• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.69-69
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• 1997

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.92-92
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• 1998

• Proceedings of the Materials Research Society of Korea Conference
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• 2008.05a
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• pp.10.1-10.1
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• 2008

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.424-429
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• 2016

In this study, the carbonized boards were manufactured from different types of wood-based panel and then their moisture absorption/desorption properties were investigated and compared. The carbonization temperature was maximum $600^{\circ}C$ with 2 h maintains. Test results showed higher absorption/desorption capacity on carbonized plywood than carbonized MDF, PB, and OSB, respectively. However, carbonized MDF, OSB, and plywood had similar absorption/desorption rate per hour. It means carbonized OSB and plywood can transfer moisture into deeper side and then possibly hold more amount of water. Based on SEM images, carbonized OSB and plywood showed more like wood structure, while carbonized MDF and PB had only wood fiber or/and chunk of wood fragments. Therefore, original wood structure may affect moisture absorption/desorption capacity. In order to manufacture high moisture absorbing/desorbing carbonized board, wood structure should be considered and then carbonized.

• Composites Research
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• v.31 no.5
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• pp.260-266
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• 2018

This study investigates thermal and mechanical characterization of Hafnium carbide coating on the $C_f-C$ composites. The hafnium carbide coatings by vacuum plasma spray on the C/C-SiC composites are prepared to evaluate oxidation and wear resistance. We perform the thermal durability tests by thermal cycling at $1200^{\circ}C$ for 10cycles in air and investigates the weight change of each cycle. We also evaluate the wear and indentation behavior using tungsten carbide ball indenter as a mechanical evaluation. As a result, the HfC coating is beneficial to reduce of weight loss during thermal cycling test and improve the elastic property of C/C-SiC composite. Especially, the HfC coating improves the wear resistance of C/C-SiC composite.

• 기계와재료
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• v.21 no.4
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• pp.30-37
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• 2010

최근 산업의 고도화에 따른 부품 소재의 고성능화에 따라 기존의 고온 세라믹의 한계를 극복하기 위한 노력으로 초고온 세라믹 재료에 대한 활발한 연구가 진행되고 있다. 초고온 세라믹은 대부분 붕화물이나 탄화물인 비산화물 세라믹으로 3000도 이상의 녹는점을 갖으며 2000도 부근에서는 사용을 목표로 하고 있다. 이 재료는 다른 세라믹들과 마찬가지로 취성파괴 거동을 나타내며, 이를 보완하기 위한 섬유강화 복합재료화도 활발히 진행되고 있다. 본고에서는 고온용 세라믹 장섬유와 세라믹 복합재료, 그리고 초고온 세라믹의 개발 현황과 산업화 전망을 정리하였다. 또한 초고온 세라믹의 발전 방향을 전망하였으며, 재료연구소에서 수행중인 초고온 세라믹의 연구 활동에 대해 간략히 언급하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.05a
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• pp.124-124
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• 1993

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.16-21
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• 1999

국민소득의 증대와 더불어 향상된 우리의 식생활 문화는 양보다 품질을 선호하게 되어 청정 농산물의 수요가 증대하였는데 이로 인하여 농작물의 유해성을 감소시킬 수 있으며 기후의 영향을 덜 받아 연중재배 및 생산이 가능한 수경재배 및 양액재배 기술이 등장하였으며, 이를 위한 첨단 시설하우스의 설립도 매우 많이 증가하였다. 또한 점점 더 확산되는 집단육묘 체계에서 살균 처리하여 사용되고 있는 관행 상토를 대체할 수 있는 무균의 배양토 재료의 개발이 관심 대상으로 떠올랐다. 토양 및 광물질, 유기물류가 혼합된 대부분의 상토재료(피트모스, 나무껍질)와 양액재배 지주물질은 매우 많은 양이 수입에 의존하고 있는 실정이다. 이러한 고가의 수입자재를 대체하기 위한 일환으로 우리 농촌에서 농업부산물로 생겨나는 왕겨를 탄화시켜 상토재료 및 양액재배용 지주물질로 사용하려는 연구가 다수 시행되었다. (중략)

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.376-380
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• 2003

The microstructure and the mechanical properties of RS-SiC and RS-$SiC_f/SiC$ materials have been investigated in conjunction with the content of residual silicon and porosity. The mechanical properties of RS-SiC materials suffered from the thermal exposure were also examined. RS-SiC based materials bave been fabricated using the complex matrix slurry with different composition ratios of SiC and C panicles. The characterization of RS-SiC based materials was investigated by means of SEM, EDS ~d three point bending test. Based on the mechanical property-microstructure correlation, the high temperature applicability of RS-SiC based materials was discussed.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.145-148
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• 2001

SiC composites were developed by incorporating glass phase into SiC, in the light of improving mechanical properties of material for spectacle lens cutting. Specimens for spectacle lens cutting with glass phase as sintering additives have been fabricated by hot-pressing at $1810^{\circ}C$ for 2 hr under a pressure of 25 MPa. The fracture toughness and hardness of hot-pressed specimens were characterized and compared with previous works. Typical hardness and fracture toughness of materials for spectacle lens cutting were 12 GPa and $5.1MPa{\cdot}m^{1/2}$ respectively.