The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads
The use of various materials in brake pad compositions is widely studied. In this study, the borax powders or the copper or bronze fibres are added in non-asbestos organic brake pad composition to examine the effects of type and quantity of additive on the friction and wear characteristics of brake...
Gespeichert in:
| Veröffentlicht in: | Металлофизика и новейшие технологии |
|---|---|
| Datum: | 2017 |
| Hauptverfasser: | , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Інститут металофізики ім. Г.В. Курдюмова НАН України
2017
|
| Schlagworte: | |
| Online Zugang: | https://nasplib.isofts.kiev.ua/handle/123456789/130463 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-130463 |
|---|---|
| record_format |
dspace |
| spelling |
İrem Burcu Algan Adem Kurt 2018-02-13T18:34:19Z 2018-02-13T18:34:19Z 2017 1024-1809 PACS: 61.72.Ff, 61.72.Qq, 62.20.Qp, 68.37.Hk, 81.05.Ni, 81.20.Ev, 81.40.Pq, 82.80.Pv DOI: doi.org/10.15407/mfint.39.11.1511 https://nasplib.isofts.kiev.ua/handle/123456789/130463 The use of various materials in brake pad compositions is widely studied. In this study, the borax powders or the copper or bronze fibres are added in non-asbestos organic brake pad composition to examine the effects of type and quantity of additive on the friction and wear characteristics of brake pads. Firstly, three different specimen groups are developed by powder metallurgy method, which contain various amounts (1.5, 3, 4.5 and 6% weight) of borax powder, copper fibre, and bronze fibre. Изучено использование различных материалов в композициях тормозных дисков. Порошки буры, медные или бронзовые волокна добавлялись в состав безасбестового органического тормозного диска, и исследовалось влияние типа и количества добавки на характеристики трения и износа тормозных дисков. Впервые методом порошковой металлургии были разработаны три разных группы образцов, содержащих различное количество порошка буры, медных и бронзовых волокон (1,5, 3, 4,5 и 6% веса). Досліджено використання різних матеріялів у композиціях гальмівних дисків. Порошки бури, мідні чи то бронзові волокна додавалися до складу безазбестового органічного гальмівного диску з метою дослідження впливу типу та кількости добавки на характеристики тертя та зносу гальмівних дисків. Вперше методою порошкової металурґії було розроблено три різних групи зразків, що містять різну кількість порошку бури, мідних і бронзових волокон (1,5, 3, 4,5 і 6% ваги). en Інститут металофізики ім. Г.В. Курдюмова НАН України Металлофизика и новейшие технологии Физика прочности и пластичности The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads Влияние металлических волокон и порошков буры на характеристики трения и износа тормозных накладок на органической основе Вплив металевих волокон і порошкової бури на характеристики тертя та зношування гальмових накладок на органічній основі Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads |
| spellingShingle |
The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads İrem Burcu Algan Adem Kurt Физика прочности и пластичности |
| title_short |
The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads |
| title_full |
The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads |
| title_fullStr |
The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads |
| title_full_unstemmed |
The Effect of Metal Fibres and Borax Powders on the Wear and Friction Performances of the Organic Based Brake Pads |
| title_sort |
effect of metal fibres and borax powders on the wear and friction performances of the organic based brake pads |
| author |
İrem Burcu Algan Adem Kurt |
| author_facet |
İrem Burcu Algan Adem Kurt |
| topic |
Физика прочности и пластичности |
| topic_facet |
Физика прочности и пластичности |
| publishDate |
2017 |
| language |
English |
| container_title |
Металлофизика и новейшие технологии |
| publisher |
Інститут металофізики ім. Г.В. Курдюмова НАН України |
| format |
Article |
| title_alt |
Влияние металлических волокон и порошков буры на характеристики трения и износа тормозных накладок на органической основе Вплив металевих волокон і порошкової бури на характеристики тертя та зношування гальмових накладок на органічній основі |
| description |
The use of various materials in brake pad compositions is widely studied. In this study, the borax powders or the copper or bronze fibres are added in non-asbestos organic brake pad composition to examine the effects of type and quantity of additive on the friction and wear characteristics of brake pads. Firstly, three different specimen groups are developed by powder metallurgy method, which contain various amounts (1.5, 3, 4.5 and 6% weight) of borax powder, copper fibre, and bronze fibre.
