摘要
研究了氰化物体系电沉积银镉合金的工艺。研究表明,提高镀液Cd^(2+)和Ag^+浓度比、提高电流密度、降低温度、增加镀液中络合剂和辅助络合剂的浓度都能使镀层镉含量提高,从而确定了电沉积含镉15％～18％的Ag-Cd合金镀层的最佳镀液组成和工艺条件。XRD分析表明,镉含量为17％的银镉合金镀层中含有金属间化合物AgCd。AgCd的存在,大大提高了镀层的硬度、耐磨性,但降低了其塑性,使镀层变脆。SEM观察含Cd17％的Ag-Cd合金镀层的形貌发现,镀层结晶细致,颗粒分布均匀。通过对不同镉含量的合金镀层的硬度测试,确定含镉15％～18％的Ag-Cd合金镀层硬度最高。利用阴极极化曲线分析了Ag-Cd合金的共沉积特征。
Electrodepositing technology of Ag-Cd alloy from cyanide bath was investigated. The influence factors, such as C'cd2+/CAg+ ratio, complexing agent, assistant complexing agent concentration, current density and bath tem-perature, were discussed. The optimal bath composition and operating condition for Ag-Cd coating containing 15% -18% Cd were decided. The crystal orientation and surface moiphology were characterized by means of X-ray diffraction analysis and scanning electron microscopy, respectively. The results indicated that the intermetallic compound AgCd existed in the Ag-Cd coating containing 17%Cd and improved the hardness and antiwear of coating. The grain of coating was fine and distributed uniformly.
出处
《材料保护》
CAS
CSCD
北大核心
2003年第5期27-30,共4页
Materials Protection
