超薄变宽涡轮叶片激光内送粉修复成形研究

Research on Repairing and Forming of Ultra-Thin and Variable Width Turbine Blades by Laser Internal Powder Feeding

基于激光内送粉熔覆技术,对超薄不等宽航空涡轮叶片的叶尖修复工艺展开研究。针对叶片几何模型,进行轨迹规划,建立不等宽熔道模型,实现逐层单道一次性扫描。设计一种水冷铜板夹紧装置,作为叶尖处的散热保护。采用CCD层高控制系统,实时修正熔覆层高度趋于期望值。实验结果表明,在0.2~2 mm厚的基体叶片上修复的熔覆层厚度在0.67~2.49 mm各处高度总体趋同。金相显微组织较为均匀致密,无明显裂纹缺陷。变斑熔覆避免了多道搭接熔道凸起和重复加热等问题,提高了熔覆精度和效率,为超薄变宽类零件的修复及成形提供参考。

Based on the laser internal powder feeding cladding technology,the tip repair technology of ultra-thin variable width aviation turbine blades is studied.According to the blade geometric model,the trajectory planning is carried out,the variable width melt channel model is established,and the single-channel one-time scanning is realized layer by layer.A water-cooled copper plate clamping device is designed as heat dissipation protection at the blade tip.The CCD layer height control system is used to correct the height of the cladding layer in real time to the desired value.The experimental results show that the thickness of the cladding layer repaired on the blade substrate with a thickness of 0.2 mm~2 mm is between 0.67 mm and 2.49 mm,and the heights are generally the same everywhere.The metallographic microstructure is relatively uniform and dense,and there is no obvious crack defect.Variable spot cladding avoids the problems of multi-lap welding channel bulge and repeated heating,improving the cladding accuracy and efficiency.Meanwhile,it provides a reference for the repair and forming of ultra-thin and variable width parts.