Изучено использование различных материалов в композициях тормозных дисков. Порошки буры, медные или бронзовые волокна добавлялись в состав безасбестового органического тормозного диска, и исследовалось влияние типа и количества добавки на характеристики трения и износа тормозных дисков. Впервые методом порошковой металлургии были разработаны три разных группы образцов, содержащих различное количество порошка буры, медных и бронзовых волокон (1,5, 3, 4,5 и 6% веса).
Досліджено використання різних матеріялів у композиціях гальмівних дисків. Порошки бури, мідні чи то бронзові волокна додавалися до складу безазбестового органічного гальмівного диску з метою дослідження впливу типу та кількости добавки на характеристики тертя та зносу гальмівних дисків. Вперше методою порошкової металурґії було розроблено три різних групи зразків, що містять різну кількість порошку бури, мідних і бронзових волокон (1,5, 3, 4,5 і 6% ваги).
|
| issn |
1024-1809 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/130463 |
| work_keys_str_mv |
AT iremburcualgan theeffectofmetalfibresandboraxpowdersonthewearandfrictionperformancesoftheorganicbasedbrakepads AT ademkurt theeffectofmetalfibresandboraxpowdersonthewearandfrictionperformancesoftheorganicbasedbrakepads AT iremburcualgan vliâniemetalličeskihvolokoniporoškovburynaharakteristikitreniâiiznosatormoznyhnakladoknaorganičeskoiosnove AT ademkurt vliâniemetalličeskihvolokoniporoškovburynaharakteristikitreniâiiznosatormoznyhnakladoknaorganičeskoiosnove AT iremburcualgan vplivmetalevihvolokoníporoškovoíburinaharakteristikitertâtaznošuvannâgalʹmovihnakladoknaorganíčníiosnoví AT ademkurt vplivmetalevihvolokoníporoškovoíburinaharakteristikitertâtaznošuvannâgalʹmovihnakladoknaorganíčníiosnoví AT iremburcualgan effectofmetalfibresandboraxpowdersonthewearandfrictionperformancesoftheorganicbasedbrakepads AT ademkurt effectofmetalfibresandboraxpowdersonthewearandfrictionperformancesoftheorganicbasedbrakepads |
| first_indexed |
2025-11-25T21:07:31Z |
| last_indexed |
2025-11-25T21:07:31Z |
| _version_ |
1850550997146927104 |
| fulltext |
1511
PACS numbers: 61.72.Ff, 61.72.Qq, 62.20.Qp, 68.37.Hk, 81.05.Ni, 81.20.Ev, 81.40.Pq, 82.80.Pv
The Effect of Metal Fibres and Borax Powders on the Wear
and Friction Performances of the Organic Based Brake Pads
İrem Burcu Algan and Adem Kurt
Gazi University,
Faculty of Technology, Department of Materials and Metallurgy,
06500 Ankara, Turkey
The use of various materials in brake pad compositions is widely studied. In
this study, the borax powders or the copper or bronze fibres are added in non-
asbestos organic brake pad composition to examine the effects of type and
quantity of additive on the friction and wear characteristics of brake pads.
Firstly, three different specimen groups are developed by powder metallurgy
method, which contain various amounts (1.5, 3, 4.5 and 6% weight) of borax
powder, copper fibre, and bronze fibre. The mixtures are blended with an in-
dustrial-type mixer, pressed by hydraulic press, and then they are post-
sintered at 185 C for 24 hours. The friction–wear tests of specimens are per-
formed by means of the Chase Machine according to the SAE-661 test stand-
ard, and then friction surfaces of the specimens are analysed with a scanning
electron microscope. Hardness tests are performed according to the Brinell
Scale test method. Test results show that, while addition of different
amounts of borax powder enhances the wear resistance of brake pads, addi-
tion of copper and bronze fibres increases recovery, normal and hot friction
coefficients’ values with increasing amount of metallic fibre.
