激光熔覆原位生成TiC-zrC颗粒增强镍基复合涂层  

In-Situ Synthesis of TiC-ZrC Particulate Reinforced Ni-Based Composite Coatings by Laser Cladding

作　　者：张现虎[1] 晁明举[1] 梁二军[1] 袁斌[1] 

机构地区：[1]郑州大学物理工程学院材料物理教育部重点实验室,河南郑州450052

出　　处：《中国激光》2009年第4期998-1004,共7页Chinese Journal of Lasers

基　　金：河南省教育厅自然科学研究计划基金项目(2000614009)资助课题

摘　　要：采用预涂粉末激光熔覆技术，在45#钢表面制备出原位生成TiC—ZrC颗粒增强的镍基复合涂层。使用扫描电镜（SEM），EDS能谱和X射线衍射（XRD）对熔覆层的显微组织和物相构成进行了分析，并对熔覆层进行了硬度、摩擦性能测试。结果表明，在适当的工艺条件下，原位生成TiCZrC颗粒增强镍基复合涂层形貌良好，涂层与基材呈冶金结合。熔覆层底部组织为定向生长的γ（NiFe）树枝晶，熔覆层中上部组织为先共晶析出的TiC—ZrC颗粒相和Cr3C2条状相均匀分布于γ（NiFe）树枝晶基体中。熔覆层具有高的硬度（平均硬度HV0.3 1300）和良好的耐磨性，与纯Ni60熔覆层相比，其磨损失重仅为纯Ni60熔覆层的1／4。熔覆层硬度和耐磨性的提高归因于大量TiC—ZrC复合颗粒的形成及其在涂层中的均匀弥散分布。A TiC-ZrC particulate reinforced Ni-based composite coating has been synthesized in-situ by laser cladding with pre-pasting on steel 45 # . The microstructural and metallographic analyses were performed by scanning electron microscopy（SEM）, energy-dispersive spectroscopy （EDS） and X-ray diffractometer （XRD）. The microhardness and wear resistance of the coatings were tested. The results indicate that the composite coating is bonded metallurgically to the substrate. The microstructure at the bottom of coating consists mainly of oriented dendrites of γ（NiFe）. The microstructure locating at the middle and upper zones contains both TiC-ZrC particle and acicular Cr3C2 phase dispersed in the matrix of γ（NiFe） solid solution. The TiC-ZrC particulate reinforced composite coating has a high average hardness of HV0.3 1300 and better wear resistance. The wear mass loss of the composite is just one fourth that of the pure Ni60 coating. The improvement in wear resistance is due to the presence of numerous of in-situ synthesized TiC-ZrC particles and their well distribution in the composite coatings.

关 键 词：激光技术 激光熔覆 原位生成TiC—ZrC 显微组织 耐磨性 

分 类 号：TN249[电子电信—物理电子学] TG665[金属学及工艺—金属切削加工及机床]