不同振动方式下的钛合金超声振动铣削表面完整性研究

钛合金在机械工程领域应用广泛,其加工表面完整性对钛合金工件的耐磨性、疲劳强度、使用寿命有着非常重要的影响。通过对工件施加不同振动方向的超声振动,开展了不同振动方向下的TC4钛合金超声振动侧铣平面试验,分析了不同振动方式的运动学轨迹特征,研究了振动方式、切削参数对钛合金加工表面完整性的影响规律。结果表明:法向振动铣削后的表面形貌变形程度、表面粗糙度均大于切向振动和轴向振动;随振幅的增大,法向振动铣削和切向振动铣削表面粗糙度呈上升趋势,轴向振动铣削呈下降趋势;法向振动铣削的表面显微硬度大于轴向振动铣削与切向振动铣削,当振幅大于3.5μm时随着振幅的增加三者都呈现出减小的趋势。法向振动铣削的表面残余应力均大于轴向振动铣削和切向振动铣削,振幅为3.5μm时的残余应力均大于振幅为5.4μm时的残余应力。与普通铣削相比,超声振动铣削能够提高加工表面的显微硬度和残余压应力,对于改善工件的耐磨性和抗疲劳性具有重要的作用。

Influence of vibration modes on surface integrity during ultrasonic vibration milling of titanium alloy

Titanium alloys are widely used in the field of mechanical engineering,and their machined surface integrity plays an important role in the wear resistance,fatigue strength and service life of titanium alloy workpieces.In this paper,ultrasonic vibration side milling experiments of TC4 titanium alloy in different vibration directions were carried out by applying ultrasonic vibration to the titanium alloy workpieces.The kinematic characteristics of different vibration modes were analyzed,and the influence of cutting parameters and vibration modes on the surface integrity of titanium alloy was studied.The results show that the surface morphology deformation degree and surface roughness of normal vibration milling were greater than tangential vibration and axial vibration.The surface roughness of normal vibration milling and tangential vibration milling shows an upward trend,while that of axial vibration milling shows a downward trend with the increase of amplitude.The surface microhardness of normal vibration milling is greater than that of tangential vibration milling.Both axial and tangential vibration milling show a decreasing trend with the increase of the amplitude when the amplitude is larger than 3.5μm.Surface residual stress in normal vibration milling is greater than that in axial vibration milling and tangential vibration milling,and residual stress in amplitude of 3.5μm is greater than that in the amplitude of 5.4μm.Compared with common milling,ultrasonic vibration milling can improve the microhardness and residual compressive stress of the machined surface,which plays an important role in improving the wear resistance and fatigue resistance of the workpieces.