熔断器用银带变色初步分析  

Research on Tarnishing Reason of Silver Strip Used for Fuse Ware

作　　者：张冠星[1] 薛行雁[1] 孙华为[1] 郭艳红[1] 张雷[1] 钟素娟[1] 

机构地区：[1]郑州机械研究所新型钎焊材料与技术国家重点实验室,郑州450001

出　　处：《贵金属》2017年第B10期45-49,共5页Precious Metals

基　　金：国家国际科技合作专项项目(2015DFA50470)

摘　　要：纯银熔体材料极易变色,采用扫描电镜(SEM)、X射线光电子能谱(XPS)和X射线衍射(XRD)等手段对银带变色状况和变色的机理进行了初步分析。结果表明,大气条件下退火会在银带表面形成一层白雾,其主要为Ag_2O;晶界处生成的一些不连续的黑色点状相,其主要成分为Ag、C和O;银带在大气条件长时间放置时,其表面将失去金属光泽,变成灰色,局部地区有黑斑散布,且斑点的分布离散,无明显的生长特点;银带加工过程中极易在其表面残留的C、Cu、Fe、Na、Mg等元素并非引起银币变色的主要因素;银带易与空气中的硫化氢、二氧化硫等发生反应,对银带产生腐蚀,致使银带变色,其腐蚀产物主要有Ag_2S、Ag_2SO_3、Ag_2O。The tarnishing mechanism of silver strip was studied by SEM, XPS, XRD . The results showed that a layer of white mist was formed on the surface of silver band during the condition of atmospheric annealing, which was mainly Ag2O . At the same time, some discontinuous black dots can be observed at the grain boundary. The main components are Ag, C and O. The surface of silver strip placed for a long time in air conditions will lose metallic luster to becomes gray, and had dark scattered spots which have no obvious growth characteristics in partial areas. The elements of C, Cu, Fe, Na, Mg are easily stayed in the surface of the silver strip during the machining process, while these residual elements are not the main factors causing silver strip tarnishing. The main reason of tarnishing was silver strip reacting with hydrogen sulfide, sulfur dioxide in the air, and the corrosion products mainly include Ag2S, Ag2SO3, Ag2O.

关 键 词：金属材料 银带 变色原因 环境 

分 类 号：TG172[金属学及工艺—金属表面处理]