Effect Of Magnetic Field On Laser Ablation Of Metal Targets

Laser is a processing tool with a wide range of applications in modern processing fields,such as laser drilling,metal cutting,material welding,cladding to prepare coatings,etc.Outer space operations have a wide range of applications.With the rapid development of the production rhythm in modern society,the productivity also needs to be improved,and how to improve the efficiency of laser processing has been closely followed by the society.The previous research results show that with the external magnetic field reasonably configured,the laser energy utilization rate can be effectively increased,and the laser ablation efficiency can be improved,thereby improving the processing efficiency of the laser.Aiming at the problem that the external magnetic field improves the processing efficiency of the laser,The thesis starts from the two aspects of numerical simulation analysis and experiments.Using two typical materials,non-ferromagnetic metal material aluminum and ferromagnetic metal material iron,as research objects,the study of the influence of magnetic field on laser ablation metal targets is carried out.The work provides a theoretical basis and experimental basis for the improvement of laser processing parameters under an external magnetic field.Aiming at the action mechanism of external magnetic field on the process of millisecond laser ablation of metal materials,this paper starts from the theoretical system of the process of laser ablation of metal and the action of electromagnetic field,and focuses on the influence of electromagnetic field on the laser-induced thermal effect.Based on Fourier's thermal conduction theory,the change in the temperature rise of the laser energy absorbed by the metal and the phase transition of the metal target after melting are analyzed.A physical model of the effect of electromagnetic force on laser ablation of aluminum and iron under a magnetic field was established.The finite element software was used for multiphysics coupling.The inheritance solution was used to change the temperature field of the laser ablation metal target in a magnetic field.The solution shows that under the action of an external magnetic field,as the magnetic induction intensity gradually increases,the ablation effect of the two metal materials changes significantly,and the influence of the magnetic field direction on the laser ablation results is not obvious and can be ignored.Under the pulsed laser energy of 2ms,the accumulation effect of thermal stress is not obvious compared with the field force of magnetic field.The results can provide a theoretical basis for subsequent experimental data analysis.Based on the theoretical calculations,an experimental device for laser ablation of metal targets under the action of a magnetic field is set up.For aluminum and iron metal targets,the study of laser damage characteristics under different laser parameters under different applied magnetic field parameters is carried out.The experimental results show that without changing the laser parameters,an external magnetic field in the radial direction of the target can significantly change the laser ablation depth,ablation area and ablation effect.Compared with aluminum targets,iron In addition to the effects of amperage,the target is also affected by the magnetic field.With the laser parameters and other conditions unchanged,increase the magnetic field intensity.With the increase of the magnetic field intensity,the ablation effect gradually increases at 0-600 mT.Under the same laser parameters and magnetic field intensity,the direction and polarity of the magnetic field have little effect on the laser ablation effect.The above research results show that the external magnetic field can effectively improve the laser ablation efficiency of metal targets.The experimental results are consistent with the theoretical results.The research results of this paper can provide a strong theoretical basis and technical guidance for the research of laser processing technology in the new era.