Ethylenediamine is used to adjust the pH value of solution A, and the silver coated copper powder is produced by the chemical displacement method. The factors that affect the conductivity of the silver coated copper powder included in the discussion are the concentration and pH value of the silver ammonia solution, and the mole ratio between silver ammonia ion and the reducing agent. As shown in the results, the powder has no decorative structure of silver grain on its surface when ethylenediamine is utilized to adjust the pH value of solution A. This method also prevents the emergence of the copper ammonia ion. In summary, the best conductivity of the silver coated copper powder is achieved when the silver ammonia solution has a concentration of 0.06 mol/L, pH value of 9. 5 and the mole ration between the silver ammonia ion and the reducing agent is 1 ;1.%采用乙二胺调节A液pH值,用化学置换法制备镀银铜粉.讨论了银氨溶液的浓度,pH值以及银氨离子和还原剂的摩尔比对镀银铜粉导电性能的影响.结果表明,采用乙二胺调节A液pH的方法,所得粉末表层无点缀结构的银颗粒生成,抑制了铜氨离子的生成.而且当银氨离子浓度为0.06 mol/L,pH为9.5,银氨离子和还原剂摩尔比为1∶1时,镀银铜粉的导电性能最佳.
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