纳米CeO_2/Co基合金复合材料激光熔覆层组织与耐磨性研究  

Microstructure and Wear Resistance of Laser Cladding Nano-CeO_2/Co-based Alloy Composite Coating

作　　者：张世宏[1] 李明喜[1] 李辉生[1] 何宜柱[1] 

机构地区：[1]安徽工业大学激光加工研究中心,安徽马鞍山243002

出　　处：《铸造技术》2006年第8期818-821,共4页Foundry Technology

基　　金：安徽省教育厅自然科学重点项目(2005KJ038ZD);安徽省科技厅项目(04022004)

摘　　要：研究了纳米CeO2对Co基合金激光熔覆层宏观质量、显微组织、相结构和性能的影响。采用OLYMPAS-PME3显微镜、PHILIP XL30扫描电镜和XD-3A型衍射仪分析了熔覆层的显微组织和相结构,利用MM-200环-块滑动磨损试验机及JSM-35C型扫描电镜检测了熔覆层的耐磨性和分析了其磨损机理。结果表明:纳米CeO2的加入能使Co基熔覆层表面平整而无气孔和裂纹,使熔覆层的宏观质量得到改善;纳米CeO2在熔覆层中能够细化组织,并且可以抑制树枝晶的生长,促使熔覆层形成了等轴晶;添加纳米CeO2后不仅有新相CeCo2产生,并且一部分-γCo转变为-εCo相。在2.0 kW功率下加入1.5%纳米CeO2时熔覆层的相对耐磨性最好,熔覆层由磨粒磨损和黏着磨损转变为微动磨损,过量的CeO2加入,反而降低耐磨性。The effects of nano-CeO2 particles on the macroscopic quality, microstructure, phase structure, and properties of Co-based cladding layer were investigated. The coatings were prepared by a 5 kW CO2 laser, the microstructure and phase structure of the cladding layers were analyzed by means of Olympus-Pme 3 type microscope, Philip XI 30 type scanning electron microscope and XD3A type X-ray diffractometer （XRD）. The wear resistance was measured with MM-200 type sliding wear tester, and the wear mechanism was analyzed by JSM-35C type scanning electron microscope （SEM） respectively. The results indicated that the addition of nano-CeO2 can improve the macroscopic quality of the cladding layers and smooth coatings without defects （such as crack, gas hole, etc. ）are obtained; the nano-CeO2 addition can not only refine microstructure, but also restrain the dendritic growth and promote the formation of equiaxed grains; the addition of nano-CeO2 can result in the formation of new phase CeCo2, and transform some γ-Co phase into ε-Co phase as well. The cladding with 1.5% CeO2 addition made at 2.0 kW laser power has the best relative wear resistance. The mechanism was found to transform from abrasive/adhesive wear to fretting wear. However,the wear resistance decreased with excess CeO2 addition.

关 键 词：激光熔覆 纳米CEO2 显微组织 耐磨性 

分 类 号：TB383.1[一般工业技术—材料科学与工程]