摘要
针对飞秒激光加工硬脆材料过程中存在重凝、微裂纹、崩边等物理缺陷,为获得高质量加工面,提出超声气体射流辅助飞秒激光加工方法。以刻蚀石英微槽为研究对象,探讨了超声气体射流辅助飞秒激光加工机理,探究了超声频率、超声功率及气体入口压力对飞秒激光刻蚀石英微槽深度及深宽比的影响规律,对比分析了有无超声气体射流辅助下飞秒激光刻蚀石英微槽形貌。实验结果表明,在飞秒激光重复频率20 kHz、单脉冲能量50μJ、离焦量0μm、扫描速度4 mm/s、单次扫描加工条件下,石英微槽深宽比从无超声气体射流辅助下的0.81提升至超声气体射流辅助下的1.23,槽深由27.16μm增加到48.82μm,此时超声气体射流参数为气体入口压力0.6 MPa、超声频率28 kHz、超声功率300 W。在超声气体射流辅助下石英微槽表面附着颗粒物减小,表面形貌显著提高。
Hard and brittle dielectric materials represented by quartz are widely used in aerospace,consumer electronics,weapons and other fields.In view of the defects such as re-condensation and microcracks in the process of femtosecond laser machining such materials,the ultrasonic gas jet assisted femtosecond laser machining technology is proposed.The steady-state jet is transformed into pulsating jet through the coupling of ultrasonic and gas jet.With the help of the purging effect of gas jet and the highfrequency scouring and crushing effect of pulsating jet,the re-condensate produced in the machining process is taken away,which reduces the adhesion of re-condensate on the machined wall,improves the machining efficiency and improves the machining quality.Firstly,this paper proposes an ultrasonic gas jet device and analyzes the coupling mechanism of ultrasonic and gas jet.The coupling effect of ultrasonic and gas jet is mainly manifested in two aspects.One is that the local shock wave structure is formed by the direct coupling of ultrasonic and inlet jet.The formation of shock wave structure originates from the combination of sound pressure and jet pressure.Due to the alternating propagation of ultrasonic sound pressure with time,the combination of sound pressure and jet pressure makes the gas jet change from a steady jet to pulsating jet with alternating high and low pressure.Second,the ultrasonic transducer is mechanically fixed with the jet nozzle,and the high-frequency micro-displacement generated by the transducer is transmitted to the nozzle.The high-frequency displacement of the nozzle drives the whole flow field to generate high-frequency vibration,thus high-frequency scouring the machined surface.The coupling effect of ultrasonic sound pressure and jet pressure is deduced theoretically,and simulated with ANSYS Fluent software.The theoretical analysis and simulation results show that the steady-state jet is transformed into a pulsating jet,alternating high and low pressure under the action of ultrasound.Secondly
作者
何魁魁
戴玉堂
严超凡
HE Kuikui;DAI Yutang;YAN Chaofan(National Engineering Research Center of Fiber Optic Sensing Technology and Networks,Wuhan University of Technology,Wuhan 430070,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2022年第11期142-152,共11页
Acta Photonica Sinica
基金
国家自然科学基金(No.51975442)。
关键词
飞秒激光
气体射流辅助
石英微槽
形貌改善
超快光学
Femtosecond laser
Gas jet assistance
Quartz microgrooves
Morphology improvement
Ultrafast optics
