Centre of Micro/Nano Manufacturing Technology (MNMT-Dublin), School of Mechanical & Materials Engineering, University College Dublin, Dublin 4, Ireland.
Centre of Micro/Nano Manufacturing Technology (MNMT-Dublin), School of Mechanical & Materials Engineering, University College Dublin, Dublin 4, Ireland.
Ultrason Sonochem. 2020 Apr;62:104858. doi: 10.1016/j.ultsonch.2019.104858. Epub 2019 Nov 4.
Ultrasonic-assisted electrodeposition was used to fabricate the nickel/graphene oxide composite coatings with high hardness, low friction coefficient, and high wear resistance. In the present study, the effects of ultrasonic power and concentration of graphene oxide on the mechanical and tribological properties of the electrodeposited nickel/graphene oxide composite coatings were systematically studied. X-ray diffraction (XRD) analyses showed that the crystallite size of the nickel decreased with an increase of ultrasonic power (0-50 W, 40 KHz, square wave) and concentration of graphene oxide (0.1-0.4 g/L). Morphologies of the surface and cross-section of the composite coatings observed by Scanning Electron Microscopy (SEM) confirmed the existence of graphene oxide particles in the nickel matrix. The results from microhardness measurement demonstrated that the hardness was increased by 1.8 times using 50 W ultrasonic-assisted electrodeposition with the fixed concentration of graphene oxide (0.1 g/L), compared to the pure nickel coating. The hardness was increased by 4.4 times for the 0.4 g/L graphene oxide with the optimized ultrasonic power of 50 W in comparison to the pure nickel coating. Meanwhile, the friction coefficient decreased gradually with an increase in ultrasonic power and concentration of graphene oxide, respectively, where the effect of the concentration of graphene oxide played a more important role.
超声辅助电沉积被用于制备具有高硬度、低摩擦系数和高耐磨性的镍/氧化石墨烯复合涂层。在本研究中，系统研究了超声功率和氧化石墨烯浓度对电沉积镍/氧化石墨烯复合涂层的力学和摩擦学性能的影响。X 射线衍射（XRD）分析表明，镍的晶粒尺寸随着超声功率（0-50 W，40 kHz，方波）和氧化石墨烯浓度（0.1-0.4 g/L）的增加而减小。扫描电子显微镜（SEM）观察到的表面和截面形貌证实了氧化石墨烯颗粒在镍基体中的存在。显微硬度测量结果表明，与纯镍涂层相比，在固定氧化石墨烯浓度（0.1 g/L）下使用 50 W 超声辅助电沉积，硬度提高了 1.8 倍。与纯镍涂层相比，在优化的 50 W 超声功率下，氧化石墨烯浓度为 0.4 g/L 时，硬度提高了 4.4 倍。同时，摩擦系数随着超声功率和氧化石墨烯浓度的增加逐渐降低，其中氧化石墨烯浓度的影响更为重要。
