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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Ceramic Society
Journal Basic Information
Journal DOI :
The Korean Ceramic Society
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Volume & Issues
Volume 27, Issue 8 - Aug 1990
Volume 27, Issue 7 - Jul 1990
Volume 27, Issue 6 - Jun 1990
Volume 27, Issue 5 - May 1990
Volume 27, Issue 4 - Apr 1990
Volume 27, Issue 3 - Mar 1990
Volume 27, Issue 2 - Feb 1990
Volume 27, Issue 1 - Jan 1990
Selecting the target year
A Study on the Character of Okchun Feldspar
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 149~154
Before benefication of Okchun feldspar, all kinds of Fe-compounds and mafic minerals which were included in feldspar were studied. Also to produce 30/140mesh products as glass materials, optimum grinding condition and degree of liberation were studied. Fe-compounds were Biotite and Limonite, and these were existed along the cleavage. Optimum grinding time was 2min. and at this time weight percent of 30/140mesh products was 72.7% and degree of liberation at this particle size was 91.5%.
Spinel Single Crystal Growth by Verneuil Process
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 155~160
Al-rich Mg-Al spinel single crystals were grown by Verneuil process using oxygen and hydrogen flame. Spinel single crystals were grown in chemical compositions from MgO : Al2O3 mole ratio 1 : 1 to 1 : 3. Mole ratio 1 : 1 was hard to be grown and mole ratio 1 : 2.5 and 1 : 3 were grown well. Selecting well-grown mole ratio 1 : 3, seeds were prepared having ,  and  orientation respectively. Growth rate were highest in  orientation and lowest in  orientation.
Corrosion Behaviro of Ceramics under Corrosive Environments -Corrosion Behavior of Reaction Bonded Silicon Carbides-
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 161~168
To evaluate the corrosion behavior of reaction bonded silicon carbides, corrosion test was studied for various corrosive environments. Corrosion test for reaction bonded silicon carbides was conducted at 900
under four different gas atmospehres ; air, So2-air, Cl2-O2-Ar, Cl2-N2 and investigated these samples using weight loss, bending strength, XRD, optical micrographs and EDS respectively.
Effects of the Colloid/Interface Variables on Densification and Pore Elimination of Zirconia
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 169~178
The sintering characteristics of ZrO2 were analyzed in terms of pore microstructure and kinetics of pore elimination. The pore structue of the ZrO2 sample prepared from colloid suspension was characterized by three distinct types of pores ; intradomain, interdomain, and intergglomerate pores. Sintering data at 1600
showed that pores larger than a certain critical size(∼3
) were difficult to remove, and this was analyzed in terms of the interagglomerate pore formed from the suspension under the condition of low kinetic stability, that is, the stability ratio smaller than its critical value. A theoretical equation for densification rate was derived and was applied to the densification rate of the ZrO2 polycrystalline body containging both the matrix(the 1st-generation) pores and the interagglomerate (the 2nd-generation) pores under the condition of slow grain growth.
Studies on the Oxide Bonded Silicon Carbide Porous Materials
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 179~186
Silicon carbide porous materials used for hot gas filters were prepared using oxide binder. Chamotte, frit and H3PO4 were starting materials to synthesize the oxide binder for high temperature-use. Room temperature bending strength of the silicon carbide porous body was increased with increasing firing temprature or with the amount of the content of frit in the oxide binder. However, in the oxidebinder fired above132
, cristobalite form of AlPO4 phase which undergoes rapid inversion became more prominent with increasing firing time. the average pore size of the silicon carbide filter materials was found to be about one third of the average grain size of the silicon carbide powder used in this study.
on the Dielectric and Piezoelectric Properties of Pb(
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 187~194
Effects of MnO2 addition ranged from 0.0wt% to 5.0wt% on the microstructure and dielectric and piezoelectric properties of the Pb(Zr0.52 Ti0.48)O3 Ceramics have been investigated. The solubility limit of MnO2 in Pb(Zr0.52 Ti0.48)O3 is about 0.5wt%, and MnO2 as a valence state of Mn3+ is substituted for (Zr, Ti) lattice site in PZT solid-solution. The addition of MnO2 up to 0.5wt% in Pb(Zr0.52 Ti0.48)O3 brings increase of density, but decreased of grain size and tetragonality. Dielectric constant slightly decreases, but both coupling factor(Kp) and mechanical quality factor(Qm) increase with the addition of MnO2. However, excess amount of MnO2 addition more than 0.75wt% results in rapid decrease of resistance. Dielectric constant and tan
increase due to the second phase and inhomogeneous Mn distribution.
Synthesis and Hydration of Modified Belite Cement Clinker
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 195~200
For the development of low energy cement, the belite cement clinker of calcium sulphoaluminate ferrite type was synthesized at 130
and containing C2S, C4A3S as the major minerals along with C3A, C4AF, CS by using limestone, dolomite, clay, iron ore, gypsum and alumina as raw materials. At over 130
, C4A3S was decomposed and thus C3A was increased. When hydrated, this cement was hardened, producing ettringite, CSH, etc.
