汽车齿轮钢电沉积Ni-TiN镀层的制备及耐磨性研究

摘要

采用直流电沉积、脉冲电沉积和超声波脉冲电沉积方法,在汽车齿轮钢20CrMnTi 表面制备 Ni-TiN 镀层.利用扫描电镜、X射线衍射仪、显微硬度计及摩擦磨损试验机等研究Ni-TiN镀层的微观组织、显微硬度和耐磨性能.结果表明,在超声脉冲电沉积获得的 Ni-TiN 镀层中,金属晶粒得到显著细化,组织结构最为致密,且TiN纳米微粒均匀分布于镀层中,Ni 晶粒和 TiN 微粒的平均粒径分别为 76.5 和 41.4 nm.当电沉积时间为50 min时,直流电沉积、脉冲电沉积和超声脉冲电沉积制得的 Ni-TiN 镀层显微硬度分别为 841,882 和 923 Hv,超声波脉冲电沉积Ni-TiN镀层的耐磨性最优.%Ni-TiN coatings were prepared on the surface of 20CrMnTi steel by direct current,pulse current and ultrasonic pulse electrodeposition methods,respectively.The microstructure,microhardness and wear property of Ni-TiN coatings were investigated by using atomic force microscope,scanning electron microscope,X-ray diffraction,microhardness tester,and friction and wear tester.The results indicate that the Ni-TiN coating de-posited by ultrasonic pulse electrodeposition has the most significantly refined metal grains and compact struc-ture.TiN nanoparticles are evenly distributed in the coating,and the average particle diameters of TiN particles and Ni grains are 76.5 and 41.4 nm,respectively.The microhardnesses of the Ni-TiN coatings obtained at 50 min by direct current,pulse current and ultrasonic pulse electrodeposition methods are 841,882 and 923 Hv, respectively.The Ni-TiN coating prepared by ultrasonic pulse electrodeposition has the optimal wear resistance.