• 제목/요약/키워드: Ceramic Surface

검색결과 2,386건 처리시간 0.024초

Plasma Resistance and Etch Mechanism of High Purity SiC under Fluorocarbon Plasma

  • Jang, Mi-Ran;Paek, Yeong-Kyeun;Lee, Sung-Min
    • 한국세라믹학회지
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    • 제49권4호
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    • pp.328-332
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    • 2012
  • Etch rates of Si and high purity SiC have been compared for various fluorocarbon plasmas. The relative plasma resistance of SiC, which is defined as the etch rate ratio of Si to SiC, varied between 1.4 and 4.1, showing generally higher plasma resistance of SiC. High resolution X-ray photoelectron analysis revealed that etched SiC has a surface carbon content higher than that of etched Si, resulting in a thicker fluorocarbon polymer layer on the SiC surface. The plasma resistance of SiC was correlated with this thick fluorocarbon polymer layer, which reduced the reaction probability of fluorine-containing species in the plasma with silicon from the SiC substrate. The remnant carbon after the removal of Si as volatile etch products augments the surface carbon, and seems to be the origin of the higher plasma resistance of SiC.

Silicate계 콘크리트 함침제 도포에 따른 부착특성 및 공극변화 (Adhesion Characteristic and Porosity Change of Alkali Silicate Impregnant of Concrete)

  • 송훈;추용식;이종규;임영철
    • 한국세라믹학회지
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    • 제47권4호
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    • pp.276-282
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    • 2010
  • There are the impregnating layer formation by surface protective materials or impregnants and the adhesion method by polymer, FRP sheet or steel plate in the surface protective method of concrete structure. The surface impregnation method by impregnants improves the durability of concrete structure by modifying the structure of the concrete surface and also have a merit that can be shortly applied in place without the decrease of concrete surface appearance and is easily applied again. This study is interested in manufacturing the concrete surface impregnants including lithium and potassium silicate for the repair of the exposed concrete and the color concrete requiring the advanced function in view of the concrete appearance. The durability and porosity properties was tested for the review of application. The result of this study show that the effective content of silicate ranges 5 to 20% and the separate application of the first impregnant and the second impregnant is effective for the optimum performance. The adhesion in tension is slightly increased but the reinforcement of concrete substrate is slight. So, the concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.

EFFECT OF GLASS-COATED Al PASTE ON BACK-SURFACE FIELD FORMATION IN Si SOLAR CELLS

  • HYEONDEOK JEONG;SUNG-SOO RYU
    • Archives of Metallurgy and Materials
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    • 제65권3호
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    • pp.989-992
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    • 2020
  • In this study, glass frit was coated uniformly on the surface of Al particles instead of adding glass frit to Al powder by simple mixing to form a nano-layer. The influence of the glass-frit coating on the formation of the back-surface field and electrical characteristics of the resulting Al electrode were investigated. Microstructural observations indicated that the glass components were uniformly distributed and the back-surface field layer thickness was more uniform compared to the simply mixed sample. In addition, the sheet resistance was <10 mΩ/□, much lower than the 23 mΩ/□ of the simply mixed Al electrode.

The effect of zirconia surface architecturing technique on the zirconia/veneer interfacial bond strength

  • Her, Soo-Bok;Kim, Kyoung Hun;Park, Sang Eun;Park, Eun-Jin
    • The Journal of Advanced Prosthodontics
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    • 제10권4호
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    • pp.259-264
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    • 2018
  • PURPOSE. The purpose of this study was to evaluate the effect of the zirconia surface architecturing technique (ZSAT) on the bond strength between veneering porcelain and zirconia ceramic. MATERIALS AND METHODS. 20 sintered zirconia ceramic specimens were used to determine the optimal surface treatment time, and were randomly divided into 4 groups based on treatment times of 0, 1, 2, and 3 hours. After etching with a special solution, the surface was observed under scanning electron microscope, and then the porcelain was veneered for scratch testing. Sixty 3 mol% yttria-stabilized tetragonal zirconia polycrystal ceramic blocks were used for tensile strength testing; 30 of these blocks were surface treated and the rest were not. Statistical analysis was performed using ANOVA, the Tukey post-hoc test, and independent t-test, and the level of significance was set at ${\alpha}=.05$. RESULTS. The surface treatment of the zirconia using ZSAT increased the surface roughness, and tensile strength test results showed that the ZSAT group significantly increased the bond strength between zirconia and veneering porcelain compared to the untreated group (36 MPa vs. 30 MPa). Optimal etching time was determined to be 2 hours based on the scratch test results. CONCLUSION. ZSAT increases the surface roughness of zirconia, and this might contribute to the increased interfacial bond strength between zirconia and veneering porcelain.

