| 摘要: |
| 采用5 kW横流CO2激光器在45钢基体上熔覆自制的镍基金属陶瓷涂层,对熔覆涂层的成型性、物相组成、组织形貌、显微硬度及摩擦磨损性能进行研究。结果表明:激光熔覆层成型良好,组织细密均匀,主要为Ni-Fe固溶体中分布Fe2B,WC,M7C3型及M23C6型碳化物。熔覆层靠近基材的组织为发达树枝晶,中上部为基体组织上分布着大量长条状及少量零散分布的菊花状物质,但上部晶粒分布的方向性减弱,晶粒更加细小致密。熔覆层搭接时,搭接界面存在着生长方向多与结合面相垂直的树枝晶组织过渡区。熔覆层的显微硬度约600 HV0.2,沿搭接方向没有明显波动,其摩擦系数、磨损失重及磨损程度较基体45钢明显降低,耐磨性显著提高。 |
| 关键词: 激光熔覆 镍基金属陶瓷 组织结构 显微硬度 耐磨性 |
| DOI：10.3969/j.issn.1673-5005.2015.02.015 |
| 分类号::TG 156.99 |
| 基金项目:国家自然科学基金项目(51179202);青岛市科技发展指导计划(KJZD-12-44-jch);中央高校基本科研业务费专项(13CX02073A) |
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| Wear properties and microstructure of Ni-based cermet layer by laser cladding |
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HAN Bin1, WAN Sheng2, ZHANG Mengke1, WANG Yong1
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(1.College of Mechanical and Electronic Engineering in China University of Petroleum, Qingdao 266580, China;2.Huasaier Heat Transfer Equipment Company Limited in Tianjin, Tianjin 301721, China)
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| Abstract: |
| Laser cladding of self-made Ni-based ceramic layer was prepared on a 45 steel surface by transverse flow CO2 laser. The morphology, phase composition, microstructure, micro-hardness and wear properties of the layer were investigated. Results show that the formability of cladding layer is excellent. There are Ni-Fe solid-solution, Fe2B, WC, M7C3 and M23C6 carbides in the coating. Dentrite is highly developed on the bottom of the cladding layer. In the microstructures of the central and top zone there are plenty of grains with long strip shape, and a few chrysanthemum-like grains are distributed on the substrate, but the grains of the top zone are finer and denser. There is an interface transition region, where coarser dendrites grow in the direction vertical to the bonding interface. The micro-hardness of cladding layer is about 600 HV0.2, and it has no significant fluctuations along the horizontal direction. The friction coefficient, the wear weight loss and the wear degree are significantly reduced compared with 45 steel, and the anti-wear characteristic is remarkably improved. |
| Key words: laser cladding Ni-based cermet microstructure micro-hardness wear resistance |
