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纯铜表面氩弧熔覆TiB2/Ni复合涂层组织及耐磨性能

Microstructure and wear resistance of TiB2/Ni composite coating on pure copper surface by argon arc cladding

  • 摘要: 通过氩弧熔覆技术在纯铜表面制备TiB2增强 Ni 基复合涂层,以改善其耐磨性能. 将钛粉、硼粉和镍粉在球磨机中充分混合,采用氩弧熔覆技术将纯铜表面预置粉末熔化制备出陶瓷颗粒增强镍基熔覆层. 采用X射线衍射仪、扫描电子显微镜、透射电子显微镜分析涂层的物相及涂层中陶瓷颗粒相的组成、分布及结构,利用显微硬度仪和摩擦磨损试验机测试涂层的显微硬度和耐磨性能. 结果表明,熔覆层物相主要包括γ(Ni, Cu)和TiB2;陶瓷颗粒增强相弥散分布于熔覆层中,其中颗粒相TiB2以六边形存在,熔覆层内部与基体界面处均无缺陷产生;熔覆涂层具有较高的显微硬度,当(Ti+B)质量分数为10%时,涂层显微硬度高达781.3 HV,与纯铜基体对比,熔覆层显微硬度提高约11.7倍;在相同磨损条件下,随(Ti+B)质量分数的增加,熔覆涂层的摩擦系数及磨损失重先减小后增大;氩弧熔覆原位自生TiB2陶瓷颗粒增强镍基熔覆层可显著提高纯铜表面的耐磨性能.

     

    Abstract: The TiB2 reinforced Ni-based composite coating is prepared on the surface of pure copper by argon arc cladding technology to improve its wear resistance. The Ti powder, B powder and Ni powder are ball-milled and mixed. The ceramic particle reinforced nickel base coating was fabricated by melting the preset powder on the surface of pure copper by using argon arc cladding. The phase of the coating and the composition, distribution and structure of ceramic particles in the coating were analyzed by X-ray diffractometer, scanning electron microscope and transmission electron microscope. The microhardness and wear properties of the coating were tested by microhardness tester and friction and wear tester. The results showed that the phases of the cladding coating mainly include γ (Ni, Cu) and TiB2. The ceramic particle reinforced phases are uniformly dispersed in the cladding coating. However, the particle phase TiB2 exists in the form of hexagon. There is no defect in the interface between cladding layer and substrate. The cladding coating has high microhardness. When the mass fraction of (Ti+B) is 10%, the microhardness of the coating is as high as 781.3 HV. Compared with the pure copper substrate, the microhardness of the cladding coating is increased by about 11.7 times. With the increase of (Ti+B) mass fraction, the friction coefficient and wear loss of the coating decrease first and then increase under the same wear conditions, respectively. The in-situ synthesized TiB2 particles reinforced nickel base coating can significantly improve the wear resistance of the pure copper surface by argon arc cladding technology.

     

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