Key words: non-asbestos organic brake pads, borax, metallic fibre, wear re-
sistance, friction coefficient.
Досліджено використання різних матеріялів у композиціях гальмівних
дисків. Порошки бури, мідні чи то бронзові волокна додавалися до складу
безазбестового органічного гальмівного диску з метою дослідження впли-
ву типу та кількости добавки на характеристики тертя та зносу гальмів-
Corresponding author: Adem Kurt
E-mail: ademkurt@gazi.edu.tr
Please cite this article as: İrem Burcu Algan and Adem Kurt, The Effect of Metal
Fibres and Borax Powders on the Wear and Friction Performances of the Organic
Based Brake Pads, Metallofiz. Noveishie Tekhnol., 39, No. 11: 1511–1523 (2017),
DOI: 10.15407/mfint.39.11.1511.
Ìåòàëëîôèç. íîâåéøèå òåõíîë. / Metallofiz. Noveishie Tekhnol.
2017, т. 39, № 11, сс. 1511–1523 / DOI: 10.15407/mfint.39.11.1511
Îòòèñêè äîñòóïíû íåïîñðåäñòâåííî îò èçäàòåëÿ
Ôîòîêîïèðîâàíèå ðàçðåøåíî òîëüêî
â ñîîòâåòñòâèè ñ ëèöåíçèåé
2017 ÈÌÔ (Èíñòèòóò ìåòàëëîôèçèêè
èì. Ã. Â. Êóðäþìîâà ÍÀÍ Óêðàèíû)
Íàïå÷àòàíî â Óêðàèíå.
https://doi.org/10.15407/mfint.39.11.1511
https://doi.org/10.15407/mfint.39.11.1511
1512 İrem Burcu ALGAN and Adem KURT
них дисків. Вперше методою порошкової металурґії було розроблено три
різних групи зразків, що містять різну кількість порошку бури, мідних і
бронзових волокон (1,5, 3, 4,5 і 6% ваги). Суміші готувалися за допомо-
гою мішалки промислово типу, пресувалися гідравлічним пресом, а потім
спікалися за температури 185 С протягом 24 годин. Тестування зразків на
тертя–знос проводили за допомогою Chase Machine відповідно до стандар-
ту SAE 661; потім поверхні тертя зразків досліджувалися сканівним еле-
ктронним мікроскопом. Випробування на твердість проводили за Бри-
неллевою методою. Результати випробувань свідчать, що, у той час як до-
давання різної кількости порошку бури підвищує зносостійкість гальмів-
них дисків, додавання мідних та бронзових волокон збільшує показники
відновлення, значення коефіцієнтів нормального та гарячого тертя зі збі-
льшенням кількости металевого волокна.
Ключові слова: безазбестові органічні гальмівні диски, бура, металеве
волокно, зносостійкість, коефіцієнт тертя.
Изучено использование различных материалов в композициях тормоз-
ных дисков. Порошки буры, медные или бронзовые волокна добавлялись
в состав безасбестового органического тормозного диска, и исследовалось
влияние типа и количества добавки на характеристики трения и износа
тормозных дисков. Впервые методом порошковой металлургии были раз-
работаны три разных группы образцов, содержащих различное количе-
ство порошка буры, медных и бронзовых волокон (1,5, 3, 4,5 и 6% веса).
Смеси готовились с помощью мешалки промышленно типа, прессовались
гидравлическим прессом, а затем спекались при температуре 185 C в те-
чение 24 часов. Тестирование образцов на трение–износ проводили с по-
мощью Chase Machine в соответствии со стандартом SAE 661; затем по-
верхности трения образцов исследовались сканирующим электронным
микроскопом. Испытания на твёрдость проводили по методике Бринелля.
Результаты испытаний показывают, что, в то время как добавление раз-
ного количества порошка буры повышает износостойкость тормозных
дисков, добавление медного и бронзового волокон увеличивает показате-
ли восстановления, значения коэффициентов нормального и горячего
трения с увеличением количества металлического волокна.
Ключевые слова: безасбестовые органические тормозные диски, бура,
металлическое волокно, износостойкость, коэффициент трения.
