Simulation and Experimental Study on Reverse Helical Milling with the Gradual-Removal Reverse Edge Milling Cutter under Ultrasonic-Assisted Condition

Abstract

As a new machining method, ultrasonic-assisted bi-direction helical milling has obvious advantages in making holes on carbon fiber-reinforced plastics (CFRP). However, cutting edges of the flat-bottomed milling cutter are easy to wear, which may cause severe defects such as burrs and tears in the outlet of the hole. In order to improve the hole-making quality of CFRP, the gradual-removal reverse edge milling cutter was proposed and designed. The finite method models of reverse helical milling CFRP with the flat-bottomed reverse edge milling cutter and the gradual-removal reverse edge milling cutter under an ultrasonic vibration were established, and the comparative cutting experiments of the two cutters were carried out. By comparing the cutting performance of the two milling cutters under the condition of ultrasonic vibration assistance, the cutting mechanism of improving the hole wall quality by the gradual-removal reverse edge milling cutter was studied. The results showed that when the reverse cumulative cutting depth reached about 60 mm, compared with the flat-bottomed reverse edge milling cutter, the gradual-removal reverse edge milling cutter transferred part of the cutting task of the peripheral edge to the end edge, and the wear of the reverse peripheral edges which directly affects the hole quality was effectively alleviated. This mechanism made the cutting state of the peripheral edge dominated by shear failure, which led to the significant improvement of the quality at the outlet of the hole.

An Analytical and Experimental Study on Cutting Characteristics and Transient Cutting Force Modeling in Feed Directional Ultrasonic Vibration-Assisted Cutting of High Strength Alloys

“…Based on the ultrasonic vibration amplitude and experimental cutting parameters in published Refs. [ 6 , 7 , 8 , 9 , 10 , 11 ], the cutting parameters for the experiment are planned and presented in Table 3 . Each cutting experiment has repeated ten times and the experimental cutting force are determined by averaging those cutting force value.…”

“…A number of studies [ 11 , 12 ] showed that the ultrasonic vibration lowered the material strength by the activation of blocked dislocations. This effect is regarded as the thermal softening and acoustic softening effect.…”

“…On the other hand, the ultrasonic vibration associated with alternation of workpiece materials properties, friction between chip and rake face, and cutting deformation was also reported to contribute to the reduced cutting force [ 10 ]. It was found that work-hardening and flow stress drops (also referred to as acoustic softening) existed in ultrasonic vibration-assisted machining [ 11 ]. The softening was caused by friction effect, thermal softening, and stress superposition [ 12 ].…”

Research on Design and Cutting Performance of Revolving Lemniscate Milling Cutter

“…Ren at al. [23] proposed a gradualremoval reverse edge milling cutter and demonstrated through simulation experiments that better accuracy can be achieved by using the gradual-removal reverse edge milling cutter in machining the inner wall of parts compared with the flat end milling cutter. Chen at al.…”