ORIGINAL ARTICLEUltrasonic vibration-assisted milling of aluminum alloy Xue-Hui Shen&Jian-Hua Zhang&Hua Li& Jin-Jun Wang&Xiao-Chen Wang Received: 29 April 2010 / Accepted: 26 December 20
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Ultrasonic vibration-assisted milling of aluminum alloy
Xue-Hui Shen&Jian-Hua Zhang&Hua Li&
Jin-Jun Wang&Xiao-Chen Wang
Received: 29 April 2010 / Accepted: 26 December 2011 / Published online: 14 January 2012
Abstract The objective of this paper is to investigate
the effects of assisted ultrasonic vibration in the
opera-tion of micro end milling Based upon numerical
anal-ysis for the trajectory of a tool tip of a two-flute end
mill, it was found that the assisted feed direction
ultra-sonic vibration can achieve separate-type milling that is
different from conventional operation by reasonable
pa-rameter matching To validate theoretical analysis and
investigate the influence of ultrasonic vibration on
mill-ing process, a slot-millmill-ing experiment was conducted on
an aluminum alloy work piece The desired ultrasonic
vibration was applied in the feed direction by an
ultra-sonic vibrator Through investigating and comparing
some experimental results involving cutting force, chip
formation, surface topography, surface roughness, and
machining dimensional accuracy, the authors found that
micro end milling with ultrasonic vibration in the feed
direction leads to a pulse-like cutting force and
produ-ces uniform small chips Assisted ultrasonic vibration in
the feed direction has a negative effect on the surface
roughness of the slot bottom, but a positive effect on
the dimensional accuracy of the slot width
Keywords Vibration cutting End milling Micro milling Ultrasonic vibration Aluminum alloy
1 Introduction
Ultrasonic vibration cutting (UVC) characterized by separate-type cutting is a cutting method in which vibration at a regular frequency within an ultrasonic range is imposed on the cutting tool or the workpiece to achieve better cutting effects Turning and drilling are two major fields of the application and study
of UVC, and a significant number of excellent cutting per-formances have been obtained
Some reports can be found in the literature on turning with ultrasonic vibration Jin and Murakawa found that precision cutting could be carried out for a workpiece with high hardness and the tool life could also be increased [1] A conclusion that cutting force would be reduced in ultrasonic cutting glasses was drawn by Zhou et al [2] Ductile ma-chining of fused silica was achieved even for 2μm depth of cut with ultrasonic vibration [3] Xiao et al pointed out that chatter could be effectively suppressed irrespective of the tool geometry by ultrasonic vibration cutting [4] Ultrasonic vibration-assisted cutting was also proved to be able to improve the ductile mode cutting performance of tungsten carbide material [5] A high-quality mirror surface was finished by ultrasonic vibration-assisted turning [6] Zhou
et al found that surface roughness of the aluminum-based metal matrix composite became better when being turned with ultrasonic vibration [7] A better surface finish and low tool wear acceleration results were obtained when ultrasonic vibration was used during low alloy steel cutting [8] Shamoto et al proposed an elliptical vibration cutting method, which is two-dimensional vibration cutting, and they also
Department of Mechanical and Automotive Engineering,
Shandong Polytechnic University,
Daxue Road, Western University Science Park,
Jinan 250353, China
e-mail: xhshen@spu.edu.cn
Department of Mechanical Engineering, Shandong University,
Jingshi Road,
Jinan 250061, China
e-mail: jhzhang@sdu.edu.cn
Int J Adv Manuf Technol (2012) 63:41–49
DOI 10.1007/s00170-011-3882-5
# Springer-Verlag London Limited 2012
Trang 2investigated the effect of ultrasonic vibration on machining
accuracy [9,10]
Drilling is another field of the application and study of
UVC Early related studies were mainly focused on the
precision drilling of wood [11, 12] Steel and aluminum
also drew some attentions in the use of ultrasonic
vi-bration drilling to prolong tool life [13, 14] Conclusion
that the heat generated during vibration drilling is
ef-fectively reduced has been drawn [1] Research has also
found that the feed direction cutting force can be
re-duced by 10–20% in the ultrasonic vibration drilling of
titanium alloy [15]
Ultrasonic vibration-assisted cutting is an effective
method to obtain better cutting performance, and this
combined machining technology has been widely used
in successful turning and drilling However, only
low-frequency vibration-assisted micro-milling was
experi-mentally studied by Chern and Chang [16], ultrasonic
vibration-assisted cutting technology has not yet been
conducted in the field of milling This paper
investi-gates the effects of assisted ultrasonic vibration in a
micro end milling operation Kinematical analysis is
achieved to describe the exact trajectory of the tool tip when ultrasonic vibration is applied in the feed direc-tion A slot-milling experiment with an aluminum alloy workpiece was carried out to investigate vibration cut-ting effects Ultrasonic vibration is conducted from the workpiece side in the feed direction by an ultrasonic vibrator The experimental results are hereby presented and discussed
2 Numerical analysis of tool tip trajectory
The exact trajectory of tool tip is trochoidal curve in micro end milling operation In the case of a two-flute end mill, the trajectories of the two tool tips during one period of motion are illustrated in Fig.1, where the dashed curve and the real line curve represent the trajectory of first and second tool tip
According to the coordinate system in Fig.1, and taking point P as the beginning point of calculation, the trajectory
of the tool tip can be expressed as follows
xi¼ vf t þ2pi
z
þ r sin wtð Þ ð1Þ
else,
xir cosðwtÞ yivf t þ2pi
z
yir sinðwtÞ ¼ 0 ð3Þ Where r is defined as tool radius, ω is defined as spindle angular velocity,vfis defined as feed rate, andi is defined as the sequence number of the cutting edge (i00, 1 for the two-flute end mill and i00, 1, 2, 3 for the four-flute end mill) When forced ultrasonic vibration with certain amplitude and
Fig 1 Coordinate system for micro end milling
Fig 2 Trajectories of tool tips (a without vibration, b with vibration in the feed direction)