(Received October 5, 2017)
1. INTRODUCTION
Brake pad is a member of the brake system and formed by a combina-
tion of numerous components, and it is used to decelerate/stop vehi-
cles. Brake pad components transform physically and chemically dur-
ing braking, which identifies the friction–wear behaviour. For this
reason, the selection of components based on their characteristics in
macro- and microlevels is crucial. Braking-related friction and wear
THE EFFECT OF FIBRES AND POWDERS ON THE WEAR AND FRICTION 1513
behaviour change depending upon driving conditions, the composition
of brake pads, production parameters, and friction film interfaces be-
tween the friction material and the rotor. Therefore, in the last decade,
experimental studies have aimed to provide stable friction, durability,
equal abrasion resistance, and low noise and vibration [1, 2].
Brake pads are classified according to the type of base material such
as metallic, carbon, and non-asbestos organic pads. Metallic-based
pads consist of metallic components, such as steel and copper, carbon
based pads have graphite, and non-asbestos organic pads have non-
ferrous metals, Kevlar, and fiberglass. Studies on organic-based brake
pads have increased due to wide availability of the organic materials
used in such pads and also because their density is much lower com-
pared to that of metallic pads. The use of steel, brass, and copper in
brake pad compositions provides an efficient heat transfer from the
friction surface because of their high thermal conductivity [3]. In re-
cent years, researchers have been conducting investigations to find
new materials to maintain the friction coefficient stability. As boron
and its compounds have high physical and mechanical properties, they
are utilized in many applications, including brake pad compositions
[4–7]. The present study aims to investigate the effects of borax pow-
der (a compound of boron) and copper and bronze fibres on friction and
wear characteristic of non-asbestos organic brake pads.
2. EXPERIMENTAL DETAILS
2.1. Specimens
Three types of ingredients (borax powder, copper and bronze fibres)
were added with different rates in the commercial organic based brake
pad composition. Firstly, base specimen and three different specimen
groups were prepared by powder metallurgy method that contain 1%,
3%, and 5% borax powder (Na2B4O7 10H2O), 1.5%, 3%, 4.5%, and 6%
copper fibres, and 1.5%, 3%, 4.5%, and 6% bronze fibres (86% Cu–
14% Sn) by weight. Copper and bronze fibres were 1 mm in size.
The mixtures were blended with an industrial type mixer for 3 min,
pressed in mould (86 mm 55 mm) under 15 MPa pressure, and post-
sintered at 185 C for 24 hours. Table 1 shows the ingredients of the
composition.
Sintered samples were resized with an ATM Brilliant 250 abrasive
cutting device according to the SAE 661 test standard (25 mm 5 mm
7 mm). Then, their densities were calculated according to the Archi-
medes principle.
Samples were named according to type of additive: BX indicates bo-
rax powder, CF indicates copper fibre, and BF indicates bronze fibre.
Density values were given in Table 2.
1514 İrem Burcu ALGAN and Adem KURT
2.2. Characterizations of Composites
Friction tests were performed using a Chase Machine friction–wear
test (Pyramid Engineering, Serial Number: 120302) according to the
SAE 661 test standard. After brake pad specimens were cut in sizes of
25 mm 25 mm 7 mm, they were scrubbed with grey cast iron drum to
simulate driving conditions, then friction force and temperature were
measured, and data were transferred to the computer.
Hardness values of the specimens were measured by means of the
Emco Test Duravision 2000 hardness test machine before and after the
test with the Brinell Scale (Brinell-S) test method.
Surface characteristics of the brake pad specimens were analysed
TABLE 1. Ingredients in brake pad composition.
Classification Materials
Binder Phenolic resin
Fillers Barite, calcium carbonate
Reinforcements Glass fibre, steel fibre, Aramid fibre, PAN
Abrasives Aluminium oxide, iron oxide
Friction modifiers
Metal oxide, metal sulphide, borax powder, bronze
fibre, copper fibre
Lubricant Graphite
TABLE 2. Density values according to ingredient type and percentage.
