摘要
用非晶态合金和纳米晶合金作电极材料各有利弊,而用酸性溶液制备的Ni-Co合金镀层存在内应力较大且电流效率低等不足。为此,采用电沉积技术在碱性镀液中制备了非晶-纳米晶Ni-Mo合金,利用X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、极化曲线等研究了电沉积工艺对镀层Mo含量、结构及形貌的影响。结果表明:镀层Mo含量随镀液中钼酸盐浓度增加而增加,随柠檬酸盐浓度增加、镀液温度升高、电流密度增大先增加后减小,pH值对镀层结构有显著影响;镀层Mo含量在21.00%～26.00%时,Ni-Mo合金镀层为非晶与纳米晶混合结构,非晶态相含量占60%以上,纳米晶的晶粒尺寸较小,镀层表面均匀、颗粒细小、致密性较高;10.0g/LNa2MoO4.2H2O,64.0g/LNa3C6H5O7.H2O,pH值10.0,电流密度5～8A/dm2,温度35℃时,获得的镀层为非晶与纳米晶混合结构,且表面质量较好。
Amorphous-nanocrystalline Ni-Mo alloy coating was electrodeposited in alkaline bath. The effects of electroplating parameters on the composition, structure and morphology of Ni-Mo alloy coatings were investigated by means of X-ray diffraction, scanning electron microscopy , energy dispersive spectrometry and electrochemical testing. It was found that the content of Mo in electroplated Ni-Mo alloy coatings increased with increasing concentration of molybdenate in the plating bath, and initially increased but then decreased with increasing concentration of citrate, temperature and current density. The pH value had a significant effect on the structure of the coating. The Ni-Mo alloy coatings with Mo content of 21. 00% ~ 26. 00% were composed of amorphous phase ( mass fraction over 60% ) and nanocrystallines, with fine nanocrystaUine grains and smooth and compact surface. Particularly, the Ni - Mo alloy coating prepared from plating bath containing 10.0 g/L Na2MoO4 ·2H2O and 64.0 g/L Na3C6H5O7·H2O at a pH value of 10.0, current density of 5 ~ 8 A/dm2 and temperature of 35 ℃ , had amorphous-nanocrystalline structure and satisfactory surface quality.
出处
《材料保护》
CAS
CSCD
北大核心
2010年第7期27-31,35,共6页
Materials Protection
