• 한국결정성장학회지
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• 제30권1호
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• pp.27-32
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• 2020

점토, 규석, 장석을 사용하여 만든 전통생활도자기는 주 결정상이 mullite와 cristobalite이다. Mullite 결정은 제품의 강도를 좋게 하지만 열팽창계수가 5.3 × 10^-6/℃로 비교적 커서 내열 도자기로는 사용할 수 없다. 본 연구에서는 산청토와 장수곱돌 sludge를 사용하여 도자기 내에 mullite 결정 대신 열팽창 계수가 2.6 × 10^-6/℃인 cordierite 결정이 생성되게 함으로써 가벼운 내열 도자기를 개발하고자 하였다. 그 결과 산청토 80 wt%, 장수곱돌 sludge 20 wt%를 사용하여 만든 도자기가 내열성이 좋고 강도와 하중연화도 우수하였으며, 부피비중도 1.7 8로 기존의 분청사기보다 가벼웠다.

• Transactions on Electrical and Electronic Materials
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• 제18권6호
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• pp.334-337
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• 2017

In this paper, to develop the ceramics with high $d_{33}$ and high $Q_m$ for ultrasonic transducer applications, $0.10Pb(Ni_{1/3}Nb_{2/3})O_3-0.07Pb(Mn_{1/3}Nb_{2/3})O_3-0.83Pb(Zr_{0.5}Ti_{0.5})_{0.83}O_3$ (PNN-PMN-PZT) ceramics were sintered at $940^{\circ}C$ using $CuO-Li_2CO_3-Bi_2O_3$ (CLBO) as a sintering aid by a traditional solid-state technique. The influence of zinc oxide additive on the physical properties of the prepared ceramics were systematically investigated. The R-T (rhombohedral-tetragonal) phase coexistence was found in the ceramics without zinc oxide additive and with increasing amounts of ZnO additive, the specimens showed a tetragonal phase. The formation of a liquid phase between ZnO and $Bi_2O_3$ contributed significantly to the grain growth of specimens. For the 0.1 wt% ZnO ceramics, the optimal physical properties of $d_{33}=370pC/N$, ${\varepsilon}_r=1,344$, $k_p=0.621$, and $Q_m=1,523$ were obtained.

• 한국정밀공학회지
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• 제19권9호
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• pp.90-97
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• 2002

Ceramics are being increasingly used in industry due to their outstanding physical and chemical properties. But these materials are difficult to machine by traditional machining processes, because they are hard and brittle. Recently, as one of various alternative processes, laser-beam machining is widely used in the cutting of ceramics. Although the use of lasers presents a number of advantages over other methods, one of the problems associated with this process is the uncertain formation of cracks that result from the thermal stresses. This paper presents a Bayesian probabilistic modeling of crack formation over thin alumina plates during laser cutting.

• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2003년도 제17회 학술대회 발표 논문집
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• pp.46-46
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• 2003

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.184-184
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• 2009

Lead-free Piezoelectric $[Li_{0.04}(Na_{0.44}K_{0.56})](Nb_{0.88}Ta_{0.1}Sb_{0.02})$ (abbreviated as NKNLTS) has been synthsized by conventional mixed oxide method traditional ceramics process without cold-isostatic pressing. Effect of $Bi_2O_3$ addition on NKNLTS ceramics was investigated. Piezoelectric properties of the ceramic were varied with the amount of $Bi_2O_3$ addition and showed the maximum Kp value at 0.4wt% $Bi_2O_3$ addition. The results show that the optimum poling condition for NKNLTS ceramics of 3.5kV/mm, poling temperature of $120^{\circ}C$ and poling time of 30min. At the sintering temperature of $1100^{\circ}C$ and the calcination temperature $800^{\circ}C$, the optimal values of density=$4.7g/cm^2$, Kp=0.44, $\varepsilon_r$=1309 were obtained. Consequently, lead free piezoelectric ceramics with the excellent piezoelectric could be fabricated using a conventional mixed oxide process and the optimal manuacturing condition of those was obtained.

• 대한화학회지
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• 제46권2호
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• pp.125-138
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• 2002

15세기 전반에 70-80년 동안 분청과 백자를 생산한 전라남도 광주시 충효동 가마터에 대하여 여러 가지 과학기술적 상황들을 조사하였다. 발굴된 위치와 퇴적층의 층위에 따라 일곱 그룹으로 나눈 분청사기의 태토와 유약 원료에 대하여 광물성분의 특징을 조사하고, 미세구조와 번조온도를 분석하여 제작 당시의 원료선택과 처리과정, 그리고 번조공정 등의 제작기술의 변화과정을 살펴보았다. 도편의 미세구조는 광학현미경과 전자현미분석장치로, 그리고 광물성분은 X-선 회절분석기와 편광현미경으로 관찰하였다. 번조온도 측정은 재번조한 후의 미세구조 변화를 관찰하는 방법을 이용하였다. CHE2그룹과 같이 왕실을 위한 최상급의 제품들도 있었지만 대중화되고 백자에 대한 선호도가 증가하면서 분청의 질이 많이 떨어진 것을 볼 수 있었다. 모두 이 지역 여러 종류의 흙을 태토와 유약원료로 사용하였으며 1100와 1225$^{\circ}C$사이에서 번조한 것으로 추정되었다.

