활성환경에서 세라믹 수복 재료의 파괴 거동

배태성,윤선중,배태성,이민호 대한치과재료학회 2022 대한치과재료학회지 Vol.49 No.3

금속 재료와 세라믹 재료에 인장응력이 작용할 때의 파괴 거동을 비교해보면, 금속 재료는 소성변형으로 인하여 외부의 형상이 변화된 후 파절이 일어나고 또한 재료 내의 결함에서 비롯한 균열의 진전속도가 매우 느리므로 미세 결함은 파절 거동에 크게 영향을 미치지 않는다. 반면 세라믹 재료는 취성이 있고 거의 소성변형이 일어나지 않으므로 재료 내의 가장 취약한 결함부의 균열선단에서 응력의 집중과 확대가 일어나고 이 확대된 응력이 파괴 한계를 초과하면 균열이 빠르게 진전하여 파괴가 일어나므로 미세 결함이 파괴에 크게 영향을 미친다. 따라서 세라믹 소결체(포세린, 글라스-세라믹, 알루미나, 지르코니아)의 파괴 특성 평가 시는 결함의 영향을 고려하는 파괴인성의 측정이 요구된다. 세라믹 소결체는 내수성이 뛰어나고 산이나 알카리에 의해서도 침식이 일어나지 어렵기 때문에 이들 환경에 장시간 노출된 경우에도 강도는 그다지 크게 저하되지 않는다. 하지만, 이러한 액상의 조건에서 인장응력이 작용하는 활성환경에서 는 응력부식에 의한 침식이 일어나므로 시간이 경과하며 강도가 저하하여 기대수명이 단축되는 문제가 발생한다. 활성환경에서 응력부식에 의한 균열성장이 일어나는 경우에 강도에 비하여 작용력의 수준이 낮은 경우에는 응력부식에 의한 균열성장이 느리므로 문제가 되지 않지만, 반대로 강도에 비하여 작용력의 수준이 높은 경우에는 균열속도가 빨라서 내구수명이 크게 저하될 수 있으므로 강도가 높은 수복재료의 사용이 요구된다.

유리의 조성에서 MgO, Li_2O의 함량변화가 유리침투 알루미나 세라믹 재료의 강도와 색조의 변화에 미치는 영향

배태성,원대희,원상용,윤여은 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.3

This study was performed to investigate the effect of composition changes in glasses on the strength and shade of glass-infiltrated alumina ceramics. Six different borosilicate glasses containing MgO, Li₂O and ZrO₂ in the glass composition were prepared, porous alumina compacts were prepared by slip casting and sintered at 1100℃ for 2 hours. Dense composites were made by infiltration of molten glass into partially sintered alumina at 1110℃ for 6 hours. Specimens were polished sequentially form #800 to #2000 diamond wheel, and the final surface finishing on the tensile side was received an additional polishing sequence through 0.3 ㎛ diamond paste. To evaluate the effect of composition change in glass on the shade changes of glass-infiltrated alumina core ceramics, the color was measured by the CIE L^*, a^*, b^* color scale relative to standard source C. The biaxial flexure strength was measured using the ball-on-three-ball method at a crosshead speed if 0.5mm/min. The color change of composites infiltrated with experimental glasses to In-Ceram Glass AL1 showed that L^* values increased but a^* and b^* values decreased with addition of MgO, Li₂O and ZrO₂ in the glass composition. Maximum color difference of experimental glass-infiltrated alumina core ceramics was obtained in the Group B containing 2.4 mol% MgO in the glass composition. The maximum biaxial flexure strength values 47.41 MPa was obtained in the Group E containing 0.3 mol% Li₂O in the glass composition. The observation of fracture surfaces indicated the microstructurally rough surface with a tendency of toughening by crack deflection and crack bridging.

지르코니아 세라믹의 물성에 미치는 표면특성과 치과 응용

배태성 한국표면공학회 2013 한국표면공학회 학술발표회 초록집 Vol.2013 No.5

시효와 Thermocycling 처리한 치관전장용 복합레진의 마모특성 평가

배태성,강정길,송광엽 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.5

同一한 衝擊에너지 條件下의 CFRP 斜交積層板의 衝擊損傷과 配向角의 關係

배태성,양동율,笠野英秋 대한기계학회 1992 대한기계학회논문집 Vol.16 No.10

본 연구에서는 충돌입자의 크기의 영향을 평가하기 위하여 동일한 운동에너지 를 갖는 직경 5mm 및 10mm의 강구를 시편에 충돌시킨 후 배항각 변화에 따른 손물역의 크기 변화를 초음파현미경(SAM)과 주사전자현미경(SEM)으로 관찰하였고, 충돌에 따른 압축강성의 변화를 고찰하기 위하여 충격전후의 압축탄성계수를 측정하였다. This study investigated the compressive Young's modulus and the impactinduced damage of CFRP angle-ply laminate under same impact energy condition. The specimens of angle-ply laminate composites [0.deg.$_{6}$/ .theta..deg.$_{10}$/ 0.deg.$_{6}$] with .theta..deg. =30.deg., 45.deg., 60.deg. and 90.deg. were employed, and damaged by steel balls of diameter of 5mm and 10mm propelled by air gun type impact testing machine. The impact damaged zones were observed through a scanning acoustic microscope(SAM), and their cross-sections were observed through a scanning electron microscope(SEM). The compressive Young's moduli before and after impact were measured, and compared with the theoretical values calculated. The results obtained were as follows: (1) The damage areas on the interfacial boundaries showed more severe change on the back side interface than on the impact side interface with increasing ply-angle. (2) The damage areas on the interfacial boundaries became larger with increasing impact velocity or ply-angle. (3) The impact damaged zone showed the delamination on the interfacial boundaries and transverse cracks inside laminas. (4) The impact damaged zone was affected by the impactor size and speed or ply-angle under same impact energy condition. (5) Compressive Young's moduli before and after impact were lower than theoretical value, but showed a similar change according to ply-angle. (6) Compressive Young's moduli after impact were higher than those before impact, but there was no remarkable change in apparent compressive modulus after impact.t.act.

