The Study On Stability Of Ultrasonic Vibration Assisted Milling System

The development of China's space industry is restricted by the higher cutting force,uncontrolled vibration and lower precision during the process of milling aviation materials.How to improve machining quality and efficiency of aviation materials has become an urgent issue to be solved for the space and other manufacturing industry.It is one of the main reasons for reducing the quality and efficiency of the product owing to improper selection of parameters in milling process.Therefore,it is imperative to research milling technology by which we can achieve the purpose of no chatter and maximum material removal rate on account of optimization process parameters.In this paper,ultrasonic vibration which is a good method of restraining chatter combined with milling is studied.Meanwhile discussing the stability of ultrasonic vibration assisted milling system is to acquire milling aviation materials without flutter and enhance aviation material processing quality and efficiency.The main research content and results are as follows:Taking the regenerative effect and edge effect of multiple directions(feed direction,vertical feed direction,elliptical,torsion)into consideration,the cutting force model of ultrasonic vibration assisted milling system was constructed on the ground of experiment modal method,while the dynamic model of this system was further established on the basis of linearization of nonlinear periodic function.The tip trajectory with different direction of ultrasonic vibration assisted milling system has been simulated and analyzed its characteristic by considering cutting separation effect.What has been discussed provided trajectory method in time domain as a window function to identify real instantaneous cutting thickness,which was connected with the full-discretization method to analysis the system stability and obtained the outcome decided by the parameters of process stability boundary and the theoretical prediction.The theoretical simulation basically matching the experimental results revealed that it was feasible and reliable for the system stability analysis by the trajectory method in time domain.In this paper,we can discuss the influence trend of various parameters on the stability boundary of ultrasonic vibration of different direction assisted milling system,acquire the influence law of various parameters on system stability lobes.The priority order of parameters and optimizing direction to improve the system stability was raised.Chatter tests confirm the predicting trends were in accord with actual cutting and provide the criterion of optimizing process parameters and achieve machining without flutter.After have been study the stability of different direction ultrasonic vibration assisted milling system,the conclusions can be drawn.The trajectory method is a simple and practical method and high computational efficiency,it creates a new method and a new way of intermittent cutting criterion.The influence of technological parameters on the system stability and surface processing quality provides the basis for the optimization of processing parameters.Ultrasonic vibration assisted milling of titanium alloy can improve the stability of the system and further improve the machining quality and machining efficiency of the workpiece.It can realize precision machining of aerospace materials.