工艺参数对脉冲电沉积Ni-TiN纳米镀层微观组织和性能的影响

Influence of Plating Parameters on Microstructure and Properties of the Ni-TiN Nanocoating Prepared by Pulse Electrodeposition

电沉积技术是一种方便、高效、低成本制备金属基纳米镀层的方法,其工艺参数直接决定金属基纳米镀层的微观组织及性能。为系统研究电沉积工艺参数对金属基纳米镀层表面形貌、显微组织、力学性能及耐磨损性能的影响规律,本实验采用脉冲电沉积制得Ni-TiN纳米镀层,并利用透射电镜(TEM)、原子力显微镜(AFM)、X射线衍射仪(XRD)、摩擦磨损试验机研究了工艺参数对Ni-TiN纳米镀层的显微结构、显微硬度和性能的影响。结果表明,当电流密度为4A/dm^2时,Ni-TiN纳米镀层的显微硬度为984.7HV,TiN微粒复合量为8.69%(质量分数)。采用不同脉冲频率制得的Ni-TiN纳米镀层,其晶面原子呈现不同方向的面心立方晶格结构。当脉冲频率为200Hz时,Ni-TiN纳米镀层中Ni和TiN的平均粒径分别为87.2nm和34.6nm。当脉冲占空比为20%时,Ni-TiN纳米镀层的显微硬度为980HV,其平均磨损量为7.56mg/mm2。

Electrodeposition technology is a kind of convenient,efficient,low cost method for preparing metal matrix nanocoatings,and the plating parameters directly determine the microstructure and properties of the coating.In order to investigate the influence of plating parameters on surface morphology,microstructure,mechanical properties and wear resistance of metal matrix nanocoatings,Ni-TiN nanocoatings were successfully prepared by using pulse electrodeposition method in this paper,and the influence of plating parameters on microstructure,microhardness and properties of the coating was investigated with the use of transmission electron microscopy（TEM）,atomic force microscopy（AFM）,X-ray diffraction（XRD）and friction wear testing machine.The results showed that the Ni-TiN nanocoating obtained at 4 A/dm^2 current density exhibited an optimum microhardness and TiN content values of 984.7 HV and 8.69 wt%,respectively.Ni-TiN nanocoatings prepared at different pulse frequencies exhibited fcc structure in different directions.The average grain diameters of Ni and TiN in the nanocoating prepared at 200 Hz were 87.2 nm and 34.6 nm,respectively.The nanocoating prepared at 20% duty cycle showed an optimum microhardness and average wear of 980 HV and 7.56 mg/mm^2,respectively.