Abstract

This article relates the friction performance to the tribolayer formation when using engineered mineral fibers in the friction formulation. A nonasbestos organic (NAO) nonsteel copper-free passenger car disc pad (PC-DP) nonsteel Cu-free formulation is used to investigate the impact of the fibers on the third body formation and its influence on performance and wear. Full-scale dynamometer performance (AK-Master) test results show the pronounced effect of the fiber length on the friction performance. While a similar overall coefficient of friction (CoF) of around 0.33 is observed in all three cases, more stable friction behavior is observed for the longer fibers, with less variation. This behavior is even more observed in the fade and high-temperature sections. Especially the use of fiber spheres shows quite some unique features over the other tested mineral fibers, especially with respect to pad/disc wear. To understand these differences in performance, the transfer layer and tribolayer on the disc and brake pad are investigated, respectively, by means of scanning electron microscopy (SEM). Formulations showing excellent performance results so far show the formation of a smooth transfer film on the disc. No grooves are visible, and a continuous iron oxide layer is formed at the surface. The tribolayer of the corresponding brake pads nicely shows the formation of a compacted thin layer at the surface. In addition, the importance of mineral fibers in the formulation is highlighted as they are at the core of the tribolayer formation. This study is a step forward toward understanding the role of mineral fibers in a friction formulation and shows its importance toward reducing nonexhaust emissions.

