中文摘要：

目的 提高Ni-Co-CeO_2纳米复合镀层的显微硬度及耐腐蚀性能。方法 利用超声技术,采用电沉积方法制备Ni-Co-CeO_2纳米复合镀层。通过正交实验方法,对Ni~（2＋）、Co~（2＋）及纳米颗粒共沉积工艺实验进行研究,以显微维氏硬度作为考察指标,通过极差分析确定电沉积的最佳工艺条件,利用极化曲线研究纳米复合镀层在3.5%NaC l水溶液中的耐腐蚀性能。通过XRD分析纳米复合镀层的相组成,采用SEM、EDAX研究纳米复合镀层的微观形貌和元素组成。结果 通过超声场的超声空化作用,将纳米稀土CeO_2弥散分布于镀层中,使镀层晶粒细化,镀层硬度由264.34HV上升到486.82HV,同时镀层的耐蚀性能也有所提高,自腐蚀电流密度由6.305μA/cm~2减小至2.012μA/cm~2。结论 由正交实验结果得出,在超声功率为160 W的实验条件下,制备镀层的最佳工艺条件为：镀液温度55℃,电流密度2 A/dm~2,纳米稀土CeO_2加入量1 g/L,pH值5。最佳工艺条件下制备的镀层表面致密均匀,硬度和耐腐蚀性均有明显提高。

英文摘要：

The work aims to improve microhardness and corrosion resistance of Ni-Co-CeO2 nanocomposite coatings. The Ni-Co-CeO2 nanocomposite coatings were prepared in the method of electrodeposition under ultrasound condition. Codeposition technology experiment involving Ni2＋, Co2＋ and nano particles was studied in the method of orthogonal experiment. With micro Vickers hardness as examining index, optimum technological conditions of electrodeposition were determined based upon range analysis, and corrosion resistance of the Ni-Co-CeO2 nanocomposite coatings in 3.5wt% NaCl solution was studied based upon po- tentiodynamic polarization. The surface morphology, microstructure and elementary composition of the nano composite coatings were studied by SEM, XRD and EDAX. Under the effect of ultrasound cavitation, nano rare earth CeO2 was dispersed in the coat- ings, the nanocomposite coatings were refined. As a result, microhardness of the coatings increased from 264.34HV to 486.82HV,corrosion resistance was improved, and Jcorr value decreased to 2.012 pA/cmz from 6.305 pA/cm2. Provided with the experimental condition of 160 W ultrasonic power, the optimum technological conditions of coatings preparation are, plating bath temperature of 55 ~C, current density of 2 A/dm2, CeO2 concentration of 1 g/L and pH of S. The coatings prepared under the optimum technological conditions are uniform and compact, and the microhardness and corrosion resistance are increased significantly.