钛合金椭圆超声振动辅助切削表面质量仿真研究

Simulation Study on Surface Quality of Titanium Alloy in Elliptical Ultrasonic Vibration-Assisted Machining

椭圆超声振动辅助切削(EVAM)技术是提高难加工材料加工质量一种有效的加工方法。建立超声振动有限元模型研究超声振动参数(频率和振幅)对Ti6Al4V加工残余应力和表面形貌的影响规律。有限元分析结果表明,超声振动切削可以增大工件的最大残余压应力分布深度,但会恶化工件表面形貌完整性。Y方向振动对工件表面的脉冲冲击载荷有利于增大工件的残余压应力场。工件表面形貌完整性随着振动频率和X方向振幅增大逐渐改善,随Y方向振幅增大逐渐恶化。提高振动频率和振幅均有利于工件表面残余压应力的形成,从而有利于提高工件的加工质量。

Elliptical ultrasonic vibration-assisted machining(EVAM) technology is an effective method to improve the processing quality of difficult-to-cut materials. The aim of the present study was to develop a finite element model in order to investigate the effects of ultrasonic vibration parameters(frequency and amplitude) on the machining residual stress and surface morphology of Ti6Al4V. The results of finite element analysis showed that ultrasonic vibration-assisted cutting could increase the maximum residual compressive stress distribution depth, but would deteriorate the surface morphological integrity of the workpiece. The Y-directiona vibration impulse impact load on the surface of the workpiece was conducive to increase the residual compressive stress field of the workpiece. The morphological integrity of the workpiece surface gradually improved with the increasing of vibration frequency and X-direction amplitude, and deteriorated with the increasing of Y-direction amplitude. Increasing the vibration frequency and amplitude was beneficial to the formation of residual compressive stresses on the workpiece surface and improve the machining quality of the workpiece.