快速凝固与普通凝固Mg-Zn-Y镁合金的耐腐蚀性能  

Corrosion Resistance of Rapidly and Conventionally Solidified Mg-Zn-Y Alloys

作　　者：王鹏程[1] 徐春杰[1] 杨林[1] 张忠明[1] 郭学锋[1] 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《铸造技术》2006年第6期609-612,共4页Foundry Technology

基　　金：国家自然科学基金(50271054);陕西省自然科学基金(2002E110);凝固技术国家重点实验室基金(200301)

摘　　要：采用失重法研究了快速凝固与普通凝固Mg-Zn-Y镁合金腐蚀速率的各种影响因素,并用极化曲线测试了它的自腐蚀电位和自腐蚀电流,通过光学显微镜(OM)、扫描电镜(SEM)及X射线衍射(XRD)研究了腐蚀形貌和腐蚀产物。结果表明,Mg-Zn-Y合金快速凝固后的组织明显细化,合金成分及组织均匀,偏析减少;在室温下,腐蚀速率随着时间的推移先增大后减小,随着pH值的增加而减小,随着氯化钠溶液浓度的增大而增大;在氯化钠溶液体系中的腐蚀形式均由局部腐蚀(点蚀)演变为全面腐蚀,腐蚀后的主要产物是Mg(OH)2。Effects of the corrosion rate of rapidly solidified （RS） Mg-Zn-Y and conventionally solidified （CS） Mg-Zn-Y alloys were studied using weightless method, and the corrosion potential and corrosion current were measured by polarization curves. The corrosive pattern and the corrosive product were analyzed using OM,SEM and XRD. The result showed that after RS the microstructure of Mg-Zn-Y alloys was refined obviously, the composition and structure were more uniform, and the segregation decreased; At room temperature, the corrosion rate increased firstly and then reduced with increase of time, decreased with increase of the pH value and increased with increase the concentration of NaCI solution~ the type of corrosion changed from pit corrosion to general corrosion when the alloy was immersed in 3.5% NaCI solution and the main corrosive product was Mg（OH）2.

关 键 词：快速凝固 MG-ZN-Y合金 腐蚀性能 失重法 极化曲线 

分 类 号：TG113.231[金属学及工艺—物理冶金]