다목적용 치과용 금합금의 소성 시 냉각속도와 계류시간에 따른 경도와 미세구조의 변화 ("Hardness and microstructural changes by cooling rate and holding time during porcelain firing of a multi-purpose dental gold alloy")

서지정보

· 발행기관 : 대한치과기공학회
· 수록지 정보 : 대한치과기공학회지 / 33권 / 4호 / 271 ~ 282페이지
· 저자명 : 조미향

초록

Purpose: The aim of this study is to investigate the changes in hardness and microstructure of a dental multipurpose alloy after simulated complete firing with controlled cooling rate and holding time by characterizing the changes in hardness and microstructure after simulated firing with various cooling rates and holding times.
Methods: Before hardness testing, the specimens were solution treated and then were rapidly quenched into ice brine. The specimens were completely fired in furnace. Hardness measurements were made using a Vickers microhardness tester. The specimens were examined at 15 kV using a field emission scanning electron microscope.
Results: The maximum hardness value was obtained at stage 0 after simulated firing with various cooling rates (quick cooling, stage 0, stage 1, stage 2, stage 3). By the repetitive firing, the hardness of the tested alloy decreased gradually. By holding the specimen at 500 for 10-20min after simulated firing, the hardness increased apparently.
However, to hold the alloy for long periods of time in the relatively high temperature after simulated firing resulted in the formation of thick oxidation layer. The oxide film formed on the surface of the alloy after simulated complete firing with controlled cooling rate, which was mainly composed of O and Zn.
Conclusion: It is reasonable to hold the alloy at 500 for 10-20min after complete firing in other to improve the final hardness of the alloy

영어초록

Purpose: The aim of this study is to investigate the changes in hardness and microstructure of a dental multipurpose alloy after simulated complete firing with controlled cooling rate and holding time by characterizing the changes in hardness and microstructure after simulated firing with various cooling rates and holding times.
Methods: Before hardness testing, the specimens were solution treated and then were rapidly quenched into ice brine. The specimens were completely fired in furnace. Hardness measurements were made using a Vickers microhardness tester. The specimens were examined at 15 kV using a field emission scanning electron microscope.
Results: The maximum hardness value was obtained at stage 0 after simulated firing with various cooling rates (quick cooling, stage 0, stage 1, stage 2, stage 3). By the repetitive firing, the hardness of the tested alloy decreased gradually. By holding the specimen at 500 for 10-20min after simulated firing, the hardness increased apparently.
However, to hold the alloy for long periods of time in the relatively high temperature after simulated firing resulted in the formation of thick oxidation layer. The oxide film formed on the surface of the alloy after simulated complete firing with controlled cooling rate, which was mainly composed of O and Zn.
Conclusion: It is reasonable to hold the alloy at 500 for 10-20min after complete firing in other to improve the final hardness of the alloy

참고자료

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