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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
Editor in Chief :
Volume & Issues
Volume 33, Issue 12 - Dec 1996
Volume 33, Issue 11 - Nov 1996
Volume 33, Issue 10 - Oct 1996
Volume 33, Issue 9 - Sep 1996
Volume 33, Issue 8 - Aug 1996
Volume 33, Issue 7 - Jul 1996
Volume 33, Issue 6 - Jun 1996
Volume 33, Issue 5 - May 1996
Volume 33, Issue 4 - Apr 1996
Volume 33, Issue 3 - Mar 1996
Volume 33, Issue 2 - Feb 1996
Volume 33, Issue 1 - Jan 1996
Volume 2, Issue 3 - 00 1996
Volume 2, Issue 2 - 00 1996
Volume 2, Issue 1 - 00 1996
Selecting the target year
Effect of Interlayers on the Bending Strength of Silicon Nitride/Staineless Steel Joints
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 251~258
The reactions between an active metal brazing alloy and interlayers together with the effects of interlayer type on the interfacial microstructure change were investiaged for silicon nitride/stainless steel joint. The bending strengths were measured for joints with Mo, Cu, Ni interlayer type of different thicknesses. It was found that the interlayer with a low yield strength value is effective to improve the bending strength of the Si3N4/stainless steel joint. The maximum joint strength obtained at room temperature for a laminated Cu/Mo interlayer was about 460 MPa. The combined use of Mo and thin Cu layer was found to be effective in enhancing the bending strength for the Si3N4/S.S.316 joint.
Sintering of Zriconium Diboride through Fe-based Liquid Phase
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 259~268
In the present study the effect of the addition of Fe on the pressureless and hot press sintering behavior was studied under Ar atmosphere. Pressureless sintering was performed 1900~220
under. Ar atmosphere. The addition of 1 wt% Fe was increased effectively of the sintered density. However it was impossible to obtain high density higher than 90%,. Zr-Fe-B compound in liquid phase was observed from the EDS and WDS analysis. It was considered that sinterability was enhanced due to the mass transfer through Fe based liquid phase formed at the sintering temperature. Hot pressing was performed at 1600~1
under Ar atmos-phere for 1 hr. It was possible obtain 95% relative density of ZrB2 specimen which is higher density at pressure-less sintering. It could be thought that ZrB2 particles was rearranged through liquid phase by applied pressure during initial stage of sintering.
on Machining of Silicon itride
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 269~276
The effect of sintering aids on the sinterability for silcion nitride has been studied by hundreds workers. However the effect of sintering aids on the machinability as the own trobles which is the major barrier for the field applications of the ceramic components has not been fully studied. in this study the contents of Al2O3 and Y2O3 in silicon nitride were varied from 0 to 8 wt% respectively. The physical and mechanical properties of the silcion nitride were measured. The optimal microstructure of silicon nitride balls with the excellent machinability by adding with various contents of sintering aids was studied by MGF(magnetic-fluid grinding)technique. An attempt to figure out how the mechanical properties influence the machinability of silicon-nitride ball was made.
Effect of Impurities in Grain Boundary Phases on Wear Behavior of
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 277~284
The water test results indicated that the impurities had detrimetal effect on the wear resistance of silicon nitride and the effects were getting severe as the temperature increased. Especially when Ca existed as an impurity the detrimental effects was the most severe. These results were resulted from the fact that impurities lowered the mechanical properties of the grain boundary phase of silicon nitride. The wear test results of glass/glass-ceramic specimens having a similar composition to the grain boundary phase of silicon nitride revea-led that the specimen containing CaO showed the lowest wear resistance. The existence of Fe and Ca at the grain boundary phase assisted forming a grain boundary phase with relatively low refractoriness. Therefore at a given wear condition the removal of deformed layer would be easier. The results showed that the glass phases could be modified by heat-treatment and this modification improved tribological characteristics of the silicon nitride.
