【摘要】 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。更多还原

【Abstract】 TiC / TiAl intermetallic matrix composite coating was fabricated on Ti-6Al-4V substrate by laser surface alloying with Al + TiC powders blend as the precursor material. The phases composition and microstructure of the composite coating were investigated by XRD,SEM and EDS. Through thermodynamic analysis and calculating,the evolution mechanism of TiC was confirmed. Results show that the coating mainly consists of TiAl and TiC,The dissolving of TiC in the alloy molten pool is driven by the diffusion of C atom. However,influenced by the non-equilibrium rapid solidification condition of molten pool formed in the process of laser surface alloying,large scale diffusion of C atoms are limited,it leads to the dissolving capacity of TiC is weakened,so the undissolved TiC grains are embeded in the TiAl matrix.更多还原