This paper presents an investigation into the influence of laser drilling on the tensile strength of carbon fiber reinforced plastic (CFRP) laminates of 1 and 2.5 mm thickness. The CFRP laminates were drilled using the microsecond laser, nanosecond laser, and picosecond laser, and the heat-affected zone (HAZ) was characterized and measured by optical microscopy. Through setting laser parameters, specimens with different HAZs were prepared, and then tensile strength tests were conducted. The results indicate that the tensile strength linearly depends on the width of HAZ. The tensile strengths of 1 mm specimens decrease by approximately 122 MPa/mm HAZ, and 2.5 mm specimens decrease by approximately 33.9 MPa/mm HAZ. Comparing the results of different thicknesses of CFRP, the effect of HAZ on tensile strength would be weakened with the increasing of laminate’s thickness. Actually, besides HAZ, cutting-induced geometric defects also seriously influence tensile strength, because of the stress concentration around these defects during the stretching process. Additionally, the mechanism why the HAZ influences tensile strength was revealed visually through FEM simulation: the resin matrix damage within HAZ causes the tensile loads not be transferred effectively between the fibers and then weakens the strength. It was the first time the underlined mechanism is revealed for HAZ-inducing strength reduction through FEM simulation. The laser machining method is more suitable for processing the thicker CFRP composites because the negative effect of HAZ is weakened for the thicker material.

1.
V. A.
Phadnis
,
F.
Makhdum
,
A.
Roy
, and
V. V.
Silberschmidt
, “
Drilling in carbon/epoxy composites: Experimental investigations and finite element implementation
,”
Compos. Part A
47
,
41
51
(
2013
).
2.
S.
Nilsson
,
A.
Bredberg
, and
L. E.
Asp
, “
Effects of CFRP laminate thickness on bending after impact strength
,”
Plast. Rubber Compos.
38
,
61
66
(
2013
).
3.
F.
Klocke
,
S. L.
Soo
,
B.
Karpuschewski
,
J. A.
Webster
,
D.
Novovic
,
A.
Elfizy
,
D. A.
Axinte
, and
S.
Tönissen
, “
Abrasive machining of advanced aerospace alloys and composites
,”
CIRP Ann.
64
,
581
604
(
2015
).
4.
S. L.
Soo
,
I. S.
Shyha
,
T.
Barnett
,
D. K.
Aspinwall
, and
W.-M.
Sim
, “
Grinding performance and workpiece integrity when superabrasive edge routing carbon fibre reinforced plastic (CFRP) composites
,”
CIRP Ann.
61
,
295
298
(
2012
).
5.
M.
Li
,
S. L.
Soo
,
D. K.
Aspinwall
,
D.
Pearson
, and
W.
Leahy
, “
Study on tool wear and workpiece surface integrity following drilling of CFRP laminates with variable feed rate strategy
,”
Procedia CIRP
71
,
407
412
(
2018
).
6.
D.
Liu
,
Y.
Tang
, and
W. L.
Cong
, “
A review of mechanical drilling for composite laminates
,”
Compos. Struct.
94
,
1265
1279
(
2012
).
7.
M.
Li
,
S.
Li
,
X.
Yang
,
Y.
Zhang
, and
Z.
Liang
, “
Effect of lay-up configuration and processing parameters on surface quality during fiber laser cutting of CFRP laminates
,”
Int. J. Adv. Manuf. Technol.
100
,
623
635
(
2018
).
8.
M.
Aamir
,
M.
Tolouei-Rad
,
K.
Giasin
, and
A.
Nosrati
, “
Recent advances in drilling of carbon fiber–reinforced polymers for aerospace applications: A review
,”
Int. J. Adv. Manuf. Technol.
105
,
2289
2308
(
2019
).
9.
A.
Alberdi
,
T.
Artaza
,
A.
Suárez
,
A.
Rivero
, and
F.
Girot
, “
An experimental study on abrasive waterjet cutting of CFRP/Ti6Al4V stacks for drilling operations
,”
Int. J. Adv. Manuf. Technol.
86
,
691
704
(
2015
).
10.
N.
Tao
,
G.
Chen
,
T.
Yu
,
W.
Li
, and
L.
Fan
, “
Dual-beam laser drilling process for thick carbon fiber reinforced plastic composites plates
,”
J. Mater. Process. Technol.
281
,
116590
(
2020
).
11.
M.
El-Hofy
,
M. O.
Helmy
,
G.
Escobar-Palafox
,
K.
Kerrigan
,
R.
Scaife
, and
H.
El-Hofy
, “
Abrasive water jet machining of multidirectional CFRP laminates
,”
Procedia CIRP
68
,
535
540
(
2018
).
12.
Y.
Wang
,
Z.
Zhang
,
G.
Zhang
,
B.
Wang
, and
W.
Zhang
, “
Study on immersion waterjet assisted laser micromachining process
,”
J. Mater. Process. Technol.
262
,
290
298
(
2018
).
13.
T.
Ohkubo
,
Y.
Sato
,
E.-i.
Matsunaga
, and
M.
Tsukamoto
, “
Thermal effect of laser ablation on the surface of carbon fiber reinforced plastic during laser processing
,”
Appl. Phys. A
124
,
149
(
2018
).
14.
M. H.
El-Hofy
and
H.
El-Hofy
, “
Laser beam machining of carbon fiber reinforced composites: A review
,”
Int. J. Adv. Manuf. Technol.
101
,
2965
2975
(
2018
).
15.
M.
Li
,
S.
Li
,
X.
Yang
,
Y.
Zhang
, and
Z.
