双脉冲电沉积Ni-SiC复合镀层的摩擦学性能

Friction and Wear Behavior of Reverse-Pulse Electrodeposit-ed Ni-SiC Composite Coatings on Mild Steel

双脉冲电沉积法制备的镀层比直流电沉积层在硬度、应力、耐蚀性方面更佳,目前就双脉冲法制备的Ni-SiC复合镀层的摩擦学行为的研究较少。为此,利用直流和双脉冲2种电沉积方法制备了Ni-SiC复合镀层,研究了加入SiC颗粒对2种复合镀层微观结构和室温干摩擦条件下磨损性能的影响,并将两者进行比较。利用X射线衍射仪(XRD)检测了镀层的微观结构,通过扫描电镜(SEM)观察了镀层的磨损表面,分析了磨损机理。结果表明:脉冲方法能够更有效地提高镀层硬度,降低宏观残余应力,随着SiC颗粒含量的增加,Ni-SiC复合镀层的摩擦系数减小,磨损率降低。

Ni-SiC composite coatings were prepared on AISI-1045 steel disc by using direct current electrodeposition and reverse-pulse elec-trodeposition.The effect of SiC particles on the microstructure and dry sliding friction and wear behavior of the composite coat-ings was investigated.The crystal structure of the composite coat-ings was analyzed by means of X-ray diffraction.The morphology of the worn surfaces of the composite coatings was observed by using a scanning electron microscope.Results indicate that Ni crystallites in the composite coating prepared by reverse-pulse electrodeposition are preferentially oriented along [111] texture,which contributes to the more effective increase of the hardness and decrease of the macro-residual stress of the composite coat-ings.Moreover,the friction coefficient and wear rate of the com-posite coatings decreased with increasing content of SiC,and the composite coating prepared via reverse-pulse electrodeposition showed better friction-reducing and antiwear ability than the one prepared via direct current electrodeposition.