送粉式激光熔覆熔池深度的分析模型及其影响因素

在分析送粉式激光熔覆过程中能量分配和粉末颗粒云对激光束衰减规律的基础上，通过建立能量平衡方程，推导出熔池深度与工艺参数之间的定量关系表达式，系统分析了影响熔池深度的因素。结合相关的物理参数、工艺参数和金相检测的熔覆层宏观参数，对方程进行了理论计算。同金相法实际检测的熔池深度相比，理论值高于实际值，两者反映的规律是一致的，客观地反映了激光熔覆中工艺参数和工艺结果之间的关系。在激光参数保持不变的条件下，熔池深度随扫描速度和送粉速率的增大而减小。为熔覆工艺参数的优化、熔覆层质量的评定和现场控制系统的设计提供了理论依据。

Analytical Model and Relevant Factors of Molten Pool Depth in Case of Laser Cladding with Powder Feeding

On the basis of an analysis on the feeding pattern of the coating material, its behavior in the laser beam, distribution of laser energy and the attenuation of laser beam caused by particle''s cloud during the process of laser coating, the methods to calculate the interaction efficiency of laser and particles speed are presented. Then an analytical model of the molten oppl depth was establised,relating to the parameters of the processes, As the molten pool depth was calculated by the oretical method and compared with measurments of metallography, it is found that the theoretical results is higher than the experimental results, but they coincide well with each other quantitatively and are consistent in reflecting the objective realty of the process. For given laser parameters, the molten pool depth becones smaller with the increase of powder feeding rate and scanning speed. This model is helpful to optimize process parameters, understand the major relationship between the process parameters and the results, and design on-time control system.