Synthesis of Mullite Powder from Alkoxides and the Properties of the Mullite-Zircocnia Composites
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 201~210
The mullite-15v/o ZrO2 composites were prepared by dispersing ZrO2-3m/o Y2O3 powders into the mullite matrix in order to improve the mechanical properties of the mullite. The densification and retention of t-ZrO2 in the matrix of synthetic mullite were also investigated. From IR spectroscopic analysis, the obtained amorphous SiO2-Al2O3 powder was observed to have Si-O-Al chemical bond in its structure which might result in the homogeneous mullite composition. The lattice parameter of the mullite powder calcined above 130
) is nearly close to the value of stoichiometric mullite (71.8wt% Al2O3, a0=7.5456
). The sintering behavior, microstructure, flexural strength and fracture toughness of the mullite and mullite-15v/o ZrO2 composites have been studied. The mullite-15v/o ZrO2(+3m/o Y2O3) ceramics with relative densities of 96% were obtained when sintered at 1
. The flexural strength and fractrue toughness of the composites sintered at 1
(calcination temperature of mullite powders ; 125
) had maximum values of 307MPa and 2.50MPa.m1/2, respectively. The fracture toughness improvement in the mullite-ZrO2 cmoposite is assumed to be resulted from the combined effect of the stress-induced phase transformation of tetragonal ZrO2 and the crack deflection due to microcracking by the monoclinic ZrO2 formation.
-based Clinker by Hydration-Burning Method (I) : Effects of Temperature on Synthesis
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 211~218
CA2-based clinker with highly activated surface and hydraulic properties was synthesized at a comparatively lowr temperature than that of conventional synthesis by "hydration-burning method". This consists of calcining the mixture of CaCO3 and Al2O3 to obtain a primary clinker, hydrating the primary clinker and reburning the hydrates to obtain final clinker. Burning of primary clinker above 1200℃ was necessary to eliminate free CaO in it and to obtain it's solid hydrate. However, rising the burning temperature above 1300℃ is ineffective due to the decrease in hydraulic properties of the primary clinker with the temperature. Hydration of primary clinker at the elevated temperature(>35℃) was required to obtain the hydrate with more porous structure and final clinker with more active surface. CA2 was formed and increased with temperature at above 1150℃, finally became a primary phase of the final clinker. However, burning at the temperature above 1300℃ resulted in reverse effect on the hydraulic properties of the final clinker due to rapid decrease in it's surface area with the temperature.
A Study on Chemical Vapor Deposited SiO2 Films on Si Water
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 219~225
Silicon dioxide thin film has been grown by a chemical vapor deposition (CVD) technique using SiH4, and O2 gaseous mixture on a silicon substrate. The experimental results indicated that the deposition rate as a function of the input ratio (O2/SiH4) shows two regions, increasing region and decreasing region. Also the deposition rate increases with increasing the deposition temperature. The microstructure of deposited silicon dioxide films is amorphous. The experimental results of infrared absorption spectrums indicate that Si-H and Si-OH bond increase with decreasing input ratio, but Si-O bond is independent on the input ratio. The interfacial charge of deposited silicon dioxide decreases with increasing input ratio.
Thermal Stability of 2.5Y-TZP under Low-Temperature Aging
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 226~232
The degradation phenomena and thermal stability of 2.5Y-TZP at low-temperature were studied by means of XRD, Raman spectra and microstructural analysis. The degradation of heat-treated 2.5Y-TZP at 20
-20hr in air was observed on the TZP surface, be caused by the cracks generated from tlongrightarrowm transformation, and the cracks was propagated inside the polycrystalline body. The ZrO2 grain boundaries and grains near the crack were revealed as if these were diffused and dissolved. And it was also observed mlongrightarrowt transformation as the degraded TZP was refired at 140
, and it was thought to be the fact that the moisture in atmosphere during the aging process contributed to the degradation. The thermal stability of 2.5Y-TZP was improved dramatically with an addition of 3w/o CeO2 or a provision of high Y2O3 concentration on the TZP surface.
A Study on the Ceria Stabilized Tetragonal Zirconia Polycrystals (Ce-TZP) (IV) ; Effect of MgO Addition on 12 Ce-TZP Ceramics
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 233~243
For theinvestigation of MgO addition effect on 12Ce-TZP ceramics, MgO-CeO2-ZrO2 ceramics was fabricated using commercial powders under sintering condition of 130
for 2hr. Fully tetragonal phase could be obtained by proper heat treatment and MgO addition amount. Minor cubic phase was appeared in relatively high MgO content composition at each sintering temperature. As alloying amount of MgO increased, tetragonal stability increased and grain size decreased. Grain size dependence on MgO content was verified by SEM observation of fractured surface. Surface bloating was observed from the 2 m/o to 6m/o in the temperature range of 150
. In spite of very porous microstructure owing to surface bloating, 100% TZP could be maintained in 2.0m/o MgO composition by heat treatment of 150
. This result indicated that MgO was more powerful stabilizer than CeO2. Mechanical proprties of MgO-CeO2-ZrO2 ceramics were consistent with the stability observation of tetragonal phase very well.
