两种铸造方式的汽车用AZ91D镁合金抗腐蚀性能对比  

Comparison of corrosion resistance of AZ91D magnesium alloys for automobile cast by the two methods

作　　者：陈超[1] 

机构地区：[1]淄博职业学院,山东淄博255314

出　　处：《轻合金加工技术》2014年第9期22-26,共5页Light Alloy Fabrication Technology

基　　金：国家社会科学基金教育学一般课题"国家示范性高等职业院校综合竞争力的研究与实践"(BJA110088)

摘　　要：采用常规铸造和差压铸造工艺分别制备了汽车发动机壳体用AZ91D镁合金,研究了两种铸造方式对该合金电化学腐蚀行为的影响。通过显微组织分析、不同电解液中的电化学腐蚀行为以及差压铸造镁合金的电化学阻抗谱的研究表明,与常规铸造相比,差压铸造明显提高了AZ91D镁合金的耐腐蚀性能;在w(NaCl)=5%的NaCl和w(KOH)=5%的KOH电解液中的开路电位分别正移176 mV、184 mV,腐蚀电位分别正移152 mV、277 mV。AZ91 D magnesium alloys for automobile motor body were prepared by the two methods, i. e. conventional casting and differential pressure casting, to study their effects on the electrochemical corrosion behavior. Through the research on the microstructure, electro- chemical corrosion behavior in different electrolyte and electrochemical impedance spectros- copy of the magnesium alloy produced by differential pressure casting, it shows that compared with conventional casting, differential pressure casting could markedly improve the corrosion resistance of AZ91D magnesium alloy. Particularly, it could change open potential of the compounds at w（NaC1） = 5% NaC1 and w（KOH） = 5% KOH electrolyte by 176 mV and 184 mV to the positive direction, respectively. Moreover, it could change corrosion potential of the compounds at w（NaC1） =5% NaC1 and w（KOH） =5% KOH electrolyte by 152 mV and 277 mV to the positive direction, respectively.

关 键 词：AZ91D镁合金 电化学腐蚀行为 常规铸造 差压铸造 电化学阻抗谱 

分 类 号：TG146.22[一般工业技术—材料科学与工程]