porosity & brake pads modulus - imsysinc.com

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1 1 ARTICLE INFO Article ID: 05-11-01-0007 Copyright © 2017 SAE International doi:10.4271/05-11-01-0007 History Received: 09 Mar 2018 Published: 17 Sep 2017 Citation Sriwiboon, M., Tiempan, N., Kaewlob, K., Rhee, S.K. et al., “Disc Pad Physical Properties vs. Porosity: the Question of Compressibility as an Intrinsic Physical Property,” SAE Int. J. Mater. Manf. 11(1):2018, doi:10.4271/05-11-01-0007. ISSN: 1946-3979 e-ISSN: 1946-3987 Disc Pad Physical Properties vs. Porosity: the Question of Compressibility as an Intrinsic Physical Property Meechai Sriwiboon, Compact International (1994) Co., Ltd. Nipon Tiempan and Kritsana Kaewlob, Compact International (1994) Co., Ltd. Seong K Rhee, SKR Consulting, LLC Donald Yuhas, Industrial Measurement Systems Inc. Abstract Disc pad physical properties are believed to be important in controlling brake friction, wear and squeal. Thus these properties are carefully measured during and after manufacturing for quality assurance. For a given formulation, disc pad porosity is reported to affect friction, wear and squeal. This investigation was undertaken to find out how porosity changes affect pad natural frequencies, dynamic modulus, hardness and compressibility for a low-copper formulation and a copper-free formulation, both without underlayer, without scorching and without noise shims. Pad natural frequencies, modulus and hardness all continuously decrease with increasing porosity. When pad compressibility is measured by compressing several times as recommended and practiced, the pad surface hardness is found to increase while pad natural frequencies and modulus remain essentially unchanged. However, there is no consistent pattern in compressibility change with increasing porosity, and thus a question arises on the validity of compressibility measurement as an intrinsic physical property measurement. Also after 12-months of ageing at room temperature, all the proper- ties are found to change significantly, but property change trends with increasing porosity remain the same except for compressibility. A large number of samples were prepared and measured. The results are presented and discussed. Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

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Page 1: Porosity & Brake Pads Modulus - imsysinc.com

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ARTICLE INFOArticle ID: 05-11-01-0007Copyright © 2017 SAE Internationaldoi:10.4271/05-11-01-0007

HistoryReceived: 09 Mar 2018Published: 17 Sep 2017

CitationSriwiboon, M., Tiempan, N., Kaewlob, K., Rhee, S.K. et al., “Disc Pad Physical Properties vs. Porosity: the Question of Compressibility as an Intrinsic Physical Property,” SAE Int. J. Mater. Manf. 11(1):2018,doi:10.4271/05-11-01-0007.

ISSN: 1946-3979e-ISSN: 1946-3987

Disc Pad Physical Properties vs. Porosity: the Question of Compressibility as an Intrinsic Physical PropertyMeechai Sriwiboon, Compact International (1994) Co., Ltd.

Nipon Tiempan and Kritsana Kaewlob, Compact International (1994) Co., Ltd.

Seong K Rhee, SKR Consulting, LLC

Donald Yuhas, Industrial Measurement Systems Inc.

AbstractDisc pad physical properties are believed to be important in controlling brake friction, wear and squeal. Thus these properties are carefully measured during and after manufacturing for quality assurance. For a given formulation, disc pad porosity is reported to affect friction, wear and squeal. This investigation was undertaken to find out how porosity changes affect pad natural frequencies, dynamic modulus, hardness and compressibility for a low-copper formulation and a copper-free formulation, both without underlayer, without scorching and without noise shims. Pad natural frequencies, modulus and hardness all continuously decrease with increasing porosity. When pad compressibility is measured by compressing several times as recommended and practiced, the pad surface hardness is found to increase while pad natural frequencies and modulus remain essentially unchanged. However, there is no consistent pattern in compressibility change with increasing porosity, and thus a question arises on the validity of compressibility measurement as an intrinsic physical property measurement. Also after 12-months of ageing at room temperature, all the proper-ties are found to change significantly, but property change trends with increasing porosity remain the same except for compressibility. A large number of samples were prepared and measured. The results are presented and discussed.

