碳纳米管-镍磷化学复合镀层的组织与性能研究

Microstructure and Properties of Ni-P-Carbon Nanotube Composite Coating Subject to Electroless Plating

目的研究碳纳米管对Ni-P化学镀层组织与性能的影响。方法将碳纳米管(CNTs)加入到镀液中,采用化学镀的方法在45#钢表面制得碳纳米管-镍磷化学复合镀层。利用扫描电镜、X射线衍射仪综合分析复合镀层的表面形貌和结构,并采用多功能材料表面性能测试仪对复合镀层的摩擦磨损性能进行了研究。利用动电位极化技术对Ni-P-CNTs复合镀层在3.5%NaCl溶液中的电化学腐蚀行为进行了研究。结果Ni-P-CNTs化学复合镀层是非晶态结构,CNTs均匀地嵌埋在基质镀层中。在耐磨性试验中,Ni-P-CNTs复合镀层的磨损率比Ni-P镀层降低了7.6×10^(-11) m^3/(N·m),而平均摩擦因数减小了0.074。在电化学腐蚀试验中,Ni-P-CNTs复合镀层的腐蚀电位比Ni-P镀层正移了222 mV,而腐蚀电流密度降低了5.234×10^(-6) A/cm^2。结论碳纳米管填补了镍磷非晶胞间的间隙,改善了复合镀层的组织结构,使Ni-P-CNTs化学复合镀层具有更好的耐摩擦磨损性能和耐腐蚀性能。

The work aims to study effects of carbon nanotubes （CNTs） on microstructure and properties of Nickel-phosphorus electroless plating. Carbon nanotubes were added in plating bath, and Nickel-phosphorus-carbon nanotubes （CNTs） composite coatings were prepared by electroless plating on 45# steel. Morphology and structure of composite coating were analyzed with scanning elctron microscope and X-ray diffractometer, respectively. Friction and wear properties of the composite coating were studied with surface property tester for multifunctional materials. The electrochemical corrosion behavior of Ni-P-CNTs coatings in 3.5 wt% NaCl solution was studied by performing potentiodynamic polarization. Ni-P-CNTs chemical composite coating was amorphous with CNTs uniformly embedded in coating substrate. The abrasion resistance test showed that wear rate of Ni-P-CNTs composite coatings was 7.6×10？11 m3/（N？m） lower than that of Ni-P coating, and its average friction factor decreased by 0.074. In the electrochemical corrosion test, corrosion potential of Ni-P-CNTs composite coatings （Ecorr） was 222 mV higher than that of Ni-P plating while its corrosion current （Jcorr） was 5.234×10？6 A/cm2 smaller than that of Ni-P coatings. Carbon nanotubes can fill gaps between the nickel-phosphorus non-cell and improve microstructure of composite coatings, so as to provide better resistance to friction, wear and corrosion for Ni-P-CNTs electroless composite coatings.