中文摘要：

先通过单因素试验研究了光亮剂苯骈三氮唑（BTA）、丙烷磺酸吡啶鎓盐（PPS）和表面活性剂OP-10、平平加对无氰镀银层光泽度的影响。基础镀液组成和工艺条件为：硝酸银45 g/L,丁二酰亚胺80 g/L,焦磷酸钾70 g/L,5,5-二甲基乙酰脲（DMH）15 g/L,氢氧化钾40 g/L,p H 9.0-9.5,温度20-30°C,电流密度0.3 A/dm2,时间30 min。再通过正交试验对上述4种物质进行复配,得到较优复合添加剂：BTA 20 mg/L,PPS 10 mg/L,OP-10 50 mg/L,平平加20 mg/L。加入复合添加剂后,镀液的电流效率、分散能力和覆盖能力分别为99.3%、75.4%和100.0%,稳定性好。所得镀银层沿（111）和（200）晶面的取向更为明显,结晶均匀、细致,表面平整,光泽度达271 Gs,结合力和抗变色性优良。

英文摘要：

The effects ofbenzotriazole （BTA） and 3-（1-pyridinio）-l-propanesulfonate （PPS） as a brightener as well as OP-10 and Peregal as a surfactant on the glossiness of silver coating prepared from a cyanide-free bath were studied by single-factor experiment. The basic bath composition and process conditions are as follows： silver nitrate 45 g/L, succinimide 80 g/L, potassium pyrophosphate 70 g/L, 5,5-dimethydrazine （DMH） 15 g/L, potassium hydroxide 40 g/L, pH 9.0-9.5, temperature 20-30 ℃, current density 0.3 A/dm2 and time 30 min. The optimal composite additive formulated with the given four kinds of compounds was obtained by orthogonal tests： BTA 20 rag/L, PPS 10 mg/L, OP-10 50 mg/L and Peregal 20 mg/L. The bath containing the composite additive is stable and has a current efficiency 99.3%, throwing power 75.4% and covering power 100.0%. The silver coating has more obvious （111） and （200） orientations and features uniform, compact and smooth crystalline surface, a glossiness of 271 Gs, and excellent adhesion and anti-tarnishing property.