论文部分内容阅读
针对现有送粉喷嘴粉末汇聚性差、出粉口容易堵塞以及受热变形的缺点,设计了一种四孔式同轴送粉喷嘴。喷嘴中央为激光束及保护气通道,沿中心锥孔轴向均布的4个小孔,为粉末通道。建立了数值计算模型,应用FLUENT软件对粉末通道不同出口形状和不同倾角条件下粉末流场情况进行数值模拟,选择最优方案。计算结果表明,在其他工艺参数一定的前提下,采用收缩出口与粉末通道倾角为70°时有利于改善熔覆成形效果。最后利用研制的送粉喷嘴进行粉末汇聚、激光熔覆成形等实验,验证该送粉喷嘴的实验效果。
In view of the disadvantages of the existing powder feeding nozzle powder, such as poor convergence, easy plugging of the powder outlet and heat deformation, a four-hole coaxial powder feeding nozzle is designed. The center of the nozzle is a laser beam and a protective gas passage, and four holes uniformly distributed along the axial center of the cone are powder channels. The numerical calculation model is established. The numerical simulation of the powder flow field under different outlet shapes and different inclinations of powder channel is carried out by using FLUENT software, and the optimal scheme is selected. The calculation results show that under the condition of certain other process parameters, it is beneficial to improve the forming effect of the cladding by adopting the outlet angle of shrinkage outlet and the inclination of the powder channel of 70 °. Finally, using the developed powder feeding nozzle for powder aggregation and laser cladding forming experiments, the experimental results of the powder feeding nozzle were verified.