摘要
研究纳米稀土添加剂(CeO2)对Ni-P镀层微观结构及其性能的影响,特别是耐蚀性.在前期试验配方的基础上,在低碳钢基体表面制备Ni-P/CeO2化学复合镀层.利用超声波振荡使纳米粉充分分散;利用环境扫描电镜(ESEM)观察镀层晶粒微观形貌及浸泡试验条件下的腐蚀形貌;利用透射电镜(TEM)观察时效热处理后的晶粒结构;采用能谱(EDS)测量对镀层进行化学成分分析;利用恒电位仪进行Tafel极化曲线测定.研究结果表明,稀土添加能有效提高化学镀层的P含量(w(P)>10%),晶粒细化且呈非晶态,孔隙率降低,耐蚀性提高;由于沉积时纳米稀土颗粒与Ni,P合金化共沉积,并与基体有效扩散,填充在位错、晶界、孔隙等缺陷处,钉扎位错滑移,间隙处生成致密氧化物CeO2,故能有效提高镀层的致密度和耐蚀性.
This paper studies the effect of rare-earth additive（CeO2） on the micro-structure and properties especially the anti-corrosive property of chemical plating Ni-P.With the optimal experimental prescription,Ni-P/CeO2 electroless deposit is co-deposited on low carbon steel substrate surface and the fine powder is dispersed effectively by ultrasonic.Environmental scanning electron microscopy（ESEM） is used to examine the surface deposit and corrosive morphology.Transmission electronic microscopy with energy dispersive spectrum（TEM/SEM） is used to analyze crystal grain structure after aging treatment and the internal chemical content of the deposit respectively.The polarization curve is determined by potentiostat.The results show that rare-earth CeO2 additive increases the content of phosphorus（w（P）〉10%）,makes the refined grain in amorphous state and low porosity which increases the corrosion resistance.The nanometer rare-earth additive co-deposited with Ni,P is filled in the defect among dislocation,grain boundary and porosity in chemical deposition and thus hinders dislocation glide.During this process,it spread with substrate of dense structure oxide CeO2 which is produced in dislocation gap.These can help to increase grain densification and corrosion resistance.
出处
《扬州大学学报（自然科学版）》
CAS
CSCD
北大核心
2010年第2期28-32,共5页
Journal of Yangzhou University：Natural Science Edition
基金
江苏省高校自然科学基金资助项目(07KJD430246)
关键词
稀土添加剂
复合化学镀
耐蚀性
rare-earth additive
electroless composite deposition
anti-corrosion
