Abstract
Titanium alloy and its thin-walled structures are widely used in the aerospace field. Aiming at the processing chatter and difficult-to-machine problem of titanium alloy thin-walled workpieces, rotary ultrasonic milling technology (RUM) is employed to restrict machining vibration in this paper. Firstly, for describing its dynamic characteristics, the titanium alloy web with low stiffness is equivalent to a mass-spring-damping system with three degrees of freedom. Then, a novel stability analysis method is proposed for RUM thin-walled workpiece (RUM-tww) through defining an ultrasonic function angle. Furthermore, RUM-tww stability lobe diagrams (SLDs) are achieved based on the semi-discrete method (SDM). The simulation results show that the milling stability of titanium alloy webs is improved effectively under the effect of ultrasonic vibration energy. Compared with conventional milling thin-walled workpiece (CM-tww), the stability region is increased by 80.32% within the spindle speed from 1000 to 5000r/min. Finally, the milling experiments are carried out to verify the validity and rationality of SLDs via analyzing chatter marks, cutter marks, and flatness on the machined surface. The experimental results are in good agreement with the theoretical prediction.
Highlights
In terms of the chatter avoidance, the stability lobe diagrams (SLDs) and online chatter detection are common methods
Thereby, the majority of studies about ultrasonic milling are based on the vibration of workpiece (VOW) which is droved by the ultrasonic vibration workbench [26]
In this paper, a novel stability analysis method is proposed for rotary ultrasonic milling (RUM) thin-walled workpiece (RUM-tww)
Summary
In terms of the chatter avoidance, the stability lobe diagrams (SLDs) and online chatter detection are common methods. Ultrasonic vibration cutting technology is widely applied for processing difficult-to-machine materials since it has the advantage of reducing milling force [18, 19], improving machined surface quality [20, 21] and strengthening structure stiffness [22]. The published literatures [27,28,29] about the chatter stability focus on ultrasonic vibration milling with absolute separation of the tool and workpiece mainly. As shown in the Fig. (a), the high frequency ultrasonic vibration causes intermittent contact between the bottom of cutter and machined surface of workpiece It affects the material removal inevitably by changing tool kinematic laws.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
