激光熔覆是钛合金表面改性的重要技术手段之一，已成为当前研究热点。综述了国内外关于钛合金表面激光熔覆抗高温耐氧化、耐腐蚀、耐磨损和生物陶瓷等涂层的熔覆材料、熔覆层相组成和强化机理等的研究现状。其中，抗高温耐氧化涂层主要由于TiO2、Al2O3等相的隔氧作用，提高了钛合金在高温下的抗氧化性；耐腐蚀涂层主要由于TiN和Ti2Ni等相的固溶强化及细小针状马氏体α’等的细晶强化，提高了其耐腐蚀性；耐磨损涂层主要由于TiC、TiB、TiB2等相的弥散强化作用，提高了涂层的耐磨性；生物陶瓷涂层由于HA、CaO等相的存在，增强了钛合金的生物相容性。其次，阐述了由于熔覆材料与基材的热物性差异、试样预处理不当和工艺调控不当等因素引起的未熔颗粒、球化效应、裂纹、气孔和夹杂等主要缺陷，以及调控激光功率、扫描速度等工艺参数，预热基体材料，通入保护气体和加入适当成分添加剂等控制和改善相关缺陷的措施。最后，展望了钛合金表面激光熔覆涂层和技术的发展方向。

Laser cladding is one of the important technical methods for surface modification of titanium alloys, and has become a current research hotspot. The research status of cladding materials, phase composition and strengthening mechanism of laser cladding high-temperature and oxidation-resistant, corrosion-resistant, wear-resistant and bio-ceramic coatings on titanium alloys at home and abroad was summarized. The high-temperature and oxidation resistant coating was mainly attributed to the oxygen barrier effect of TiO2, Al2O3 and other phases, which improved the oxidation resistance of titanium alloys at high temperature; the corrosion-resistant coating was mainly due to the solid solution strengthening of TiN and Ti2Ni phases and the fine-grained strengthening of martensitic α‘, which improved the corrosion resistance; the wear-resistant coating mainly improved the wear resistance due to the dispersion strengthening of TiC, TiB, TiB2 and other phases; and bio-ceramic coating enhanced the biocompatibility of titanium alloys due to the presence of HA, CaO and other phases. Then, the main defects such as un-melted particles, spheroidization effect, cracks, pores and inclusions caused by the differences in thermal properties between the cladding material and the substrate, improper sample pretreatment, and improper process control were described, and the laser power, scanning speed and other process parameters were regulated to preheat the base material and introduce protective gas and add appropriate component additives to control and improve related defects. Finally, the development direction of laser cladding coating and technology on the surface of titanium alloy was prospected.