脉冲电沉积CeO_2-SiO_2/Ni-W-P纳米复合镀层性能研究

Properties of Pulse Electroplated CeO_2-SiO_2/Ni-W-P Nano-Composite Coatings

为了探讨脉冲参数对CeO2-SiO2/Ni-W-P四元纳米复合镀层性能的影响,采用脉冲沉积的方法,在普通碳钢表面制备了CeO2-SiO2/Ni-W-P纳米复合镀层。在脉冲关断时间1 000μs和脉冲峰值电流密度30 A/dm2下,研究了脉冲导通时间对纳米复合镀层组织及性能的影响,采用能谱分析、硬度测试、扫描电镜(SEM)等技术对镀层化学组成、沉积速率、显微硬度和表面形貌进行了表征。结果表明,纳米复合镀层中CeO2和SiO2颗粒的质量分数随着脉冲导通时间的延长而增加,当脉冲导通时间为400～600μs时,沉积速率为32.33～38.22μm/h,显微硬度为609～674 HV;脉冲导通时间由100μs增加到400μs时,纳米复合镀层晶粒尺寸降低,但当脉冲导通时间再由400μs增加到1 000μs时,纳米复合镀层晶粒尺寸又有所增加。

CeO2-SiO2/Ni-W-P nano-composite coatings were prepared on the surface of carbon steel by pulse co- deposition of Ni, W, P, nano-CeO2 and nano-SiO2 particles. The influence of pulse on-time on microstructures and properties of the nano-composite coatings was studied at a constant pulse off-time of 1 000 s and pulse peak current density of 30 A/dm2. Moreover, the chemical composition, microhardness, deposition rare and surface morphologies of the composite coatings were analyzed by means of energy dispersive spectrometry, microhardness measurement, and scanning electron microscopy (SEM). Results showed that the content of nano-CeO2 and nano -SiO2 particles in the composite coatings increased with increasing pulse on-time. When the pulse on-time was controlled at 400-600 s, the nano-composite coatings had a deposition rate of 32. 33-38.22 μm/h and microhardness of 609-674 HV. Moreover, the crystal size of the nano-composite coating initially decreased with increasing pulse on-time within 100-400 s and then increased with further increasing pulse on-time within 400-1 000 s.