激光熔覆制备TiC颗粒增强涂层的组织和性能

Microstructure and property of laser cladding TiC reinforced composition coating

  • 摘要: 为了改进TC4 钛合金的耐磨性能,开发具有热应力缓和功能的梯度涂层,在对梯度涂层优化设计的基础上,采用激光熔覆的方法在TC4 钛合金的表面上制备耐磨钛基功能梯度(Ti-FGM)复合涂层,观察了微观组织,测量了Ti-FGM 涂层和基材在大气环境室温下的摩擦磨损性能和显微硬度。结果表明:原位自生的增强相TiC 颗粒均匀分布在梯度功能耐磨熔覆层中,微观组织沿熔覆方向呈现粗大树枝晶到颗粒状晶体的变化。复合涂层硬度呈现梯度上升趋势且涂层顶部表现出较优异的耐磨性能。

     

    Abstract: Based on the optimum component design,wear resistant Ti-matrix functional gradient materials composite coating was fabricated on substrate of a titanium alloy TC4 by laser cladding process using TC4, Cr2C3 and Ti powder blends in order to enhance the tribological properties of TC4. Microstructure of the coating was characterized and the coating microhardness was tested. And its wear resistance was evaluated under room-temperature dry-sliding wear test conditions. The results show that the composite coating has fine microstructure consisting of in-situ TiC particles uniformly distributed in the matrix in the form of big dendrite and graininess structure along cladding direction and is metallurgically bonded to the titanium substrate. The coatings exhibit excellent wear resistance due to the rapidly solidified fine microstructure and the presence of a large amount of in-situ TiC.

     

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