(1. 河南科技大学 机电工程学院,洛阳 471003;
2. 河南科技大学 河南省机械设计及传动系统重点实验室,洛阳 471003)
摘 要: 采用扫描电镜和X射线衍射分析Ni-CeO2纳米复合电铸层的表面形貌和结晶取向,研究超声波对电铸层显微硬度和耐磨损性能的影响。结果表明:由于电铸过程中引入的超声波的强力搅拌作用、超声空化效应和声流扰动效应,可以有效抑制CeO2纳米颗粒在镀液中的团聚,并促使其在电铸层中均匀分布,进一步细化了Ni结晶晶粒;超声波的引入可促进Ni晶体沿(111)和(220)晶面方向的生长,改变电铸层的结晶取向;与无超声波作用相比,超声波作用下制备的纳米复合电铸层显微硬度高、耐磨损性能优良,在CeO2添加量为40 g/L时所制备的纳米复合电铸层的显微硬度最高、磨损率最低。
关键字: CeO2纳米颗粒;纳米复合电铸层;电铸;超声波
(1. School of Mechatronics Engineering, Henan University of Science and Technology, Luoyang 471003, China;
2. Henan Key Laboratory for Machinery Design and Transmission System,
Henan University of Science and Technology, Luoyang 471003, China)
Abstract: The surface morphologies and crystal orientation of the prepared Ni-CeO2 nanocomposite electroforming deposits were examined by scanning electron microscopy (SEM) and X-ray diffractometry (XRD), respectively. The effects of ultrasound on the microhardness and wear resistance of the nanocomposite electroforming deposits were also evaluated. The results show that because of the introduction of ultrasound in the electrodepositing process, the strong stirring effect, cavitation effect and acoustic streaming effect by ultrasound effectively restrain the agglomeration of CeO2 nanoparticles in the bath, and promote the uniform distribution of CeO2 nanoparticles in the electroforming deposit. The CeO2 nanoparticles with uniform distribution in the electroforming deposit can contribute to further refine the nickel electrocrystalline grains. The crystal growth of Ni electrocrystalline along the (111) face and (200) face is promoted in the presence of ultrasound, so that the crystal orientation of the electroforming deposit changes. The Ni-CeO2 nanocomposite deposits prepared with ultrasound exhibit higher microhardness and better wear resistance than those prepared without ultrasound. The Ni-CeO2 nanocomposite deposits with an addition of 40 g/L CeO2 nanoparticles in the presence of ultrasound have a maximal microhardness and minimal wear rate.
Key words: CeO2 nanoparticles; nanocomposite electroforming deposits; electroforming; ultrasound