• 한국결정성장학회지
• /
• 제29권6호
• /
• pp.372-378
• /
• 2019

산화구리를 함유하는 전통 세라믹 유약은 황색포도상구균과 대장균에 대해 항균활성을 나타낸다. 환원 분위기에 소결한 모든 시편들은 황색포도상구균과 대장균에 대해 항균활성을 나타내나 산화분위기에서 소결한 일부 시편들만 황색포도상구균과 대장균에 대해 항균활성을 나타내었다. 산화구리를 함유하는 전통 세라믹 유약의 항균기작을 설명하기 위해 유약의 결정상, 미세구조, 이온용출, 표면 제타전위 분석을 실시하였다. 환원 분위기에서 소결한 시편들은 유약층에 Cu 입자들이 형성되는 것을 확인할 수 있다. Cu 용출량은 전체적으로 0.05 ppm 이하이며 가장 많이 용출되는 이온은 Ca 이었다. 산화구리를 3 wt.% 이상 첨가한 모든 시편들은 높은 음극의 표면 제타전위를 나타내었다. 세라믹 유약의 항균활성은 일반적으로 용출되는 양이온들과 연관되어 보이나 산화분위기에서 소결한 시편들의 대장균에 대한 항균활성은 직접적인 연관성이 나타나지 않는다. 세라믹 유약 시편의 표면 제타전위가 이온용출과 더불어 대장균에 대한 항균활성에 보조적 기여를 하는 것으로 보인다.

• 보존과학회지
• /
• 제36권4호
• /
• pp.275-283
• /
• 2020

Iron oxides are the essential coloring oxides in traditional ceramic glazes. However, when Fe is involved in the coloration in the form of ions or colloids in glazes with low Fe content, it is difficult to identify the iron oxide phases. Generally, in many these glazes, Ca-rich minerals are observed by X-ray diffraction (XRD) or microscopic images, owing to their devitrification by the high Ca content. This study attempts to elucidate the correlation between the crystalline structure and coloration in the glazes while mainly focusing on neoformed Ca-rich minerals and Fe content. An experimental firing was carried out to produce tree ash glazes, with pine tree ash and Buyeo feldspar. In the case of oxidation glazes, the scanning electron microscopy (SEM) images and XRD patterns did not exhibit any Ca-rich crystals, and all the visible light reflectance spectra lines exhibited a similar shape. In contrast, the reduction glazes divided into blue glazes and other colored glazes according to the shapes of their reflectance spectra. It was confirmed that the influence of Ca-rich minerals on the glaze color was more pronounced than the blue color of the reduction glazes when the Ca and feldspar contents were sufficiently high and low, respectively, to form wollastonite. As the Ca content increased and the elemental composition of the reduction glazes changed, the neoformation of the Ca-rich minerals, such as wollastonite, anorthite, diopside, and akermanite was sequentially observed.

• 한국세라믹학회지
• /
• 제13권3호
• /
• pp.3-12
• /
• 1976

The corelation between surface tensions and surface appearances of SK O5a opaque glazes for earthen wares were investigated. The surface tension values were theoretically calculated by using Dietzel's factors of constituent oxides of glaze. The surface appearances of glazes, especially the pinhole phenomena were strongly effected by the surface tension values showing the following general tendencies: (1) In the range of 305±3 dynes/cm of surface tensions, glazes showed almost no pjnholes. (2) In the range of surface tensions less than 300 dynes/cm, the large numbers of small pinholes or eggshell textures were observed. (3) In the range of surface tensions higher than 310 dynes/cm, large and deep pinholes were observed. (4) The contact angles of glazes on the wall tile body substrate are in the good proportional agreement with the surface tension values calculated by Dietzel's factors.

• 한국세라믹학회지
• /
• 제52권3호
• /
• pp.186-191
• /
• 2015

Tribological properties of whiteware with various transparent glazes, which have different composition and microstructure, were investigated. The wear resistance and friction behavior of the glazed whiteware are a very important aspect if the whiteware is used as tableware and for sanitation purposes. Generally, the wear property is influenced by the microstructure and surface morphology of the material. The whiteware specimens with two kinds of transparent glazes were fabricated by using the commercially available porcelain body. Furthermore, the commercial tableware, such as bone china, and traditional tableware were also examined as reference materials. All of the specimens showed that different pore structures might affect the mechanical and tribological properties. It seems that the wear resistance of whiteware is substantially related to the pore size and distribution of glaze rather than the hardness value of the specimen.

• 한국세라믹학회지
• /
• 제52권3호
• /
• pp.197-203
• /
• 2015

The colorization of $Zn_2SiO_4$ crystal glazes was investigated by adding nucleating seeds with various coloring agents. The addition of color fixing agents such as $Fe_2O_3$, $MnO_2$, and NiO with seeds caused changes in the colors of glazes. The crystallinity and crystal size were dependent on glaze composition and firing schedules. By controlling coloring agents and firing schedules, it was possible to create various colors and sizes of crystals in a zinc-based crystalline glaze.