A Study on the Electrical and Optical Properties of PZT Produced by Coprecipitation -The Effect of Nd-
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 244~248
The effect of Nd3+ on the electrical and optical properties in PZT ceramics were investigated. The powders were prepared by the coprecipitation method using the salt solutions and Nd3+ was partially substituted for Pb2+ of Pb(Zr0.54 Ti0.46)O3. The coprecipitate were obtained under pH 11.8-12 and the single phase of PLZT powders were synthesized at about 500
. In the case of specimens with 4at.% of Nd which were sintered at 1250
for 55 hours under 1atm, showed 50% of transmittance for 600nm(wave length).
Composition Control and Annealing Effects on the Growth of YBaCuO Superconducting Thin Films by RF Magnetron Sputtering
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 249~255
High Tc Supperconducting thin films were fabricated by rf magnetron sputtering method. We have successfully controlled the compositions of films by adding sintered CuO pellets on YBa2Cu3O7-x single target. High Tc thin films with large grian size and good crystal habit were obtained by rapid thermal annealing process. The films deposited on SrTiO3(100) single crystal substrate indicated the existence of c-axis prefered orientation confirmed by XRD and SEM analysis. The Tc, zero's of sharp resistive transition for rapid annealed films deposited on polycrystalline YSZ substrate and on SrTiO3(100) single crystal substrate were 79K and 88K, respectively.
A Study on the Cordierite Ceramic Composite Dispersed with the Zirconia
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 256~264
5SiO2) was known to display low thermal expansions over wide temperature ranges, but showed poor mechanical strength. The present studies have been concerned with the sintering of cordierite based ceramics containing pure or stabilized zirconia. The crystallographic and microstructural results were not affected by the fact whether added zirconia was stabilized or not. As the contents of zirconia were increased, M.O.R., KIC, bulk densities were increased but the thermal expansion coefficients were decreased.
Synthesis ofSialon-SiC Composite Powder from Alkoxides and the Powder Properties(I)
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 265~273
Fine Si-Al-OH-C coprecipitate powders were prepared from Si(OC2H5)4, Al(i-OC3H7)3, and carbon black by a hydrolysis method before fabrication of Sialon-SiC composite powder by carbothermal reduction at 1350
for 10h under N2/H2 mixed atmosphere. The characterization of the synthesized Sialon-SiC composite powders was performed using XRD, BET, SEM, TEM and particle size analysis methods. The average particle size and specific surface area of the synthesized Sialon-SiC composite powder were 0.13
and 20.1㎡/g, respectively when Z=1 and N2 : H2=50 : 50.
Powder Preparation from Hydroxide and Oxalate and its Characterization
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 274~282
SnO2 powder was prepared by hydroxide method and oxalate method. In hydroxide method, the pH dependence of powder characteristics was investigated by using buffer solution. As increasing the pH of solution, SnO2 powder size was decreased because nucleation rate was inctreased by more supersaturation of solution. Also, we found that the powder by our method has larger specific surface area in comaprison with other method. And the degree of agglomeration of precipitate with the change of precipitation temperature was investigated in oxalate method. The SnC2O4 was angular shape precipitate, and the size of the SnC2O4 was increased with the increase of precipitation temperature in methanol solvent.
The Thermally Resistance Strength of LAS(
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 283~287
The study was aimed at investigating sintering characteristics, the overall properties from the ternary Li2O-Al2O3-SiO2 system. This system, which was considered without additives and selected five compositions, was studied with variation of the amount of SiO2. The reactivity of the system was observed by D.T.A.. Characteristics of sintering, microstructure, property and stability of produced phase were studied. It was found that because the range of sintering was narrow and the temperature of sintering was close to the melting temperature, the sintering by the general method was difficult. Also, these linear thermal expansion coeffecients were measured.
Studies on the Structure of Transparent Glass Ceramics
Journal of the Korean Ceramic Society, volume 27, issue 2, 1990, Pages 288~296
Parent glasses for the experiments were prepared to be ratio of Li2O : Al2O3 : SiO2=4.5 : 25 : 70.5 as basic components, and TiO2 and ZrO2 in the mixing ratio of 1 : 1 were added as the nucleating agents, whose contents were increased in each sample. DTA, XRD, SEM, IR were observed, and thermal expansion and transmissivities were measured for the crystallized samples under the controlled heat-treatments. The transformation temperatures and the dilatometric softening temperatures in thermal expansion curves, and also the exothermic peaks in differential thermo-analytical curves were shifted to lower temperature. The crystal phase deposited through the heat-treatment was identified as
-quartz solid solution with XRD and IR analysis. The crystalline phases in oopactified samples were
-spodumene coexiting with
-quartz solid solution. The samples having more than 3% nucleating agents were transparent. The crystallized grain sizes were ranged 0.05 to 0.1
. The crystallized transparent samples were exceeded 85% in the transmissivity.