The effect of silane applied to glass ceramics on surface structure and bonding strength at different temperatures

  • Yavuz, Tevfik;Eraslan, Oguz
    • The Journal of Advanced Prosthodontics
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    • 제8권2호
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    • pp.75-84
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    • 2016
  • PURPOSE. To evaluate the effect of various surface treatments on the surface structure and shear bond strength (SBS) of different ceramics. MATERIALS AND METHODS. 288 specimens (lithium-disilicate, leucite-reinforced, and glass infiltrated zirconia) were first divided into two groups according to the resin cement used, and were later divided into four groups according to the given surface treatments: G1 (hydrofluoric acid (HF)+silane), G2 (silane alone-no heat-treatment), G3 (silane alone-then dried with $60^{\circ}C$ heat-treatment), and G4 (silane alonethen dried with $100^{\circ}C$ heat-treatment). Two different adhesive luting systems were applied onto the ceramic discs in all groups. SBS (in MPa) was calculated from the failure load per bonded area (in $N/mm^2$). Subsequently, one specimen from each group was prepared for SEM evaluation of the separated-resin-ceramic interface. RESULTS. SBS values of G1 were significantly higher than those of the other groups in the lithium disilicate ceramic and leucite reinforced ceramic, and the SBS values of G4 and G1 were significantly higher than those of G2 and G3 in glass infiltrated zirconia. The three-way ANOVA revealed that the SBS values were significantly affected by the type of resin cement (P<.001). FIN ceramics had the highest rate of cohesive failure on the ceramic surfaces than other ceramic groups. AFM images showed that the surface treatment groups exhibited similar topographies, except the group treated with HF. CONCLUSION. The heat treatment was not sufficient to achieve high SBS values as compared with HF acid etching. The surface topography of ceramics was affected by surface treatments.

IPS-Empress 도재에 대한 콤포짓트 레진의 전단결합강도 (EFFECTS OF SURFACE TREATMENT AND BONDING AGENTS ON SHEAR BOND STRENGTH OF THE COMPOSITE RESION TO IPS-EMPRESS CERAMIC)

  • 윤병식;임미경;이용근
    • Restorative Dentistry and Endodontics
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    • 제23권1호
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    • pp.413-423
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    • 1998
  • Dental ceramics exhibit excellent esthetic property, compressive strength, chemical durability, biocompatibility and translucency. This study evaluated the shear bond strength of composite resin to the new heat-pressed ceramic material (IPS-Empress System) depending on the surface treatments and bonding agents. The surface treatments were etching with 4.0% hydrofluoric acid, application of silane, and the combination of the two methods. Composite resin was bonded to ceramic with four kinds of dentin bonding agents(All-Bond 2, Heliobond, Scotch bond Multi-purpose and Tenure bonding agents). The ceramic specimen bonded with composite resin was mounted in the testing jig, and the universal testing machine(Zwick 020, Germany) was used to measure the shear bond strength with the cross head speed of 0.5 mm/min. The results obtained were as follows 1. The mean shear bond strength of the specimens of which the ceramic surface was treated with the combination of hydrofluoric acid and silane before bonding composite resin was significantly higher than those of the other surface treatment groups(p<0.05). 2. In the case of All-Bond 2 and Scotchbond Multi-purpose bonding agent group, the surface treatment methods did not influenced significantly on the shear bond(p>0.05). 3. Of the four bonding agents tested, the shear bond strength of Heliobond was significantly lower than those of other bonding agents regardless of the surface treatment methods(p<0.05). 4. The highest shear bond strength($12.55{\pm}1.92$ MPa) was obtained with Scotchbond Multipurpose preceded by the ceramic surface treatment with the combination of 4% hydrofluoric acid and silane.

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다공성 원료를 사용한 석고보드의 흡습 특성 (Hygroscopic Characteristic of Gypsum Boards Using Porous Materials)

  • 정의종;이종규;정덕수;추용식;송훈
    • 한국재료학회지
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    • 제19권10호
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    • pp.538-543
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    • 2009
  • Active clays, Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic gypsum boards. Pohang active clay and Cheolwon diatomite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Moisture adsorption content of gypsum board with 10% active clay(P1) was 62.0 g/m$^2$, and moisture desorption content was 50.2 g/m$^2$. Moisture adsorption content of gypsum board with 10% diatomite(P) was 59.5 g/m$^2$, and moisture desorption content was 49.0 g/m$^2$. Moisture adsorption contents of gypsum boards with porous materials were higher than that moisture desorption contents of gypsum board without porous materials. Correlation coefficient between surface area and moisture adsorption content of gypsum boards was 0.98. Also, correlation coefficient between surface area and moisture desorption content of gypsum boards was 0.97. Moisture adsorption and desorption contents were influenced by surface area and pore volume of the gypsum boards, and surface area had a larger effect on moisture adsorption and desorption.

