稀土银合金显微组织观察与分析

Microstructural Observation and Analysis of Rare Earth Silver Alloy

对稀土银合金材料进行了金相观察和电子探针扫描分析以及显微硬度测定。实验结果表明， 添加两种性质差异较大的稀土元素可以充分发挥互补作用， 改善银合金的组织与性能。含有稀土钇的银合金有较强的加工硬化效果和较好的抗高温氧化作用。稀土钇与轻稀土元素组合添加将有助于改善银合金的综合性能。

The distribution and function of rare earths in a rare earth silver alloy have been studied by means of metallographic examination, electron probe microanalysis and hardness measurement. It has been found that the rare earth compounds distribute in the dendrite grain boundaries of the cast silver alloy. The rare earth compounds congregated in the grain boundaries remarkably result in pronounced grain boundary strengthening, and small amount of rare earth compounds within the grains play a role in solution strengthening. The crushed rare earth compounds in the strong deformed silver alloy lead to a cluster structure after annealing. 'Double rare earths', i.e. a pair of similar rare earth elements distribute themselves in similar ways within the silver alloy. If the natures of two rare earth elements are different from each other, their functions are complementary, and the performance of the silver alloy is improved. The addition of yttrium to silver improves work hardenability and high temperature oxidation resistance; further improvement is obtained when yttrium and light rare earth elements are added together.