References

References
1.
European Commission
,
2020
, .
2.
Brink
,
C.
, and
Smeets
,
W.
,
2017
, “
EU Targets for Air Quality, Climate and Energy for 2030
,”
PBL Netherlands Environmental Assessment Agency
, Personal Communication.
3.
Nosko
,
O.
, and
Olofsson
,
U.
,
2020
, “
Optical Aerosol Properties of Megacities: Inland and Coastal Cities Comparison
,”
Air Qual. Atmos. Health
,
13
(
1
), pp.
25
33
. 10.1007/s11869-019-00769-7
4.
Chandra
,
C. P.
,
Menapace
,
L.
, and
Bonfanti
,
A.
,
2018
, “
Braking Pad-Disc System: Wear Mechanisms and Formation of Wear Fragments
,”
Wear
,
322–323
(
1
), pp.
251
258
. 10.1016/j.wear.2014.11.019
5.
European Commission
,
2020
,
6.
7.
Grigoratos
,
T.
, and
Martini
,
G.
,
2015
, “
Brake Wear Particle Emission: A Review
,”
Environ. Sci. Pollut. Res.
,
22
(
4
), pp.
2491
2504
. 10.1007/s11356-014-3696-8
9.
Gerlofs-Nijland
,
M. E.
,
Bokkers
,
B. G. H.
,
Sachse
,
H.
,
Reijnders
,
J. J. E.
,
Gustafsson
,
M.
,
Boere
,
A. J. F.
,
Fokkens
,
P. F. H.
,
Leseman
,
D. L. A. C.
,
Augsburg
,
K.
, and
Cassee
,
F. R.
,
2019
, “
Inhalation Toxicity Profiles of Particulate Matter; a Comparison Between Brake Wear With Other Sources of Emission
,”
Inhalation Toxicol.
,
31
(
3
), pp.
89
98
. 10.1080/08958378.2019.1606365
10.
Barosova
,
H.
,
Chortarea
,
S.
,
Peikertova
,
P.
,
Clift
,
M. J. D.
,
Petri-Fink
,
A.
,
Kukutschova
,
J.
, and
Rothen-Rutishauser
,
B.
,
2018
, “
Biological Response of an In Vitro Human 3D Lung Cell Model Exposed to Brake Wear Debris Varies Based on Brake Pad Formulation
,”
Arch. Toxicol.
,
92
(
7
), pp.
2339
2351
. 10.1007/s00204-018-2218-8
11.
Lyu
,
Y.
,
Leonardi
,
M.
,
Wahlström
,
J.
,
Gialanella
,
S.
, and
Olofsson
,
U.
,
2019
, “
Friction, Wear and Airborne Particle Emission From Cu-Free Brake Materials
,”
Tribol. Int.
,
141
(
1
), pp.
105959
105966
. 10.1016/j.triboint.2019.105959
12.
Ciudin
,
R.
,
Verma
,
P. C.
,
Gialanella
,
S.
, and
Straffelini
,
G.
,
2014
, “
Wear Debris Materials From Brake Systems: Environmental and Health Issues
,”
Sust. City
,
191
(
2
), pp.
1423
1434
. 10.2495/SC141202
13.
Maiorana
,
S.
,
Teoldi
,
F.
,
Silvani
,
S.
,
Mancini
,
A.
,
Sanguineti
,
A.
,
Mariani
,
F.
,
Cella
,
C.
,
Lopez
,
A.
,
Potenza
,
M. A. C.
,
Lodi
,
M.
,
Dupin
,
D.
,
Sanvito
,
T.
,
Bonfanti
,
A.
,
Benfenati
,
E.
, and
Baderna
,
D.
,
2019
, “
Phytotoxicity of Wear Debris From Traditional and Innovative Brake Pads
,”
Environ. Int.
,
123
(
2
), pp.
156
163
. 10.1016/j.envint.2018.11.057
14.
Neis
,
P. D.
,
Ferreira
,
N. F.
, and
Da Silva
,
F. P.
,
2014
, “
Comparison Between Methods for Measuring Wear in Brake Friction Materials
,”
Wear
,
319
(
1–2
), pp.
191
199
. 10.1016/j.wear.2014.08.004
15.
Kazimirova
,
A.
,
Peikertova
,
P.
,
Barancokova
,
M.
,
Staruchova
,
M.
,
Tulinska
,
J.
,
Vaculik
,
M.
,
Vavra
,
I.
,
Kukutschova
,
J.
,
Filip
,
P.
, and
Dusinska
,
M.
,
2016
, “
Automotive Airborne Brake Wear Debris Nanoparticles and Cytokinesis Block Micronucleus Assay in Peripheral Blood Lymphocytes: A Pilot Study
,”
Environ. Res.
,
148
(
7
), pp.
443
449
. 10.1016/j.envres.2016.04.022
16.
Malachova
,
K.
,
Kukutschova
,
J.
,
Rybkova
,
Z.
,
Sezimova
,
H.
,
Placha
,
D.
,
Cabanova
,
K.
, and
Filip
,
P.
,
2016
, “
Toxicity and Mutagenicity of Low-Metallic Automotive Brake pad Materials
,”
Ecotoxicol. Environ. Saf.
,
131
(
9
), pp.
37
44
. 10.1016/j.ecoenv.2016.05.003
17.
Menapace
,
C.
,
Mancini
,
A.
,
Federici
,
M.
,
Straffelini
,
G.
, and
Gialanella
,
S.
,
2019
, “
Characterization of Airborne Wear Debris Produced by Brake Pads Pressed Against HVOF-Coated Discs
,”
Friction
,
8
(
2
), pp.
421
432
. 10.1007/s40544-019-0284-4
18.
Chen
,
R.
,
Zhao
,
C.
, and
Nie
,
X.
,
2020
, “
Alumina-Based Coating With Dimples as Enabling Sustainable Technology to Reduce Wear and Emission of the Brake System
,”
ACS Sustainable Chem. Eng.
,
8
(
2
), pp.
893
899
. 10.1021/acssuschemeng.9b05302
19.
Perricone
,
G.
,
Matějka
,
V.
,
Alemani
,
M.
,
Valota
,
G.
,
Bonfanti
,
A.
,
Ciotti
,
A.
,
Olofsson
,
U.
,
Söderberg
,
A.
,
Wahlström
,
J.
,
Nosko
,
O.
,
Straffelini
,
G.
,
Gialanella
,
S.
, and
Ibrahim
,
M.
,
2018
, “
A Concept of Reducing PM10 Emissions for Car Brakes With 50%
,”
Wear
,
396
(
1
), pp.
135
145
. 10.1016/j.wear.2017.06.018
20.
Santamaria Razo
,
D.
, and
Persoon
,
F.
,
2017
, “
Bio-Soluble Chemical Composition for Complementary Mineral Fibers : An Enhanced Tribological Effect and Its Influence on Disc Wear
,”
SAE Int. J. Mater. Manf.
,
10
(
1
), pp.
1
18
. 10.4271/2016-01-1909
21.
Österle
,
W.
, and
Urban
,
I.
,
2004
, “
Friction Layers and Friction Films on PMC Brake Pads
,”
Wear
,
257
(
1–2
), pp.
215
226
. 10.1016/j.wear.2003.12.017
22.
Filip
,
P.
,
Weiss
,
Z.
, and
Rafaja
,
R.
,
2002
, “
On Friction Layer Formation in Polymer Matrix Composite Materials for Brake Applications
,”
Wear
,
252
(
3–4
), pp.
189
198
. 10.1016/S0043-1648(01)00873-0
23.
Wirth
,
A.
,
Eggleston
,
D.
, and
Whitaker
,
R.
,
1994
, “
A Fundamental Tribochemical Study of the Third Body Layer Formed During Automotive Friction Braking
,”
Wear
,
179
(
1–2
), pp.
75
81
. 10.1016/0043-1648(94)90222-4
24.
Cho
,
M. H.
,
Cho
,
K. H.
,
Kim
,
S. J.
,
Kim
,
D. H.
, and
Jang
,
H.
,
2005
, “
The Role of Transfer Layers on Friction Characteristics in the Sliding Interface Between Friction Materials Against Gray Iron Brake Disks
,”
Tribol. Lett.
,
20
(
2
), pp.
101
108
. 10.1007/s11249-005-8299-6
25.
Österle
,
W.
,
Dörfel
,
I.
,
Prietzel
,
C.
,
Rooch
,
H.
,
Cristol-Bulthé
,
A.-L.
,
Degallaix
,
G.
, and
Desplanques
,
Y.
,
2009
, “
A Comprehensive Microscopic Study of Third Body Formation at the Interface Between a Brake Pad and Brake Disc During the Final Stage of a Pin-on-Disc Test
,”
Wear
,
267
(
5–8
), pp.
781
788
. 10.1016/j.wear.2008.11.023
26.
Dwivedi
,
U. K.
, and
Chand
,
N.
,
2009
, “
Influence of Fibre Orientation on Friction and Sliding Wear Behavior of Jute Fibre Reinforced Polyester Composite
,”
Appl. Compos. Mater.
,
16
(
2
), pp.
93
100
. 10.1007/s10443-008-9079-x
28.
Barros
,
L. Y.
,
Neis
,
P. D.
,
Ferreira
,
N. F.
,
Pavlak
,
R. P.
,
Masotti
,
D.
,
Matozo
,
L. T.
,
Sukumaran
,
J.
,
De Baets
,
P.
, and
Andó
,
M.
,
2016
, “
Morphological Analysis of Pad-Disc System During Braking Applications
,”
Wear
,
352–353
(
4
), pp.
112
121
. 10.1016/j.wear.2016.02.005
29.
Yoon
,
S. W.
,
Shin
,
M. W.
,
Lee
,
W. G.
, and
Jang
,
H.
,
2012
, “
Effect of Surface Contact Conditions on the Stick-Slip Behavior of Brake Friction Material
,”
Wear
,
294–295
(
1
), pp.
305
312
. 10.1016/j.wear.2012.07.011
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