同步送粉激光增材制造是一种通过粉末添加方式快速制造实体零件的先进技术。在激光增材制造过程中, 激光与粉末束流将产生相互作用, 激光能量的损失是由于粉末束流对激光的散射作用。本文基于米氏散射理论建立数学模型, 研究粉末束流对激光能量的散射损失规律。结果表明: 激光能量散射损失与粉末颗粒物理特性、激光波长、粉末颗粒大小、送粉量等因素有关。粉末颗粒导电性能越好, 其对激光的散射损失越大；激光波长越长, 散射损失也越大；而在相同送粉量时, 粉末颗粒半径越小, 激光能量散射损失越大。从激光能量散射损失角度考虑, 激光增材制造宜选择短波长激光和大颗粒粉末。

Laser additive manufacturing with synchronous powder feeding is an advanced technology for rapid manufacturing of metal components. In laser additive manufacturing, the laser beam and the powder stream interact with each other, the laser beam energy loss is due to the scattering of the powder steam. In this paper, a mathematical model with Mie’ scatter theory was built and the laser beam energy loss by the powder stream scattering was investigated. The results show that scattering loss of the laser beam energy is related to the physical properties of the powder particles, the laser wavelength, the particle size and powder feeding rate. The better electrical conductivity of powder particles, the greater of the scattering loss, and the longer of the laser wavelength, or the finer of the powder particles with the same powder feed rate, the greater of the scattering loss. From the viewpoint of laser beam energy scattering loss, it will be better choosing lasers with a shorter wavelength and powder of coarser particles in laser additive manufacturing.