Effect of AlN Addition on the Thermal Conductivity of Sintered
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 285~292
The effect of AlN on the thermal conductivity of aluminum oxide pressurelessly sintered at nitrogen atmos-phere was investigated. Increasing aluminium nitride content up to 1~10 mol% the thermal conductivity of
-AlN system was singnificantly decreased and was constant with adding 20 and 25 mol% aluminium nitride. The thermal conuctivity of
containing 1~10 mol% the thermal conductivity of
-AlN system was singificantly decreased and was constant with adding 20 and 25mol% aluminum nitride. The thermal conctivity of
containing 1~10 mol% AlN showed a maximum at
and decrea-sed with increasing sintering tempertures. This phenomenon was attributed to
and ALON formed by reacting
with AlN up to
and the secondary phases such as
.AlN) phase above
The thermal conductivity of
containing 20 and 25 mol% AlN showed maximum value at
and ALON existed up to
and ALON existed up to
while only AlON phase existed above
Lithium Ion Conductivity in
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 293~298
Room temperature Li+ ion conductivities of Li3xLa(2/3-x)TiO3 system with x=0.117~0.317 were measured by complex impedance method. ICP, SEM and XRD analysis were conducted to study the main factor which influence the Li+ ion conductivity. Li+ ion conductivity seems to have a close relationship with the crystal structure of primitive cell increase as the primitive cell as close to cubic.
Chemical Beam Deposition of
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 299~306
We invesgated the fesibility of thin films deposition by pyrolysis of metalorganic precursors using chemical beam deposition (CBD) process. We attempted to understand the effects of deposition variables such as substrate temperature operating pressure effusion cell temperature and H2 partial pressure on the properties of MgF2 grown by CBD. Mg(tfac)2 was used as a precursor. MgF2 thin films were always grown in an amorphous state and crystallized bypost-annealing. he higher the substrate temperature and the lower the operating pressure the less the impurities I the deposited MgF2 thin films. H2 gas has to be supplied for the pyrolitic reaction of Mg(tfac)2 decomposition. MgF2 films annealed in H2 have lower C impurity than those annealed in O2. But their crysatllinity was independent of annealing atmosphere. The optimum conditions for the prepara-tion of MgF2 films by CBD process were as following : The substrate temperature 55
the operating pressure 10-4 torr; effusion cell temperature 21
the percentage of H2 100% Post-annealing in H2 gas was required to remove residual carbon and to form MgF2 crystalline phase.
A Study on the Retarding effects of Cememtn Mortar Setting
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 307~312
In following addition of 0.3, -0.6, 0.8, 1.0 and 5 weight percent MgSiF66H2O studies have been made of the setting and hardening characteristics of ordinary portland cement. MgSiF66H2O retarded the setting time of ordinary portland cement and extended the induction pariod of the hydration. In ordinary portland cement the setting characteristics were drastically altered especially at high MgSiF66H2O contents. Evidence was also obtained by the formation of a KSiF6 which was very fine particle. The results wee as follows. 1. Slump was slightly decreased when MgSiF66H2O added. 2. Setting time was retarded depending on the amount of retarding agent 2 to 8 hours 3. Compressive strength was almost same or some increased in comparision with opc. 4. When MgSiF66H2O was added to cement paste K2SiF6 were formed It was fine-sized distributed uniformly in cement grain and caused retardation of cement setting.
Fabrication of the in-plane Aligned a-Axis Oriented
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 313~320
We have fabricated an in-plane aligned a-axis oriented YBa2Cu3O7-x (a-YBCO) thin film on a LaSrGaO4(100) substrate with a PrBa2Cu3O7-x(PBCO) template layer by two step plused laser deposition using 308 nm XeCl excimer laser. A YBCO layer and PBCO layer grown at low temperatures were used as template layers. We have investigated the effect of the deposition temperature of template layers on the superconducting and struc-tural properties of in-plane aligned a-YBCO thin films. An optimal deposition temperature of the PBCO template layers was 630. In-plane aligned a-YBCO thin films showed an anisotropy ratio in resistivity of 11.5 and a zero resistance temperature of 88 K.
Stress Analysis of
Swirl Chamber during Thermal Fatigue Test
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 321~326
Thermal fatigue test and stress analysis of Si3N4 and metal swirl chamber were carried out to investigate the reliability of the swirl chambers. Conditions of the thermal fatigue test were severer than those in real engine and FEM was used to analize the stress distribution in the swirl chambers. Fatigue cracks of the maximum length 2.4 mm and deformation were occurred at the corner of the jet in metal swirl chamber but not observed in Si3N4 swirl chamber. Maximum tensile stress in Si3N4 swirl chamber calculated by FEM was 300 MPa.
