机器臂缸套表面电沉积Ni-P-x ZrO_(2)纳米复合镀层性能表征

Performance Characterization of Ni-P-x ZrO_(2) Nano-Composite Coating by Electrodeposition on Cylinder Liner Surface of Robot Arm

为了提高机器臂缸套表面电沉积Ni-P复合镀层的综合性能,通过电沉积工艺使ZrO_(2)掺入Ni-P镀层内,研究了Ni-P-x ZrO_(2)纳米复合镀层的组织结构、润湿性、硬度以及电化学腐蚀性能。结果表明:逐渐提高电沉积液内的ZrO_(2)含量后,位于8.94°处的ZrO_(2)衍射峰强度不断提高。镀层进行煅烧后析出了Ni与Ni 3 P 2种物相成分,ZrO_(2)已经掺杂到Ni-P镀层内。当在电沉积液内加入更高含量的ZrO_(2)后,镀层形成了更粗糙的表面,产生了更多树枝晶,镀层表面从最初的亲水性变为疏水性。在一定范围内提高ZrO_(2)含量后可获得硬度更高的Ni-P-ZrO_(2)复合镀层,在ZrO_(2)浓度为5 g/L时复合镀层的硬度最大,接近1110 kg/mm^(2)。析出硬质相Ni 3 P的过程中形成了大量的晶界,从而引起大量位错堆积在晶界区域,导致发生应变硬化现象。腐蚀电流密度随着ZrO_(2)含量的增大先降低后增加,最小值发生在ZrO_(2)浓度为5 g/L时;腐蚀电压表现出的规律与之相反。

In order to improve the comprehensive performance of the electrodeposited Ni-P composite coating on the cylinder liner surface of the robot arm,ZrO_(2)was doped into the Ni-P coating through the electrodeposition process,and the structure,wettability,hardness and electrochemical corrosion performance of the Ni-P-x ZrO_(2)nano-composite coating were studied.Results showed that the intensity of ZrO_(2)diffraction peak at 8.94°increased continuously with the gradual increase of ZrO_(2)content in the electrolyte solution.After the calcination of the coating,Ni and Ni 3P phase components were precipitated,and ZrO_(2)was doped into the Ni-P coating.When higher content of ZrO_(2)was added to the electrodeposition solution,the coating formed a rougher surface and produced more dendrites,and the coating changed from hydrophilic to hydrophobic.After increasing the ZrO_(2)content within a certain range,the Ni-P-ZrO_(2)composite coating with higher hardness was obtained,and the maximum hardness of the composite coating was close to 1110 kg/mm^(2)when the ZrO_(2)concentration was 5 g/L.A large number of grain boundaries were formed during the precipitation of hard phase Ni 3P,resulting in a large number of dislocation accumulation in the grain boundary area,leading to strain hardening.The corrosion current density decreased first and then increased with the increase of ZrO_(2)content,and the minimum value was obtained at 5 g/L,whereas the changing law of corrosion voltage was opposite.