激光宽带熔覆技术广泛应用于大型工件表面的强化、修复和改性，较少的搭接次数使其更容易获得表面质量较好的熔覆层和较高的熔覆效率。针对现有激光宽带熔覆中光外送粉不精准、金属粉末受热不均匀和光粉同轴耦合精度不高等问题，本文提出了一种光内送粉激光宽带熔覆工艺及方法，实现了在宽带激光束内部均匀，准确地垂直于熔池表面送粉。在水平和30°斜壁上分别进行单道堆积熔覆实验。结果表明，重力对斜壁熔池影响不明显，两组实验均获得了熔层高度较为均匀的直壁墙。对熔层组织分析可知，二次重熔区组织较为粗大，非搭接区组织由较多的树枝晶组成，二者显微硬度波动值约为90HV0.5，熔层组织整体较为均匀、致密。

Broadband laser cladding technology is widely used in the reinforcement, repair and modification of large surface, and less lap times make it easier to get better quality and the higher efficiency. In order to solve the problems of uneven heating of metal powder and low coaxial coupling accuracy in the current broadband laser cladding, an inside-laser powder feeding broadband laser cladding method has been designed, which can realize uniform powder feeding and exactly perpendicular to the surface of molten pool inside the laser. Two cladding accumulation experiments have been done on the horizontal and 30° inclined walls, and both of them achieve straight wall with uniform height of melt layer. The results show that molten pool is not sensitive to gravity. The microstructure analysis of molten layer shows that the microstructure in secondary remelting zone is relatively coarse, and the microstructure in non- overlapping zone is composed of more dendrites. The microhardness fluctuation of them is about 90HV0.5. The microstructure of the cladding layer is relatively uniform and densification.