Samples Density (g/cm3)
Base (non-asbestos organic pad composition) 2.1
BX1 2.1
BX3 2.2
BX5 2.3
CF1.5 2.1
CF3 2
CF4.5 1.9
CF6 2
BF1.5 2.1
BF3 2
BF4.5 2
BF6 2
THE EFFECT OF FIBRES AND POWDERS ON THE WEAR AND FRICTION 1515
using a Jeol JEM 6060 LV SEM, and energy dispersive x-ray spectros-
copy (EDX) was performed on the specimens.
3. RESULTS
3.1. Friction–Wear Behaviour
The SAE-J661 standard is given in Table 3. According to this standard,
friction coefficient values at the fade and recovery stages have differ-
ent features. For example, fade stage starts when the temperature of
the drum is 82 C, the heater gets activated until the temperature
reaches at 345 C, and then friction coefficient values were recorded.
After this stage completion, heater stops and cooler steps in. Tem-
perature decreases gradually at the recovery stage, and friction coeffi-
cient values are recorded.
To understand the friction–wear characteristic of the specimens at
the fade and recovery stages clearly, some of performance parameters
were identified [8–10]. These parameters are following: normal fric-
tion coefficient ( ): average value at 93, 121, 149, and 205 C; hot
friction coefficient ( ) for fade: average value at 345, 317, 289, 261,
and 233 C; hot friction coefficient ( ) for recovery: average value at
261, 205, and 149 C; -fade: minimum value at the fade stage
% fade rate 100( min max);
-recovery: maximum value at the recovery stage
% recovery rate 100( min max);
TABLE 3. Stages of SAE-J661 test standard.
Name Speed Load
On
time
Off
time
App.
Temp.
L
Temp.
H
Temp.
Mode
Burnish 308 45 1200 0 1 0 93 Strict
Reset 205 23 300 0 1 0 93 Strict
Baseline-1 411 67 10 20 20 82 104 Auto
Fade-1 411 67 600 0 1 82 289 Heater
Recovery-1 411 67 10 0 4 261 93 Blower
Wear 411 67 20 10 100 193 205 Auto
Fade-2 411 67 600 0 1 82 345 Heater
Recovery-2 411 67 10 0 5 317 93 Blower
Baseline-2 411 67 10 20 20 82 104 Auto
1516 İrem Burcu ALGAN and Adem KURT
%thickness loss rate
thickness before test thickness after test
100.
thickness before test
As seen in Figure 1, the highest value at the fade stage is BX1 and
the friction coefficient increased with temperature increase up to
205 C. At the recovery stage, the friction characteristics of the samples
changed and the base sample had the highest value. The cause of fluctu-
ation at this stage was attributed to non-uniform thermal loads [7].
Figure 1, a shows fade, recovery, normal and hot friction coefficients.
The desired values of industrial brake pads are between 0.3 and 0.4.
Standard test stages involve three basic parameters: load, tempera-
ture, and speed [11, 12]. According to these parameters, -fade and
normal µ values of borax-added specimens are low; however, -
recovery and hot friction coefficients are average in present study. The
BX5 has higher performance than other borax-added specimens do;
however, base sample has the highest performance. Results indicate
that the addition of borax powder does not increase the brake pad per-
formance. The copper-fibre-added samples generally have good fric-
Fig. 1. Friction test results at the fade (a) and recovery (b) stages, and general
characteristics of fade, recovery, normal and hot friction coefficient values (c).
THE EFFECT OF FIBRES AND POWDERS ON THE WEAR AND FRICTION 1517
tion characteristics because the thermal conductivity coefficient of
copper is high ( 401 W/(m K)) and the generated heat is transferred
efficiently for this reason. This situation improves organic brake pad
friction coefficient. Furthermore, normal and hot friction coefficients
increase with increasing copper fibre rate, thus CF6 (copper 6% wt.)
has the highest performance. Fade and recovery characteristics of the
bronze fibre-added specimens are nearly same with the copper fibre-
added specimens, however, the addition of copper enhanced the -fade
values unlike bronze, which has lower thermal conductivity than
bronze (kbronze 354.3 W/(m K)). The rest results indicate that friction
coefficient values increase with temperature up to 205 C, and then de-
crease from this temperature, which is similar to resin behaviours at
high temperature and bond strengths between brake pad components
as described in the literature [5].
