纳米CeO_2对Ni基合金激光熔覆层的组织与耐蚀性的影响  

Effect of Nano-CeO_2 on Microstructure and Corrosion Resistance of Ni-Based Alloy Coating by Laser-Melting

作　　者：颜永根[1] 李明喜[2] 张世宏[2] 何宜柱[2] 

机构地区：[1]上海宝钢研究院,上海宝山201900 [2]安徽工业大学激光加工研究中心,安徽马鞍山243002

出　　处：《中国稀土学报》2007年第5期620-624,共5页Journal of the Chinese Society of Rare Earths

基　　金：安徽省自然科学基金项目(070414182);安徽省教育厅自然科学研究重点项目(2005KJ038ZD;2006KJ071A)资助

摘　　要：利用5 kWCO2激光器,在Q235低碳钢表面熔覆微米或纳米CeO2/Ni基合金复合材料,制备了涂层。利用光学显微镜、扫描电镜和X射线衍射仪分析了熔覆层的组织和相结构,利用CHI604b型电化学分析仪测定了熔覆层的阳极极化曲线。结果表明:加入微米CeO2的熔覆层组织明显细化,并出现大量的等轴晶,加入纳米CeO2的熔覆层等轴晶更加细小,并且组织致密;加入微米CeO2后Ni基合金熔覆层主要相结构的为γ-Ni,Cr23C6,CeNi3,γ-CeO2,Ni3Si和Ni3B等相,加入纳米CeO2的熔覆层中出现γ-Ni,Cr23C6,CeNi3,CeNi5,Ni3Si和Ni3B等相;当纳米CeO2的添加量为1.5%时,熔覆层的耐蚀性能大幅度提高,并且形成相对稳定的钝化膜。Composite coatings CeO2/Nickel-based alloy,produced by a 5 kW CO2 laser on Q235 low carbon steel were prepared.Cross-section of the coatings was examined to reveal their microstructure using the optical microscope,scanning electron microscope（SEM） and X-ray diffraction instrument（XRD）.The polarization curves of the coatings were measured with the CHI604b electrochemical analyzer.The results showed that fine microstructure and equiaxed dendrite were observed by adding micron-CeO2,finer and compact equiaxed dendrite was obtained with nano-CeO2 addition.There were γ-Ni,Cr23C6,CeNi3,CeO2,Ni3Si and Ni3B in the coatings with micron-CeO2 addition,while γNi,Cr23C6,CeNi3,γ-CeO2,Ni3Si and Ni3B existed by adding nano-CeO2.The corrosion resistance of the coating was improved and the relatively stable passive film was obtained by adding 1.5% nano-CeO2.

关 键 词：激光熔覆 纳米CEO2 耐腐蚀性 稀土 

分 类 号：TG174.4[金属学及工艺—金属表面处理]