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2 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

Introduction

M. Sriwiboon et al. [1] reported that pad hardness and natural frequencies continuously decreased with increasing pad porosity, but pad compressibility

showed no consistent trends and no correlation to brake squeal. In addition, the authors reported that friction coeffi-cient, pad wear, disc wear and brake squeal were all influenced by pad porosity [2,3]. As many engineers still believe there is a close correlation between pad compressibility and brake squeal, and many others dispute this belief, this investigation was undertaken to generate additional data using a large number of samples to help clarify the situation. In addition to measuring pad natural frequencies, hardness and compress-ibility, modulus measurements were added using the latest ultrasonic technique in order to answer the question of compressibility being an intrinsic material property or not.

Experimental

Disc Pads2 production NAO formulas were selected for this investiga-tion; low-copper and copper-free. The pads were suitable for the twin-piston caliper of a 3,200 kg pickup truck. Experimental pads were fabricated by traditional hot press molding, oven curing and finish grinding. 3 porosity levels were achieved by adjusting molding temperature, pressure and time; 13 v%, 18 v% and 22 v% porosity for each formula. These pads had no underlayer, no scorching and no noise shims in order to minimize variables. The total thickness of the pad assembly was 15.5 mm; the backing plate 5.5 mm. and the friction material 10.0 mm.

Pad Physical Property MeasurementsPad thickness, pad-backing plate assembly natural frequen-cies, pad dynamic modulus, pad surface hardness and pad compressibility were measured. The measurement locations on the pad are shown in Figure 1.

Pad Dynamic Modulus MeasurementThe use of ultrasound to determine the mechanical properties of materials is based on the fundamental relationship between the ultrasonic velocity and the material elastic constants. These methods have been described in a number of books and review articles [4, 5, 6]. Equation 1 shows the relationship between the measured ultrasonic velocity and the dynamic modulus along the propagation path. Because the ultrasonic wave is in the MHz frequency regime, the dynamic modulus is measured using this technique.

E k V= r ^2 Eq.1

Where ρ is the density; V is the ultrasonic propagation velocity through the friction material, and the factor k is dependent upon the velocity mode (shear or longitudinal) and the Poisson's ratio. For shear modulus measurement, the value of k is unity. For Young’s modulus measurements the value of k is 1.21 based on the historical analysis of more than 100 friction material formulations using the complete SAE J2725 protocol for anisotropic friction materials.

The ultrasonic technique used in this study to measure the dynamic modulus is a through-transmission technique. As illustrated in Figure 1, a short burst of high frequency sound, (~ 1 MHz) is generated from the transmitting trans-ducer and propagates through the steel backing, then the friction material and finally to the receiving transducer. Precise measurements are made of the total time-offlight, ToFpad, from the transmitter to receiver. Ultrasonic velocity is calculated by combining this ToF measurement with the pad thickness. Using a signal digitization rate of 100 MHz, the precision of the ToF measurement is ~10 nanoseconds. Typical ToF for transmission through a brake pad is ~15 microseconds so the baseline precision of the method is on the order of 0.6%.

It is desirable to measure the properties of the friction material in an intact, as-manufactured brake pad. As described above, the baseline ToF is comprised of the transit-time through the steel backing, ToFsteel as well as the transit time through the friction material, ToFfm, as shown in Equation 2.

ToF ToFX

Cfm pad

steel

steel

= - Eq.2

Where Xsteel is the steel thickness and Vsteel is the steel backing ultrasonic velocity.

 FIGURE 1  Pad property measurement locations.

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Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 3

It is relatively straight forward to remove the influence of the steel backing as both the steel thickness and its velocity are known and well controlled. The velocity of the steel is typically 3 to 4 times that of the friction material while the thickness of the steel is about 2 times smaller than that of the friction material. Thus the elimination of the steel contribu-tion from the measured ToF is typically a 10% correction. More importantly, because the modulus and density in the steel backing is well controlled. Any variation in the ToF can be attributed to the friction material.

The velocity in the friction material is given in Equation 3 by:

VX

ToFfm

fm= Eq.3

Where Xfm = Xpad - XSteel is the thickness of the friction material.

This velocity is used in Equation 1 to compute the dynamic modulus.

For the dynamic modulus measurements a commer-cially available iETEK measurement instrument depicted in Figure 2 is used.4 For this system, the transmitting sensor is attached to a stepper motor driven actuator to provide a user-defined preload. The pre-load is measured using a load cell mounted on the bottom surface of the receiving sensor. As illustrated in Figure 1, the ultrasonic sensors are mounted in a co-linear configuration. The brake pad is inserted between the sensors and the user defined preload applied through the sensors. The “footprint” of the sensors is 15mm in diameter. The region influencing the ultrasonic propaga-tion is the cylindrical volume directly beneath the sensors. As such, only a portion of the brake pad is measured for a single position of the brake pad. In order to obtain an average of the dynamic modulus in the pad, multiple positions are measured in each pad.

