| In recent years,the application of high temperature alloy materials is increasingly widespread.Due to the excellent properties of this material,superalloys have recently become the main application materials for aero-engines,gas turbines and other devices.At the same time,superalloys are also one of the most difficult materials to process.In order to solve the machining problems of superalloys,the ultrasonic assisted threading technology of superalloys was studied in this paper.According to the processing characteristics of superalloy,a set of ultrasonic assisted turning machining system was established.The ultrasonic assisted machining technology is analyzed theoretically,and the mechanism of ultrasonic assisted machining to improve machining quality is discussed.At the same time,ultrasonic assisted thread turning machining experiment of GH4169 superalloy was carried out by using the established ultrasonic turning system,and a good machining result was obtained.It provides a reference for the theory and experimental research of high temperature alloy ultrasonic assisted thread processing technology.The main research contents are as follows:(1)The research status of ultrasonic turning machining technology and high temperature alloy turning machining technology are introduced.The application fields,material characteristics and processing characteristics of high temperature alloy materials are analyzed.Clarified the research purpose and significance of the subject,and discussed the processing characteristics of ultrasonic assisted thread turning.(2)Discusses the basic principle of ultrasonic assisted turning machining,and analyzes the tool path during machining.By analyzing the relationship between the tool path and the workpiece surface,the reason of the ultrasonic machining to improve the surface quality of the workpiece is analyzed.At the same time,the influence of machining parameters on the performance of the ultrasonic machining is analyzed.(3)According to the processing characteristics of superalloy material,a set of ultrasonic assisted thread turning processing system was established.The classification and characteristics of ultrasonic transducers and horn are introduced,and the appropriate ultrasonic vibration unit is selected to form the processing system.Dedicated fixtures were designed to assemble the ultrasonic system with the lathe to achieve the ultrasonic assisted thread turning process.(4)ANSYS software is used to analyze the key components of ultrasonic assisted machining system.The natural frequencies of the ultrasonic vibrating unit,the screwdriver and the fixture base were obtained.The dynamic changes of each device are analyzed to ensure the stability of the system.(5)Comparative experiment on ultrasonic assisted thread turning of GH4169 nickelbase superalloy by ultrasonic assisted machining system.The effects of ultrasonic assisted machining technology on workpiece surface quality,chip morphology and tool wear and the relationship between processing parameters and ultrasonic assisted machining performance were analyzed. |
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