• Restorative Dentistry and Endodontics
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• 제28권3호
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• pp.209-221
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• 2003

The objectiveness of this study was to evaluate whether low-viscosity composite can bond effectively to dentin surface without bonding resin. The low-viscosity composites being 50wt% filler content were made by the inclusion of bonding resin of two self-etching systems(Cleafil SE Bond, Unifil Bond) varied with contents as 0, 10, 20, 30, 40, 50wt%. Exposed dentin surfaces of extracted 3rd molars are used. Dentin bond strengths were measured. The tests were carried out with a micro-shear device placed testing machine at a CHS of 1mm/min after a low-viscosity composite was filled into an iris cut from micro tygon tubing with internal diameter approximately 0.8mm and height of 1.0mm. 1 Flexural strength and modulus was increased with the addition of bonding resin. 2. Micro-shear bond strength to dentin was improved according to content of bonding resin irrespective of applying or not bonding resin in bonding procedure, and that of Clearfil SE Bond groups was higher than Unifil Bond. 3. There were no significant difference whether use of each bonding resin in bonding procedure for S-40, S-50, U-50(p＞0.05). 4. In SEM examination, resin was well infiltrated into dentin after primed with self-etching primer only for S-50 and U-50 in spite of the formation of thinner hybrid layer. Low viscosity composite including some functional monomer may be used as dentin bonding resin without an intermediary bonding agent. It makes a simplified bonding procedure and foresees the possibility of self-adhesive restorative material.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 추계학술발표회
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• pp.25-25
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• 1997

• Restorative Dentistry and Endodontics
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• 제47권2호
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• pp.21.1-21.11
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• 2022

Objectives: This study aimed to investigate the bonding effects of cleaning protocols on dentin impregnated with endodontic sealer residues using ethanol (E) or xylol (X). The effects of dentin acid etching immediately (I) or 7 days (P) after cleaning were also evaluated. For bonding to dentin, universal adhesive (Scotchbond Universal; 3M ESPE) was used. The persistence of sealer residues, hybrid layer formation and microshear bond strength were the performed analysis. Materials and Methods: One hundred and twenty bovine dentin specimens were allocated into 4 groups (n = 10): G1 (E+I); G2 (X+I); G3 (E+P); and G4 (X+P). The persistence of sealer residues was evaluated by SEM. Confocal laser scanning microscopy images were taken to measure the formed hybrid layer using the Image J program. For microshear bond strength, 4 resin composite cylinders were placed over the dentin after the cleaning protocols. ANOVA followed by Tukey test and Kruskal-Wallis followed by Dunn test were used for parametric and non-parametric data, respectively (α = 5%). Results: G2 and G4 groups showed a lower persistence of residues (p < 0.05) and thicker hybrid layer than the other groups (p < 0.05). No bond strength differences among all groups were observed (p > 0.05). Conclusions: Dentin cleaning using xylol, regardless of the time-point of acid etching, provided lower persistence of residues over the surface and thicker hybrid layer. However, the bond strength of the universal adhesive system in etch-and-rinse strategy was not influenced by the cleaning protocols or time-point of acid etching.

• 한국도로학회논문집
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• 제7권4호
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• pp.9-20
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• 2005

본 연구는 아스팔트 덧씌우기 포장에 나타나는 반사균열을 제어하기 위하여 노후된 시멘트 콘크리트 포장과 아스팔트 덧씌우기 포장 경계면에 보강재의 효과적인 부착 방법을 찾기 위하여 수행하였다. 이를 위한 부착재로는 RSC-4 유화아스팔트, 컴파운드, 불포화 폴리에스터 수지 (UPR) 등 3종류를 사용하였다. 또한 아스팔트 혼합물은 3종류의 밀입도 혼합물(AC 60-80, RLDPE 8%, PG 76-22)을 사용하였다. 보강 재료로서 유리섬유 그리드 하부에 직포가 부착된 것을 사용하였다. 복합모드 파괴(mode II)의 모사를 위한 촉진시험은 휠트랙킹 장비를 이용하여 수행하였다. 반사균열의 진전은 피로수명으로서 하중 사이클 수에 따라 측정하였고, 공시체의 변위는 각각 시험 공시체에 대하여 demec 게이지를 이용하여 측정하였다. 본 연구 결과, UPR 부착이 가장 효과적이었으며 다음은 RSC-4의 순이었다. 그러나 현장 적용성을 고려할 때 , RSC-4 유제가 보강 재료의 부착을 위해 적절한 선택으로 판단된다.

• 센서학회지
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• 제12권6호
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• pp.265-272
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• 2003

본 논문은 파이렉스 #7740 유리 박막을 이용한 MEMS용 MLCA (Multi Layer Ceramic Actuator)와 Si기판의 양극접합 특성에 관한 것이다. 최적의 RF 마그네트론 스피터링 조건 (Ar 100%, input power $1\;W/cm^2$)하에서 MLCA기판위에 파이렉스 #7740 유리의 특성을 갖는 박막을 증착하였다. $450^{\circ}C$에서 1시간 열처리한 다음, -760 mmHg, 600V 그리고 $400^{\circ}C$에서 1시간동안 양극접합했다. 그 다음에 Si 다이어프램을 제조한 후, MLCA/Si 접합계면과 MLCA 구동을 통한 Si 다이어프램 변위특성을 분석 및 평가하였다. 다이어프램 형상에 따라 정밀한 변위 세어가 가능했으며 0.05-0.08 %FS의 우수한 선형성을 나타내었다. 또한, 측정동안 접합계면 균열이나 계면분리가 일어나지 않았다. 따라서, MLCA/Si기판 양각접합기술은 고성능 압전 MEMS 소자 제작공정에 유용하게 사용가능할 것이다.