The iETEK is capable of measuring the dynamic modulus using a single user defined pre-load or continuously over pre-loads from 100 N to 800 N on both the loading and unloading portion of the pre-load cycle as illustrated in Figure 2b.

Pad Property Measurement SequencePad thickness first, then the natural frequencies, surface hardness and compressibility by compressing once were measured. This sequence is designated as Cycle 1. Cycle 2 repeated the Cycle 1 on the same sample to detect any property changes taking place as the compressibility measurement technique requires 3 compressions. So the pad thickness, natural frequencies, modulus and hardness during the first cycle represent the pad properties before the first compression. The properties measured after the first compression appear in the second cycle, and so on.

Results and Discussion UNIBRITE DF5BTest results are summarized in Appendix 1-1 for 50 bars compression testing and Appendix 1-2 for 100 bars compres-sion testing. From Appendix 1-2 of 100 bars compression series, the pad natural frequencies, modulus, pad surface hardness and compressibility are graphically shown in Figure 4-1 for the low-copper samples and Figure 4-2 for the copper-free samples. The pad thickness data are not shown here as they showed no measurable variations. As can be seen, the natural frequencies, modulus and hardness all decrease continuously and measurably with increasing porosity while the compressibility shows no general trends. When the porosity increases from 13 to 18%, the compressibility stays more or less the same or goes down slightly, not up, and then at 22%, the compressibility goes up in the case of the low-copper samples, but stays more or less the same in the case of copper-free samples. After 5 compressions, the natural frequencies and modulus show no significant changes, but the compressibility decreases in all cases while the pad surface hardness shows an increasing trend, which suggests the possi-bility of pad surface being compacted during compression. The results of 50 bars compression series follow similar trends. As high-frequency squeals (disc squeals) are usually observed under 5-30 bars of brake line pressure while low-frequency squeals (caliper-knuckle assembly squeals) are observed under 5-60 bars, the pressure of 50 bars represents a reasonable pressure for measurements rather than 100 or 160 bars.

A limited number of samples were aged at room tempera-ture for 12 months and then the properties were measured in order to see ageing effects if any. The results are summarized in Appendix 2. As these samples came from a separate lot, there is some degree of uncertainty, but directional trends would be still valid. The data are presented graphically in Figures 4-1 and 4-2 (red lines). With ageing, the natural frequencies, modulus and hardness all increased, but the compressibility increased rather than decreasing. In the case of a high-copper formula as manufactured using a different process and scorched (not reported here), the hardness was

 FIGURE 2  Measurement configuration for ultrasonic-based dynamic modulus measurements.

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4 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

 FIGURE 3  a) iETEK instrument; b) Typical data showing % modulus variation as a function of pre-loading for both loading and unloading of pad at a single position.

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 FIGURE 4-1  Low-Copper NAO pad physical properties; 13 v%, 18 v%, 22 v%; 5 test cycles; compression 100 bars.

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Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 5

found to decrease, not increase, after 12 months. So one has to be careful not to generalize in terms of ageing effects.

Based on all the data, one has to question the validity of the compressibility measurement technique as measuring an intrinsic pad property such as electrical conductivity or thermal conductivity, etc., which is repeatable whether measured once or several times. If an intrinsic property is not being measured by the technique, then what is being measured? In turn, one has to question the validity of trying to relate pad compressibility to brake squeal generation.

As pad properties are found to age with time, one has to find out when the aging process comes to completion (1 day, 1 week, 1 month or longer?) and decide on the length of time to wait for complete aging /curing before testing. In other words, one has to ensure brake testing is done with fully cure/aged pads for consistent results.

Summary and Conclusions 1. Pad natural frequencies, modulus and hardness

continuously decrease with increasing pad porosity. 2. Pad compressibility shows no clear trends vs. pad

porosity. One has to question the validity of this method for measuring intrinsic material properties.

3. As compressibility does not represent an intrinsic pad property, compressibility must not be used to relate to brake squeal.

4. Pad surface hardness increases with successive compression.

5. Pad natural frequencies and modulus remain essentially the same after increasing number of compressions, indicating physical changes taking place just on the surface of the pad after compression.