• 한국전기전자재료학회논문지
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• 제36권5호
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• pp.433-441
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• 2023

Piezoelectric ceramics play an important role in electrical and electronic devices such as sensors, actuators, and microelectronic devices. However, traditional ceramics are difficult to be used in various process industries due to their high brittleness and low flexibility. Therefore, piezoelectric paint sensors have been designed for application to the curved surfaces of complicated structures. Furthermore, recently, significant attention has been focused on the development of paint sensors that can be used as structure health monitoring sensors for vibration, impact, and acoustic emission. Several studies have successfully demonstrated the possibility that smart paint sensors can take the place of traditional ceramic sensors. In this review, we briefly introduce the concept of the piezoelectric paint sensors and the expected application field as well as their preparation and history.

• International Journal of Human Ecology
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• 제9권1호
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• pp.29-40
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• 2008

This study clarified the classifications of Vietnamese traditional patterns and analyzed the symbolic meanings that reflect the emotional and cultural background of the Vietnamese. The type and symbolism of Vietnamese traditional patterns were analyzed through research on the history of Vietnamese costumes, the history of Vietnamese arts, the history of Vietnamese traditional culture, and a Vietnamese museum survey. The results of this study were as follows: 1. Animal patterns are diverse and include dragons, unicorns, tortoises, phoenixes, cranes, lions, bats, tigers, and buffalo patterns. 2. Dragon patterns are the most utilized pattern for practical purposes. They are often used in royal costumes, Vietnamese traditional dresses, mandarin boots, bamboo fans, silk, satin, ceramics, and other detailed decorations. 3. The patterns symbolized fortune that meant good luck and longevity so people can live long and happy. Then the symbolic meanings of patterns were followed by prosperity, nobleness, apotropism, prolificacy, and wealth. 4. Since the most of animal patterns have symbolic meanings of fortune and longevity, animal patterns can be utilized as the source of traditional patterns of design inspiration for the development of Vietnamese modern patterns and the application on Vietnamese fashion products.

• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1531-1540
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• 2002

With the invention of the inlaying technique for celadon in the latter half of the 12th century, the Koryo potters reached a new height of artistic and scientific achievement in ceramics chemical technology. Inlaid celadon shards, collected in 1991 during the surface investigation of Kangjin kilns found on the southwestern shore of South Korea, were imbedded in epoxy resin and polished for cross-section examination. Backscattered electron images were taken with an electron microprobe equipped with an energy dispersive spectrometer. The spectrometer was also used to determine the composition of micro-areas. Porcelain stone, weathered rock of quartz, mica, and feldspar composition were found to be the raw material for the body and important components in the glaze and white inlay. The close similarity between glaze and black inlay in the microstructure suggests that the glaze material was modified by adding clay with high iron content, such as biotite, for use as black inlay. The deep soft translucent quality of celadon glaze is brought about by its microstructure of bubbles, remnant and devitrified minerals, and the schlieren effect.

• 보존과학회지
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• 제27권1호
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• pp.75-90
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• 2011

분청사기는 조선초기에 고려상감청자의 무늬가 간소화 된 상태로 시작되었다. 그 후 200여 년 동안에 다양하고 활달한 문양의 민속공예로 발달하였고, 점점 백자를 닮아가는 방향으로 변해가다가, 임진왜란이후에 생산이 중단되었다. 이 논문에서는 분청의 태토와 유약에 대한 화학조성을 분석하고, 여러 도요지들의 결과들을 서로 비교하였다. 또한 다른 논문들에서 중국의 경우와 비교 관찰된 고려청자와 조선백자들에 대한 결과들과 비교 하였다. 생산도요지와 고고학적인 특성에 의하여 28 그룹으로 나누었으며, 각 각의 그룹에서 셋에서 다섯편의 도편을 분석하고, 그들의 평균값을 비교자료로 사용하였다. 분청태토는 한국청자와 백자와 같이 중국 남쪽의 월주요, 경덕진요에서 사용된 운모-석영계의 도석으로 만들어졌다. 유약은 점토질의 원료에 나무재, 태운 석회석과 곱게 빻은 석회가루를 다양한 비율로 혼합되었다. 분청유약의 특성은 조선백자보다는 고려청자와 고려백자에 더 가깝다. 다만 티타늄산화물의 함량은 조선백자와 같이 낮은데, 그 이유는 글래이즈 스톤으로 알려진 도석계의 점토가 분청유약을 제조 하는데 혼합 되었기 때문으로 추정된다. 이 연구의 체계적인 비교방법과 물질적 특성에 대한 내용들은 현재 빠른 속도로 발굴되고 있는 도요지들에 대해서 적용될 수 있을 것이다.