• 한국세라믹학회지
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• 제29권6호
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• pp.480-488
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• 1992

The sintering behaviors of seeded alumina from alkoxide were studied. Room temp. desiccated powder exhibited better sintering behavior due to its packing ability and powder activity. $\alpha$-Al2O3 2wt% seeded compacts sintered with 97.5%TD, 1~3${\mu}{\textrm}{m}$ diameters at 140$0^{\circ}C$, 2hrs. Fe-nitrate doped compacts resulted in enhanced initial sintering behavior due to ionic effects of Fe3+ but failed to refined microstructure.

• 한국세라믹학회지
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• 제29권6호
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• pp.489-495
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• 1992

The continuous compaction response of zirconia powders prepared by different processing treatments was investigated. Though the yield point could be or not below 1 MPa, the change of slope was always observed at high pressure range around 60 MPa. Powder compaction was mainly governed by second compaction stage and compaction rate was decreased with increasing forming pressure. Rotary vacuum dried powder favored a high compaction density, whereas freeze dried and calcined powders favored an increase in the pressing efficiency. In order to extract more reliable information about powder compaction, it was necessary to use not only compaction response diagram but also compaction rate diagram.

• 한국세라믹학회지
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• 제31권11호
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• pp.1265-1270
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• 1994

Ultra-fine hydroxyapatite powder were synthesized by the hydrothermal reaction at 10 atm, 3 hrs of Ca(OH)2 suspension with (NH4)2HPO4 solution, and were characterized sintering behavior. Sintered bodies of hydroxyapatite powders which synthesized by hydrothermal reaction method has less weight loss, less sintering shrinkage and superior mechanical property, and was more dense than sintered bodies of hydroxyapatite powder which synthesized by wet method. Sintered bodies were hydroxyapatite single phase. When soack in Ringer's solution for 2 weeks, hydroxyapatite powders preserved hydroxyapatite and sintered body absorbed trace of Ca2+ ion with soaked time.

• 한국세라믹학회지
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• 제24권6호
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• pp.602-604
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• 1987

The high TcY1Ba2Cu3Ox superconductor has recently gained widespread interest in the scientific community. The principal problems at the present time are how to densify this material and how to raise the critical current density. To date the majority of samples have had densities of 90%(of theoretical) or less. In this study we report that we obtained density of 96% by Hot-Pressing method.

• 한국세라믹학회지
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• 제33권12호
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• pp.1373-1379
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• 1996

Change of sintering shrinkage in alumina-based multilayer ceramics was observed in various lamination condi-tions and binder burnout (BBO) temperatures. It was found that the linear shrinkages in X and Y directions were nearly the same with the BBO temperatures but a large shrinkage difference in Z direction was observed. However this phenomenon was diminished when BBO temperature was increased. A linear relationship between the laminated density and the sintering shrinkage was found and the slope was independant on the BBO temperature but dependant on the shrinkage direction.

• 한국세라믹학회지
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• 제32권1호
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• pp.45-50
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• 1995

In order to densify LAS(Lithuim Aluminosilicate)system compounds, we used metal alkoxides as precursors. Also Mg was added by sol-gel method using metal alkoxides to the LAS system for improving the sinterability, thermal and mechanical properties. The result was that the synthesizing temperature was lowered about 10$0^{\circ}C$, the sintering temperature was lowered by over 10$0^{\circ}C$ and MOR of samples from metal alkoxides was two times larger than that of sample form oxide.

• 한국세라믹학회지
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• 제33권11호
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• pp.1237-1244
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• 1996

• 한국세라믹학회지
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• 제34권4호
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• pp.357-367
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• 1997

A fast process for producing pure silica glasses with the reproducibility of 100% by means of sintering of silica aerogels was optimized. The density of silica glasses synthesized by heat-treating upto 110$0^{\circ}C$ with the heating rate of 0.1$^{\circ}C$/min was 2.197 g/㎤. Synthetic silica glasses(5 mm thickness) exhibited the transmittance of 92% in the near IR range as well as they had the excellent mechanical properties such as flexural strength of 162 MPa and hardness of 778 kg/$\textrm{mm}^2$.

• 한국세라믹학회지
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• 제15권3호
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• pp.135-139
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• 1978

Sintering oxide which was prepared by sintering at $1200^{\circ}C$ the mixture of ${\gamma}$-$Fe_2O_3$ and $Sb_2O_3$ in 2 : 1 mol ratio, showed 1st electrical switching and stable 2nd switching when D.C. voltage was applied. This electrical switching mechanism was known to be thermal mechanism from dependence of environmental temperature of threshold Voltage(Vm), Current(Im) and the conductivity of the current filament of the sintering oxide.

• 한국세라믹학회지
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• 제14권2호
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• pp.73-77
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• 1977

The surface diffusion coefficients for nickel, nickel oxide, cuppric oxide, cobalt oxide, alumina and ferric oxide have been determined at various temperatures using the sintering technique. This investigation is based on the model accounting for the sum of the contribution of volume and surface diffusion to the overall shrinkage rate during the initial stage of sintering. Simultaneous measurements of shrinkages and shrinkage rates of the materials compacts were conducted for various annealing times, the results of which were then correlated to the diffusion coefficient.