为研究同轴送粉熔覆中YAG激光束与粉末流的相互作用机理, 采用CCD检测技术, 对不同功率、不同送粉量下粉末流分布进行检测, 得到不同参数下粉末流的图像、灰度分布图和伪彩色分布图。结果表明: 随着激光功率增加, 粉末流图像由暗变亮, 最后到白炽状态, 其温度逐渐升高。激光功率400 W时, 随着送粉量的增加, 粉末流图像由暗变亮, 到一定程度后变暗。该检测结果可用于激光熔覆工艺优化, 提高熔覆的质量以及材料的利用率。

In this paper, the mechanism of interaction between the YAG laser beam and powder stream in coaxial laser cladding was studied by CCD detection technology, temperature distributions of powder stream with different laser power and powder mass flow rate were detected. Experiment images, pseudo-color pictures and gray-scale pictures of powder stream were obtained with different process parameters. Experimental results show that the brightness of images varies from weak to strong , and the temperature of powder stream increases as well when the laser power increases, and finally the images become incandescence. With the increase of powder mass flow rate, when the laser power is 400W, the brightness of images varies from weak to strong and begin to be weak as the powder mass flow rate reaches to a certain quantity. The detection results can be used to optimize laser cladding parameters and improve the quality of laser cladding.