文档介绍：宁夏大学
硕士学位论文
NdFeB永磁材料化学镀Ni-P-W/nano-Al2O3复合镀层及其性能研
究
姓名:高亚红
申请学位级别:硕士
专业:凝聚态物理
指导教师:陈焕铭
2011-03
摘要
本文采用化学镀方法制备了 Ni-P-W/nano-Al2O3 复合镀层。利用 X 射线衍射仪(XRD)、
扫描电镜(SEM)及其附带的能谱仪(EDS)、显微硬度仪、WS-2005 涂层附着力自动划痕仪等
分析手段对复合镀层的结构、表面形貌、显微硬度、结合强度等进行了分析。最后,利用电
极化曲线方法和 HNO3 溶液腐蚀失重方法对所制备的 Ni-P-W/nano-Al2O3 复合镀层的耐腐蚀
性能进行了测试。
对镀层表面形貌的观察表明:Ni-P-W/nano-Al2O3 复合镀层呈致密胞状结构,纳米 Al2O3
颗粒弥散分布于 Ni-P-W 合金镀层中,X 射线衍射分析表明,由于 nano-Al2O3 的含量较低,
难以检测到 Ni-P-W/nano-Al2O3 复合镀层中 Al2O3 的衍射峰,Ni-P-W/nano-Al2O3 复合镀层的
结构随 P 含量的不同呈晶态结构或非晶态结构,nano-Al2O3 的加入并没有改变镀层的结构。
对不同 nano-Al2O3 含量复合镀层的硬度测试表明,Ni-P-W/nano-Al2O3 复合镀层的硬度明显
高于 Ni-P-W 合金镀层,且随纳米 Al2O3 含量的增加,Ni-P-W/nano-Al2O3 复合镀层的硬度呈
线性增加趋势。
HNO3 溶液腐蚀失重和电极化曲线测量实验结果表明,Ni-P-W/nano-Al2O3 复合镀层的耐
腐蚀性能随镀层中 Al2O3 含量的增加而增加,当 Al2O3 含量 25g/L 时,复合镀层的腐蚀速率
2
为 -005g/(cm ·min),镀层的耐腐蚀性能最好,划痕实验结果表明:Ni-P-W/nano-Al2O3
复合镀层的临界应力()较纯 Ni-P-W 合金镀层()有明显提高。
关键词:化学复合镀,Ni-P-W/nano-Al2O3,耐腐蚀性
I
Abstract
This dissertation prepared Ni-P-W/nano-posite coatings deposited on NdFeB
permanent s materials by using electroless method. The phase structure, surface
morphology, microhardness and bond-strength of the posite coatings had been
investigated by X-ray diffraction (XRD), scaning electron microscope (SEM) equipped with
energy dispersive X-ray spectrometer (EDX), and a coating adhesion automatic scratches
apparatus (Model, WS-2005, China). The corrosion resistance of Ni-P-W/nano-posite
coatings was characterized by electric polarization curve and tested by weight loss experiment in
HNO3 solutions respectively.
The results indicated that posite coatings morphology appears closely nodules
morphologies, and the nano-Al2O3 particles were dispersed in the Ni-P-W alloy coatings
uniformly. The identifying results of XRD indicated that there is no indication of Al2O3 phase in
Ni-P-W/nano-posite coatings. It may be that the Al2O3 peaks are located below the
Ni-P-W peaks due to the low percentage of Al2O3