摘要
采用"电泳+电沉积"两步法在金属基体上先预沉积CrAlSiC电泳层,再电沉积Ni,制备了NiCrAlSiC复合涂层,并制备不含SiC的NiCrAl涂层为对比样品。采用XRD、SEM、EPMA和TEM对复合涂层进行形貌、结构和成分表征,并研究其高温氧化性能和摩擦磨损性能。结果表明:复合涂层致密并与基体结合良好,涂层内颗粒分散均匀。与不含SiC的NiCrAl复合涂层相比,NiCrAlSiC复合涂层的氧化膜由NiO、NiAl2O4和Al2O3三层结构转变为NiAl2O4和Al2O3两层结构,且氧化膜更薄;同时,涂层硬度提高26%,磨损速率下降52%,磨损机制由磨粒磨损转变为黏着磨损。SiC颗粒的加入同时提高了NiCrAl涂层的抗高温氧化性能和耐磨性能。
MCrAl(M=Ni, Co, or their combinations) coatings have been widely used as high temperature oxidation protection coatings on turbine blades, as they can thermally grow stable, dense and well adherent Al2O3 protective scales. Due to the particulate nature of the exhaust, MCrAl coatings often fail owing to severe high-temperature wear. To improve the anti-wear resistance of the MCrAl coatings,NiCrAlSiC composite coatings were designed and fabricated by the combination of electrophoretic deposition(EPD) and electrodeposition(ED). The compositions, morphologies and structures of the as-deposited composite coatings were characterized by XRD, SEM, EPMA and TEM. A Ni7.4 Cr6.2 Al14.3 SiC(mass fraction, %) coating, as well as a contrast SiC-free Ni7.2 Cr6.2 Al coating, was prepared. No cracks or micro pores were found either at the coating/substrate interface or in the coating, and elements distributed uniformly in the coating. Compared to the SiC-free coating, oxide scale on the NiCrAlSiC coating transformed from a three-layered structure(NiO, NiAl2O4 and Al2O3) to a thinner two-layered structure(NiAl2O4 and Al2O3), showing better high temperature oxidation resistance. And microhardness of the NiCrAlSiC coating increased 26%, together with the wear rate reduced 52%. Wear mechanism of the Ni CrAl coating was abrasive wear, while that of the NiCrAlSiC coating switched to adhesive wear. These results indicate that the addition of SiC improves both high temperature oxidation resistance and wear resistance of the NiCrAl composite coating obviously.
作者
赵明雨
甄会娟
董志宏
杨秀英
彭晓
ZHAO Mingyu;ZHEN Huijuan;DONG Zhihong;YANG Xiuying;PENG Xiao(Shenyang Institute of Technology,Fushun 113122,China;Laboratory for Corrosion and Protection,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第7期902-910,共9页
Acta Metallurgica Sinica
基金
辽宁省自然科学基金项目No.20170540666~~
关键词
NiCrAl复合涂层
高温氧化
摩擦磨损
电泳
电沉积
NiCrAl composite coating
high temperature oxidation
friction and wear
electrophoretic deposition
electrodeposition