Surface treatment, liquid, and aging effects on color and surface properties of monolithic ceramics

  • Sertac Sariyer;Meryem Gulce Subasi
    • The Journal of Advanced Prosthodontics
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    • 제16권3호
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    • pp.174-188
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    • 2024
  • PURPOSE. The purpose of this study was to investigate the effects of surface treatments, liquids, and aging on color, translucency, and surface properties of monolithic ceramics. MATERIALS AND METHODS. Lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) ceramics (n = 135 each) were cut and divided into three groups [crystallization+glaze (single stage), crystallization-glaze (two stages), and crystallization-polish (two stages)]. One sample from each group was examined using scanning electron microscopy (SEM). Remaining samples were divided into four subgroups (distilled water, coffee, grape juice, and smoothie) (n = 11 each), stored for 12 d in the respective liquids, and thermally aged. One sample from each subgroup was analyzed using SEM. The color, gloss, and roughness values of the samples were analyzed after surface treatment (initial) and storage under different liquids+aging conditions. The initial data and both the aged data and data change values were analyzed using robust two- and three-way analyses of variance. RESULTS. The glazed groups exhibited smoother surfaces. Ceramic type and ceramic-surface treatment interactions affected the initial translucency parameter (TP) (P < .001) and the initial and aged roughness values (P ≤ .001). Surface treatment type affected the color change (P < .001), and ceramic type affected the aged TP values (P < .001). Type of ceramic, surface treatment, and their interactions affected both the initial and aged gloss (P ≤ .001) and TP change values (P ≤ .015). Surface treatment type and ceramic-surface treatment interactions affected the gloss change values (P ≤ .001). CONCLUSION. Although both ceramics and all surface treatments are clinically applicable, crystallization-glaze is recommended. When gloss and smoothness are important or when translucency is important, ZLS or LDS may be preferred, respectively.

Asperities on the Surface of Plate-like Alumina and their Effect on Nacre-inspired Alumina-PMMA Composites

  • Kim, Bo-Yeon;Lee, Yoonjoo;Kim, Soo-Ryong;Shin, Dong-Geun;Kwon, Woo-Teck;Choi, Duck-Kyun;Kim, Younghee
    • 한국세라믹학회지
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    • 제52권4호
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    • pp.248-252
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    • 2015
  • Natural materials often have unique mechanical properties, such as the hierarchical structure of nacre formed through mineral bridges or asperities created between an inorganic particle and a natural-layer surface. As these asperities produce an exceptional shear resistance, in this study, we aimed to emulate the natural structure of nacre by synthesizing inorganic asperities and mineral bridges with different temperatures in the range of $1100-1300^{\circ}C$ and clay contents from 10 - 50 wt%. Following the infiltration of methyl methacrylate, we measured the mechanical properties to assess whether they were improved by the asperities. It was confirmed that the asperities improved the bending strength by 10%, and the anchoring effect was observed on the fracture surface.

Sintering Behavior of Ag-Ni Electrode Powder with Core-shell Structure

  • Kim, Kyung Ho;Koo, Jun-Mo;Ryu, Sung-Soo;Yoon, Sang Hun;Han, Yoon Soo
    • 한국표면공학회지
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    • 제49권6호
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    • pp.507-512
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    • 2016
  • Expensive silver powder is used to form electrodes in most IT equipment, and recently, many attempts have been made to lower manufacturing costs by developing powders with Ag-Ni or Ag-Cu core-shell structures. This study examined the sintering behavior of Ag-Ni electrode powder with a core-shell structure for silicon solar cell with high energy efficiency. The electrode powder was found to have a surface similar to pure Ag powder, and cross-sectional analysis revealed that Ag was uniformly coated on Ni powder. Each electrode was formed by sintering in the range of $500^{\circ}C$ to $800^{\circ}C$, and the specimen sintered at $600^{\circ}C$ had the lowest sheet resistance of $5.5m{\Omega}/{\Box}$, which is about two times greater than that of pure Ag. The microstructures of electrodes formed at varying sintering temperatures were examined to determine why sheet resistance showed a minimum value at $600^{\circ}C$. The electrode formed at $600^{\circ}C$ had the best Ag connectivity, and thus provided a better path for the flow of electrons.