| 摘要: |
| 利用等离子熔覆技术,选择适当的工艺参数,在Q235钢表面熔覆形成TiC/Ni超厚熔覆层。采用扫描电镜、X射线衍射仪、金相显微镜、显微硬度计分析测试了涂层的相、组织、成分及性能。结果表明,熔覆层厚度可达2.7mm,无裂纹、气孔等缺陷。从熔覆层底部到表层,TiC颗粒的含量和粒径均呈梯度变化;熔覆层中的组织由界面到表层依次为:平面晶、胞状晶、树枝晶;从基体到熔覆层Fe元素含量逐渐减少,而Ni,Cr,Si元素含量则逐渐增加,TiC颗粒呈弥散分布。熔覆层硬度最大可达800HV,平均硬度是基体的4~5倍。 |
| 关键词: 等离子熔覆 TiC颗粒 梯度涂层 |
| DOI： |
| 分类号: |
| 基金项目:江苏省自然科学基金项目(BK2004117);江苏省自然科学基金项目(BK2007180) |
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| Properties and microstructures of ultra-thick gradient TiC/Ni coating by plasma cladding |
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CAO Ming1,2, WU Yuping1, HU Junhua1, LIN Pinghua1
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1.School of Materials Science and Engineering, Hohai University, Nanjing 210098, China;2.Department of Mechanical Engineering, Nanjing Technician, College, Nanjing 210033, China
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| Abstract: |
| By plasma cladding technology and appropriate cladding parameter, an ultra-thick gradient TiC/Ni composite cladding layer was synthesized on Q235 steel.Composition, microstructures and performance were analyzed by scanning electron microscope, X-ray diffraction, optical microscopy and microhardness tester.The cladding coating was about 2.7 mm in thickness and without any crack and gas pore.TiC particles exhibit a continuous increase both in volume fraction and size from the bottom of the coating to the top surface;the microstructures of the coating matrix present distribution from planar to cellular to dendrite crystal.Fe decreases and Ni, Cr, Si increase gradually from the substrate to the cladding coating.TiC particles distributes in dispersivity within the coating matrix.The maximal microhardness value of the plasma cladding coating is about 800 HV and 4-5 times of the substrate (Q235). |
| Key words: plasma cladding TiC particles gradient cladding layer |