Figure 2 shows wear behaviour and fade and recovery rates for all
samples. Bijwe et al. stated that acceptable % fade rate between 80 and
100 and recovery rate between 75% and 100% [11]. Although the fade
Fig. 2. Fade and recovery rate (a), wear rate and thickness loss (b).
1518 İrem Burcu ALGAN and Adem KURT
rate of borax powder-added specimens is below the industrial expecta-
tion, their recovery rate is high. The addition of borax improves the
recovery performance of organic brake pads slightly; however, their
fade characteristic was substantially inadequate. The examination of
the wear behaviour of borax-added specimens showed that wear rate
and thickness loss decreased with increasing rate of borax weight,
which indicates that wear resistance increased partially with increas-
ing borax rate as the composite density (Table 2) increased. Metallic-
fibre addition in the brake pad composition results in inclusions, which
increases the thermal conductivity and provides effective heat removal
as reported in the literature. Furthermore, metallic materials exhibit
aggressive behaviour that abrades and renews the layer on the inter-
face between brake pad and disc. Thereby, both thermophysical proper-
ties and the tribofilm quality improve the fade resistance of the brake
pad [9]. Based on this characteristic, wear rate and thickness loss in-
crease with increasing copper and bronze rates, as seen in Fig. 2. Even
though fade rate is low, recovery rate is high for copper-added and
bronze-added specimens.
3.2. Hardness Results
Figure 3 shows the hardness values of specimens obtained by the fric-
tion test based on the Brinell-S method. Borax-added specimens exhib-
it higher hardness values than the base specimen, and BX3 has the
highest hardness due to the work hardening caused by the increasing
temperature during friction. Hardness values of copper-added and
Fig. 3. Brinell-S hardness results of specimens after friction test.
THE EFFECT OF FIBRES AND POWDERS ON THE WEAR AND FRICTION 1519
bronze-added specimens are high because metallic fibres increase wear
and deformation. The increase of hardness leads to noise, thus bronze-
added specimens appear to be more advantageous than the other
groups.
3.3. SEM Observations
The friction surface was analysed using SEM in combination with en-
ergy dispersive x-ray spectroscopy (EDS) mapping analysis to under-
stand the relationship between worn surfaces and friction–wear char-
acteristics of organic-based brake pads. Micrographs clearly show four
distinct regions for all the specimen groups, which are black, white,
grey, and wear debris. The EDS analysis indicates for all groups that
the black region involves substantial amount of C, O, and S as well as a
slight amount of B, Cu, or Sn (according to type of addition); the white
region involves O, Ca; the grey region involves C, Ca, O, and Fe; and
wear debris region involves Fe, O, Al, Si, and Ca. Regional EDS results
were given in Table 4 for some specimens. Figure 4 shows micrographs
Fig. 4. SEM micrographs ( 200) of borax powder-added specimens BX1 (a),
BX3 (b), and BX5 (c).
1520 İrem Burcu ALGAN and Adem KURT
of borax-added specimens, where black-white regions take a large pro-
portion.
According to the EDS results, the existing boron–oxygen com-
pounds appear to have improved the wear resistance of brake pads as
seen in Fig. 2. In Figure 4, b, it is observed that undistracted glass fi-
bres are perpendicularly oriented towards the sliding direction due to
the adhesive bonding of glass fibres at high temperatures.
The EDS results of the wear debris region indicate that this region
TABLE 4. Regional EDS results for certain samples.
