Cu-based brake pads applied in high-speed railway trains containing Ni-coated graphite flake and uncoated graphite flake were fabricated by powder metallurgy. The braking properties of the brake pads were investigated by a scaled down testing apparatus with the pad-on-disk configuration under various braking speeds and braking pressures. Compared with the brake pads containing uncoated graphite flake (designated GF), the brake pads containing Ni-coated graphite flake (designated NGF) exhibits a similar braking performance at lower braking speed and pressure. However, NGF shows more stable friction coefficient, lower linear wear loss, and lower maximum temperature during the braking process at worse braking conditions, e.g., 350 km/h, 1.5 MPa. The Ni-coating on the surface of Ni-coated graphite can transfer the mechanical bonding between copper and graphite to diffusion bonding so that there is a stronger interface bonding between copper and Ni-coated graphite. Further, the multiple linear regression analyses reveal that the mean friction coefficient of NGF is more sensitive to braking pressure than braking speed because of the better thermal resistance of NGF, while the mean friction coefficient of GF and the linear wear loss are mainly affected by braking speed.

References

1.
Xiao
,
Y.
,
Zhang
,
Z.
,
Yao
,
P.
,
Fan
,
K.
,
Zhou
,
H.
,
Gong
,
T.
et al
,
2018
, “
Mechanical and Tribological Behaviors of Copper Metal Matrix Composites for Brake Pads Used in High-Speed Trains
,”
Tribol. Int.
,
119
, pp.
585
592
.
2.
Zhang
,
X.
,
Zhang
,
Y.
,
Du
,
S.
,
He
,
T.
, and
Yang
,
Z.
,
2018
, “
Influence of Braking Conditions on Tribological Performance of Copper-Based Powder Metallurgical Braking Material
,”
J. Mater. Eng. Perform.
,
27
(
9
), pp.
4473
4480
.
3.
Peng
,
T.
,
Yan
,
Q.
,
Li
,
G.
,
Zhang
,
X.
,
Wen
,
Z.
, and
Jin
,
X.
,
2017
, “
The Braking Behaviors of Cu-Based Metallic Brake Pad for High-Speed Train Under Different Initial Braking Speed
,”
Tribol. Lett.
,
65
(
135
), pp.
1
13
.
4.
Kovalchenko
,
A. M.
,
Fushchich
,
O. I.
, and
Danyluk
,
S.
,
2012
, “
The Tribological Properties and Mechanism of Wear of Cu-Based Sintered Powder Materials Containing Molybdenum Disulfide and Molybdenum Diselenite Under Unlubricated Sliding Against Copper
,”
Wear
,
290–291
, pp.
106
123
.
5.
Kennedy
,
F. E.
,
Balbahadur
,
A. C.
, and
Lashmore
,
D. S.
,
1997
, “
The Friction and Wear of Cu-Based Silicon Carbide Particulate Metal Matrix
,”
Wear
,
203–204
, pp.
715
721
.
6.
Grandin
,
M.
, and
Wiklund
,
U.
,
2018
, “
Wear Phenomena and Tribofilm Formation of Copper/Copper-Graphite Sliding Electrical Contact Materials
,”
Wear
,
398–399
, pp.
227
235
.
7.
Rodrigues
,
A. C. P.
,
Österle
,
W.
,
Gradt
,
T.
, and
Azevedo
,
C. R. F.
,
2017
, “
Impact of Copper Nanoparticles on Tribofilm Formation Determined by Pin-on-Disc Tests With Powder Supply: Addition of Artificial Third Body Consisting of Fe3O4, Cu and Graphite
,”
Tribol. Int.
,
110
, pp.
103
112
.
8.
Su
,
L.
,
Gao
,
F.
,
Han
,
X.
,
Fu
,
R.
, and
Zhang
,
E.
,
2015
, “
Tribological Behavior of Copper–Graphite Powder Third Body on Copper-Based Friction Materials
,”
Tribol. Lett..
60
(
1
), pp.
1
12
.
9.
Zhan
,
Y.
, and
Zhang
,
G.
,
2004
, “
Friction and Wear Behavior of Copper Matrix Composites Reinforced With SiC and Graphite Particles
,”
Tribol. Lett.
,
17
(
1
), pp.
91
98
.
10.
Prasad
,
B. K.
,
Rathod
,
S.
,
Yadav
,
M. S.
, and
Modi
,
O. P.
,
2010
, “
Effects of Some Solid Lubricants Suspended in Oil Toward Controlling the Wear Performance of a Cast Iron
,”
ASME J. Tribol.
,
132
(
4
), p.
041602
.
11.
Kim
,
C.
,
Lim
,
B.
,
Kim
,
B.
,
Shim
,
U.
,
Oh
,
S.
,
Sung
,
B.
, et al
,
2009
, “
Strengthening of Copper Matrix Composites by Nickel-Coated Single-Walled Carbon Nanotube Reinforcements
,”
Synthetic Met.
,
159
(
5-6
), pp.
424
429
.
12.
Dorfman
,
S.
,
Fuks
,
D.
, and
Suery
,
M.
,
1999
, “
Diffusivity of Carbon in Copper and Silver-Based Composites
,”
J. Mater. Sci.
,
34
(
1
), pp.
77
81
.
13.
Lloyd
,
J. C.
,
Neubauer
,
E.
,
Barcena
,
J.
, and
Clegg
,
W. J.
,
2010
, “
Effect of Titanium on Copper-Titanium/Carbon Nanofibre Composite Materials
,”
Compos. Sci. Technol.
