激光熔覆技术研究进展

激光熔覆技术是一种先进的材料表面改性技术，具有稀释率小、熔覆层组织致密、涂层与基体结合良好及工作环境无污染等优点。从激光熔覆喷头、激光熔覆工艺、激光熔覆材料、激光熔覆技术的工业应用这4个方面，综述了激光熔覆的研究进展。其中，在激光熔覆喷头方面，介绍了激光光斑的种类及转换原理和熔覆材料的引入方式，总结了激光束与粉束的耦合模式和熔覆喷头的种类，包括旁轴送粉熔覆喷头、光外同轴送粉喷头、光内同轴送粉喷头以及特殊工况下的熔覆喷头。在激光熔覆工艺方面，阐述了工艺参数对熔覆层宏观形貌和组织性能的影响，总结了激光熔覆复合工艺的辅助加工方法，论述了超高速激光熔覆新工艺的原理及技术优势，并介绍了激光熔覆过程控制的研究进展。在激光熔覆材料方面，阐述了熔覆材料的种类及增强相的添加方式。在激光熔覆技术的工业应用方面，介绍了激光熔覆技术在矿山机械、模具再制造以及铁路修复等领域的应用。最后对激光熔覆技术的发展趋势及应用前景做出了展望。

Research Progress of Laser Cladding Technology

Laser cladding technology is an advanced surface treatment technology and has the advantages of low dilution rate, dense structure, good bonding between coating and substrate, and pollution-free working environment. The research progress of laser cladding technology was reviewed from four aspects: laser cladding nozzle, laser cladding process, laser cladding material, and industrial application. In the aspect of laser cladding nozzles, the types and conversion principles of laser spots and the introduction methods of cladding materials were introduced. In addition, the coupling mode of laser beam and powder beam and the types of cladding nozzles were summarized, including paraxial powder feeding cladding nozzle, outside-laser coaxial powder feeding nozzle, inside-laser coaxial powder feeding nozzle and cladding nozzle under special working conditions. In terms of laser cladding process, the influence of process parameters on the macro morphology and microstructure of the cladding layer was described. The auxiliary processing methods of laser cladding were summarized. The principle and technical advantages of extreme high-speed laser cladding, and the research progress of process control of laser cladding were introduced. In laser cladding materials, the types of cladding materials and the addition methods of reinforcement phase were introduced. In the industrial applications of laser cladding technology, the application of mining machinery, mold and rails was described. Finally, the development trend and application prospects of laser cladding technology were prospected.