含Bi易切削变形Zn-Al合金的腐蚀行为  

Corrosion Behavior of Free-Cutting Zn-Al Alloy Contained Bi

作　　者：张锐[1] 林高用[1,2] 王莉[1] 贺家健[1] 

机构地区：[1]中南大学材料科学与工程学院 [2]中南大学有色金属材料科学与工程教育部重点实验室

出　　处：《特种铸造及有色合金》2012年第8期779-782,共4页Special Casting & Nonferrous Alloys

基　　金：国家十一五科技支撑计划项目(2009BAE71B04)

摘　　要：对自行研制的4种不同Bi含量易切削Zn-Al合金在3.5%的NaCl溶液中进行浸泡腐蚀试验,并与潮湿和干燥空气中的试样作对比。采用X射线衍射、场发射扫描电镜、能谱分析以及电化学测试等手段研究了合金在不同介质中的腐蚀行为。结果表明,合金的腐蚀主要表现为点蚀。随着Bi含量的增加,平均腐蚀速率加快。合金中的富铝α相是易腐蚀相,Zn-Al合金的腐蚀过程是以η相作为阴极,Al组元作为阳极而溶解的电化学腐蚀过程。Corrosion experiment of four self-developed free-cutting Zn-A1 alloys with varied Bi was con- ducted in the 3.5%NaC1 solution, and the comparative testing was performed both in the humid air and dry air. The corrosion behavior was investigated by means of X-ray diffraction （XRD）, field emission scanning electron microscopy, energy spectrum analysis and electrochemistry testing. The results show that the main corrosion exhibits spot corrosion in the alloy. With increasing in the content of Bi, the av- erage rate of corrosion is increased. The Al-rich phase in Zn-A1 alloy is easier to be corroded, and the corrosion process belongs to electrochemical corrosion, in which ~ phase is acted as the anode and A1 as cathode.

关 键 词：易切削Zn-Al合金 腐蚀速度 电化学腐蚀 

分 类 号：TG171[金属学及工艺—金属表面处理]