热处理对自研牙科贵金属合金铸件机械性能的影响  

Mechanical properties of BS-1 low-gold dental casting alloy under different heat treatment conditions

作　　者：曹洪喜[1] 张建中[1] 丁伟山[2] 薛淼[1] 

机构地区：[1]上海第二医科大学附属第九人民医院,上海200011 [2]山东大学口腔医院

出　　处：《口腔材料器械杂志》2002年第2期69-72,共4页Chinese Journal of Dental Materials and Devices

摘　　要：目的　通过对Au50 -Ag -CuX多元贵金属合金 (BS 1金合金 )的铸件不同热处理后的性能进行研究测试 ,了解热处理对BS 1金合金机械性能的影响。方法　制作金合金表面显微硬度和伸强度标准铸件 ,分别进行软化热处理 (70 0℃ 10min) ,时效硬化热处理 (70 0℃ 10min后 40 0℃ 10min) ,恒温时效硬化热处理(70 0℃ 10min后 37℃ 7d) ,用表面显微硬度计及拉伸实验机分别测试铸件的表面显微硬度和抗张强度、延伸率及弹性模量。硬化热处理组又进行了 3种不同温度的时效硬化热处理 (2 5 0℃ ,30 0℃ ,35 0℃ )并与 40 0℃组的表面显微硬度进行统计学上的比较。另外从微观结构上也对此研究进行了探讨。结果　热处理明显影响BS - 1金合金的机械性能 ,软化热处理组的硬度值 (VHN)和机械强度明显小于另外 3组 (未处理组 ,恒温组和时效硬化热处理组 )。时效硬化组中 ,2 5 0℃对金合金的表面显微硬度不起主要作用 ,而 35 0℃、40 0℃时的时效硬化效果最好。结论　BS - 1金合金的热处理温度为 35 0℃～ 40 0℃时可获得最大硬度 ;在恒温时效硬化热处理 (37℃ )一定时间后可进一步增加合金的硬度和机械强度。Objective The mechanical propeties of BS-1 Au-Ag-Cu alloy used for dental casting restorations were evaluated to find optimal parameters in terms of various heat treatment conditions.Methods Round-disc-shaped and dumbbell-shaped specimens were cast with BS-1 gold alloy according to ISO Specification 8891.Three different heat treatments were perfomed:solution heat treatment(ST)at 700℃ for 10 min(treatment A);aging at 400℃for 10 min after ST (treatment B);and aging at 37℃ for 7d after ST(treatmnet C).Tensile strength,elongation,and microhardens were evaluated in the treatment groups and non-treatment group.In addition,three various age-hardening heat treatments were also performed on the gold alloy group after ST:aging at 250℃ for 10 min;aging at 300℃for 10 min;and aging at 350℃ for 10 min.After the treatments,microhardness was tested on all the groups.Finally,the microstructure of the gold alloy groups after three heat treatments(ST,Agehardening at 400℃ and 37℃)were evaluated by SEM. Results The hardness values and tensile strength of BS-1 gold alloy increased after the treatments aging at 37℃ and 400℃(treatment C and B),but the treatment B group increased significantly.In the age-hardening treatment groups,the microhardness results emerged as follows:aging at 350℃ and 400℃ for 10 min groups were the strongest, the 300℃ group ranged second,and the 250℃ group was the weakest.SEM analyses supported the above results.Conclusion The mechanical properties of BS-1 gold alloy casting might be changed by different heat treatments according to the various requests for different dental restorations.The highest microhardness was obtained at the age-hardening heat treatment conditions of 350℃ and 400℃ for 10 min.The gold alloy could be age-hardened at oral temperature(37℃) after a certain time.Therefore,the gold alloy had excellent age-hardening heat treatment properties.

关 键 词：机械性能 贵金属合金 时效硬化 显微结构 牙科材料 

分 类 号：R783.1[医药卫生—口腔医学]