摘要
采用包埋渗铝技术在C103铌合金基体上制备Al/C103,通过微弧氧化(MAO)处理获得Al_2O_3陶瓷膜外层。利用X射线衍射仪(XRD)和配有能谱仪(EDS)的扫描电镜(SEM),分析复合涂层高温腐蚀前后的成分和组织结构,并研究其高温氧化和热腐蚀行为与机理。结果表明:包埋渗铝处理的Al/C103经1000℃氧化10h后增重为6.98mg/cm^2,微弧氧化结合包埋渗铝制备的MAO/Al/C103增重为2.89mg/cm^2;氧化20h后,MAO/Al/C103增重为57.52mg/cm^2,高于Al/C103的28.08mg/cm^2。在900℃熔融混合盐(75%Na2SO4和25%NaCl,质量分数)中腐蚀50h后,Al/C103和MAO/Al/C103的增重分别为70.54,55.71mg/cm^2,表面生成了Al_2O_3和钙钛矿结构NaNbO3相;部分NaNbO3堵塞MAO微孔,阻碍熔盐向内扩散,MAO/Al/C103试样表现出较优的抗热腐蚀性。
Al2O3 ceramic film was obtained by micro-arc oxidation （MAO） process on A1/C103 speci-men, which was prepared by pack cementation aluminizing technology on C103 niobium alloy. With the aid of XRD and SEM equipped with EDS, chemical compositions and microstructures of the com-posite coatings before and after high-temperature corrosion were analyzed. The behavior and mecha-nism of the composite coatings in high-temperature oxidation and hot corrosion were also investigated. The results indicate that oxidation mass gain at 1000 ℃for10 h of the Al/C103 specimen is 6.98mg/cm2, and it is 2. 89mg/cm2 of the MAO/A1/C103 specimen. However, the mass gain of MAO/A1/C103 specimen （57. 52mg/cm2） is higher than that of A1/C103 specimen （28. 08mg/cm2） after oxidation 20h. After hot corrosion in 75%Na2S04 and 25%NaCl at 900℃ for 50h, the mass gain of A1/C103 and MAO/A1/C103 specimens are 70. 54mg/cm2 and 55. 71mg/cm2 respectively, A1203 and perovskite NaNb03 phases are formed on the surface; the diffusion of molten salt is suppressed, due to part of NaNb03 accumulated in the MAO micropores. Therefore, MAO/A1/C103 specimen ex-hibits better hot corrosion resistance.
作者
黄祖江
蒋智秋
董婉冰
童庆
李伟洲
HUANG Zu-jiang;JIANG Zhi-qiu;DONG Wan-bing;TONG Qing;LI Wei-zhou(School of Materials Science and Engineering, Guangxi University,Nanning 530004,China;Center of Ecological Collaborative Innovation for Aluminum Industry in Guangxi, Nanning 530004, China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2018年第1期44-52,共9页
Journal of Materials Engineering
基金
国家自然科学基金项目资助(51371059)
广西自然科学基金项目资助(2014GXNSFCA118013
2016GXNSFDA380022)
南宁市科学研究与技术开发计划项目(20161312)
关键词
微弧氧化
包埋渗铝
高温氧化
热腐蚀
铌合金
micro-arc oxidation
pack cementation aluminizing
high-temperature oxidation
hot corro-sion
niobium alloy
