금합금에서 납착되는 면의 간격이 파절저항에 미치는 영향 = The Effects of Gap Distance between Soldered Surface to the Fracture Load in Gold Alloy

국문 초록 (Abstract)

납착될 부위의 간격에 따른 파절하중을 비교하기 위하여 5㎝길이의 13개의 아크릴릭봉을 금합금(Au:70%, Pt:7%, Pd:2%)을 사용하여 주조한 후 1개는 대조군으로 두고, 12개를 중간점에서 장축에 수직되게 자르고 선반가공하였다.
0.13mm의 간격을 가진 Ⅰ군, 0.38mm간격의 Ⅱ군, 0.72mm 간격의 Ⅲ군, 1.13mm 간격의 Ⅳ군으로 각 군당 3개의 시편을 레진으로 고정시키고 납착용 합금을 만들어서 납착하였다.
인스트론 만능시험기에 4-점 테스트가 되도록 거상한 후 cross head speed 1mm/min으로 압축하중을 가하여 파절하중을 측정하였다.
주사전자미경으로 Ⅰ군과 Ⅱ군의 납착된 면 및 대조군을 관찰하여서 다음과 같은 결과를 얻었다. 1. 파절은 Ⅰ군과 Ⅱ군에서만 일어났으며, Ⅱ군에서 63.84kg으로 Ⅰ군의 31.63kg보다 높게 나타났고, Ⅲ군과 Ⅳ군의 대조군과 같이 파절이 되지 않고 bending만 일어났다.
2. 납착된 면의 주사전자현미경 관찰에서 대조군에서는 기포가 거의 없는 파절면을 관찰하였으며 Ⅰ군에서는 납착면의 중앙부가 납착되지 않은 상태이고 테두리만 납착된 상태로 나타났으며, Ⅱ군에서는 대조군보다 기포가 많은 것을 관찰하였다.

다국어 초록 (Multilingual Abstract)

In ordor to compare the fracture load according to the gap distance between the surface to be soldered.
Thirteen samples were made with acrylic rods(length : about 5㎝, diameter 3.1mm) and casted with gold alloy(Au: 70%, Pt:7%, Pd:2%).
One specimen was remained for the control group, and each of the twelve specimens was cut perpendicularly to the long axis inthe middle point, and then cut surface was lathed perpendicularly to the long axis.
These specimens were divided into four groups as followings:
Group Ⅰ was composed of 3 specimens and was held to 0.13mm gap distance.
Group Ⅱ was composed of 3 specimens and was held to 0.38mm gap distance.
Group Ⅲ was composed of 3 specimens and was held to 0.72mm gap distance.
Group Ⅳ was composed of 3 specimens and was held to 1.13mm gap distance.
Each specimen was fixed with Duraray resin and soldered with solder alloy according to each group.
After mounting on Instron universal testing machine in order to accomplish 4-point test, the fracture load of the specimens was measured.
Scanning electron microscophy was examined the fractured surface of group Ⅰ, group Ⅱ and control group.
The results were as follows.
1. Fracture was only occur group Ⅰand Ⅱ and mean fracture load was 63.84kg in group Ⅱ and 31.63kg in group Ⅰ. And group Ⅲ,Ⅳ and control group were bent and were not fractured.
2. In examination by scanning electron microscopy, conterol group largely had no voids and group Ⅰ had unsoldered surface in the central part and group Ⅱ had soldered surface with scattered voids.