Regions Samples BX3 BX5 CF3 CF4.5 CF6 BF3 BF4.5 BF6
Black
C
O
S
B
Fe
Cu
Sn
76.8
5.8
–
15.7
–
–
–
–
5.1
–
92.5
–
–
–
85.8
6.6
–
–
–
–
–
84
11.2
3
–
–
–
–
94
3
–
–
–
–
–
94
–
–
–
–
–
2.4
38
20.4
–
–
24.8
–
4.2
90
4
–
–
–
–
2
White
C
O
Ca
Fe
B
Sn
Si
Ti
Al
74.1
5.8
–
–
16
–
–
–
–
–
–
28.2
14
–
–
43
–
10.4
69.4
27.2
–
–
–
–
–
–
–
73.7
20.2
–
–
–
–
–
–
–
11.5
28
40.4
–
–
–
–
5
–
80
15
–
–
–
–
–
–
–
41
19
17
12.4
–
–
–
–
–
–
29.3
23
–
–
8
27
–
–
Wear
debris
O
Al
Fe
Ca
O
Cu
Sn
Si
7.7
–
84.6
–
–
–
–
3
–
–
91.3
2.7
–
–
–
3.1
–
–
86.8
–
–
4.1
–
–
–
–
88.4
–
–
5.4
–
–
–
–
85.7
–
5.1
4.1
–
–
–
–
79
–
7
–
3.5
–
–
–
85
–
–
–
6
–
–
–
10.5
–
17
–
53.5
–
Grey
O
Fe
C
Ca
Si
Sn
Al
Mg
Cu
31.4
14
30.5
–
–
–
–
–
–
–
41.9
–
27
15
–
6.1
–
–
–
92.7
–
–
–
–
–
–
3.2
33.4
8.7
43.2
9.3
–
–
–
–
–
21.1
–
65.4
–
–
–
–
5.7
–
20
12.3
50.1
–
–
–
–
–
–
23.3
21
37
5
–
–
–
–
–
32
–
27
27.3
–
6
–
–
–
THE EFFECT OF FIBRES AND POWDERS ON THE WEAR AND FRICTION 1521
involves Fe, and O, as well as Ca, Si, and Al, as reported in the litera-
ture. The amount of this region is higher in BX1 compared to the other
borax powder-added specimens. Larger wear debris regions are caused
by the numerous contact points in the friction interfaces [13, 14]. For
this reason, BX1 appears to have the highest hot friction coefficient,
normal friction coefficient, and -fade. A sample EDS mapping image
provided in Fig. 5 clearly shows that the components of the composite
are dispersed homogeneously.
Wear debris are fragmented and spread on the wear surface and also
embedded into the matrix as shown in Fig. 6, c, which was considered
to be a factor increasing the friction coefficient.
Table 4 shows clearly that the amounts of Fe and O are high in wear
debris region for certain sample, and they control the wear–friction
behaviour as reported in the literature [13, 16, 17]. Since broken parti-
cles coming from the grey cast iron disc accumulate in wear surfaces,
the amount of Fe is the highest in this region [18]. As apparent in Figs.
6, a and 7, d, the long and large wear debris regions are secondary re-
gions consisting of graphite and aramid fibres, which appear to be
leading to a decrease in the friction coefficient. BF4.5 and BF6 involve
substantial amount of Fe and Cu elements, which appears to be provid-
ing an increase in -recovery (0.36–0.41) and recovery rate. Addition-
ally, Figure 7 shows that wear debris regions are much larger in BF6
because its normal , hot , and recovery values are high. Moreover,
wear rate and thickness loss increased especially for BF4.5.
4. DISCUSSION
In the present study, the effect of type and quantity of additive on the
wear and friction behaviours of non-asbestos commercial organic brake
pad compositions was examined. The important conclusions resulting
from the above present study are as follow.
Fig. 5. EDS mapping image of BX3.
1522 İrem Burcu ALGAN and Adem KURT
Fig. 6. SEM micrographs ( 200) of copper fibre-added specimens CF1.5 (a),
CF3 (b), CF4.5 (c), and CF6 (d).
Fig. 7. SEM micrographs ( 200) of bronze fibre-added specimens BF1.5 (a),
BF3 (b), BF4.5 (c), and BF6 (d).
THE EFFECT OF FIBRES AND POWDERS ON THE WEAR AND FRICTION 1523
1. Addition of different amounts of borax powder enhances the wear
resistance of brake pads, where thought in that, and the minimum
wear rate and thickness loss were observed in BX5.
2. Friction test results show that fade and normal friction coefficient
values are low; however, yet recovery and hot friction coefficients are
within the desired range due to borax, and other components were not
observed to be not forming a compatible compound, where thought.
