Research On Fused Silica Glass Welding Based On Ultrashort Laser

Glass micro-joining is widely used in various fields,including electronic components,sensor packaging and medical fields.As a noncontact and high-precision machining method with nonlinear effects,ultrashort laser can achieve glass welding without any new materials and it has small heat affected area.Meanwhile,the requirements of high precision and small heat-affected zone can be met.Still,glass welding based on ultrashort laser has shortcomings,for example,it depends on high numerical aperture lens,factors affecting welding are not clear,and the evaluation criteria after welding is not determined yet.In order to achieve glass welding with high quality,a three-step method is put forward,in which the glass welding is achieved under different laser parameters firstly,and then the modification of glass is studied,glass welding performance is finally carried out to realize the analysis of welded glass.The specific research contents are as follow:(1)Achieve glass welding by ultrashort laser with low numerical aperture to study the influence of processing parameters on glass welding.The glasses are welded under different laser pulse energy,scanning speed and focal position,and the welding results of different laser parameters are qualitatively analyzed.(2)Reveal the ultrashort laser welding mechanism based on the modified morphology of glass.According to the principle of ultrashort laser welding glass,the internal modification morphology of the glass after laser processing is studied.The relationship between the initial modification point,the modification length and the interface between the two glasses under different laser processing parameters is analyzed.(3)Build up a prediction model for the offset of the initial modification point,and select the welding parameters by combining the modified features.Oriented to explain the phenomenon that the initial modification point offset from the focal position in modification morphology,a predictive model concerning with laser pulse energy and scanning velocity is put forward and the accuracy of predictive model is verified by experiment.Based on the modification features,the relationship between modification length and different processing parameters is established to realize the selection of glass welding parameters.(4)Complete evaluation of welded morphology performance and the shear strength.The micro indentation instrument is used to measure the hardness of the glass after welding.Combined with the Raman spectroscopy experiment,the internal structure change of the glass after processing is studied to reveal the influence of laser radiation on the glass.The tensile device is designed to realize the glass welding strength test and factors affecting the welding strength of glass is analyzed.In this paper,welding of fused silica glass based on ultrashort laser is taken as the research goal.Different laser processing parameters are used to carry out qualitative research.Based on the welding results,the modified morphology is studied to reveal the cause of welding failure.The prediction model of modified initial point offset is established,combined with the modification feature data,the selection of welding parameters is realized.The weld seam and welding strength are tested to evaluate the welding performance to provide a technical method for ultrashort laser welding of glass.