replacement.
Photo-Defined and Photo-Imaged Films
Published in Fred D. Barlow, Aicha Elshabini, Ceramic Interconnect Technology Handbook, 2018
William J. Nebe, Terry R. Suess
Borosilicate glasses, such as lead borosilicate, barium, calcium, bismuth, or other alkaline earth borosilicate frits are desirable because they can be efficiently processed and sintered in the temperature range of 475–750°C. Preparation of the glass frit consists of melting mixtures of the constituents of the glasses as their oxides and quenching the molten composition to form the frit. Frits are typically quenched in a water bath or on chilled rolls. The melt ingredients may be any compound that yields the desired oxides under the conditions of frit preparation. For example, boric oxide will result from boric acid, barium oxide from barium carbonate, etc. The glass is then milled to reduce particle size and obtain a frit composition of substantially homogeneous size.
Effect of heat treatment parameters on the crystallization of feldspathic-based dental glass-ceramics
Published in Journal of Asian Ceramic Societies, 2020
Emre Yalamaç, Mucahit Sutcu, Elif Sıla Ergani
Leucite-containing glass-ceramics were derived by processing naturally occurring mineral of potash feldspar (KAlSi3O8). Additional alkalis (e.g. Li2O, Na2O or CaO) were used as fluxing agents to reduce the liquidus temperature of the parent mineral source. Additionally, nucleating agents (e.g. TiO2, B2O3, BaO or their combination) were added to initiate an incongruent crystallization of leucite or to lower the maturing temperatures. The composition of the starting glass was 64.5% SiO2, 15.6% Al2O3, 10.4% K2O, 5.4% Na2O, 1.3% CaO, 0.5% and 1% other oxides by weight. The glass components were melted in an alumina crucible without lid in an electrical furnace at 1200°C for 4 h, with heating rate of 10°C/min. Then, the melting glass removed from the furnace and allowed to cool in air. The glass frit was crushed and ground by milling, then sieved under 125 μm to produce frit powders. The particle size distribution of frit powder was analyzed by laser diffraction particle size analyzer (Mastersizer 3000, Malvern). Particle size and morphology were also examined by scanning electron microscopy (SEM) with a secondary electron (SE) detector. The phases in frit powder were investigated by X-ray diffractometer (XRD). The measurement was performed with a range of 10° to 60°° degrees using CuKα (λ = 1.54 A°). For the thermal behavior of frit, differential scanning calorimetry (DSC) analysis was performed at a heating rate of 10°C/min within the temperature range of 25–1000°C to evaluate the glass transition and crystallization of frit.
Waste recycling of cathode ray tube glass through industrial production of transparent ceramic frits
Published in Journal of the Air & Waste Management Association, 2019
Ceramic frits are the primary raw material for ceramic glazes, providing a chemically resistant, functional surface that allows for the formation of decorative designs, owing to their glass ceramic characteristics. Frits can be considered a highly active flux in an amorphous phase, containing crystal nuclei, such as those of LiO2, P2O5, and B2O3, which result in a glass ceramic structure that contains both amorphous and crystalline phases.