In view of the key technical problems of ultrahigh-speed laser cladding, this paper has studied the influence of different laser power, powder feeding rate, and carrier gas velocity on the formation of the cladding layer. A theoretical model of the powder flow field in the laser cladding process has been established. An energy attenuation algorithm based on the powder shading ratio has been designed, and the particle thermal field has been analyzed. We verified their feasibility with four radially symmetrical powder flow nozzles and extended them to the annular cladding nozzles. It is found that the powder spot temperature can be increased by increasing the laser power and setting powder focus point 0–2 mm above the laser focus point, and the utilization of laser energy in powder can be improved by reducing the particle size and increasing the powder feeding rate and carrier gas velocity. The results provide theoretical references for the application of ultrahigh-speed laser cladding on the surface strengthening of shaft components.

中文翻译：

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超高速激光熔覆粉末动力学研究

针对超高速激光熔覆的关键技术问题，研究了不同激光功率、送粉速度、载气流速对熔覆层形成的影响。建立了激光熔覆过程中粉末流场的理论模型。设计了一种基于粉末遮光率的能量衰减算法，并对颗粒热场进行了分析。我们用四个径向对称的粉末流喷嘴验证了它们的可行性，并将它们扩展到环形包覆喷嘴。发现通过增加激光功率和将粉末焦点设置在激光焦点上方0-2 mm可以提高粉末光斑温度，通过减小粒径，提高送粉速度和载气速度，可以提高激光能量在粉末中的利用率。研究结果为超高速激光熔覆在轴类零件表面强化中的应用提供了理论参考。