摘要
采用料浆法在镍基高温合金。M951上制备Al-Si共渗涂层,研究了合金及涂层样品在1100℃恒温、循环氧化及在850℃在Na_2SO_4+25%K_2SO_4和Na_2SO_4+25%NaCl两种混盐中的热腐蚀行为。同时利用SEM、EDS对氧化膜表截面形貌进行了观察,并结合X射线衍射对相组成进行了分析。结果表明,在1100℃恒温及循环氧化时,M951合金表面生成NiO、NiAl_2O_4、Nb_2O_5及A1_2O_3等的混合氧化物膜,氧化膜不均匀且剥落严重。在Al-Si涂层样品表面形成稳态的α-A1_2O_3,大幅度提高了合金的抗高温氧化性能。在850℃热腐蚀试验中,M951合金40 h后发生灾难性腐蚀,而Al-Si涂层经100 h腐蚀后仍保持完整,表面形成极薄且连续的θ-A1_2O_3氧化膜,大幅度提高了合金的抗热腐蚀性能。
Al–Si coating was deposited on a nickel-base super-alloy M951 by slurry technique. Isothermal and cyclic oxidation at 1100℃, hot corrosion behaviors in Na2SO4＋25%K2SO4 and Na2SO4＋25%NaCl at 850℃ were investigated. Morphologies and phase structure of the scale were analyzed by SEM, EDS and XRD. After isothermal and cyclic oxidation, mixed oxides of NiO, NiAl2O4, Nb2O5 and Al2O3 formed on the surface of the alloy, which spalled seriously during cyclic oxidation process. Stable α–Al2O3 scales were formed on the surface of Al–Si coating, which improve the oxidation resistance of the alloy significantly. Catastrophic corrosion occurred for the alloy after 40 hours in molten salts, while thin and continious θ–Al2O3 film formed on the surface of the coating, which provided effective protection for the alloy during the corrosion process.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2012年第6期643-651,共9页
Chinese Journal of Materials Research
基金
国家自然科学基金51071163
国家重点基础研究发展计划2010CB631206和2012CB625102资助项目~~
