Developments in Ceramic Materials Research

C hipping thickness (mm)
1.2
1
0.8
0.6
0.4
Recent Advances in Rotary Ultrasonic Machining of Ceramics 39
1000 3000
Spindle speed (rpm)
C hipping thickness (mm)
1.2
1
0.8
0.6
0.4
0.09 0.155
Feedrate (mm/s)
C hipping thickness (mm)
1.2
1
0.8
0.6
0.4
4.5 8 10.5
Support length (mm)
(a) (b) (c)
Figure 3. Effects of process parameters on edge chipping thickness (After [Jiao et al., 2005; Li et al.,
2006]).
The support length is the radial length of the contact area between the workpiece and the
fixture, as shown in Figure 1. It also has a significant effect on the edge chipping thickness
[Li et al., 2006]. The edge chipping thickness decreases as the support length increases, as
shown in Figure 3(c).
It is reported that grit size, ultrasonic vibration power, and pretightening load do not
affect the edge chipping thickness significantly [Jiao et al., 2005, Li et al., 2006].
The interaction between spindle speed and feedrate has a significant effect on edge
chipping thickness when RUM of alumina [Jiao et al., 2005]. As shown in Figure 4(a), at the
high level of feedrate (0.155 mm/s), a change in spindle speed causes a larger change in edge
chipping thickness than at the low level of feedrate (0.09 mm/s).
The interaction between feedrate and grit size also has a significant effect on edge
chipping thickness. As shown in Figure 4(b), at the low level of grit size (mesh 140/170), a
change in feedrate causes a larger change in edge chipping thickness than at the level of grit
size (mesh 270/350).
Chipping thickness (mm)
1.2
1
0.8
0.6
Feedrate
low
Feedrate
high
1000 3000
Spindle speed (rpm)
Chipping thickness (mm)
1.2
1
0.8
0.6
Grit size
high
Grit size
low
0.09 0.155
Feedrate (mm/s)
(a) (b)
Figure 4. Two-factor interaction effects on edge chipping thickness (after [Jiao et al., 2005]).