Z-map based cutting force prediction for elliptical ultrasonic vibration-assisted milling process

Zhongqun Li,Jiandong Xiao,Weifeng Zhang,Xiong Han

doi:10.1007/s00170-022-08976-w

Abstract

Elliptical ultrasonic vibration-assisted milling (EUVAM) adds high-frequency vibration to conventional milling (CM) to realize high-frequency intermittent milling. It has broad application prospects in the processing of difficult-to-cut materials such as titanium alloys, superalloys, and hard and brittle materials. To reveal the mechanism of the highly intermittent cutting nature in EUVAM, according to the motion relationship between the cutting edge and the workpiece and the Z-map representation of the workpiece, a method and its algorithm for calculating the undeformed cutting thickness and thus the cutting force in EUVAM are proposed. The simulation results show that EUVAM can improve the actual cutting speed when compared with CM, and the proportion of idle cutting time will directly determine the intermittent degree of the milling process. The experiment of EUVAM is performed to verify the correctness of the proposed cutting force model, and the impact of spindle speed on the cutting force in EUVAM is also analyzed. It is shown that UEVAM can reduce the cutting force by up to 50% under appropriate cutting conditions.

Highlights

When elliptical ultrasonic vibration machining technology is combined with the conventional milling technology, it is called Elliptical ultrasonic vibration-assisted milling (EUVAM)
Tong et al [12] using both finite element method and experimental method to investigate the transient cutting processes of titanium alloy with EUVAC method, compared the main cutting force of EUVAC with that of convention cutting (CC) and discovered that under EUVAC, the reduction rate of cutting forces decreases with the increase in cutting depth, and increases with the increase in cutting speed
4 Cutting force modeling for EUVAM In order to reveal the detailed process of cutting force modeling for the elliptical ultrasonic vibration milling process, this paper focuses on cylindrical end mill

Summary

Tooltip velocity equation

Find the derivative of Eq (5), the velocity equation of tooltip can be obtained as follows:. We show that due to the participation of elliptical ultrasonic vibration, the tangential cutting speed in EUVAM fluctuates around that in CM; when the spindle speed is high, the minimal tangential cutting speed is always greater than zero, that is, during one tooth-passing period, the tooth keeps cutting the workpiece until it exceeds the exit angle As shown in Fig., Op(t) is the origin of the workpiece coordinate system, Ot(t) is the tool center position which is affected by the feed rate, the elliptical vibration amplitude, and frequency, P(t) and Q(t) are the current tooth position and the intersection point of the machined surface with the cutting tool in the radial direction of the cutting tooth respectively, h(t) is the undeformed cutting thickness in the radial direction.

Methodology and algorithm for obtaining the undeformed cutting thickness

Conclusions

Findings

Ethics approval Not applicable