摘要
用氢还原Ag_2WO_4制得的Ag-W复合粉烧结的Ag-W电接触合金由于晶粒细和成分均匀,能提高合金的抗熔焊性和电腐蚀性能。本文研究了Ag_2WO_4-Ag_2CO_3共沉淀的生成条件及还原工艺对所得Ag-W复合粉性能的影响,证明:AgNO_3溶液的pH值和共沉淀时Na_2CO_3的加入量影响共沉淀料的Ag含量;反应温度,特别是二阶段还原的温度和时间决定了复合粉的费氏平均粒度。
Ag-W electrical contacts made from composite powders produced by H_2-
reduction of a precipitated silver tungstate have excellent electrical properties
because of their finer grain structure and homogeneous chemical compositions.
In this paper, a silver tungstate and silver carbonate mixture coprecpitated by
an aqueous solution reaction has been investigated with respect to the reaction
conditions and the influence of reduction procedure on the properties of the
composite powder. The results showed the pH-value of AgNO_3 solution and the
amount of added Na_2CO_3 have a significant effect on the silver content of the
coprecipitated mixture, and the reaction temperature especially the temperature
and time of the second stage reduction are the main parameters affecting the
mean particle size of the composite powder.
关键词
Ag-W复合粉
粉末
化学共沉淀法
chemical coprecipitation
silver-tungsten composite powder
preparation method
