Miyajima Y
Shika Rikogaku Zasshi. 1975 May;16(35):150-60.
The precipitation of cobalt from gold-rich solid solution was studied about Au-Co binary alloys containing less than 5 wt.% cobalt by correlating the results of metallographic observation and micro-hardness measurement to electrical resistivity measurements. The hardness curves of the alloys showed to hardness peaks after isothermal ageing below a certain temperature. It was considered that the first peak was due to formation of G. P. zone which was confirmed by reversion phenomenon. The second peak was due to growing of metastable cobalt rich precipitate. The maximum hardness obtained by ageing was higher in Au-5 wt.% Co alloy than in Au-1 wt.% Co alloy. Difference in growing mechanism of metastable precipitate was deduced from the kinetics data and the values of time exponent obtained by Johnson-Mehl equation.
通过将金相观察和显微硬度测量结果与电阻率测量结果相关联，研究了钴含量低于5 wt.%的富金固溶体中钴的析出情况，涉及Au-Co二元合金。合金的硬度曲线在低于某一温度等温时效后出现两个硬度峰值。认为第一个峰值是由于形成了G.P.区，这通过回复现象得到了证实。第二个峰值是由于亚稳富钴析出相的长大。时效获得的最大硬度在Au-5 wt.% Co合金中比在Au-1 wt.% Co合金中更高。从动力学数据和通过约翰逊-梅尔方程获得的时间指数值推导出亚稳析出相生长机制的差异。
