超声波搅拌-脉冲电沉积法制备纳米镍

NANOCRYSTALLINE NICKEL COATING PREPARED BY PULSED ELECTRODEPOSITION COMBINED WITH ULTRASONIC AGITATION

在脉冲电沉积过程中,采用超声波搅拌制备了厚度约为90μm的金属镍镀层.XRD和TEM对不同超声波强度下制备的镀层的分析表明,镍镀层的晶粒尺寸随着超声波强度的变化而变化.在固定脉冲电解参数导通时间(t_(on))和关断时间(t_(off))分别为0.2和0.8ms、平均电流密度为10A/dm^2、镀液pH值为4.0、温度为50℃的条件下,当施加的超声波强度由0W增至50W时,镀层平均晶粒尺寸从45nm减至24nm;但当超声波强度增至70W时,镀层的平均晶粒尺寸增至38nm.显微硬度测试结果表明,平均粒径为24nm的镍镀层的HV高达760.

Continuous ultrasonic wave was introduced into pulse-electrodeposition, which was used in synthesized nanocrystalline （nc） nickel coatings with a thickness of about 90 μm. The grain sizes of the coatings deposited under different ultrasonic intensities and electrolysis technique parameters were measured by XRD and TEM, and the results show that the variation of grain sizes was dominated by ultrasonic intensities. The typical electrolysis technique parameters were followed as ： average current density was 10 A/dm^2 with a on-time （ton） of 0.2 ms and off-time （toff） of 0.8 ms, and the electrolyte with pH 4.0 was controlled at a temperature of 50 ℃. Under above conditions, it was found that the grain sizes of deposited coatings varied with variation of ultrasonic intensity, and the average grain sizes of obtained coating decreased from 45 nm to 24 nm when ultrasonic intensity increased from 0 W to 50 W. However, the grain size of deposited coatings increased to 38 nm when ultrasonic intensity further increased to 70 W. The microhardness （HV） value of deposited coating with an average grain size of 24 nm was found to be 760.