ZrO_2含量与占空比对Ni-Co-ZrO_2复合镀层显微组织及耐蚀性的影响  

Influences of ZrO_2 Content and Duty Ratio on Microstructure and Corrosion Resistance of Ni-Co-ZrO_2 Composite Coating

作　　者：张佩[1] 孙万昌[1] 田苗苗[1] 王莹[1] 董储蓄 

机构地区：[1]西安科技大学材料科学与工程学院,陕西西安710054

出　　处：《稀有金属与硬质合金》2015年第6期33-38,共6页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金(50172023);陕西省科技攻关项目(2014K08-09);榆林市产学研科技计划项目(2012年)

摘　　要：以硫酸镍(Ni_SO4·6H_2O)、硫酸钴(CoSO_4·7H_2O)和氧化锆(ZrO_2)为主要原料,采用脉冲电沉积法在Q235钢基体表面制备了Ni-Co-ZrO_2复合镀层,通过扫描电镜和能谱仪分别分析了复合镀层的显微形貌及成分组成,并对Ni-Co-ZrO_2复合镀层的耐蚀性进行了研究。结果表明:镀层组织均匀、致密,与基体之间无裂纹、气孔等缺陷;ZrO_2颗粒弥散分布于Ni-Co合金基体中,随着ZrO_2颗粒的嵌入,Ni-Co合金的晶粒形貌由针状向菜花状转变;沉积1.5h后,镀层厚度约60μm,且镀态条件下Ni-Co-ZrO_2复合镀层为晶态结构;随着镀液中ZrO_2颗粒浓度增大及占空比降低,Ni-Co合金晶粒得到细化,复合镀层的耐蚀性显著提高,当ZrO_2含量为20g/L、占空比为40%时,复合镀层的耐蚀性最佳。Ni-Co-ZrO_2 composite coating was successfully fabricated on the substrate of Q235 steel by pulse electro-deposition of nickel sulfate(NiSO4·6H2O),cobalt sulfate(CoSO4·7H2O)and zirconia(ZrO_2)particles.Microstructure and chemical components of the composite coating were analyzed by SEM and EDS,respectively.Moreover,the corrosion resistance of Ni-Co-ZrO_2 composite coating was investigated.The results show that the coating has homogeneous and compact microstructure without defects such as pores and cracks at the interface with the substrate.ZrO_2 particles dispersed in Ni-Co alloy substrate,and the morphology of Ni-Co alloy grains changes from fibril-like shape to cauliflower-like shape with the addition of ZrO_2 particles.The thickness of the coating is about 60μm after 1.5hdeposition,and Ni-Co-ZrO_2 composite coating has crystalline microstructure in the coated state.With the content of ZrO_2 particles increasing and duty ratio decreasing in the coating,Ni-Co alloy grains are refined and the corrosion resistance of the composite coating is significantly improved.The best corrosion resistance is obtained when ZrO_2 content is 20g/L and duty ratio is 40%.

关 键 词：脉冲电沉积 Ni-Co-ZrO2复合镀层 ZrO2含量 占空比 显微组织 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]