• 한국세라믹학회지
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• 제43권12호
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• pp.859-864
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• 2006

For the pressure compaction process of the ceramic powder, the green density is very different with both the ceramic body shape and the processing conditions. The density difference cause non-uniform shrinkages and deformations, and make cracks in the sintered ceramics. In this paper, Material properties of the alumina powder mixed with binder and the friction coefficient between the powder and the tool set were determined through the simple compaction experiments: Also the powder flow characteristics were simulated and the green density was analyzed during the powder compaction process with Finite Element Method (FEM). The results show that the density distributions of the green body were improved at the optimized processing condition and both the possibility of the farming crack generation and rho deformation of the sintered Alumina body were reduced.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.20-21
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• 2006

Through different projects, CETIM and its scientific and industrial partners have evaluated the potential of the High Velocityy Compaction Technology in terms of materials and component shape. Various kinds of powder materials were studied: metals, ceramics and polymers. The HVC process was used with success to manufacture gears, large parts and multilevel components. Due to the high density of HVC parts, the green machining process enables shapes to be produced that would otherwise be impossible to compact and components to be produced with very hard sintered and homogeneous materials.

• 한국결정성장학회지
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• 제15권1호
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• pp.21-26
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• 2005

세라믹 분말 가압 성형 공정을 전산모사 하고 패킹의 임의성과 입자 배열의 효과를 평가하기 위해서 유사한 임의 다중 입자 배열을 사용하여 2차원 막대 배열 가압 성형 모델을 도입하였다. 3개의 Al₂O₃ 입자와 3개의 Al 입자를 가지고 기공과 관련된 가압 성형 공정을 균질화 탄성계수를 사용하여 외연적 유한요소 해석하였다. 해석 결과는 이전 해석 결과 및 실험 결과와 비교하였다. 마지막으로, 분말 입자의 마찰계수와 상대밀도의 관계를 얻기 위한 해석이 수행되었다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.368-369
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• 2006

By means of magnetic pulsed compaction and sintering of weakly aggregated alumina based nanopowders the jet forming nozzle samples for the hydroabrasive cutting were fabricated. The ceramics was obtained from pure alumina, as well as from alumina, doped by $TiO_2$, MgO and AlMg. It was shown that the samples sintered from AlMg doped $Al_2O_3$ powder have the best mechanical properties and structural characteristics: relative density ${\sim}0.97$, channel microhardness. - 18-20 GPa, channel surface roughness ${\sim}0.7\;{\mu}m$, average crystallite size ${\sim}1\;{\mu}m$.

• 한국결정성장학회지
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• 제15권1호
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• pp.27-33
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• 2005

본 연구에서는 세라믹 제품의 고밀도를 얻기 위해 분말 압축 성형 공정 변수의 최적화가 수행되었다. 이를 위해 먼저 임의의 초기 밀도를 갖는 분말 성형체를 모델링하였다. 그리고 반복 가압 성형 공정시 상대밀도에 영향을 주는 Al₂O₃ 입자의 크기, 반복 가압 진폭 크기, 그리고 마찰계수에 따른 상대밀도의 변화를 유한요소법으로 해석하였다. 유한요소 해석 결과를 반응 표면법으로 수식화한 후, 격자 탐색법으로 가압 성형 공정 변수의 최적 조건을 찾았다. 입자의 크기가 22.5 ㎛, 반복 가압 진폭이 75 MPa, 마찰계수가 0.1103인 경우에 상대 밀도 값이 0.9390으로 최대가 되었다.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2004년도 추계총회 및 연구발표회 초록집
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• pp.88.2-88.2
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• 2004

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.24-25
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• 2006

High-Speed Centrifugal Compaction Process is one of slip-using compacting method originally developed for processing of oxide ceramics. In this study, we apply the HCP to ultra-fine (0.1 micron) WC powder. Organic liquid of heptane was chosen as dispersing media to avoid possible oxidation of WC. The mixing apparatus was a key to obtain dense compacts. Only the slips mixed by high energy planetary ball mill were packed up to 55% by the HCP, and sintered to almost full density at 1673 K without any sintering aids. This sintered compact marked Vickers hardness of Hv 2750 at maximum.

• 한국재료학회지
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• 제27권12호
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• pp.716-721
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• 2017

SiAlON-based ceramics are some of the most typical ceramic materials used as cutting tools for HRSA(Heat Resistant Super-Alloys). SiAlON can be fabricated using ceramic processing, such as mixing, granulation, compaction, and sintering. Spray drying is a widely-used method for producing a granular powder of controlled morphology and size with flowability. In this study, we report a systematic investigation aimed at optimizing spherical granule morphology by controlling spray-drying parameters such as gas flow and feed rate. Before spray drying, the viscosities of the raw material slurries were also optimized with the amount of dispersant added.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.775-775
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• 2006

• 한국분말재료학회지
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• 제12권5호
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• pp.345-350
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• 2005

In this study the nanostructured ${\alpha}-Al_{2}O_3$ ceramics have been fabricated by the combined application of magnetic pulsed compaction (MPC) and subsequent spark plasma sintering (SPS), and their density and hardness properties were investigated. The ${\alpha}-Al_{2}O_3$ prepared by the combined processes showed an increase by $8.4\%$ in density, approaching the value close to the true density, and an enhancement by $210\~400\;Hv$ in hardness, compared to those fabricated by MPC or static compaction method followed by sintering treatment.