Theoretical And Experimental Research On Optimum Matching Parameters Of Composite Laser Drilling

Laser drilling technology is widely used in various fields because of its advantages such as high speed,low cost and high universality.In order to make full use of the laser energy and improve the drilling efficiency,the optimal matching parameters of composite laser drilling were studied theoretically and experimentally.The optimal matching model of composite laser drilling is established.The long-pulsed laser energy is mainly used to melt the metal material to form a molten layer.The short-pulsed laser produces a saturated vapor pressure to remove the melt in the form of liquid sputtering.Theoretically,when the generation and removal of the melt reaches equilibrium,the composite laser punching achieves the best matching state.In the case of the best match,the composite laser drilling velocity to achieve the maximum,that is the melting velocity of the long pulse laser.According to the theoretical model,the optimal matching parameters of long pulse laser and short pulse laser are obtained.In the case of the best match,the composite laser drilling velocity is 1.24-3.68 times the drilling velocity of long pulse laser.In the experiment,a composite laser beam of ms pulse laser and ns pulse laser was irradiated on a stainless steel plate of 5 mm thickness.By changing the laser parameters,the drilling time of the ms pulse laser and the composite laser is obtained.The experimental results show that the composite punching time decreases with the increase of the peak power density before the optimal peak power density is reached for the ms pulsed laser with parameters.When the optimum peak power is reached,the composite laser drilling velocity reaches the maximum and remains constant.For a ms pulsed laser with a pulse width of 5ms and a pulse energy of 4J,the best matching peak power density is 8.22×10~6 W/cm~2.In the case of the best match,the composite laser drilling velocity is 3.3 times the drilling velocity of the ms pulse laser and the drilling efficiency is 3.06 times.The experimental results show that the theoretical model is correct and provides the basis for the selection of compound laser drilling parameters in practical application.