电沉积Ni-W纳米晶镀层制备与显微硬度研究  

Preparation and Microhardness of Electrodeposited Ni-W Nanocrystalline Coatings

作　　者：张冰怡 张莎莎 姚正军[1,2] 亚历山大·莫利亚尔 刘睿翔 彭琳涵 刘畅 ZHANG Bingyi;ZHANG Shasha;YAO Zhengjun;Oleksandr Moliar;LIU Ruixiang;PENG Linhan;LIU Chang(College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics, Nanjing 210016,China;Key Laboratory of Material Preparation and Protection Technology for Harsh Environment,Ministry of Industry and Information Technology,Nanjing 210016,China)

机构地区：[1]南京航空航天大学材料科学与技术学院,南京210016 [2]面向苛刻环境的材料制备与防护技术工业和信息化部重点实验室,南京210016

出　　处：《电镀与精饰》2019年第8期20-24,共5页Plating & Finishing

基　　金：大学生创新训练计划项目(201810287052);面向苛刻环境的材料制备与防护技术工业和信息化部重点实验室开放课题基金资助项目(No.56XCA17006)

摘　　要：采用直流电沉积方法在Cu基体表面制备Ni-W纳米晶镀层,研究了电沉积过程中电流密度、pH值和温度对镀层物相结构和力学性能的影响。结果表明,W含量和镀层显微硬度随着电流密度和温度的增加而逐渐增加。对电沉积层进行不同温度下的真空热处理,研究了热处理温度对Ni-1.3%W和Ni-29%W两种合金镀层晶粒尺寸和硬度的影响,发现W含量的增加显著抑制了镀层的晶粒粗化过程。在固溶强化效应的作用下,Ni-29%W热处理前的显微硬度明显高于Ni-1.3%W。经过200℃真空热处理后Ni-1.3%W显微硬度显著增加并高于Ni-29%W,这可能是固溶在Ni里的W发生扩散和偏析,钉扎晶界引起的。合金在较高温度真空热处理后出现显微硬度下降主要是由于晶粒粗化引起的。In present study,the Ni-W nanocrystalline coating was prepared on the surface of Cu sub. strate by direct current electrodeposition. The effect of current density,pH value and temperature on the phase structure and mechanical properties of the coating were studied. The results show that the tungsten concentration and the micro-hardness of the coating increase with the increase of current density and tem. perature. At the same time,heat treatment in vacuum was carried out on the electrodeposited films at dif. ferent temperatures,and the influence of heat treatment temperature on the grain size and hardness of the Ni-1.3%W and Ni-29%W alloy coatings was studied. It is found that the increase of the tungsten concentration significantly inhibits the grain coarsening process. Under the effect of solid solution strengthening,the micro-hardness of Ni-29%W before heat treatment is significantly higher than that of Ni-1.3%W. After heat treatment at 200 ℃,the microhardness of the Ni-1.3%W alloy increases signifi? cantly,which is higher than that of Ni-29%W. This is probably due to the diffusion and segregation of tungsten in the solid solution of nickel,leading to the pinning of grain boundaries. The microhardness starts to decrease at high temperature,which is due to the coarsening of the grain size.

关 键 词：电沉积 Ni-W纳米晶 热处理 晶粒尺寸 显微硬度 

分 类 号：TG146.15[一般工业技术—材料科学与工程]