,
70
(
16
), pp.
2284
2289
.
14.
Tang
,
Y. P.
,
Liu
,
L.
,
Li
,
W. W.
,
Shen
,
B.
, and
Hu
,
W. B.
,
2009
, “
Interface Characteristics and Mechanical Properties of Short Carbon Fibers/Al Composites With Different Coatings
,”
Appl. Surf. Sci.
,
255
(
8
), pp.
4399
4400
.
15.
Chu
,
K.
,
Liu
,
Z.
,
Jia
,
C.
,
Chen
,
H.
,
Liang
,
X.
, and
Gao
,
W.
,
2010
, “
Thermal Conductivity of SPS Consolidated Cu/Diamond Composites With Cr-Coated Diamond Particles
,”
J. Alloy Compd.
,
490
(
1–2
), pp.
453
458
.
16.
Moustafa
,
S. F.
,
El-Badry
,
S. A.
,
Sanadb
,
A. M.
, and
Kieback
,
B.
,
2002
, “
Friction and Wear of Copper Graphite Composites Made With Cu Coated and Uncoated Graphite Powders
,”
Wear
,
253
(
7–8
), pp.
699
710
.
17.
Chen
,
J.
,
Ren
,
S.
,
He
,
X.
, and
Qu
,
X.
,
2017
, “
Properties and Microstructure of Nickel-Coated Graphite Flakes/Copper Composites Fabricated by Spark Plasma Sintering
,”
Carbon
,
121
, pp.
25
34
.
18.
Zhao
,
J.-H.
,
Li
,
P.
,
Tang
,
Q.
,
Zhang
,
Y.-Q.
,
He
,
J.-S.
, and
He
,
K.
,
2017
, “
Influence of Metal-Coated Graphite Powders on Microstructure and Properties of the Bronze-Matrix/Graphite Composites
,”
J. Mater. Eng. Perform.
,
26
(
2
), pp.
792
801
.
19.
Sun
,
S. J.
, and
Zhang
,
M. D.
,
1991
, “
Interface Characteristics and Mechanical Properties of Carbon Fiber Reinforced Copper Composites
,”
J. Mater. Sci.
,
26
(
21
), pp.
5762
5766
.
20.
Jayashree
,
P.
,
Federici
,
M.
,
Bresciani
,
L.
,
Turani
,
S.
,
Sicigliano
,
R.
, and
Straffelini
,
G.
,
2018
, “
Effect of Steel Counterface on the Dry Sliding Behaviour of a Cu-Based Metal Matrix Composite
,”
Tribol. Lett.
,
60
(
123
), pp.
1
14
.
21.
Gultekin
,
D.
,
Uysal
,
M.
,
Aslan
,
S.
,
Alaf
,
M.
,
Guler
,
M. O.
, and
Akbulut
,
H.
,
2010
, “
The Effects of Applied Load on the Coefficient of Friction in Cu-MMC Brake Pad/Al-SiCp MMC Brake Disc System
,”
Wear
,
270
(
1–2
), pp.
73
82
.
22.
Kato
,
H.
,
Takama
,
M.
,
Iwai
,
Y.
,
Washida
,
K.
, and
Sasaki
,
Y.
,
2003
, “
Wear and Mechanical Properties of Sintered Copper–Tin Composites Containing Graphite or Molybdenum Disulfide
,”
Wear
,
255
(
1–6
), pp.
573
578
.
23.
Alemani
,
M.
,
Gialanella
,
S.
,
Straffelini
,
G.
,
Ciudin
,
R.
,
Olofsson
,
U.
,
Perricone
,
G.
, and
Metinoz
,
I.
,
2017
, “
Dry Sliding of a Low Steel Friction Material Against Cast Iron at Different Loads: Characterization of the Friction Layer and Wear Debris
,”
Wear
,
376–377
(
PartB
), pp.
1450
1459
.
24.
Uyyuru
,
R. K.
,
Surappa
,
M. K.
, and
Brusethaug
,
S.
,
2007
, “
Tribological Behavior of Al-Si-SiCp Composites/Automobile Brake Pad System Under Dry Sliding Conditions
,”
Tribol. Int.
,
40
(
2
), pp.
365
373
.
25.
Patil
,
S. P.
,
Chilakamarri
,
S. H.
, and
Markert
,
B.
,
2018
, “
A Novel Nonlinear Nano-Scale Wear Law for Metallic Brake Pads
,”
Phys. Chem. Chem. Phys.
,
20
(
17
), pp.
12027
12036
.
26.
Preacher
,
K. J.
,
Curran
,
P. J.
, and
Bauer
,
D. J.
,
2006
, “
Computational Tools for Probing Interactions in Multiple Linear Regression, Multilevel Modeling, and Latent Curve Analysis
,”
J. Educ. Behav. Stat.
,
31
(
4
), pp.
437
448
.
27.
Peng
,
T.
,
Yan
,
Q.
, and
Zhang
,
X.
,
2018
, “
Stability of Metal Matrix Composite Pads During High-Speed Braking
,”
Tribol. Lett.
,
66
(
63
), pp.
1
13
.
28.
Österle
,
W.
,
Prietzel
,
C.
,
Kloß
,
H.
, and
Dmitriev
,
A. I.
,
2010
, “
On the Role of Copper in Brake Friction Materials
,”
Tribol. Int.
,
43
(
12
), pp.
2317
2326
.
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