| 摘要: |
| 采用横流CO2激光,在Ni基高温合金表面激光熔覆HøgaäsCo钴基非自熔性合金粉末,制备了无缺陷的涂层。利用光学显微镜、扫描电镜及附件(EDS)、透射电镜(TEM)、X射线衍射仪分析了Co钴基合金熔覆层的组织结构,比较了熔覆层两道之间搭接重熔区与非重熔区的组织特征。结果表明,熔覆层的初生相为γ-Co枝晶,枝晶间为γ-Co+Cr23C6共晶;熔覆层与基体交界具有快速定向凝固特征,晶粒生长方向为垂直于界面,而表层则倾向于平行激光扫描方向;熔覆层两道搭接重熔区界面部分晶粒的结晶方向继承了第一道的结晶方向。 |
| 关键词: 激光熔覆 钴基合金 显微组织 结晶方向 |
| DOI： |
| 分类号: |
| 基金项目:中韩政府间国际合作(项目号2002009);安徽省科技厅中美国际合作项目(项目号01088013) |
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| Microstructure of Laser Cladding Co-based Alloy on Ni-based Superalloy |
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LI Ming xi,HE Yi zhu,SUN Guo xiong
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Department of Mechanical Engineering, Southeast University, Nanjing 210018, China
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| Abstract: |
| Defect free coatings of Høganäs Co based non self fluxing alloy deposited by crosscurrent CO2 laser on Ni-based superalloy are introduced.Section and remelted zone between two tracks of the coatings have been examined to reveal their microstructure and phase composition using optical microscope,SEM(including EDS microanalysis),XRD and TEM.The results showed that there were primary phase(γ Co)and eutectic(γ Co+Cr23C6)in the coatings.Rapid directional solidification was found at the interface where the growth direction was perpendicular to the interface.Multi-orientation and direction paralleling to the scanning speed were also found at the center area and near the top surface correspondingly.A novel microstructure was found to transmit the crystallization direction of the first layer at the remelted boundary between two tracks. |
| Key words: laser cladding Co-based alloy microstructure crystallization direction |
