摘要
采用脉冲电沉积法,通过调节电流密度控制涂层的晶粒尺寸,在铜基体上制备了平均晶粒尺寸为6～32nm的Zn涂层,采用XRD,SEM和显微硬度、摩擦实验等手段,表征了涂层的微观结构,并研究了其力学性能与摩擦学性能.结果表明,纳米晶Zn涂层的表面平整致密,平均晶粒尺寸随电流密度增大而减小,随着晶粒尺寸减小,涂层的显微硬度增大,摩擦系数降低.当电流密度从0.3A/cm2增大至2.4A/cm2时,平均晶粒尺寸从32nm下降为6nm,显微硬度从低于0.5GPa增大至2.0GPa以上,在大气环境中与Si3N4球之间的滑动摩擦系数从0.18降低至0.05.硬度随晶粒尺寸的变化规律符合经典的Hall-Petch关系.
Nanocrystalline zinc coatings with the average grain size from 6 to 32 nm were prepared on copper substrate by pulse electrodeposition. Microstructure and mechanical and tribologieal properties of the coatings were characterized by XRD, SEM, Vickers microhardness, and pin-on-disk tribo-test. The effects of current density on average grain size and the further effects of average grain size on Vickers microhardness and friction coefficient of the coatings were investigated. The results showed that the average grain size decreased from 32 to 6 nm with current density from 0.3 to 2.4 A/cm^2. While the average grain size decreasing, Vickers microhardness of the coatings increased from lower than 0.5 GPa to over 2.0 GPa, and the friction coefficient against Si3N4 ball in ambient air decreased from 0.18 to 0.05. Moreover, the variation of microhardness with average grain size exhibited a conventional Hall-Petch relationship.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2008年第5期1022-1025,共4页
The Chinese Journal of Process Engineering
关键词
电沉积
纳米晶
ZN
显微硬度
摩擦学性能
electrodeposition
nanocrystal
zinc
microhardness
tribological property
