针对直升飞机发动机涡轮叶片采用连续激光熔覆出现裂纹及叶片变形的问题, 在5 kW连续横流CO2激光器上, 采用新的电源控制方案, 通过软件及相关控制, 实现了脉冲激光功率输出。克服了采用高功率开关电源带来的成本和稳定性问题, 且脉冲调制频率可达到5 Hz, 调制占空比可达到5%～100%。当采用4 kW峰值功率, 4 Hz脉冲重复频率, 占空比为20%时, 在发动机叶片K403合金表面进行合金粉末Stellite X-40的熔覆实验。结果表明, 熔覆后热影响区比连续激光减少50%, 硬度提高5%, 界面结合性能与母材相当, 无熔覆裂纹及叶片变形。

For cracks and deformations appeared in continuous laser cladding in aircraft engine turbine blade, we propose a new method on power supply control based on the 5-kW continuous transverse flow CO2 laser. Pulse laser power can be obtained by the control of software and interrelated components. The method can over come the problem of high costs and instability by using high power switch source supply. The pulse modulation frequency can reach 10 Hz and the duty cycle can be modulated between 5% and 100%. K403 alloy of the turbine blade is cladded with Stellite X-40 alloy powder in the surface using this kind of pulse laser power whose maximum laser power is 4 kW, and the repetitive frequency is 5 Hz with the duty cycle of 20%. The result shows that, compared with that using the continuous laser power, the heat affected zone is reduced 50%, and the microhardness is improved 5%. So the binding performance of the interface is as good as the base metal, and the cladding cracks and blade deformations disappear.