Glass and Ceramics最新文献

This study investigates the influence of tempering parameters on the mechanical strength of safety glass products. We examined the effects of press configuration and temperature settings within the chambers of tunnel furnace on the fracture patterns of glass during strength testing. A logistic regression model was developed to predict fracture behavior during mechanical strength testing of produced glass, facilitating real-time adjustments to the tempering process. This approach aims to enhance quality control and optimize production efficiency.

This study investigates the physical and mechanical properties of ceramic materials with compositions 97ZrO₂–3Sm₂O₃ and 94ZrO₂–6Sm₂O₃ (mol.%), fabricated from initial nanopowders. The ceramics exhibit a two-phase structure comprising tetragonal and cubic solid solutions based on ZrO₂. The Sm₂O₃ content is shown to significantly influence the phase ratio, thereby affecting the grain structure and properties of the material. An increase in the volume fraction of the tetragonal ZrO₂-based solid solution from 46 to 85 vol.% leads to an enhancement in mechanical strength from 600 to 850 MPa and in fracture toughness K_1c from 8.0 to 10.5 MPa · m^1/2.

This study examines the synthesis of YAG:Ce precursor powder and luminescent ceramics by reverse chemical co-precipitation. We investigated the effects of sintering additives (CaO, MgO, and TEOS), Ce³⁺ activator concentration, vacuum sintering temperature, and the temperature of air annealing on the luminescent properties of YAG:Ce ceramics. The optimal parameters for achieving high luminescence efficiency were defined: sintering additive concentration of 0.01 wt.%, TEOS as the sintering additive, vacuum sintering temperature of 1800°C, and air annealing temperature of 600°C for TEOS-containing samples. A ceramic sample exhibiting a luminescence efficiency of 319 lm/W was achieved under laser radiation with a power of 190 mW and a spot diameter of approximately 5 mm.

The paper proposes a beneficiation approach for natural milky-white quartz. By using quartz samples from the Naily gold deposit (South Urals), we validated the developed processing methods through the melting of certified reference glass ingots.

This study examines the synthesis of porous materials derived from various types of coal combustion by-products (fly ash, boiler slag, and bottom ash) using a self-foaming approach with the fluxing agent Na₂B₄O₇. The internal structure and density of the samples were analyzed in relation to foaming temperature and flux content. The results indicate that samples based on boiler slag exhibit the most uniform structure. The study also elucidates the influence of phase composition on sintering and foaming intensity, including the enhanced reactivity of glass-phase components and the facilitated softening of aluminosilicate matrices.

This study examines the impermeability and sorption properties of palygorskite and other clays from the Borshchevskoye and Voskresenskoye deposits, which are overburden associated with the extraction of raw materials for the cement industry. Experimental findings demonstrate that the filtration coefficients of the studied samples comply with current regulatory standards, confirming their suitability for use as impermeable barriers for municipal solid waste (MSW) landfills. The palygorskite clay sample exhibited a filtration coefficient of 8 × 10 ^–10 m/sec. Key sorption characteristics of the palygorskite clay sample were also established, including a specific surface area of 85.1 m²/g and specific micro- and mesopore volumes of 0.0138 cm³/g and 0.127 cm³/g, respectively. The efficiency of the clay in purifying individual model solutions under static conditions was evaluated, demonstrating a removal efficiency of > 94% for heavy metals from aqueous solutions and > 60% for petroleum products.

This study investigates the properties of a borophosphate glass (BPG) matrix incorporating lithium chloride (LiCl) as a simulated spent electrolyte, a type of radioactive waste (RAW) generated during the pyrochemical reprocessing of spent nuclear fuel (SNF). X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed the amorphous structure and homogeneity of the synthesized material. The thermal properties of the glass were characterized using differential scanning calorimetry (DSC) and thermal conductivity measurements. The incorporation of LiCl had no significant effect on the glass transition temperature, which remained at approximately 410°C; however, it influenced the electrical conductivity, as determined by electro-chemical impedance spectroscopy. Mechanical strength and hydrolytic stability tests were carried out in accordance with established requirements for RAW immobilization matrices. The analysis of surface morphology revealed the formation of a diffusion layer due to the leaching of sodium ions into the solution. The results demonstrate the feasibility of using the selected glass composition as an immobilization matrix for LiCl-based spent electrolytes.

This study examines the dielectric properties and harmonic distortion coefficients of barium titanate ceramics fabricated using a mixture of BaTiO₃ powders with particle sizes of 400 nm and 50 nm, sintered at varying temperatures. The findings demonstrate that as the content of the fine-grained component (50 nm) increases from 0 to 100%, the permittivity ε(x) and harmonic distortion coefficient γ(x) exhibit non-monotonic behavior, reaching maximum values at x = 0.25 and x = 0.30, respectively. This trend is likely attributed to alterations in packing density resulting from variations in the percentage composition of the components.

Titanium oxide powders with different crystal structures and textural characteristics were synthesized. Metallic titanium and rutile (rutile particle size 25 μm, specific surface area 3 m²/g) were used as starting materials for the synthesis of titanium salts, which were subsequently decomposed. Titanium salts were obtained by interaction with mineral acids and ammonium carbonate. The obtained salts were thermally decomposed or hydrolyzed by the addition of ammonium hydroxide, which resulted in the precipitation of titanium oxide. The phase composition of the synthesized samples included rutile and anatase, as well as impurities of titanium fluoride observed at low firing temperatures. A relatively simple and economically feasible method for the synthesis of titanium oxide with specific surface area up to 92 m²/g has been proposed. This method involves simple chemical transformations, which include thermal decomposition of synthesized titanium halides. The best of the synthesized anatase samples had the shape of irregular polyps, specific surface from 56 – 92 m²/g, and particle size in the range of 20 – 60 μm.

The methodological approach to the creation of a hardware-software solution for debugging and testing of algorithms and control systems of actuators of a glass forming machine in real time mode is presented. Model tests are used to evaluate the compliance of algorithms with technical specifications and their reliability. The tests were carried out on a test bench built on the basis of an industrial sample. On the test bench the operation of the object is modeled, parameters are recorded and transferred to the monitoring system for post-processing. In the course of testing, the component base of various manufacturers available under the sanctions policy was tested. It was confirmed that such a stand can be used for rapid prototyping of control algorithms, semi-natural testing, and training of glass industry specialists. The independent control of the process control system is a contributing factor to the development of industrial equipment engineering and the localization of critical technologies. Consequently, this contributes to the formation of technological sovereignty.