激光熔覆原位合成多相陶瓷增强铁基复合涂层组织与耐磨性能研究

    Research on Microstructure and Wear Resistance of In-situ Synthesized Multiphase Ceramics Reinforced Fe-based Composite Coatings by Laser Cladding

    • 摘要: 为改善钛合金表面的耐磨性能,以Fe60自熔合金粉末与B4C、TiN和Y2O3陶瓷粉末混合作为前驱体预置材料,利用激光熔覆技术在Ti6Al4V基体表面制备了原位合成多相陶瓷增强的铁基复合涂层。采用扫描电子显微镜、X-衍射仪、摩擦试验机等分析手段,对不同激光扫描速度条件下熔覆涂层的微观组织、物相组成、耐磨性能等进行研究。结果表明,涂层主要由激光快速熔凝条件下原位合成的棒状TiB2、树枝晶TiC、颗粒状TiC0.7N0.3、Fe等物相组成。在3 mm/s扫描速度下可获得无明显裂纹的Fe基复合涂层,其硬度和耐磨性分别为基体的2.8倍和2.0倍,该涂层磨损机制为磨粒磨损和粘着磨损。激光熔覆原位合成多相陶瓷增强的铁基复合涂层能够显著改善钛合金表面的耐磨性能。

       

      Abstract: To improve the wear resistance of titanium alloy surface, Fe60 self-melting alloy powder was mixed with B4C, TiN, and Y2O3 ceramic powders as preplaced materials, and in-situ synthesized multiphase ceramic reinforced Fe-based composite coatings were prepared by laser cladding on the surface of Ti6Al4V substrate. The microstructure, phase composition, and wear resistance of the coatings by laser cladding under different scanning speeds were investigated using analysis methods such as scanning electron microscopy, X-ray diffraction, and friction testing machine. The results indicate that the coating is mainly composed of in-situ synthesized rod-like TiB2, dendritic TiC, granular TiC0.7N0.3, and Fe under the conditions of laser rapid remelting and solidification. Fe-based composite coatings without obvious cracks can be obtained by laser cladding at a scanning speed of 3 mm/s, and its hardness and wear resistance are 2.8 times and 2.0 times than that of the substrate, respectively. The wear mechanism of the coating is abrasive wear and adhesive wear. In-situ synthesis multiphase ceramic reinforced Fe-based composite coatings fabricated by laser cladding can significantly improve the wear resistance of titanium alloy surfaces.

       

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