Liang
, “
Fiber laser cutting of CFRP laminates with single- and multi-pass strategy: A feasibility study
,”
Opt. Laser Technol.
107
,
443
453
(
2018
).
16.
R.
Staehr
,
S.
Bluemel
,
P.
Jaeschke
,
O.
Suttmann
, and
L.
Overmeyer
, “
Laser cutting of composites—Two approaches toward an industrial establishment
,”
J. Laser Appl.
28
,
022203
(
2016
).
17.
Z. L.
Li
,
H. Y.
Zheng
,
G. C.
Lim
,
P. L.
Chu
, and
L.
Li
, “
Study on UV laser machining quality of carbon fibre reinforced composites
,”
Compos. Part A
41
,
1403
1408
(
2010
).
18.
A.
Salama
,
L.
Li
,
P.
Mativenga
, and
A.
Sabli
, “
High-power picosecond laser drilling/machining of carbon fibre-reinforced polymer (CFRP) composites
,”
Appl. Phys. A
122
,
73
(
2016
).
19.
C.
Leone
,
S.
Genna
, and
V.
Tagliaferri
, “
Fibre laser cutting of CFRP thin sheets by multi-passes scan technique
,”
Opt. Lasers Eng.
53
,
43
50
(
2014
).
20.
C.
Leone
and
S.
Genna
, “
Heat affected zone extension in pulsed Nd:YAG laser cutting of CFRP
,”
Compos. Part B
140
,
174
182
(
2018
).
21.
R.
Weber
,
C.
Freitag
,
T. V.
Kononenko
,
M.
Hafner
,
V.
Onuseit
,
P.
Berger
, and
T.
Graf
, “
Short-pulse laser processing of CFRP
,”
Phys. Procedia
39
,
137
146
(
2012
).
22.
C.
Freitag
,
T. V.
Kononenko
,
R.
Weber
,
V. I.
Konov
, and
T.
Graf
, “
Influence of pulse repetition rate and pulse energy on the heat accumulation between subsequent laser pulses during laser processing of CFRP with ps pulses
,”
Appl. Phys. A
124
,
479
(
2018
).
23.
T. V.
Kononenko
,
C.
Freitag
,
M. S.
Komlenok
,
V.
Onuseit
,
R.
Weber
,
T.
Graf
, and
V. I.
Konov
, “
Oxygen-assisted multipass cutting of carbon fiber reinforced plastics with ultra-short laser pulses
,”
J. Appl. Phys.
115
,
103107
(
2014
).
24.
R.
Negarestani
,
L.
Li
,
H. K.
Sezer
,
D.
Whitehead
, and
J.
Methven
, “
Nano-second pulsed DPSS Nd:YAG laser cutting of CFRP composites with mixed reactive and inert gases
,”
Int. J. Adv. Manuf. Technol.
49
,
553
566
(
2010
).
25.
A.
Wolynski
,
T.
Herrmann
,
P.
Mucha
,
H.
Haloui
, and
J.
L’huillier
, “
Laser ablation of CFRP using picosecond laser pulses at different wavelengths from UV to IR
,”
Phys. Procedia
12
,
292
301
(
2011
).
26.
D.
Herzog
,
P.
Jaeschke
,
O.
Meier
, and
H.
Haferkamp
, “
Investigations on the thermal effect caused by laser cutting with respect to static strength of CFRP
,”
Int. J. Mach. Tools Manuf.
48
,
1464
1473
(
2008
).
27.
Y.
Harada
,
K.
Kawai
,
T.
Suzuki
, and
T.
Teramoto
, “
Evaluation of cutting process on the tensile and fatigue strength of CFRP composites
,”
Mater. Sci. Forum
706–709
,
649
654
(
2012
).
28.
J.
Hu
and
D.
Zhu
, “
Experimental study on the picosecond pulsed laser cutting of carbon fiber-reinforced plastics
,”
J. Reinf. Plast. Compos.
37
,
993
1003
(
2018
).
29.
F.
Chen
,
W.
Yao
, and
W.
Jiang
, “
A macro-meso correlation model for numerical simulation of CFRP tensile notched strength
,”
Math. Probl. Eng.
2020
,
1
14
.
30.
H.
Zhang
,
P.
Zhu
,
Z.
Liu
,
S.
Qi
, and
Y.
Zhu
, “
Research on prediction method of mechanical properties of open-hole laminated plain woven CFRP composites considering drilling-induced delamination damage
,”
Mech. Adv. Mater. Struct.
(published online, 2020).
31.
S.
Oh
,
I.
Lee
,
Y.-B.
Park
, and
H.
Ki
, “
Investigation of cut quality in fiber laser cutting of CFRP
,”
Opt. Laser Technol.
113
,
129
140
(
2019
).
32.
M.
Li
,
S.
Li
,
G.
Gan
,
Y.
Zhang
,
Z.
Liang
, and
X.
Yang
, “
Experimental study on hole quality and tensile progressive failure following fiber laser cutting of multidirectional carbon fiber reinforced plastic laminates
,”
J. Laser Appl.
31
,
012004
(
2019
).
33.
F. A.
Al-Sulaiman
,
B. S.
Yilbas
, and
M.
Ahsan
, “
CO2 laser cutting of a carbon/carbon multi-lamelled plain-weave structure
,”
J. Mater. Process. Technol.
173
,
345
351
(
2006
).
34.
G. L. G.
Jose Mathew
,
N.
Ramakrishnan
, and
N. K.
Naik
, “
Parametric studies on pulsed NdYAG laser cutting of carbon fibre reinforced plastic composites
,”
J. Mater. Process. Technol.
89–90
,
198
203
(
1999
).
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