Copper Welding Research Based On Hybrid Light Source Of Blue Diode Laser And Fiber Laser

The high reflectivity and high thermal conductivity of copper is a huge challenge for laser welding.The absorption rate of infrared wavelength fiber laser for copper welding is low.While using 450 nm blue diode laser for copper welding,the absorption rate is high,which becomes an important development trend in the future.But the blue laser diodes are expensive,this paper focuses on the compound method of blue diode laser and fiber laser,simulated the process parameters of the hybrid light source for copper material welding,and designed the 450 nm blue diode laser and 1060 nm fiber laser composite device to provide manufacturers with a cost-effective and efficient copper material laser welding solution.The main research work is as follows:(1)The advantages of blue diode laser welding copper materials,the influence of welding joint design,laser energy density,focal position,shielding gas and other process parameters were analyzed.A physical model of energy absorption for the temperature field of hybrid laser deep penetration welding of copper materials was established,and a Gaussian rotating body heat source was used for welding simulation.(2)The hybrid laser welding temperature field was simulated by COMSOL.Compared with single fiber laser welding,the fiber laser absorption rate of hybrid beam welding can be increased by 20%.The relationship between the power combination of 300 W,500W,700 W blue diode laser and 1000 W fiber laser,hybrid heat source distance in 2.2-6.2mm and welding speed at 10-30mm/s on welding temperature field and light source absorption rate was analyzed.(3)The 450 nm blue laser and 1060 nm fiber laser composite device for copper material welding was designed,including laser isolation protection and optical composite path.The laser isolation protection part divides the light emitted by the laser into ordinary rays and extraordinary rays when passing through the first combined birefringent prism.The polarization planes are respectively rotated by 45 ° and then combined into a beam in the second combined birefringent prism.The reflected light by the copper material is also divided into ordinary rays and extraordinary rays when passing through the second group of birefringent prisms,but returns through the original path when passing through the first combined birefringent prism,thereby preventing the laser from being damaged.(4)The composite part of the optical path of the welding device includes a 1060 nm fiber laser mirror,a focusing lens mirror,a 450 nm semiconductor laser focusing mirror and a dichroic lens.The dichroic mirror is used to make the 450 nm semiconductor laser transmit97.2% and the 1060 nm fiber laser 98.2% reflect.The moving fiber laser mirror can make hybrid beam spot distance and position adjustable.It is suitable for any welding direction and the energy loss is about 10%.The research work of the thesis is of great significance for promoting the development of blue lasers for copper welding,power batteries manufacturing,aerospace and 3D printing in China.