The Joint Strike Fighter jet engine contains more than 1.2 million holes. The cooling holes with a diameter of 0.2 mm are drilled by laser radiation with high aspect ratios up to 50 and hole densities up to 100 per square centimeter. Due to the requirements for efficient laser drilling, much work is performed regarding a deeper process understanding on improving the underlying physical process and influence of process gases on the drilling process. Percussion drilling with temporal and spatial superposed laser radiation exhibits an increase in drilling speed. However, there are fewer papers reported about the in-fluence of double pulse drilling on cooling holes quality, and engine manufacturers stress the need for repeatability in the diameter of these holes that enable reduced fuel consumption. The paper consists of three parts. Firstly, the configurations of double pulse lasers are described and the features are compared. Secondly, the influence of double pulse on drilling speed and quality are concisely reviewed. Third, the approach of improving the double pulse drilling quality is summarized.

Topics
Electronic transport, Jet engine, Lasers, Energy consumption
1.
Poprawe
,
R.
 (
2008
)
Lasertechnik prospects for the production bases and examples for the innovative engineer
,
Zhang
,
D.P.
, Transl., (in Chinese),
Tsinghua Univer. Press, & Springer
,
240
–
242
.
Google Scholar
 
2.
Walther
,
K.
,
Brajdic
,
M.
, &
Kreutz
,
E.W.
 (
2008
)
Enhanced processing speed in laser drilling of stainless steel by spatially and temporally superposed pulsed Nd:YAG laser radiation
,
Int. J. Adv. Manuf. Technol.
,
35
(
9–10
),
895
–
899
.
https://doi.org/10.1007/s00170-006-0768-z
Google Scholar
Crossref
Search ADS
 
3.
Wang
,
X.J.
 (
2009
)
Improving double-pulse laser drilling quality with detection of breakthrough, in CLEO/Pacific Rim
2009
,
Shanghai, China
, TuP13–07,
1
–
2
.
Google Scholar
 
4.
Penn State Electro-Optics Center
. (
2006
)
Micro-machining laser will explore manufacturing applications for materials
,
Penn State Electro-Optics Center newsFlash
, June,
5
–
5
.
5.
Johnson
,
B.
,
Forsman
,
A.
 &
Benda
,
S.
 (
2007
)
Dual-wavelength double-pulse laser machining
,
Industrial Laser Solutions
,
22
(
11
),
24
–
26
.
Google Scholar
 
6.
Campbell
,
B.R.
,
Lehecka
,
T.M.
,
Semak
,
V.V.
 &
Thomas
,
J.G.
 (
2007
)
Effect of the double pulse format for picosecond pulse laser drilling in metals, ICALEO
2007
Congress Proceedings, Paper
M906
,
45
–
51
.
Google Scholar
 
7.
Campbell
,
B.R.
,
Campbell
,
R.C.
,
Lehecka
,
T.M.
,
Semak
,
V.V.
 &
Thomas
,
J.G.
 (
2007
)
Performance of picosecond laser pulse drilling, including an evaluation of the double pulse machining method
, in
Proc 4th International WLT, Conference on lasers in manufacting
,
605
–
611
.
Google Scholar
 
8.
Wang
,
X.D.
,
Michalowski
,
A.
,
Walter
,
D.
,
Sommerc
,
S.
,
Kraus
.
M.
,
Liu
,
J.S.
, &
Dausinger
,
F.
 (
2009
)
Laser drilling of stainless steel with nanosecond double-pulse
,
Optics & Laser Technology
41
(
2
),
148
–
153
.
https://doi.org/10.1016/j.optlastec.2008.05.021
Google Scholar
Crossref
Search ADS
 
9.
Schoonderbeek
,
A.
,
Biesheuvel
,
C.A.
,
Hofstra
,
R.M.
,
Boller
,
K.J.
 &
Meijer
,
J.
 (
2004
)
The influence of the pulse length on the drilling of matals with an excimer laser
,
J. Laser Applications
,
16
(
2
),
85
–
91
.
https://doi.org/10.2351/1.1710888
Google Scholar
Crossref
Search ADS
 
10.
Forsman
,
A.C.
,
Banks
,
P.S.
,
Perry
,
M.D.
,
Campbell
,
E.M.
,
Dodell
,
A.L.
, &
Armas
,
M.S.
 (
2005
)
Double-pulse machining as a technique for the enhancement of material removal rates in laser machining of metals
,
J. Appl. Phys.
,
98
(
3
),
033302
, 1–6.
https://doi.org/10.1063/1.1996834
Google Scholar
Crossref
Search ADS
 
11.
Yokotani
,
A.
,
Fukumoto
,
H.
,
Kanamitsu
,
Y.
,
Nagatomo
,
S.
,
Maezono
,
Y.
, &
Katto
,
M.
 (
2007
)
High speed imaging of drilling process of thin silicon substrates with double-pulsed femtosecond laser
, in
XVI International Symposium on Gas Flow, Chemical Lasers, and High-Power Lasers, Gmunden, Austria
,
Proc. SPIE
, Vol.
6346
,
63462V
, 1–7.
Google Scholar
Crossref
Search ADS
 
12.
Han
,
Z.H.
,
Zhou
,
C.H.
,
Dai
,
E.W.
, &
Xie
,
J.
 (
2008
)
Micromaching with polarized light femtosecond double pulses, (in Chinese
),
Chin. J. Lasers
,
35
(
5
),
768
–
771
.
https://doi.org/10.3788/CJL20083505.0768
Google Scholar
Crossref
Search ADS
 
13.
Brown
,
R.T.
 (
2001
) Percussion Drilling, in
Ready
,
J.F.
 &
Farson
,
D.F.
 (ed.)
LIA Handbook of Laser Materials Processing
,
497
–
498
.
Google Scholar
 
14.
Forsman
,
A.C.
,
Lundgren
,
E.H.
,
Dodell
,
A.L.
, &
Komashko
,
A.M.
 (
2007
)
Double-pulse format for improved laser drilling
,
Photonics Spectra
,
41
(
9
),
72
–
78
.
Google Scholar
 
15.
Forsman
,
A.
,
Lundgren
,
E.
, &
Komashko
,
A.
 (
2008
)
Laser-matter interactions confined in small high aspect ratio holes
,
2008
Warm Dense Matter Winter School, Lawrence Berkeley National Laboratory
,
1
–
38
.
Google Scholar
 
16.
Naeem
,
M.
 &
Chinn
,
J.
 (
2008
)
Advancement in laser drilling for aerospace gas turbines
, in
PICALO 2008 Conference Proceedings
,
Beijing, China
,
197
–
202
.
Google Scholar
Crossref
Search ADS
 
This content is only available via PDF.
© 2010 Laser Institute of America.
2010
Laser Institute of America
You do not currently have access to this content.