Effects of dopants with various valences on densification behavior and phase composition of a ZrO2–SiO2 nanocrystalline glass-ceramic

Effects of B4C and C additives on the densification behavior, phase composition, and microstructure of TiB2 ceramics were studied. The relative density of pure TiB2 ceramics by hot pressing at 2000°C for 1 h was only 77.4%. With the introduction of B4C and C additives, the relative density increase to 97.4% and 98.1%, respectively. The great improvement on densification was due to the removal of surface oxides of TiB2 powders by reaction with B4C and C additives. Microstructure observation showed the addition of B4C led to some TiB2 grains abnormal growth (>10 µm), whereas the addition of C produced a uniform and fine-grained microstructure.

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Influence of SiO2/Al2O3 Molar Ratio on Phase Composition and Surfaces Quality of Aluminum Silicate Sanitary Glazes in the SiO2-Al2O3-CaO-Na2O System

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0279 ◽

2016 ◽

Vol 61 (4) ◽

pp. 1739-1746 ◽

Cited By ~ 3

Author(s):

M. Leśniak ◽

J. Partyka ◽

M. Sitarz

Keyword(s):

Surface Roughness ◽

Phase Composition ◽

Surface Quality ◽

Glass Ceramic ◽

Glass Phase ◽

Molar Ratio ◽

Aluminum Silicate

Abstract This paper presents the results of research on aluminum silicate sanitary glazes in the SiO2-Al2O3-CaO-Na2O system with different SiO2/Al2O3 molar ratio. XRD, SEM-EDS and FITR measurement indicated that SiO2/Al2O3 molar ratio has a significant impact on the phase composition of the obtained glazes. Glass-ceramic glazes were obtained that consisted of both the glass phase and pseudowollastonite (Ca3[SiO3]3) or anorthite (Ca[Al2Si2O8]) crystals. Subsequently, the influence of phase composition on surface quality (roughness) was examined for the obtained samples. On the basis of the conducted examination of glaze surface roughness was observed that glazes of extreme SiO2/Al2O3 molar ratio are characterized with greatest surface roughness when compared to other glazes.

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Study of phase composition on resorption glass-ceramic соatings for titanium

Eastern-European Journal of Enterprise Technologies ◽

10.15587/1729-4061.2014.20071 ◽

2014 ◽

Vol 1 (6(67)) ◽

pp. 49

Author(s):

Галина Миколаївна Шадріна ◽

Оксана Вікторівна Саввова ◽

Дарина Юріївна Шемет

Keyword(s):

Phase Composition ◽

Glass Ceramic

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Alumina silicate glass-ceramic materials for electrical purposes

Scientific research on refractories and technical ceramics ◽

10.35857/2663-3566.120.17 ◽

2020 ◽

Vol 120 ◽

pp. 174-185

Author(s):

O. V. Savvova ◽

G. K. Voronov ◽

S. A. Ryabinin ◽

E. Yu. Fedorenko ◽

V. D. Timofeev

Keyword(s):

Heat Treatment ◽

Phase Composition ◽

Electrical Properties ◽

Silicate Glass ◽

Glass Ceramic ◽

Breakdown Strength ◽

Chemical Properties ◽

Ceramic Materials ◽

Silicate System ◽

Glass Ceramic Materials

The prospects for use of glass-ceramic materials as electrical products were analyzed. The priority of a self-organized macro- and nanostructure formation of the glass-ceramic materials under conditions of low-temperature heat treatment to ensure their high physical and chemical properties was shown. The choice of an alumina silicate system of materials for obtaining high-strength glass-ceramic materials with improved electrical properties was substantiated, taking into account the aspects of energy saving. The technological modes of cooking, forming and heat treatment of glass-ceramic materials were determined. Resistance, dielectric constant and dielectric loss tangent at 106 Hz were measured using an E6-13A teraometer on a trielectrode system at a temperature of +29 °C and a DE-5000 RLC meter. Electric strength (Em) and cold crushing strength were determined according to GOST 24409-80. Tensile strength according to GOST 32281.1-2013 (EN 1288-1: 2000). The decisive influence on the electrical properties of glass-ceramic materials the crystalline phases of α-cordierite, β-spodumene or lithium disilicate, as well as the residual glass phase composition has been established. The structure influence of the alumina silicate glass-ceramic materials on the provision of their electrical (tgδ∙104 = 70 ÷ 80; ε = 8.0 ÷ 9.3 (at f = 106 Hz); lg ρv = 12.9 ÷ 15.0 (ρv, Ohm·cm at Т = 20 °C) and mechanical (K1C = 3.15 ÷ 4.3 МPа∙м1/2; σ comp = 630 ÷ 700 МPа, σbend = 300 ÷ 350 МPа; KCU = 4.8 ÷ 5.9 kJ/m2) properties. It was found that, the defining condition for the developed glass-ceramic materials use as insulating materials under repeated exposure to high-temperature operations is their high breakdown strength Em = 37 ÷ 42 MV/m and thermal shock resistance due to low TCLE (α∙107 = 21.5 ÷ 31.8 deg-1). The influence of phase composition and structure of the alumina silicate glass-ceramic materials on their electrical and mechanical properties was analyzed. A comparative assessment of the known ceramic and glass-ceramic materials for electrical purposes has made it possible to establish the feasibility of using the developed materials as substrates in the design of a hybrid integrated circuit, vacuum-tight shell and capacitor dielectrics.

