Ni-纳米Al_2O_3复合镀层结构和耐磨性能研究

Microstructure and Wear Resistance of Electroplated Ni-nano Al_2O_3 Composite Coating

采用复合电镀技术通过向电镀溶液中加入平均粒度为90 nm的Al2O3粉,在Ni基材上制备了Ni-纳米Al2O3复合镀层,应用扫描电镜(SEM)、X射线衍射(EDAX)及透射电镜(TEM)等手段对复合镀层的表面形貌和结构进行了表征,并通过试验考察了镀层的磨损性能。结果表明,纳米Al2O3颗粒均匀分布在Ni纳米晶中;纳米Al2O3颗粒的加入不仅细化了基体Ni的晶粒尺寸,而且还具有弥散强化作用,从而提高了Ni-Al2O3纳米复合镀层的硬度和耐磨性能。

Ni-Al2O3 nanocomposite coatings were prepared on Ni substrates by electroplating in the bath containing Al2O3 particles with an averaged size of 90 nm. The morphology and microstructure of the coatings were analyzed by means of scanning electron microscopy and X-ray diffraction, while the wear resistance of the coatings was evaluated as well. It was found that Al2O3 nanoparticles were homogeneously dispersed among Ni nanocrystallites, and the introduction of Al2O3 nanoparticles was helpful to reducing the grain size of Ni matrix, leading to increased microhardness and wear resistance of the coating by way of grain refining strengthening and dispersion strengthening as well.