银在硫化钠溶液中的变色行为  

Tarnishing Behavior of Silver in Sodium Sulfide Solution

作　　者：张丽丽[1] 王振尧[1] 韩薇[1] 

机构地区：[1]中国科学院金属研究所材料环境腐蚀研究中心,沈阳110016

出　　处：《装备环境工程》2008年第5期33-37,共5页Equipment Environmental Engineering

摘　　要：为研究银在硫化钠溶液中的变色机理及表面粗糙度对银变色的影响，使用扫描电镜和X-射线光电子能谱对银在硫化钠溶液中形成的变色膜进行表面形貌观察和成分分析，并通过电化学极化曲线和电化学阻抗谱技术对变色过程进行表征。结果显示银变色表面由一层均匀多孔的微小硫化银颗粒覆盖，颜色变化是颗粒大小以及覆盖密度在宏观上的反映。银在硫化钠溶液中的变色过程为硫化银粒子的不断长大堆积过程。通过比较表面粗糙度不同对银变色的影响，发现1500^#。砂纸打磨样品表面变色程度最轻，抛光样品变色最重，150^#、400^#、800^#砂纸打磨表面变色程度相近，居于二者之间。In order to find the mechanism of silver tarnishing in sodium sulfide solution and the impact of surface roughness on silver tarnishing, SEM and XPS were used to analyze the appearance and composition of tarnished surface formed in sodium sulfide solution. Besides, electrochemical polarization and EIS were used to analyze the process of tarnishing. The results showed that the tarnished surface is covered by a thin and porous film which is composed of tiny silver sulfide particles. The differences in particles diameter and coverage density result in the change of color. It was found that 1500^# finished surface tarnishes the least seriously, polished surface tarnishes the most seriously, and 150^# , 400^# , and 800^# finished surface tarnishes at the similar middle degree.

关 键 词：银 变色 硫化钠溶液 表面粗糙度 

分 类 号：TG172.6[金属学及工艺—金属表面处理] TG146.32[金属学及工艺—金属学]