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采用方波脉冲电流电沉积了含有CeO2、SiO2纳米颗粒掺杂的Ni-W-P合金镀层。在脉冲峰值电流密度恒定(30A/dm2)下,研究了脉冲导通时间和脉冲关断时间对纳米复合镀层特性的影响,采用化学组成、显微硬度和微观组织进行表征。结果表明:通过Ni、W、P和CeO2、SiO2纳米颗粒的脉冲共沉积,在普通碳钢表面制备了具有细晶结构的Ni-W-P-CeO2-SiO2纳米复合镀层。当脉冲导通时间和脉冲关断时间均控制在100μs时,纳米复合镀层显微硬度最高,为6890MPa。当脉冲关断时间控制在1000μs时,纳米复合镀层晶粒尺寸随脉冲导通时间(100～400μs)的增加而降低,但若脉冲导通时间(400～1000μs)继续增加,晶粒尺寸又开始增大。当脉冲导通时间控制在100μs时,增加脉冲关断时间(100～4000μs),纳米复合镀层晶粒尺寸增大。
The square wave pulse current was used to electrodeposit Ni-W-P alloy coating containing CeO2 and SiO2 nanoparticles. The effects of pulse on-time and pulse-off time on the properties of nanocomposite coatings were studied at constant pulse peak current density (30A / dm2). The chemical composition, microhardness and microstructure were characterized. The results show that the Ni-W-P-CeO2-SiO2 nano-composite coating with fine crystalline structure was prepared on the surface of common carbon steel by pulsed co-deposition of Ni, W, P, CeO2 and SiO2 nanoparticles. When the pulse on-time and pulse off time are controlled at 100μs, the micro-hardness of the nano-composite coating is the highest, 6890MPa. When the pulse turn-off time is controlled at 1000μs, the grain size of the nano-composite coating decreases with the increase of the pulse on time (100-400μs), but the grain size begins again when the pulse on time (400-1000μs) continues to increase Increase. When the pulse on time is controlled at 100μs, the pulse off time (100 ~ 4000μs) is increased and the grain size of nano-composite coating is increased.