6. After 12-months of aging at room temperature, pad natural frequencies, modulus and hardness all increased, but compressibility showed no trends.

7. Fully cured/aged pads must be tested for consistent results.

8. The ultrasonic technique is a convenient method for detecting pad porosity and pad porosity variations, and modulus.

References 1. Sriwiboon, M., Rhee, S., Kaewlob, K., Tiempan, N. et al., “A

Study of Pad Properties vs. Friction, Wear and Brake Squeal: Processing/Porosity Effects,” SAE Int. J. Mater. Manf. 10(1):26-33, 2017, doi:10.4271/2016-01-1915.

 FIGURE 4-2  Copper-Free NAO pad physical properties; 13 v%, 18 v% and 22 v%; 5 test cycles; compression 100 bars.©

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6 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

2. Sriwiboon, M., Tiempan, N., Kaewlob, K., and Rhee, S., “Influence of Formulation and Process Modifications on Brake Friction, Wear and Squeal: Low-Copper NAOs and Importance of Disc Wear,” SAE Technical Paper 2014-01-2482, 2014, doi:10.4271/2014-01-2482.

3. Sriwiboon, M., Tiempan, N., Kaewlob, K., and Rhee, S., “Brake Squeal and Wheel Dust vs. Disc Wear: No-Copper, Low-Copper and High-Copper NAOs,” SAE Int. J. Mater. Manf. 9(1):112-117, 2016, doi:10.4271/2015-01-2660.

4. Every A.G., “Determination of the Elastic Constants of Anisotropic Solids”, NDT & E International 27(1):3-10, 1993, doi:10.1016/0963-8695(94)90003-5.

5. Chen, F., Tan, C., and Quaglia, R., “Disc Brake Squeal: Mechanism, Analysis, Evaluation, and Reduction/Prevention,” (Warrendale, Society of Automotive Engineers, Inc., 2006), ISBN:978-0-7680-1248-4.

6. Malmassari C. M., Cucchi F., Yuhas, D. E., Vorres, C. L., and Remiasz, J.R., “Evolution of Brake Noise Performance and Its Relation to Variations in Friction Material Elastic Properties,” Proceedings of EuroBrake 2015, Paper # EB2015-NVH-011, Dresden Germany, May 4-6, 2015.

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Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 7

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8 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

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(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 5

0 b

ar

LC_1

8%N

ew S

ampl

e C

ycle

114

03.

551

22.8

1017

52.

9118

2.85

09

2.38

832.

4461

2.64

9377

.572

.969

.667

.271

.810

.362

.6

New

Sam

ple

Cyc

le 1

140

3.5

5122

.810

175

2.89

482.

8341

2.37

422.

4317

2.63

3763

.364

.562

.260

.062

.54.

563

.6

New

Sam

ple

Cyc

le 1

140

3.5

5122

.810

175

2.90

302.

8421

2.38

102.

4386

2.64

1270

.574

.565

.465

.769

.09.

166

.7

New

Sam

ple

Cyc

le 1

140

3.5

5122

.810

175

2.86

832.

8082

2.35

242.

4093

2.60

9678

.378

.462

.164

.070

.716

.371

.7

Avg

140

451

22.8

1017

52.

8945

2.83

382.

3740

2.43

142.

6334

72.4

72.6

64.8

64.2

68.5

10.1

66.2

Rang

e-

--

0.0

434

0.0

427

0.03

590.

0368

0.03

9715

.013

.97.

57.

29.

311

.89.

1

LC_1

8%N

ew S

ampl

e1 C

ycle

214

03.

551

22.8

1017

52.

9137

2.85

252.

3890

2.44

682.

650

582

.674

.371

.479

.777

.011

.254

.5

New

Sam

ple1

Cyc

le 2

140

3.5

5122

.810

175

2.90

142.

840

32.

3789

2.43

652.

6392

65.3

74.8

68.7

72.0

70.2

9.5

56.5

New

Sam

ple1

Cyc

le 2

140

3.5

5122

.810

175

2.90

922.

8478

2.38

532.

4431

2.64

6374

.776

.670

.772

.873

.75.

960

.6

New

Sam

ple1

Cyc

le 2

140

3.5

5122

.810

175

2.87

592.

8155

2.34

02

2.41

522.

6117

86.9

75.7

72.9

67.3

75.7

19.6

66.0

Avg

140

451

22.8

1017

52.

