Mechanism and microstructure of nickel-ceria composite coatings prepared by pulse current deposition under the ultrasonic field
来源期刊：JOURNAL OF RARE EARTHS2011年第9期
论文作者：周小卫 沈以赴 郑莹莹 靳惠明
文章页码：883 - 887
摘 要：In recent research, a novel method combined with pulse current （PC） deposition and the ultrasonic （U） field was used to fabricate pure nickel and nickel-ceria composite coatings, respectively. Morphology, crack propagation, and crystal texture were observed and analysed by using environment scanning electron microscopy （E-SEM） and transmission electron microscopy （TEM）. Orthogonal experiment [L16 （45）] was designed to optimize the parameters of pulsed power and the appropriate amount of RE addition based on microhardness. Effect of RE addition and pulsed current on the mechanism of co-electrodeposition was also investigated and compared. Experimental results indicated that it produced the alloying coatings, exhibiting compact grain and amorphous state. Nano-sized RE would preferentially occupy and pad at the edge of cracked gaps and micropore to limit the growing location and space for coarse Ni grain. Furthermore, during annealing at 480 ℃ for 2 h, a solid-solution precipitated phase named NiCexO1-x （0<x<0.5） dispersed along the large crystal boundary, which would make RE diffused sufficiently to improve crack propagation resistance and promote densification efficiently.
周小卫1，沈以赴1，郑莹莹1，靳惠明2
1. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics2. College of Mechanical Engineering, Yangzhou University
摘 要：In recent research, a novel method combined with pulse current （PC） deposition and the ultrasonic （U） field was used to fabricate pure nickel and nickel-ceria composite coatings, respectively. Morphology, crack propagation, and crystal texture were observed and analysed by using environment scanning electron microscopy （E-SEM） and transmission electron microscopy （TEM）. Orthogonal experiment [L16 （45）] was designed to optimize the parameters of pulsed power and the appropriate amount of RE addition based on microhardness. Effect of RE addition and pulsed current on the mechanism of co-electrodeposition was also investigated and compared. Experimental results indicated that it produced the alloying coatings, exhibiting compact grain and amorphous state. Nano-sized RE would preferentially occupy and pad at the edge of cracked gaps and micropore to limit the growing location and space for coarse Ni grain. Furthermore, during annealing at 480 ℃ for 2 h, a solid-solution precipitated phase named NiCexO1-x （0<x<0.5） dispersed along the large crystal boundary, which would make RE diffused sufficiently to improve crack propagation resistance and promote densification efficiently.
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