The relationships between focal position and diameter or taper of holes drilled by CO2 laser in ceramics were investigated by a new method named “equivalent stack plate method”(ESPM). The diameter of holes in different depth can be accurately measured by the new method. The present study reported a statistical analysis to study the effects of the focal position on the quality of the drilled holes and optimization of the processing parameter. The study was conducted based on the statistical experiments with the variable focal position from +1mm to −3mm. Then the relationship between focal position and diameter in different depth and corresponding mathematical model were ascertained by polynomial fitting analysis. The unique characteristics of ceramic during laser drilling were also discussed. The results indicate that the ideal focal position to achieve minimum taper in laser drilling holes should be set above the surface of workpiece.

1.
Yilbas
,
B.S.
&
Aleem
,
A.
(
2004
)
Laser hole drilling quality and efficiency assessment
,
Proc. Instn Mech. Engrs Part B: J. Engineering Manufacture
218
,
225
233
2.
Ghoreishi
,
M.
Low
,
D.K.Y.
&
Li
,
L.
(
2002
)
Comparative statistical analysis of hole taper and circularity in laser percussion drilling
,
International Journal of Machine Tools & Manufacture Design Research and Application
42
,
985
995
3.
Radley
,
W.O.
&
William
C. S.
(
1992
)
Laser drilling with focused Gaussian beams
,
Journal of Applied Physics
72
,
3686
3696
4.
Rok
,
P.
Igor
,
P.
Ales
,
B.
Janez
,
M.
(
2006
)
Optodynamic study of multiple pulses micro drilling
,
Ultrasonics
44
,
1191
1194
5.
Voisey
,
K.T.
Kudesia
,
S.S.
Rodden
,
W.S.O.
Hand
,
D.P.
Jones
,
J.D.C.
&
Clyne
,
T.W.
(
2003
)
Melt ejection during laser drilling of metals
,
Materials Science and Engineering A
356
,
414
424
6.
Low
,
D.K.Y.
Li
,
L.
&
Byrd
,
P.J.
(
2000
)
The effects of process parameters on spatter deposition in laser percussion drilling
,
Optics & Laser Technology
32
,
347
354
7.
Low
,
D.K.Y.
Li
,
L.
&
Corfe
,
A.G.
(
2001
)
Characteristics of spatter formation under the effects of different laser parameters during laser drilling
,
Journal of Materials Processing Technology
118
,
179
186
8.
Lu
,
R.X.
(
1981
)
A THEORETICAL CALCULATION OF METAL DRILLING BY LASER
,
ACTA PHYSICA SINICA
30
,
633
641
9.
Ghoreishi
,
M.
Low
,
D.K.Y.
&
Li
,
L.
(
2002
)
Comparative statistical analysis of hole taper and circularity in laser percussion drilling
,
International Journal of Machine Tools & Manufacture
42
,
985
995
10.
Ghoreishi
,
M.
(
2005
)
Statistical analysis of repeatability in laser percussion drilling
,
Int J Adv Manuf Technol
29
,
70
78
11.
Bandyopadhyay
,
S.
Gokhale
,
H.
Sarin Sundar
,
J.K.
Sundararajan
,
G.
&
Joshi
,
S.V.
(
2005
)
A statistical approach to determine process parameter impact in Nd: YAG laser drilling of IN718 and Ti-6Al-4V sheets
,
Optics and Lasers in Engineering
43
,
163
182
12.
Kanaoka
M.
(
2005
)
Laser Processing
,
CHINA MACHINE PRESS
,
14
pp.
13.
Guan
Z. Z.
(
1998
)
Laser Processing Hand Book
,
CHINA METROLOGY PRESS
,
30
pp.
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