900

02.

8390

2.37

332.

4354

2.63

6977

.475

.470

.973

.074

.211

.659

.4

Rang

e-

--

0.03

780.

0371

0.0

489

0.03

160.

0388

21.6

2.3

4.2

12.4

6.8

13.7

11.5

LC_1

8%N

ew S

ampl

e 1 C

ycle

314

03.

551

22.8

1017

52.

9148

2.85

372.

390

02.

4480

2.65

1680

.279

.880

.875

.179

.05.

752

.0

New

Sam

ple

1 Cyc

le 3

140

3.5

5122

.810

175

2.90

192.

8410

2.37

942.

4369

2.63

9874

.077

.887

.877

.179

.213

.860

.5

New

Sam

ple

1 Cyc

le 3

140

3.5

5122

.810

175

2.90

852.

8473

2.38

452.

4424

2.64

5774

.595

.573

.071

.878

.723

.758

.3

New

Sam

ple

1 Cyc

le 3

140

3.5

5122

.810

175

2.87

712.

8167

2.35

902.

4162

2.61

7272

.568

.972

.264

.369

.58.

264

.8

Avg

140

451

22.8

1017

52.

900

62.

8397

2.37

822.

4359

2.63

8675

.380

.578

.572

.176

.612

.958

.9

Rang

e-

--

0.03

780.

0371

0.03

100.

0319

0.03

447.

726

.615

.612

.89.

718

.012

.8

LC_1

8%N

ew S

ampl

e 1 C

ycle

414

03.

551

22.8

1017

52.

9160

2.85

492.

3907

2.44

872.

6526

88.8

67.9

77.7

62.7

74.3

26.1

53.8

New

Sam

ple

1 Cyc

le 4

140

3.5

5122

.810

175

2.90

562.

8445

2.38

192.

4398

2.64

3066

.061

.470

.467

.766

.49.

058

.7

New

Sam

ple

1 Cyc

le 4

140

3.5

5122

.810

175

2.91

392.

8525

2.38

882.

4466

2.65

05

69.5

71.8

77.3

77.7

74.1

8.2

60.6

New

Sam

ple

1 Cyc

le 4

140

3.5

5122

.810

175

2.88

492.

8242

2.36

502.

4223

2.62

4178

.080

.565

.865

.972

.614

.766

.5

Avg

140

451

22.8

1017

52.

9051

2.84

402.

3816

2.43

942.

6425

71.2

71.2

71.2

70.4

71.0

10.6

61.9

Rang

e-

--

0.03

120.

0307

0.02

570.

0264

0.02

8512

.019

.111

.511

.87.

76.

57.

8

LC_1

8%N

ew S

ampl

e 1 C

ycle

514

03.

551

22.8

1017

52.

9023

2.84

142.

380

82.

4384

2.64

0786

.670

.183

.476

.679

.216

.552

.5

New

Sam

ple

1 Cyc

le 5

140

3.5

5122

.810

175

2.89

08

2.83

01

2.37

112.

4284

2.63

0176

.876

.180

.278

.677

.94.

156

.9

New

Sam

ple

1 Cyc

le 5

140

3.5

5122

.810

175

2.90

072.

8398

2.37

942.

4369

2.63

9280

.290

.174

.276

.680

.315

.959

.8

New

Sam

ple

1 Cyc

le 5

140

3.5

5122

.810

175

2.86

412.

8042

2.34

942.

4063

2.60

6079

.878

.871

.269

.174

.710

.767

.8

Avg

140

451

22.8

1017

52.

8895

2.82

892.

3701

2.42

752.

6290

80.9

78.8

77.3

75.2

78.0

11.8

59.3

Rang

e-

--

0.03

820.

0373

0.03

140.

0321

0.03

489.

820

.012

.29.

55.

612

.415

.3

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 9: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 9

TAB

LES

1-1

-3 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of l

ow c

oppe

r 22%

por

osity

sam

ples

.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 5

0 b

ar

LC_2

2%N

ew S

ampl

e C

ycle

113

33.3

4736

.897

19.3

2.18

692.

2952

1.933

01.9

436

2.0

897

68.2

72.7

48.3

57.5

61.7

24.4

57.1

New

Sam

ple

Cyc

le 1

1333

.347

36.8

9719

.32.

1556

2.26

231.9

053

1.915

72.

059

754

.867

.066

.462

.262

.612

.256

.5

New

Sam

ple

Cyc

le 1

1333

.348

71.2

9929

.82.

