目的 研究Ti含量对因瓦合金基熔覆层原位增强的影响。方法 运用半导体激光器制备了Fe-Ni-Ti激光熔覆层，研究了Ti含量对熔覆层的影响。利用金相显微镜、扫描电子显微镜（SEM）、X射线衍射仪对熔覆层显微组织进行了表征，运用硬度计和摩擦磨损实验机对熔覆层的显微硬度和耐磨性进行了分析。结果 在Fe-Ni因瓦合金粉末中加入Ti元素，原位生成了TiC/Fe-Ni激光熔覆层，原位TiC对熔覆层基体晶粒具有明显的细化作用。随着Ti含量的增加，复合涂层的晶粒尺寸减小，然后保持稳定。当Ti含量较低时，熔覆层主要由γ-[Fe,Ni]奥氏体组成；当Ti含量达到8%时，熔覆层基体相结构变成了α相，因瓦效应消失，产生了微裂纹和孔洞缺陷。Ti元素最佳添加量为6%，此条件下熔覆层没有裂纹，显微硬度最高，熔覆层耐磨性最好。结论 因瓦合金涂层中添加钛可以形成良好的原位强化，钛的添加量具有最佳值，过量添加钛将消除Fe-Ni合金激光熔覆层特有的因瓦效应，熔覆层磨损机制主要为粘着磨损，兼具磨粒磨损。

The work aims to study the effect of Ti content on in-situ reinforcement of invar alloy-based laser cladding. Fe-Ni-Ti laser cladding was fabricated by diode laser equipment, and the effect of Ti content on the laser cladding was investigated. The microstructure of the laser cladding was characterized with the optical microscopy (OP), scanning electron microscopy (SEM) and X-ray diffractometer. The microhardness and wear resistance were analyzed by the microhardness tester and the M-2000 abrasion testing machine. TiC/Fe-Ni laser cladding layer was formed in situ by adding Ti element into Fe-Ni invar alloy powder and in-situ TiC could obviously refine the matrix grains of cladding layer. With the increase of Ti content, the grain size of the composite cladding decreased and then remained stable. When the Ti content was low, the main matrix phase in cladding was γ-[Fe,Ni]. When the content of Ti was up to 8%, the cladding matrix phase γ was changed into α phase, which indicated that the invar effect in Fe-Ni alloy disappeared and cracks and pores were observed. When the content of Ti was 6%, there was no crack in the cladding and the microhardness and wear resistance of the cladding had peak value. In-situ strengthening can be achieved by adding titanium to invar alloy cladding, and the amount of titanium added has the best value. Excessive addition of titanium will eliminate the unique invar effect of Fe-Ni alloy laser cladding, and the wear mechanism of cladding layer is mainly adhesive wear and abrasive wear.