Research On Single Excitation Ultrasonic Elliptical Vibration Cutting System For Titanium Alloy TC4

Titanium alloy is widely used in many fields due to its high strength, great resistance to corrosion and heat. However, its mechanical machining performance is extremely poor, the traditional cutting method can’t achieve satisfying effect, while the ultrasonic vibration cutting technology provides a solution for this problem.Ultrasonic vibration cutting technology loads the high-frequency vibration on the cutting tool, makes the tool contacting and separating from the workpiece intermittently. Thus, applying this technology can decrease the average cutting force, extend tool life and improve the machined surface quality. The main research content of this paper is to design an ultrasonic vibration cutting system for titanium alloy turning, to improve the cutting environment and processing quality.This thesis expounded the cutting principle and advantage of ultrasonic vibration assisted machining system, and designed a single excitation ultrasonic elliptical vibration cutting system according to the machining features of titanium alloy TC4. The designed ultrasonic vibration cutting system got a working frequency of 43.4k Hz, and composed of ultrasonic generator, transducer, horn and the corresponding turning tool. The function and selection of various parts of the system were discussed. The design and optimization of the horn is the most important part of the research. The preliminary design to the horn’s structural is accomplished with vibration theory and formula. The horn’s structure is optimized with the help of the modal analysis function of ANSYS Workbench, and the harmonic response analysis and transient analysis to the optimized structure were also achieved.Impedance characteristics and vibration performance of the system were tested by impedance analyzer and laser displacement sensor. The designed vibration system was applied to the cutting processing of titanium alloy, and its cutting effects were compared with the traditional cutting method’s.The simulation analysis to the tool tip’s vibration proved that the output vibration’s trajectory on the tool tip is elliptical. The vibration performance test to the vibration system proved that the actual output vibration’s trajectory on the tool tip is elliptical, too. And the turning experiments, verified that applying the designed single excitation ultrasonic elliptical vibration cutting system to the cutting process can significantly improve the machined surface quality in turning titanium alloy TC4.