3. The addition of copper and bronze fibre increased recovery, normal,
and hot friction coefficient values with increasing amount of metallic
fibre, that e.g. CF6 and BF6 has have the maximum values. Consider-
ing test results and similar studies in the literature, 6% and above of
metallic fibres’ addition increases and improves the friction coeffi-
cient, while it increases the wear rate, where thought.
REFERENCES
1. R. Ertan and N. Yavuz, Wear, 268: 11 (2010).
2. S. J. Kim, K. S. Kim, and H. Jang, J. Mater. Process. Technol., 136, Nos. 1–3:
202 (2003).
3. H. Jang, K. Ko, S. J. Kim, R. H. Basch, and J. W. Fash, Wear, 256, Nos. 3–4:
406 (2004).
4. T. R. Chapman, D. E. Niesz, R. T. Fox, and T. Fawcett, Wear, 236,
Nos. 1–2: 81 (1999).
5. U. S. Hong, S. L. Jung, K. H. Cho, M. H. Cho, S. J. Kim, and H. Jang, Wear,
266, Nos. 7–8: 739 (2009).
6. I. Mutlu, C. Oner, and F. Findik, Materials and Design, 28, No. 2: 480 (2007).
7. I. Sugözü, I. Can, and C. Oner, Industrial Lubrication and Tribology, 66: 6
(2014).
8. M. Kumar and J. Bijwe, Wear, 269, Nos. 11–12: 826 (2010).
9. M. Kumar and J. Bijwe, Wear, 303, Nos. 1–2: 569 (2013).
10. M. Kumar and J. Bijwe, Tribology International, 44, No. 2: 106 (2011).
11. M. Kumar and J. Bijwe, Wear, 270, Nos. 3–4: 269 (2011).
12. P. Filip, Z. Weiss, and D. Rafaja, Wear, 252, Nos. 3–4: 189 (2002).
13. M. Eriksson and S. Jacobson, Tribology International, 33, No. 12: 817 (2000).
14. T. Singh and A. Patnaik, Archives of Civil and Mechanical Engineering, 15,
No. 1: 142 (2015).
15. M. Kchaou, A. Sellami, R. Elleuch, and H. Singh, Materials and Design, 52:
533 (2013).
16. A. Sellami, M. Kchaou, R. Elleuchi, A.-L. Cristol, and Ya. Desplanques,
Materials and Design, 59: 84 (2014).
17. B. Öztürk and S. Öztürk, Tribology Letters, 42: 339 (2011).
18. B. Öztürk, S. Öztürk, and A. Adigüzel, Tribology Transactions, 56: Iss. 3: 428
(2013).
https://doi.org/10.1016/j.wear.2010.02.026
https://doi.org/10.1016/S0924-0136(03)00159-6
https://doi.org/10.1016/S0924-0136(03)00159-6
https://doi.org/10.1016/S0043-1648(03)00445-9
https://doi.org/10.1016/S0043-1648(03)00445-9
https://doi.org/10.1016/S0043-1648(99)00259-8
https://doi.org/10.1016/S0043-1648(99)00259-8
https://doi.org/10.1016/j.wear.2008.08.008
https://doi.org/10.1016/j.wear.2008.08.008
https://doi.org/10.1016/j.matdes.2005.09.002
https://doi.org/10.1108/ILT-03-2012-0029
https://doi.org/10.1108/ILT-03-2012-0029
https://doi.org/10.1016/j.wear.2010.08.011
https://doi.org/10.1016/j.wear.2013.03.053
https://doi.org/10.1016/j.triboint.2010.09.013
https://doi.org/10.1016/j.wear.2010.10.068
https://doi.org/10.1016/S0043-1648(01)00873-0
https://doi.org/10.1016/S0301-679X(00)00127-4
https://doi.org/10.1016/j.acme.2014.01.009
https://doi.org/10.1016/j.acme.2014.01.009
https://doi.org/10.1016/j.matdes.2013.05.015
https://doi.org/10.1016/j.matdes.2013.05.015
https://doi.org/10.1016/j.matdes.2014.02.025
https://doi.org/10.1007/s11249-011-9779-5
https://doi.org/10.1080/10402004.2012.758333
https://doi.org/10.1080/10402004.2012.758333
|