CFRP 사교적층판의 충격손상에 관한 연구

배태성,입야영,양동률 대한기계학회 1993 대한기계학회논문집 Vol.17 No.2

본 연구에서는 CFRP 적층재를 구조재료로 사용할 경우 우수한 인장강도를 갖 지만, 충격하중에 취약한 특성을 갖기 때문에 구조안정성에 관한 큰 문제의 하나로 충 격손상을 받은 적층판의 잔류 압축강도가 현저히 저하되는 것이 문제점으로 지적되어 왔다.특히, 충격손상에 의한 압축강도의 저하는 인장강도보다 압축강도에 중점을 두는 항공기의 강도설계에서 중요한 문제가 되므로, 저속충격에 의한 복합재료 구조체 의 충격파괴의 문제를 잘 이해하는 것이 요구된다. 지금까지의 연구에 의하면 CFRP 복합적층재의 손상은 주로 층간박리현상과 손상역의 크기변화를 실험적으로 고찰하였 다. Carbon fiber reinforced plastics(CFRP) have gained increased application in aerospace structures because of their specific strength and stiffness, but are sensitive to impact-induced damage. An experimental investigation was carried out to evaluate the impact resistance of CFRP according to the ply angle. The specimens of angle ply laminate composites were employed with [0.deg. $_{6}$/ .deg.$_{10}$/0.deg.$_{6}$], in which 6 kinds of ply angle such as .deg.=15.deg., 30.deg., 45.deg., 60.deg., 75.deg. and 90.deg. were selected. The impact tests were conducted using the air gun type impact testing machine by steel balls of diameter of 5 mm and 10 mm, and impact-induced damages were evaluated under same impact speed of V=60m/s. The impact damaged zones were observed through a scanning acoustic microscope (SAM). The obtained results were summarized as follows: (1) Delaminations on the interfacial boundaries showed th directional characteristics to the fiber directions. The delamination area on the impact side (interface A) was considerably smaller compared to that of the opposite side (interface B). (2) Cracks corresponding to other delaminations than those mentioned in SAM photographs were also seen on the impact damaged zone. (3) The delamination patterns were affected by the ply-angle, the dimensions of the specimen, and the boundary conditions. (4) The impact damaged zone showed zone showed the delamination on the interfacial boundaries, transverse shear cracks of the surface layer, and bending cracks of the bottom layer.r.r.r.

광중합형 수복용 복합레진의 기계적 성질에 미치는 수중침적과 Thermal Cycling의 영향

배태성,김태조,김효성,Bae, Tae-Sung,Kim, Tae-Jo,Kim, Hyo-Sung 대한의용생체공학회 1996 의공학회지 Vol.17 No.3

This study was performed to investigate the effec% of immersion in water and thermal cycling on the mechanical peoperties of light cured restorative composite resins. Five commerically available light-cured composite resins(Photo Clearfil A : CA, Lite-Fil A . LF, Clearril Photo Posterior CP, Prisms AP.H.. PA, 2100 : ZH) were unto The specimens of 12 m in diameter and 0.7 m in thickness were made, and an immersion in $37^{\circ}C$ water for 7 days and a thermal cycling of 1000 cycles at 15 second dwell time each in $5^{\circ}C$ and $55^{\circ}C$ baths were performed. Biaxial flexure test was conducted using the ball-on-three-ball method at the crosshead speed of 0.5mm/min. In order to investigate the deterioration of composite resins during the thermal cycling test, Weibull analysis for the biaxial flexure strengths was done. Fracture surfaces and the surfaces before and after the thermal cycling test were examined by SEM. The highest Weibull modulus value of 10.09 after thermal cycling tests which means the lowest strength variation, was observed in the CP group, and the lowest value of 4.47 was obsered in the LF Group. Biaxial flexure strengths and Knoop hardness numbers significantly decreased due to the thermal cycling ($\textit{p}$< 0.01), however, they recovered when specimens were drie4 The highest biaxial flexure strength of 125.65MPa was observed in the ZH group after the thermal cycling test, and the lowest value of 64.86MPa was observed in the CA group. Biaxial flexure strengths of ZH and CP groups were higher than those of PA, CF, and CA groups after thermal cycling test($\textit{p}$< 0.05). Knoop hardness numbers of CP group after the thermal cycling test was the highest(95.47 $\pm$ 7.35kg/$mm^2$) among the samples, while that of CA group was the lowest(30.73 $\pm$ 2.58kg/$mm^2$). Knoop hardness numbers showed the significant differences between the CP group and others after the thermal cycling test(($\textit{p}$< 0.05). Fracture surfaces showed that the composite resin failure developed along the matrix resin and the filler/resin interface region, and the cracks propagated in the conical shape from the maximum tensile stress zone.

EN12663 규격을 적용한 철도차량 아티큘레이션의 강도평가

배태성,김승택,최영진 한국철도학회 2021 한국철도학회 학술발표대회논문집 Vol.2021 No.6

치과용 저온 및 초저온 용융형 도재의 파괴 특성 평가

배태성 대한치과재료학회 2003 대한치과재료학회지 Vol.30 No.3

티타늄 임플란트의 표면특성

배태성 대한치과재료학회 2008 대한치과기재학회 학술대회 Vol.2008 No.5