摘要
目的优选脉冲参数,以获得具有较高显微硬度的复合镀层。方法超声条件下,采用脉冲电镀方法制备Ni-纳米Al2O3复合镀层。以显微硬度作为性能指标,对比考察平均电流密度、占空比、频率和施镀时间的影响。结果 Ni-纳米Al2O3复合镀层的显微硬度随着平均电流密度升高,占空比增大,频率升高,均呈现出先增后减的趋势,而随着施镀时间延长,呈现出近似递减的趋势。结论在平均电流密度8 A/dm2、占空比0.6、频率1.5 k Hz、施镀时间3 min的条件下,制备的Ni-纳米Al2O3复合镀层显微硬度最高,约为427.1HV。较高复合量的纳米微粒有效起到了弥散强化和细晶强化作用,改善了复合镀层结构致密程度,进而提高了显微硬度。
Objective To optimize pulse parameters in order to prepare the composite coating with high microhardness. Methods Ni-nano Al2 O3 composite coatings were prepared by pulse electroplating under ultrasound condition, and the influences of average current density, duty cycle, frequency and electroplating time on the microhardness were also investigated. Results The microhard-ness of Ni-nano Al2 O3 composite coatings increased first and then decreased with the increase of average current density, duty cycle and frequency, and it tended to decrease approximately with the electroplating time prolonging. Conclusion The Ni-nano Al2 O3 composite coating prepared under the condition of average current density 8 A/dm2 , duty cycle 0. 6, frequency 1. 5 kHz and elec-troplating time 3 min had the highest microhardness of about 427. 1HV. It was concluded that nano Al2 O3 particles of high compos-ite quantity had effects of dispersion strengthening and grain refinement strengthening and improved the density of composite coating structure, thus improving microhardness.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2015年第5期53-57,82,共6页
Surface Technology
作者简介
周言敏（1972-），男，重庆人，讲师，主要研究方向为光学薄膜设计与制备。