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Structure and microwave dielectric characteristics of Sr(La1−xSmx)2Al2O7 ceramics

RSC Advances ◽

10.1039/c6ra20776f ◽

2016 ◽

Vol 6 (98) ◽

pp. 96229-96236 ◽

Cited By ~ 11

Author(s):

Zhi Qi Yuan ◽

Bing Liu ◽

Xiao Qiang Liu ◽

Xiang Ming Chen

Keyword(s):

Phase Composition ◽

Solid State ◽

Solid State Reaction ◽

Solid State Reaction Method ◽

Densification Behavior ◽

Dielectric Characteristics ◽

Reaction Method ◽

Microwave Dielectric

Sr(La1−xSmx)2Al2O7 (0 ≤ x ≤ 1) ceramics were synthesized by a standard solid-state reaction method, and the microwave dielectric characteristics were investigated together with the densification behavior, microstructure and phase composition.

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Constrained-film sintering of cordierite glass-ceramic on silicon substrate

Journal of Materials Research ◽

10.1557/jmr.1998.0326 ◽

1998 ◽

Vol 13 (8) ◽

pp. 2334-2341 ◽

Cited By ~ 22

Author(s):

Jesus Noel Calata ◽

Allen Matthys ◽

Guo-Quan Lu

Keyword(s):

Electron Microscope ◽

Tensile Stress ◽

Cross Sections ◽

Glass Ceramic ◽

Silicon Substrate ◽

Densification Behavior ◽

Time Profiles ◽

Ceramic Films ◽

Cordierite Glass ◽

Scanning Electron

The densification behavior of cordierite glass-ceramic films constrained on a rigid silicon substrate was studied in the temperature range from 900 °C to 1000 °C. An optical setup was used to obtain the thickness versus time profiles and in-plane stresses of the constrained glass-ceramic during isothermal sintering. The thickness profiles showed a rapid shrinkage due to sintering followed by an expansion corresponding to crystallization of the glass-ceramic. Measurements of in-plane stresses in constrained-sintering films showed a rapidly rising tensile stress during densification followed by a slight drop during crystallization. In films sintered above 950 °C, the tensile stress rose rapidly again near the end of crystallization, suggesting a further densification in a mostly crystallized film. Scanning electron microscope (SEM) micrographs of the film cross sections revealed the formation and growth of large pores along the interface between the glass-ceramic and silicon substrate that may have contributed to the observed film expansion. These pores are substantially larger than the initial pore size in the films, indicating that they were formed during sintering. We believe that poor wetting of the glass-ceramic on silicon may have contributed to the formation of the porous structure at the interface.

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Preparation and Characterization of Bioactive and Magnetic Biphasic Thermo-Seeds Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.834-836.301 ◽

2013 ◽

Vol 834-836 ◽

pp. 301-304

Author(s):

Jian An Liu ◽

Xue Na Yang ◽

Mei Mei Zhang

Keyword(s):

Magnetic Property ◽

Phase Composition ◽

Glass Ceramic ◽

Body Fluid ◽

Glass Ceramics ◽

Magnetic Behavior ◽

In Vitro Bioactivity ◽

Magnetic Glass

A novel biphasic material has been synthesized from a melt-derived bioactive glass (45S5) and a glass-ceramic obtained from a melt-derived magnetic glass-ceramics for hyperthermia application. The biphasic material obtained from a mixture 1:1 of these components. The phase composition was investigated by XRD. The magnetic property was measured by VSM. The in vitro bioactivity was investigated by simulated body fluid (SBF) soaking experiment. The glass-ceramic shows magnetic behavior and bioactive, useful for hyperthermia.

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Glass-ceramics obtained by the crystallization of basalt

Science of Sintering ◽

10.2298/sos1003383c ◽

2010 ◽

Vol 42 (3) ◽

pp. 383-388 ◽

Cited By ~ 10

Author(s):

M. Cocic ◽

M. Logar ◽

B. Matovic ◽

V. Poharc-Logar

Keyword(s):

Mechanical Properties ◽

Phase Composition ◽

Ceramic Material ◽

Glass Ceramic ◽

Dynamic Modulus ◽

Glass Ceramics ◽

Glass Ceramic Material ◽

Time Interval ◽

Approximate Relationship ◽

Two Phases

The possibility to obtain glass-ceramics from basalt from the locality on Vrelo (Kopaonik mt.) is shown in this paper. The parent rock was ground to fraction -0.4 +0.1 mm, and then melted at 1250 - 1300?C. The crystallization melted bazaltic glass at 950?C during the time interval of 3 hours caused synthesis of a glass-ceramic material with a microstructure that has excellent mechanical properties according to the determined dynamic modulus of elasticity and uniaxial compresive strength. The phase composition of the obtained glass ceramic material was determined by XRPD using Rietveld refinement and SEM. Two phases were found: pyroxene which corresponds to omphacite of the composition (Na0.199 K0.180 Ca0.471 Mg0.249)1.1(Mg0.271Fe0.299Al0.430)1.0(Si1.704Ti0.046Al0.250)2.0O6 and glass with an approximate relationship 69:31.

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