• 한국재료학회지
• /
• 제9권2호
• /
• pp.181-187
• /
• 1999

In this study, the effect of residual stress on mechanical strength was investigated with 1 kind of whiteware body and 4 kinds of glazes which are produced in succeeding ceramic art place. Using dipping method, the body was coated for different times in order to manipulate the coating thickness and sintered in the different temperatures ($1200^{\circ}C$, $1250^{\circ}C$, $1300^{\circ}C$, $1350^{\circ}C$) for two thus hours. The sintered bodies were characterized by XRD, EPMA, FEM and UTM in order to study the forming of reaction layer between body and glazes, residual stresses and the effects of residual stresses on mechanical strength of pottery. At $1300{\circ}C$, we obtained maximum density and mechanical strength. By the finite element method, the residual stresses in surface of body were minimum in specific thickness of glazes and the mechanical strength of body in that thickness of glazes showed maximum when the firing temperature was settled.

• 한국세라믹학회지
• /
• 제17권4호
• /
• pp.213-216
• /
• 1980

A glass-ceramics material of composition %SiO_2$: 38.50, $Al_2O_3$: 26.00, $Na_2O$: 18.00, CaO: 6.00, MgO: 4.00, $TiO_2$: 7.50 was strengthened by coating a series of glazes$(SiO_2-B_2O_3-Al_2O_3-CaO-PbO-Na_2O-)$, which has lower thermal expansion coefficient than that of the glass-ceramics. The thermal expansion coefficient of the glazes ranges $80~90{\times}10^{-7}$cm/cm/$^{\circ}C$, whereas that of the glass-ceramics is $115{\times}10^{-7}$cm/cm/$^{\circ}C$. The glass-ceramics was identified to be composed of nepheline, carnegieite low form, and meta sodium silicate crystal by X-ray diffraction phase analysis. The glaze, having lower melting point and appropriate thermal expansion coefficient, was tried to be stable and good at secondary heat treatment.

• 한국결정성장학회지
• /
• 제21권2호
• /
• pp.87-91
• /
• 2011

본 연구에서는 우리나라의 도자기 제조업체가 밀집되어 있는 경기도 이천, 여주 지역에서 발생되는 백자, 청자, 본차이나 폐도자기를 도자기 유약용 원료로서 재활용하여 도자기 제조에 적합한 도자기 유약를 개발해 보고자 한다. 연구결과, 폐백자분에는 규석이 많이 함유되어 있어서 규석을 사용하지 않고서도 맑고 투명한 백자 유약을 만들 수 있다. 또한 폐청자분에는 $Fe_2O_3$이 많이 함유되어 있어서 청자유약제조에 적합하였다. 폐본차이나분에는 $P_2O_5$이 많이 함유되어 있어서 부드러운 느낌의 유백유약제조에 적합하였다. 이와같이 폐도자기를 사용하여 도자기 유약를 제조함에 의해 매립에 의해 발생되는 환경 문제를 해결함과 동시에 자원의 재활용, 특히 일부 수입되고 있는 도자기 원료의 대체원료로서의 활용도 기대되어 경제적 효과도 얻을 수 있을 것으로 판단된다.

• 대한안전경영과학회지
• /
• 제9권6호
• /
• pp.197-204
• /
• 2007

Ceramic pigments were developed by using 4 kinds of Brass scraps. Each Brass scraps were mixed with same weight-ratio of Husk ash, and fine-ground by Rotate ring mill(RRG-120, Armstech industrial. co. Ltd, Korea) after firing at $900^{\circ}C$, $1000^{\circ}C$ and $1100^{\circ}C$. As a result, analysis of particle size of synthetic pigments by particle size analyser, they are $3{\mu}m$ as average. The resulting pigments were characterized by using XRD, FT-IR, SEM Structure of the crystals are Zn2SiO4,, and ZnO, Cu2O, CuO, and cristobalite are existed and particles' shape are plate or needle. As a result of analysis of chemical composition by XRF, synthetic pigments have high SiO2 and CuO content and have SnO2, ZnO and NiO, too. 1wt%, 3wt% and 5wt% pigments were added in each lime glaze, lime-barium glaze and lime-magnesia glaze, and fired at oxidation and reducing atmosphere to figure hue in glazes out. As a result of analysis of color, chroma and brightness by UV, colors of glazes fired at oxidation atmosphere turned into green from sky blue, and colors of glazes fired at reducing atmosphere turned into pink and red.

• 한국결정성장학회지
• /
• 제31권6호
• /
• pp.240-246
• /
• 2021

도자 생산현장에서 아연결정유약을 제조하여 사용할 때 조성원료에 따라 유약의 결정생성이 불안정하고, 특히 결정이 잘 생성되는 유약도 습식제조 후 시간이 경과하면 결정생성이 급격히 저하되는 문제점이 있다. 도예가들이 주로 사용하는 산화아연(ZnO)과 하소아연(calcined ZnO), 프리트 3110, 그리고 규석을 출발 물질로 3성분계 실험을 통하여 아연결정 조성을 선택하고 선 연구된 소성 조건을 사용하였다. 유약을 제조하고 1일~24주까지 습식으로 보관하면서 침수 과정에서 아연이 아연결정유의 결정생성에 미치는 영향을 규명하고자 하였다. 원료 입도 및 침수 영향을 측정하기 위해 입도분석, XRD, Raman Spectroscopy 그리고 SEM 분석 등을 하였다. 연구결과, 산화아연은 습식으로 유약 사용 시 willemite 결정 생성 및 성장이 우수하지만 유약을 보관하는 동안 ZnO가 물과 반응하여 Zn(OH)2를 생성하고 응집되면서 유약내 ZnO량이 감소되어 willemite 생성을 저해하여 결정이 감소됨을 확인하였다.