汽车齿轮钢电沉积Ni-TiN镀层的制备及耐磨性研究

Study on the preparation and wear property of Ni-TiN coatings deposited by ultrasonic electrodeposition on the surface of auto gear steel

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41.4nm。当电沉积时间为50min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 deposited by ultrasonic pulse electrodeposition has the most significantly refined metal grains and compact structure. 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.