Ceramic Materials Micro-hole Processing Technology And Quality Evaluation Based On Short-pulse Laser

Alumina ceramics with high temperature resistance,as one of the most common materials,corrosion resistance,high hardness,high strength and other excellent mechanical,thermal,chemical properties,is often used in various structural components of advanced ceramics.It is used in electrical parts because of its high electrical insulation,and in mechanical parts because of its high strength,no corrosion and wear.However,these important devices have high requirements for hole making in the process of micromachining,which affects the machining quality and production efficiency,but the current research is not in-depth.In this paper,alumina ceramic materials as the research object,to carry out the short-pulse laser surface through hole precision machining technology research.This paper describes the basic principle and classification of laser drilling,studies the mechanism and process of the interaction between ultraviolet nanosecond laser and alumina ceramic,and designs and constructs the calculation model of fluid combined heat transfer by COMSOL Multiphysics finite element simulation technology,and analyzes the laser processing mechanism.The effect of multi-pulse nanosecond laser on alumina surface morphology evolution was studied.Different heat transfer and hydrodynamic boundary conditions as well as thermodynamic properties are used to better predict temperature evolution as well as aperture and hole depth under different laser processing conditions.Drilling experiments of alumina ceramic materials with ultraviolet nanosecond laser rotational scanning were carried out based on Huarary P-plus-355-5B ultraviolet nanosecond laser.The principle and process method of making holes on alumina ceramic surface were analyzed and studied.The influence of laser parameters such as laser power,repetition rate,scanning frequency,scanning speed and trajectory parameters on UV nanosecond laser rotary cutting drilling quality was analyzed from the perspectives of micropore surface aperture,taper,roundness,surface morphology and sidewall morphology.For different laser parameters,it is found that the laser power is positively correlated with the aperture size,and the influence on the inlet aperture is greater than that on the outlet aperture.The influence degree of laser power on the roundness of the outlet part of the microhole is greater than that of the inlet part.With the increase of laser power,the taper of the microhole will increase correspondingly.The laser power has great influence on the quality of micropore morphology.The repetition frequency has a certain effect on the aperture of the outlet,but has little effect on the inlet aperture and roundness of the micropore.Reducing the repetition frequency can improve the morphology quality of the micropore.For trajectory parameters,when the scanning speed increases,the diameter of the entrance and exit of the hole decreases.The higher the scanning speed,the larger the error of the roundness of the hole,and the higher the scanning speed and the fewer scanning times are not conducive to the formation of the through hole.By establishing the simulation model of laser punching,this paper theoretically analyzes the microscopic process mechanism of laser punching,and obtains the rule that the increase of laser power enhances the thermal effect and material removal ability in the process of laser punching,which provides theoretical guidance for the subsequent experimental research of punching.On the basis of simulation,the punching experiment was carried out,and the influencing factors of micromachining quality were analyzed.The conclusion was consistent with the simulation process,and the optimal technological parameters of UV nanosecond laser micromachining of alumina ceramics were formed,and the defects such as low efficiency and unsatisfactory quality of microholes were solved.