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以Al+TiC混合粉末为原材料,采用激光表面合金化技术,在Ti-6Al-4V基材表面制备了TiC/Ti Al金属间化合物基复合涂层。通过X射线衍射仪(XRD)、扫描电镜(SEM)和能谱仪(EDS)对涂层的相组成和显微组织结构进行分析,通过热力学分析计算,探讨了TiC的演变机制。结果表明:涂层主要组成相为Ti Al和TiC,TiC在合金熔池中的溶解以C原子的扩散作为驱动,受激光表面合金化过程中熔池非平衡快速凝固的影响,C原子大范围扩散受阻,导致TiC的溶解能力降低,未溶TiC颗粒以嵌入的形式分布于涂层基材上。
TiC / TiAl intermetallic compound coating was prepared on the surface of Ti-6Al-4V substrate by using laser surface alloying technology with Al + TiC mixed powder as raw material. The phase composition and microstructure of the coating were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The evolution mechanism of TiC was discussed by thermodynamic analysis. The results show that the main phase of the coating is TiAl and TiC. The dissolution of TiC in the alloy melt pool is driven by the diffusion of C atoms. Due to the non-equilibrium rapid solidification of the molten pool during laser alloying, Difficulties in diffusion lead to a decrease in the dissolution capacity of the TiC, and the undissolved TiC particles are distributed in the embedded form on the coated substrate.