• 대한치과기공학회지
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• 제23권1호
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• pp.31-43
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• 2001

This study was performed to observe the micro-structure change of surface, behavior of oxide change of element, the component transformation of the alloy and the bonding strength between the porcelain interface in order to investigate effects of indium, tin on interfacial properties of porcelain fused to low gold alloy. Hardness of castings was measured with a micro-Vicker's hardness tester. The compositional change of the surface of heat-treated specimen was analyzed with an EDS and an EPMA. The interfacial shear bonding strength between alloy specimen and fused porcelain was measured with a mechanical testing system(MTS 858.20). The results were as follows: 1) The hardness value of alloy increased as increasing amount of indium addition. 2) The formation of oxidation increased as increasing indium and tin contents after heat treatment. 3) Diffusion of indium and tin elements increased as increasing indium and tin contents in metal-porcelain surface after porcelain fused to metal firing. 4) The most interfacial shear bonding strength was increased as increasing a composition of adding elements, and a heat-treatment time, and an oxygen partial pressure. From the results of this study it was found that the addition of alloying elements such as indium and tin increase hardness of as-cast alloy, produce surface oxide layer of adding elements by heat-treatment which may improve interfacial bonding strength between alloy and porcelain.

• 마이크로전자및패키징학회지
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• 제26권4호
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• pp.133-140
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• 2019

열 사이클 조건이 전해 Cr/Ni-P 이중도금 시편의 접합강도 및 균열성장거동에 미치는 영향을 분석하였다. 전해 Ni-P 도금층을 열처리를 통해 결정화 시킨 후 전해 Cr 도금 후 한번 더 열처리한 결과, Cr/Ni-P 계면에서 상호확산으로 인해 Cr-Ni 고용체 band layer가 관찰되었다. 열 사이클 전 접합강도는 25.6 MPa이였으나, 1,000사이클 후 Cr 도금층의 균열 밀도 및 표면 거칠기 증가로 인해 도금층과 접착제 사이의 기계적 고착효과가 향상되어 접착제와 Cr 도금층 사이에서 박리되었고, 접합강도는 47.6 MPa로 점차적으로 증가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.874-877
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• 2001

SOI(Silicon-On-Insulator) technology is proposed as an alternative to bulk silicon for MEMS(Micro Electro Mechanical System) manufacturing. In this paper, we fabricated the SOI wafer with uniform active layer thickness by silicon direct bonding and mechanical polishing processes. Specially-designed electrostatic bonding system is introduced which is available for vacuum packaging and silicon-glass wafer bonding for SOG(Silicon On Glass) wafer. We demonstrated thermopile sensor and RF resonator using the SOI wafer, which has the merits of simple process and uniform membrane fabrication.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.87-93
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• 1997

The bonding strength evaluation of light weight materials for electrical vehicle applications has been performed through single lap joint tests in which the design parameters such as fillet, joint style, adherend, bonding overlap length,bonding thickness, and environmental condition(soaking time in $25^{\circ}C$ water) are considered. It is experimentally oberved that lap shear strength of joint increases for higher fillet height, longer overlap length, and thinner bonding layer thickness. Al-Al adherend combination shows much higher lap shear strength than AL-FRP and FRP-FRP adherend combinations. Riveting at adhesive bonded joint of AL-AL adherend combination makes lap shear strength decrease. Effect of soaking time on lap shear strength is negligible.

• 한국표면공학회지
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• 제48권6호
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• pp.260-268
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• 2015

The thermal barrier coating (TBC) for inner wall of liquid-fuel rocket combustor consists of NiCrAlY as bonding layer and $ZrO_2$ as a top layer. In most case, the plasma spray coating is used for TBC process and this process has inherent possibility of cracking due to large difference in thermal expansion coefficients among bonding layer, top layer and metal substrate. In this paper, we suggest crack-free TBC process by using a precise electrodeposition technique. Electrodeposited Ni-P/Cr double layer has similar thermal expansion coefficient to the Cu alloy substrate resulting in superior thermal barrier performance and high temperature oxidation resistance. We studied the effects of phosphorous concentrations (2.12 wt%, 6.97 wt%, and 10.53 wt%) on the annealing behavior ($750^{\circ}C$) of Ni-P samples and Cr double layered electrodeposits. Annealing temperature was simulated by combustion test condition. Also, we conducted SEM/EDS and XRD analysis for Ni-P/Cr samples. The results showed that the band layers between Ni-P and Cr are Ni and Cr, and has no formed with heat treatment. These band layers were solid solution of Cr and Ni which is formed by interdiffusion of both alloy elements. In addition, the P was not found in it. The thickness of band layer was increased with increasing annealing time. We expected that the band layer can improve the adhesion between Cr and Ni-P.