-FeOOH by Coprecipitation Method and Its Magnetic Properties
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 327~331
A Study on characteristics of AUC Powder Prepared with the Waste AC Solution
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 332~338
This study was investigated on the recycle feasibility of the waste AC(Ammonium Carbonate) solution produ-ced in a commercial AUC(Ammonium Uranyl Carbonate) conversion plant. AUC particles were produced with the AC solution which was prepared with AC solid-agent instead of ammonia and carbon-dioxide gases. As the results particles of monoclinic shapes has been obtained regardless of the pH change if the carbonate concentration is sufficient in the mother liquore. Also a lot of twinned or aggregated particles were formed in case of the increase of pH in the reaction system but not affected in the change of temperature. Consequen-tly the characteristics of the particles which converted for AUC were produced withAC solution to UO2, particles specific surface area shape sintered density and others were similar to that of the particles which were produced with gases only when the pellets are fabricated in the nuclear fuel manufacturing process So the waste AC solution which is produced in the commercial AUC conversion plant is possible to recycle.
The Evaluation of Mechanical Properties for Alumina Ceramics
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 339~347
Mechanical properties(flexural strength hardness fracture toughness) of alumina ceramics were evaluated. Alumina products of four companies were selected and three of those were made in Korea and one of those was made in Japan. The large differences according to manufacturing companies had resulted from flexural strength and weibull modulus which had a wide ranges of 300 to 400 MPa and 5 to 15 respectively. Critical indenstation load which could be neglected the effect of elastic recovery was about 9.8N and Vickers' hardness were about 15 GPa. Fracture toughnesses were evaluated by IF and ISB method. It was more preferable to the average at one indentation load that fracture toughness were obtained from the slope of the relationship between indentation load and crack length in IF method and between indentation load and fracture load in ISB method and fracture toughness was about 4 MPa·m1/2
Characteristics of Alumina Prepared by Hydrolysis of Al-Alkoxide
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 348~354
Al2O3 gel was prepared by hydrolysis of aluminum alkoxide. The prepared Al2O3 gel powder was calcineel at the various temperature in the electric furnace. To investigate thetransition of crystals thermal properties X-ray diffractometry SEM specific surface area by BET nitrogen adsorption FT-IR and TG-DTA technique were employed. Transparent alumina gel was opalized at 120
The alumina gel was transformed along the rising of temperature as follows ; Boehmite (AlOOH) longrightarrow
Influences of Electrochemical Vapor Deposition Conditions on Growth Rate ad Characteristics of YSZ Thin films(II)
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 355~361
Yttria stabilized zirconia (YSZ) thin films were prepared by the electrochemical vapor deposition (EVD) method on the porous Al2O3 substrates. Y2O3 mol% of thin film was linearly increased with yttrium mole fraction of vapor phase. As yttrium mole fraction(Zyc13=0.18) increased dense and faceted thin films were enhanced. However as the yttrium mole fraction (Zyc13=0.04) decreased porous thin films with monoclinnic phase prevailed. With increasing pressure difference of substrate sides penetration depth decreased porosity and amount of monoclinic phase in the films increased.
Crystal Growth and Phase Transition of Piezoelectric
Journal of the Korean Ceramic Society, volume 33, issue 3, 1996, Pages 362~370
Kalsilite (KAlSiO4) system undergoes a displacive phase transition from hexagonal phase with p63 space group to the phase with P63mc at 886
. The flux composition having kalsilite :K2O:B2O3=1:2:2 has enabled the growth of hexagonal kalsilite with the size of 0.5~1 mm at a slow cooling rate (0.3
/hr). On decreasing the cooling rate the size has increased and pyramidal (1011) faces are newly developed with the shape of (0001) and (1010) faces. Upon stirring (1011) faces are degraded. The space group of O1 and O2 are P21221 and C2221 respectively. Their orthorombic modification O1 and O2 are synthesized at relatively low and high temperature respectively.