钼对钴基合金激光熔覆层组织与耐磨性的影响  

Effect of Mo content on microstructure and wear resistance of Co-based coatings by laser cladding

作　　者：李明喜[1] 修俊杰[1] 赵庆宇[1] 何宜柱[1] 

机构地区：[1]安徽工业大学材料科学与工程学院,安徽马鞍山243002

出　　处：《焊接学报》2009年第11期17-20,共4页Transactions of The China Welding Institution

基　　金：安徽省国际科技合作项目资助计划(08080703020);安徽省教育厅自然科学研究资助项目(KJ2007A106ZC)

摘　　要：利用激光熔覆技术在低碳钢基体表面制备了钴基合金涂层.利用金相显微镜(OP)、扫描电镜(SEM)及X射线衍射仪(XRD)等研究了不同Mo元素含量的钴基合金涂层的组织结构;通过采用显微硬度试验、滑动磨损试验等方法进行性能测试.结果表明,含5.4%Mo的合金熔覆层主要组成相为-γCo,Cr23C6,而含28%Mo的合金涂层主要相组成为-γCo,Cr23C6,Co3Mo2Si和NiCoCr等相;含5.4%Mo涂层的组织主要为柱状生长树枝晶;含28%Mo单道涂层的结合区为紊乱的粗大树枝晶,中部为向上生长的细小的树枝晶,表层为细小的等轴晶,多道搭接涂层组织为细小的等轴晶;含28%Mo涂层的显微硬度可达800 HV以上,比含5.4%Mo涂层的硬度提高了一倍;耐磨性也有不同程度的提高.Co-based alloy coatings with different Mo content(5.4% and 28%) on the surface of low carbon steel were prepared by laser cladding.The microstructure and phases composition of the coatings were investigated by means of optical microscope(OP),scanning electron microscope(SEM) and X-ray diffraction instrument(XRD).Microhardness and sliding wear resistance of the coatings were also tested.The results indicated that the main phases in Co-based alloy coatings with 5.4%Mo were γ-Co and Cr23C6.Another two phases of Co3Mo2Si and NiCoCr were identified in Co-based alloy coatings with 28% Mo.Directional dendrite was observed in Co-based alloy coatings with 5.4% Mo.Unidirectional dendrite at the interface,followed by fine dendrite at the central zone and equiaxed grain near top surface were found in Co-based alloy single coatings with 28% Mo,and almost all fine equiaxed grains appear in the multi-track coatings.The microhardness of Cobased alloy coatings with 28% Mo reaches up to 800 HV,which was 2 times of that of Co-based alloy coatings with 5.4% Mo.The sliding wear resistance was also improved.

关 键 词：激光熔覆 钴基合金 钼 组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]