基于中空激光光内送粉技术,利用该技术粉末流发散小, 挺直度高的特点, 进行了垂直表面(立面)熔覆试验。分析了熔覆工艺参数(扫描速度、功率、送粉量)对立面熔道宽度、高度及宽高比, 特别是重力作用下的熔道顶点下垂量的影响规律, 得出了控制下垂量的最佳工艺参数组合。在立面进行水平方向的熔道堆积生长, 实现了立面斜壁墙的成形。成形过程稳定, 成形熔覆层与基体形成冶金结合, 显微组织细密均匀。

Based on hollow-laser beam internal powder feeding technology, with the features of small divergence angle and nice straightness of the powder stream, cladding on vertical surface is tested. The effects of cladding process parameters(scanning speed, power and powder feeding rate)on layer width, height and aspect ratio, especially the droop offset of layer track vertex under gravity is analyzed. The optimal combination of process parameters for controlling the droop offset is obtained. Deposition on vertical surface along horizontal direction is tested, and forming of an inclined wall is realized. The forming process is stable. There is metallurgic bonding between forming cladding layer and substrate, and the microstructure is fine and uniform.