A Study on Structure and Phase Composition of Cellular Ceramic Materials from Dispersed Silica-Rich Rocks

2018 ◽  
Vol 284 ◽  
pp. 893-898
Author(s):  
Andrey Yu. Stolboushkin ◽  
A.I. Ivanov ◽  
O.A. Fomina
Keyword(s):  
Phase Composition ◽  
Cellular Structure ◽  
Solid Phase ◽  
Foam Glass ◽  
Physical And Mechanical Properties ◽  
Ceramic Materials ◽  
Average Density ◽  
Crystalline Material ◽  
Pore Glass ◽  
Cellular Ceramic

Studies on structure, phase composition and properties of ceramic wall materials with a glass-crystalline framework from dispersed silica-rich rocks are described. The results of chemical, mineralogical and granulometric compositions of tripolite and granulated foam-glass crystalline material (GFGCM) are presented. The dependence of physical and mechanical properties of cellular ceramic materials on GFGCM content in the composition in the amount from 5 to 75% is determined. Test samples of cellular ceramic materials with dimensions 250 × 120 × 65 mm, having a compressive strength 16.2-20.8 MPa, water absorption 7.1-7.9 % and an average density 0.99-1.32 g/m3 were produced at the factory. At the macroscale level the cellular structure of the ceramic material consists of closed pores with a vitrified inner surface pore, glass-crystalline outer shell of the pores and solid phase of the framework walls. It was established that after firing in the temperature range 850-900 °C the walls of the framework are represented by quartz, feldspar and hematite, a pronounced halo is indicating a significant amount of glass phase.

Filled Heat Efficient Ceramics

2021 ◽  
Vol 887 ◽  
pp. 493-498
Author(s):  
Alexey D. Zhukov ◽  
I.I. Popov ◽  
Igor V. Bessonov ◽  
S.P. Chernukhin
Keyword(s):  
Water Content ◽  
Foam Glass ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Average Density ◽  
Experimental Results ◽  
The Other ◽  
Other Hand ◽  
The One ◽  
The Cost

The increase of thermo-physical properties of masonry made of ceramic burnt products is possible through the use of heat-efficient ceramics and, in particular, porous building tiles. The use of combustible additives or foaming technology is related to increased energy costs and difficulties in obtaining products with uniformly distributed porosity.The analysis of the state of the technology of ceramic materials made it possible to formulate a research hypothesis according to which the use of a porous non-combustible additive in the composition of ceramic masses, on the one hand, will make it possible to obtain materials with a lower density compared to traditional ceramic products, and, on the other hand, will allow the use of hard mixtures with reduced water content, and therefore significantly save the cost of drying products, while increasing the uniformity of the porous ceramic crock.The purpose of the research was to develop recipes for ceramic porous products and to develop modes of their burning. The use of crushed foam glass as a lightweight non-burning and exhausting additive, on the one hand, made it possible to use tough ceramic mixtures (with a water content not exceeding 18%), and, on the other hand, to use more rigid and shorter drying modes, which also reduced the energy and material consumption of the technology.The most energy-intensive burning process was optimized by the methods of mathematical planning and processing of experimental results. The average density of crushed foam glass (140–150 kg/m3), optimal for the burnt product, was established, and also, as a result of analytical optimization and interpretation of the experimental results, dependencies that allow choosing parameters and evaluating product properties depending on foam glass consumption and burning temperature were obtained.

Firing of Cellular Ceramics from Granulated Foam-Glass

2020 ◽  
Vol 992 ◽  
pp. 265-270
Author(s):  
O.A. Fomina ◽  
А.Yu. Stolboushkin
Keyword(s):  
Raw Materials ◽  
Foam Glass ◽  
Average Density ◽  
Firing Process ◽  
Ceramic Samples ◽  
Three Phase ◽  
Study Results ◽  
Intensive Formation ◽  
Solid Glass ◽  
Cellular Ceramic

It has been presented the study results of the firing process of cellular ceramics from granulated foam glass. The chemical, mineral and granulometric compositions of the raw materials are given. It has been shown the characteristic of ceramic-technological properties of raw materials. The samples were burned from the granulated mixture in the temperature range of 850-1000 ° C. It has been established the change dependence in the physicomechanical properties of cellular ceramic samples on the temperature and firing duration. The results of the study of the macro-and microstructure of cellular ceramics are given. It has been revealed the effect of intensive formation of the pyroplastic phase and the connection between small pores at a temperature of more than 950 ° C. After the enlargement, the cells leave the three-phase ceramic system and it was the increase in the average density of cellular ceramics is 1.4-1.5 times. The influence of a solid glass-ceramic shell along the inner surface of the pores on the decrease in water absorption of cellular ceramics to 6.5-7% is established.

Interface structures in polycrystalline ceramic materials

1986 ◽  
Vol 44 ◽  
pp. 468-471
Author(s):  
K. J. Morrissey
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Physical And Mechanical Properties ◽  
High Resolution Electron Microscopy ◽  
Ceramic Materials ◽  
Polycrystalline Materials ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Interface Structures

Grain boundaries and interfaces play an important role in determining both physical and mechanical properties of polycrystalline materials. To understand how the structure of interfaces can be controlled to optimize properties, it is necessary to understand and be able to predict their crystal chemistry. Transmission electron microscopy (TEM), analytical electron microscopy (AEM,), and high resolution electron microscopy (HREM) are essential tools for the characterization of the different types of interfaces which exist in ceramic systems. The purpose of this paper is to illustrate some specific areas in which understanding interface structure is important. Interfaces in sintered bodies, materials produced through phase transformation and electronic packaging are discussed.

