• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.553-558
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• 2019

In present study, the cylindrical susceptor by the slip casting method was designed to apply high-temperature induction heating by using $(Mo,W)Si_2$ ceramics. $MoSi_2$-based materials were synthesized by SHS (Self-propagating High-temperature Synthesis) method. The phase and crystal structure of $MoSi_2$-based materials were confirmed by XRD analysis. The shape of cylindrical mold was synthesized for various thickness by using the slip casting method. Finally, the susceptor for induction heating was processed by sintering and heat treatment to form $SiO_2$ layer, which was confirmed on the surface of susceptor by SEM/EDS analysis. To evaluate the heating performance of $(Mo,W)Si_2$ cylinder susceptor, we measured the maximum surface temperature and heating rate in comparison with the rod heating element under constantly applied power. The induction heating of the $(Mo,W)Si_2$ cylinder showed excellent heating performance, reaches the maximum temperature of $1457^{\circ}C$, with the average heating rate of $19^{\circ}C/s$ at 2 kW

• Steel and Composite Structures
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• v.34 no.4
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• pp.581-597
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• 2020

Light-Weight Concrete containing Expanded Poly-Styrene Beads (EPS-LWC) is an approved structural and non-structural material characterized by a considerably lower density and higher structural efficiency, compared to concrete containing ordinary aggregates. The experimental campaign carried out in this project provides new information on the mechanical properties of structural EPS-LWC, with reference to the strength and tension (by splitting and in bending), the modulus of elasticity, the stress-strain curve in unconfined compression, the absorbed energy under compression and reinforcement-concrete bond. The properties measured at seven ages since casting, from 3 days to 91 days, in order to investigate their in-time evolution. Mathematical relationships are formulated as well, between the previous properties and time, since casting. The dependence of the compressive strength on the other mechanical properties of EPS-LWC is also described through an empirical relationship, which is shown to fit satisfactorily the experimental results.

• Transactions of Materials Processing
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• v.12 no.6
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• pp.521-528
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• 2003

Powder injection molding (PIM) uses the shaping advantage of injection molding but is applicable to metals and ceramics. This process combines a small quantity of polymer with an inorganic powder to form a feedstock that can be molded. After shaping, the polymeric binder is extracted and the powder is sintered, often to near-theoretical densities. According1y, PIM delivers structural materials in a shaping technology previously restricted to polymers. The process overcomes the shape limitations of traditional powder compaction, the costs of machining, the productivity limits of isostatic pressing and slip casting, and the defect and tolerance limitations of conventional casting. Since 1980s when major attention was given to PIM process, it has been widening the application area from small parts with complex shape and tailored properties to structural parts requiring strength and ductility as in automotive, military and medical industries.

• Journal of Powder Materials
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• v.9 no.4
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• pp.211-217
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• 2002

It is well known that the powder injection molding(PIM) process can overcome the shape limitations of traditional powder compaction, the costs of machining, the productivity limits of isostatic pressing and slip casting, and the defect and tolerance limitations of conventional casting. Increasing demands from industry for not only the dimensional accuracy nut mechanical strength in PIMed parts have had much effort focused on the investigation of mechanical properties of mechanical strength in PIMed parts have had much effort focused on the investigation of mechanical properties of sintered parts formed with high-strength metallic powders. The 17_4 PH $10\mu{m}$ were injection-molded into flat tensile specimens. Sintering of the compacts was carried out at the various temperatures ranging from 900 to $1350^{\circ}C$. Sintering behavior of the compacts and tensile properties of sintered specimens were investigated.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.141-149
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• 2021

3D printers, which emerged in the late 20th century, have become a key part of the fourth industrial revolution in the 21st century. Although 3D printers, the key equipment of the maker movement and the starting point of the new cottage industry in the 21st century, still reveal the limitations of mass production with low output speed and limited filament materials, the use of 3D printers by ceramic craftsmen has recently increased exponentially. However, as part of a way to overcome the discord between craftsmanship and the new technology, which has been repeated over and over in the past in craft history, the study focused on the 'plaster mold casting' technique using 3D printers. Therefore, after analyzing casting techniques of Tony Hansen, Webe van Gansbeck, Jade Crompton, and Ryu Hee-do, the potters who actively developed gypsum techniques in the world's ceramic crafts field and applied them to their own designs, I tried to find the point of convergence between 3D printers and ceramic crafts by presenting examples of effective 3D modeling methods and optimal slip casting methods using 3D printers.

