目的 在钛合金表面制备陶瓷相增强复合耐磨涂层。方法 采用等离子弧熔覆技术，在Ti6Al4V钛合金表面制备了原位自生TiB2、TiC、CrB陶瓷相增强镍基耐磨涂层。采用X射线衍射仪、扫描电镜、能谱仪检测了涂层的物相组成、组织组织以及微区化学成分，采用显微硬度计测试了涂层的硬度。结果 涂层靠近熔合线区域由Ni-Ti树枝晶及枝晶间的共晶组成，在涂层的中上部，大量原位增强相分布于镍基固溶体基体之中。在熔覆过程中，钛合金基材中的Ti元素同熔覆粉末中的B、C元素发生原位冶金反应形成TiB2、TiC增强相，CrB增强相为Ni基熔覆粉末中Cr、B元素反应形成，增强相的形态由各自的晶体结构及熔池凝固热力学与动力学条件决定。涂层的显微硬度得到显著提高，最高达1037HV0.2。结论 采用等离子弧熔覆技术，利用熔池内Ni-Cr-Ti-B-C合金体系的原位冶金反应，可以在钛合金表面制备原位自生TiB2、TiC、CrB增强镍基复合耐磨涂层。同Ti6Al4V基材相比，由于涂层具有大量增强相分布于镍基固溶体的组织特征，其显微硬度得到了显著提高。

The work aims to prepare ceramic reinforced composite wear-resistant coating on titanium alloy. In-situ self-generated TiB2, TiC and CrB ceramic reinforced Ni-based wear-resistant coatings were fabricated on Ti6Al4V by plasma arc cladding. X-ray diffractometer, scanning electron microscopy, energy dispersive spectroscopy and microhardness tester were used to characterize and test the phase composition, microstructure, chemical components in micro zone and mircohardness of the coating. Microstructure of the area nearby the fusion line consisted of Ni-Ti dendrites and eutectic phase dispersed between dendrites. A large amount of in situ reinforcing phase in the middle and upper part of the coating distributed in the Ni-based solid solution matrix. TiB2 and TiC reinforcing phases were formed by the in situ reaction between B and C elements from the melted titanium base metal and the cladding powder; while CrB reinforcing phase was formed by the reaction of Cr and B elements from the Ni-based cladding powder. Morphology of the reinforcing phase was determined by the combination of crystal structure and thermodynamic and kinetic condition of the cladding pool. Therefore, the microhardness of the coating increased apparently with the highest value of 1037HV0.2. By the plasma cladding technology, in-situ self-generated TiB2, TiC and CrB ceramic reinforced Ni-based wear-resistant coatings can be prepared on titanium alloy with in situ metallurgical reaction of Ni-Cr-Ti-B-C system in bath. Compared with Ti6Al4V, the microhardness of the coating increases significantly due to the presence of massive reinforcing phase dispersed in the Ni-based solid solution matrix.