| With the rapid development of modern industrial technology,complex parts with new structures and new materials continue to appear,and the corresponding processing requirements are constantly increasing.The processing of micro-holes in various industries such as aerospace,electronics,and automobile manufacturing has always been a key manufacturing technical problem,and has been highly valued by all walks of life at home and abroad.Jet electrochemical machining is one of the main methods of micro-hole machining,but there are also disadvantages such as weak localization,hydraulic jump,and insufficient machining stability.Considering that ultrasonic has the advantages of directivity,energy concentration,and good penetration,and physical and chemical effects such as cavitation,thermal,and mechanical effects during the propagation process,this thesis combines jet electrochemical machining with ultrasonic machining technology,and proposes a method of immersed ultrasonicassisted jet electrochemical machining system.The main research contents of this thesis are as follows:(1)Introduce the composite electrochemical machining technology,focusing on the research status of jet electrochemical machining,jet electrochemical composite machining,and ultrasonic machining,and analyze the principle of jet electrochemical technology and related ultrasonic theories.Based on the related theoretical research,the method of immersed ultrasonic-assisted jet electrochemical machining is proposed,and the corresponding structural scheme is designed.(2)The 20 k Hz ultrasonic vibration system is designed by using the transmission matrix method and the half-wavelength principle.According to the working requirements of the ultrasonic vibration system,the immersed ultrasonic-assisted jet electrochemical machining system and its corresponding connection and sealing form are designed.(3)Modal analysis and optimization on the designed three-dimensional model of ultrasonic vibration system are performed by using ANSYS Workbench,so that its resonance frequency is close to the design frequency,and the optimized ultrasonic vibrator frequency is 19.952 k Hz.The harmonic response analysis of the optimized ultrasonic vibrator is carried out to ensure that the output amplitude of the ultrasonic vibrator meets the processing requirements.(4)By using the finite element analysis software COMSOL,the acoustic field of the electrolysis chamber is analyzed and the corresponding structure is optimized.The flow field analysis obtains the flow of the electrolysis chamber,and simulates the effect of ultrasound to obtain the flow change of the electrolysis chamber.Using COMSOL to conduct multi-physics coupling analysis on the electric field,flow field and geometric deformation of the machining gap,the erosion rule of the workpiece under jet electrochemical machining is obtained.(5)The designed and processed immersed ultrasonic-assisted jet electrochemical machining system is assembled to build an experimental platform,and the rationality of the ultrasonic vibration system design is verified through impedance testing.The effect of ultrasound on the conductivity of the electrolyte is explored.The preexperiments are carried out to verify the reliability and rationality of the entire system.The ultrasonic-assisted jet electrochemical machining experiment is conducted according to a single variable,and an ultra-depth-of-field microscope is used to detect the surface of the processed small hole,and the experimental results are obtained.The experimental results show that the immersion ultrasonic assisted jet electrochemical machining system can effectively improve the fluidity of the jet liquid beam,improve the hydraulic jump phenomenon,make the processing stable,reduce the processing gap,significantly reduce the processing aperture,increase the depth-todiameter ratio,and enhance the localization of processing Performance and improve processing quality. |
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