• Proceedings of the Membrane Society of Korea Conference
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• 1992.10a
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• pp.7-7
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• 1992

Slip-casting 법으로 제조한 튜브형 다공성 $Al_2O_3$ 담체에 boehmite 입자를 단층 및 다층 졸-겔 침지코팅법과 본 실험실에서 개발한 새로운 가압 졸-겔 코팅법을 이용하여 알루미나 복합막을 제조하였다. 종래의 Yoldas법을 보완한 새로운 졸 제조방법에 의하여 입자크기가 작고 안정한 boehmite 졸을 제조 하였으며 졸의 제조조건에 따른 입자크기 변화와 열처리에 따른 겔의 상전이 및 비표면적 변화, 그리고 pH와 aging에 따른 안정성등을 규명하였다. 졸의 농도와 코팅시간 및 코팅 방법에 따른 코팅특성 등을 비교, 분석하여 복합막 제조에 최적인 코팅용 졸을 이용함으로써 담체 튜브내에 균열이 없고 재현성 있는 복합분리막을 제조할 수 있었다.

• Korean Journal of Materials Research
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• v.11 no.6
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• pp.465-471
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• 2001

The effect of sintering condition on the mechanical properties and leachability of polydispersed ceramic core body made by gel-casting process in aqueous medium have been investigated. The polydispersed ceramic slip that has low viscosity($\leq$1000cP, at 1000cP (at $50sec^{-1}$ ) and high solid loading(50vo1%) was obtained. The green bodies were fabricated through casting and gelation at room temperature followed by drying at $25^{\circ}C$for 48hrs under relative humidity of 80%. Crack-free green body was successfully fabricated through the above process. The strength at room temperature, apparent bulk density, and shrinkage of the ceramic core body increased propotionally with increasing sintering temperature(1100~150$0^{\circ}C$). However, porosity of the ceramic core body showed relatively low vague. Leaching rate of sintered core body increased with increasing porosity of the sintered body, and was significantly dependent upon the concentration of alkali caustic solution at the same leaching temperature.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1153-1157
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• 2002

The fabrication of a three-layered asymmetric ceramic membrane was performed by slip casting of the porous alumina support and dip coating of the alumina intermediate layer using high purity ${\alpha}-Al_2O_3$ powders that have different particle size, followed by screen printing-pyrolysis of the $Tio_2$ layer as an ultrafilteration membrane using Ti-naphthenate solution. The bending strength, porosity and mean pore size of the alumina support were 231 kg/$cm^2$s, 30.26% and 0.19 ${mu}m$, respectively. The thickness of the intermediate layer was 30 ${mu}m$ and the mean pore size of that was 0.063 ${mu}m$. Also, the top layer was 0.5 ${mu}m$ thick and micropores with about 20 nm size were formed uniformly.

• Journal of the Korean Ceramic Society
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• v.36 no.1
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• pp.89-96
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• 1999

Manufacturing conditions of the porous alumina mold were established to overcome various limits of the gypsum mold. For the preparations of the porous alumina mold, an activated charcoal was added to the Al2O3 with the wt% variation and then mixed. The binary slurry was study dispersed based on the examination of the ESA and rheological behaviro. The cylinder type alumina mold was cast in the gyspum mold and characterized by the shrinkage rate at the variable sintering temperature and the resistance against wear. It was proper to make a sintering of the Al2O3 by the surface diffusion which was non-shrinkage sintering mechansim, and intergranular neck growed stronger while sintering was being made. We studied a sintering by three categories; 1) thermodynamic method below 1,000$^{\circ}C$, 2) kinetic method above 1,000$^{\circ}C$ and 3) combined method. In the results of the respective works, combined method was superiro to the others. The prepared Al2O3 mold had relatively high strength, low drying rate, the resistance against the acid or base and good casting behavior.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.305-308
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• 2001

Powder injection molding (PIM) uses the shaping advantage of injection molding but is applicable to metals and ceramics. This process combines a small quantity of polymer with an inorganic powder to form a feedstock that can be molded. After shaping, the polymeric binder is extracted and the powder is sintered often to near-theoretical densities. Accordingly, PIM delivers structural materials in a shaping technology previously restricted to polymers. The process overcomes the shape limitations of traditional powder compaction, the costs of machining, the productivity limits of isostatic pressing and slip casting, and the defect and tolerance limitations of casting. The 17-4 PH stainless steel powders with average diameter of $10{\mu}m$ were injection-molded into flat tensile specimens. Sintering of the compacts was carried out at the various temperatures ranging from 900 to $1350^{\circ}C$. Sintering behavior of the compacts and tensile properties of sintered specimens were investigated.