Tanaka S
Shika Rikogaku Zasshi. 1980 Oct;21(56):263-70.
Commercial Ag-Pd-Cu-Au alloys of which Au content was changed form 0 to 50 wt. % were quenched from 800 degrees designated by JIS as solution treatment temperature and aged isochronically. The maximum hardness of the alloys by ageing decreased with increasing the Au content. Shape of age-hardening curve of the alloys was divided into two groups, one was of the lower Au content alloys containing below 30 wt. / Au and the other was of the higher Au content alloys containing more than 40 wt. % Au. As quenched structure of the lower Au content alloys was mixture of f.c.c alpha 2 phase and L20 type ordered phase (beta phase), on the other hand, the higher Au content alloys was composed simply by f.c.c alpha phase only. The maximum hardness of the lower Au content alloys given by ageing was caused by precipitates appeared at grain boundary, and of the higher Au content alloys was caused by precipitates in the grain were found. These facts may suggest that the mechanism of age hardening for the alloys change with increasing the Au content.
金含量从0到50 wt.%变化的商用Ag-Pd-Cu-Au合金，从800摄氏度（JIS指定为固溶处理温度）淬火并进行等时时效处理。合金时效后的最大硬度随金含量的增加而降低。合金时效硬化曲线的形状分为两组，一组是金含量低于30 wt.%的低金含量合金，另一组是金含量高于40 wt.%的高金含量合金。另一方面，低金含量合金的淬火组织是面心立方α2相和L20型有序相（β相）的混合物，而高金含量合金仅由面心立方α相组成。低金含量合金时效后的最大硬度是由晶界处出现的析出物引起的，高金含量合金的最大硬度是由晶内析出物引起的。这些事实可能表明，合金的时效硬化机制随金含量的增加而变化。