Laboratory Determination of the Solid Phase Composition of Technogenically Salinized Peatlands: Possibilities and Limitations

2020 ◽  
Vol 75 (3) ◽  
pp. 131-137
Author(s):  
Yu. N. Vodyanitskii ◽  
N. A. Avetov ◽  
A. T. Savichev ◽  
S. Ya. Trofimov ◽  
E. A. Shishkonakova
Keyword(s):  
Phase Composition ◽  
Solid Phase ◽  
Laboratory Determination ◽  
Solid Phase Composition

Improved Conditions for Solid Phase Synthesis of Oligonucleotides on PS-PEG Copolymers

1995 ◽  
Vol 50 (7) ◽  
pp. 1096-1100 ◽  
Author(s):  
Ernst Bayer ◽  
Konrad Bleicher ◽  
Martin Maier
Keyword(s):  
Electrospray Mass Spectrometry ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Chemical Properties ◽  
Oligonucleotide Synthesis ◽  
Phase Synthesis ◽  
Controlled Pore Glass ◽  
Product Identification ◽  
Pore Glass ◽  
And Chemical Properties

Polystyrene-polyethylene glycol (PS-PEG) tentacle polymers with loadings of up to 60/<μmol/g were used for standard oligonucleotide synthesis. As these resins are easy to handle and stable under reaction and cleavage conditions they may be used alternatively to controlled pore glass (CPG) as the most commonly used solid support for oligonucleotide synthesis. However, structural and chemical properties of the PS-PEG resins require modified conditions to guarantee syntheses with high coupling efficiencies. Oligonucleotides (ODN ) of various sequences and lengths have successfully been synthesized using HPLC and capillary electrophoresis (CE) for purity control. Additionally, electrospray mass spectrometry (ES-MS) was used for product identification.

First Stages of Nano-Crystallization of Amorphous Fe75.5Cu1Si12.5B8 Studied by the Positron Annihilation Lifetime Technique

1993 ◽  
Vol 321 ◽  
Author(s):  
A. J. Kruk ◽  
H. Schut ◽  
J. Sietsma ◽  
A. Van Veen
Keyword(s):  
Positron Annihilation ◽  
Crystallization Process ◽  
Positron Lifetime ◽  
Early Stage ◽  
Average Density ◽  
Crystalline Material ◽  
Positron Annihilation Lifetime ◽  
Resistivity Measurements ◽  
Nano Crystalline ◽  
Crystallisation Process

ABSTRACTThe first stages of the nano-crystallization process of amorphous Fe75.5Cu1Nb3Si12.5B8 into a nano-crystalline structure are investigated by the positron annihilation lifetime technique. Samples have been isothermally annealed at 643 K for times varying between 600 and 105 seconds. The positron lifetime spectra have been analyzed allowing for three lifetimes. The shortest and the longest lifetime, τ1 = 150 ± 2 ps and τ3 = 1500–2000 ps respectively, are attributed to annihilation of positrons in the amorphous phase and to the formation and annihilation of ortho-positronium at the surface of the stacked foils and did not change significantly upon the annealing. The intermediate positron lifetime τ2 increased from 324 ps to 387 ps. The intensity of this component increased from 5 to 15%. Comparison with resistivity measurements indicates that the change of this lifetime component occurs at an early stage in the crystallisation process, i.e. when the fraction of crystalline material is on the order of 10−3. The increase of τ2 is attributed to positrons annihilating in a region with lower average density surrounding the small crystallite.

Use of controlled pore glass in solid phase oligosaccharide synthesis. Application to the semiautomated synthesis of a glyconucleotide conjugate

1998 ◽  
Vol 39 (14) ◽  
pp. 1953-1956 ◽  
Author(s):  
Matteo Adinolfi ◽  
Gaspare Barone ◽  
Lorenzo De Napoli ◽  
Alfonso Iadonisi ◽  
Gennaro Piccialli
Keyword(s):  
Solid Phase ◽  
Oligosaccharide Synthesis ◽  
Controlled Pore Glass ◽  
Pore Glass

Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  
Keyword(s):  
Silicic Acid ◽  
Cell Walls ◽  
Cellular Structure ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Silica Particles ◽  
Low Ph ◽  
Cellular Structures ◽  
Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

Heat treatememt effect on microstructure and mechanical properties of precipitation hardening elinvar alloy

2021 ◽  
pp. 68-73
Author(s):  
G.V. Shlyakhova ◽  
◽  
A.V. Bochkareva ◽  
M.V. Nadezhkin ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Structural Analysis ◽  
Thermal Treatment ◽  
Precipitation Hardening ◽  
Physical And Mechanical Properties ◽  
Alloy Structure ◽  
Treatment Mode ◽  
Elinvar Alloy

This study presents experimental results of structural analysis, such as phase composition, grains size assessment, strength and hardness of Ni-SPAN-C alloy 902 after various heat treatment modes (hardening and aging for stress relaxation). A thermal treatment mode has been selected to obtain higher physical and mechanical properties of the elinvar alloy. It is shown that the improvement of the alloy structure in thermal treatment occurs due to the thermic stresses, as well as the formation and dissolution of intermetallides.

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