摘要
采用阴极等离子电解沉积(CPED)在镍基高温合金上制备了一层Al_2O_3涂层。通过测试对比阴极表面在3个不同方向下的电压-电流密度曲线来分析CPED动力学过程。结果表明:在电解液中加入聚乙烯吡咯烷酮(PVP)后,临界起弧电流密度急剧下降,而且阴极表面的朝向对CPED过程的影响也相应的减弱。划痕实验结果表明,随着PVP添加量的增加,涂层的结合力得到明显的提高。通过添加PVP,等离子放电过程可以随机地、均匀地发生在各个阴极表面,因此可以在大面积复杂形状的阴极表面上沉积出均匀的Al_2O_3涂层。
Al2O3coatings were prepared on Ni-base superalloy surface by cathode plasma electrolytic deposition（CPED）.The kinetics of CPED process was investigated by cathode current density-voltage curves on the cathode with different surface placement directions.As polyvinylpyrrolidone（PVP） is added in solution,the spark ignition current density is reduced significantly,and the influence of surface placement directions of cathode on CPED process becomes very weak.Meanwhile,the results of scratching test show that the adhesion of coating is increased with the increasing PVP content in solution.Consequently,plasma discharges ignite randomly at whole cathode surface,which will be favorable for the formation of uniform Al2O3 coatings on large-sized cathode with complex shapes.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2016年第6期187-192,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51171021)
