Microstructure,tribological behavior and magnetic properties of Fe−Ni−TiO_(2) composite coatings synthesized via pulse frequency variation

脉冲频率变化制备Fe−Ni−TiO_(2)复合涂层的显微组织、摩擦学行为和磁性能

The Fe−Ni−TiO_(2) nanocomposite coatings were electrodeposited by pulse frequency variation.The results showed that the nanocomposite with a very dense coating surface and a nanocrystalline structure was produced at higher frequencies.By increasing the pulse frequency from 10 to 500 Hz,the iron and TiO_(2) nanoparticles contents were increased in expense of nickel content.XRD patterns showed that by increasing the frequency to 500 Hz,an enhancement of BCC phase was observed and the grain size of deposits was reduced to 35 nm.The microhardness and the surface roughness were increased to 647 HV and 125 nm at 500 Hz due to the grain size reduction and higher incorporation of TiO_(2) nanoparticles into the Fe−Ni matrix(5.13 wt.%).Moreover,the friction coefficient and wear rate values were decreased by increasing the pulse frequency;while the saturation magnetization and coercivity values of the composite deposits were increased.

利用脉冲频率变化电沉积Fe−Ni−TiO_(2)纳米复合涂层。结果表明,在较高的频率下可以制备出表面致密、具有纳米晶结构的涂层。当脉冲频率从10 Hz增加到500 Hz,涂层中Fe和TiO_(2)纳米颗粒含量增加,Ni含量降低。XRD结果显示,当频率增加到500 Hz,BCC相的峰强度增加,沉积物的晶粒尺寸减小至35 nm。而且,由于晶粒尺寸减小和Fe−Ni基体中TiO_(2)纳米颗粒的掺入率较高(5.13 wt.%),显微硬度和表面粗糙度分别达到647 HV和125 nm。另外,脉冲频率增大,复合涂层的摩擦因数和磨损率减小,饱和磁化强度和矫顽力均增加。