1719

2.27

941.9

197

1.930

22.

0753

63.8

74.5

61.4

56.4

64.0

18.1

56.6

New

Sam

ple

Cyc

le 1

1333

.348

71.2

9929

.82.

1622

2.26

921.9

112

1.921

62.

066

050

.173

.258

.149

.857

.823

.456

.2

Avg

1333

.348

04.

098

24.6

2.16

912.

2765

1.91

731.

9278

2.07

2759

.271

.958

.656

.561

.519

.556

.6

Rang

e-

--

0.03

130.

0329

0.02

770.

0279

0.03

00

18.1

7.5

18.1

12.4

6.2

12.2

0.9

LC_2

2%N

ew S

ampl

e1 C

ycle

213

33.3

4736

.897

19.3

2.18

792.

2964

1.933

61.9

442

2.0

905

66.6

69.8

52.4

52.1

60.2

17.7

51.2

New

Sam

ple1

Cyc

le 2

1333

.347

36.8

9719

.32.

1592

2.26

621.9

082

1.918

62.

063

056

.670

.268

.866

.665

.613

.646

.9

New

Sam

ple1

Cyc

le 2

1333

.347

36.8

9719

.32.

1671

2.27

451.9

152

1.925

72.

070

664

.872

.466

.654

.264

.518

.248

.7

New

Sam

ple1

Cyc

le 2

1333

.347

36.8

9719

.32.

1649

2.27

221.9

132

1.923

72.

068

552

.168

.862

.152

.158

.816

.750

.1

Avg

1333

.347

36.8

9719

.32.

1698

2.27

731.

9175

1.92

802.

0732

60.0

70.3

62.5

56.3

62.3

16.6

49.2

Rang

e-

--

0.02

880.

0302

0.02

540.

0256

0.02

7514

.53.

616

.414

.56.

84.

64.

3

LC_2

2%N

ew S

ampl

e 1 C

ycle

313

33.3

4736

.897

19.3

2.17

572.

2598

1.918

31.9

157

2.0

674

65.8

74.2

56.8

60.2

64.3

17.4

49.1

New

Sam

ple

1 Cyc

le 3

1333

.347

36.8

9719

.32.

1471

2.23

01

1.893

11.8

905

2.0

402

55.5

68.8

66.4

60.1

62.7

13.3

58.9

New

Sam

ple

1 Cyc

le 3

1333

.347

36.8

9719

.32.

1559

2.23

921.9

00

81.8

982

2.0

485

66.3

74.2

66.1

60.2

66.7

14.0

48.0

New

Sam

ple

1 Cyc

le 3

1333

.347

36.8

9719

.32.

1515

2.23

471.8

969

1.894

42.

044

455

.569

.859

.852

.359

.417

.547

.8

Avg

1333

.347

36.8

9719

.32.

1576

2.24

101.

9023

1.89

972.

050

160

.871

.862

.358

.263

.315

.651

.0

Rang

e-

--

0.02

860.

0297

0.02

520.

0252

0.02

7210

.85.

49.

67.

97.

44.

211

.1

LC_2

2%N

ew S

ampl

e 1 C

ycle

413

33.3

4736

.897

19.3

2.17

132.

2551

1.914

51.9

119

2.0

632

65.5

55.5

52.8

47.1

55.2

18.4

50.0

New

Sam

ple

1 Cyc

le 4

1333

.347

36.8

9719

.32.

1419

2.22

461.8

886

1.886

02.

0353

57.5

61.2

62.7

62.2

60.9

5.2

46.0

New

Sam

ple

1 Cyc

le 4

1333

.347

36.8

9719

.32.

1533

2.23

641.8

986

1.896

02.

046

165

.164

.368

.850

.362

.118

.552

.1

New

Sam

ple

1 Cyc

le 4

1333

.347

36.8

9719

.32.

1519

2.23

501.8

975

1.894

92.

044

867

.972

.573

.954

.267

.119

.748

.0

Avg

1333

.347

36.8

9719

.32.

1546

2.23

781.

8998

1.89

722.

047

364

.063

.464

.653

.561

.315

.549

.0

Rang

e-

--

0.02

940.

030

60.

0259

0.02

590.

0280

10.4

17.0

21.1

15.1

11.9

14.5

6.1

LC_2

2%N

ew S

ampl

e 1 C

ycle

513

33.3

4736

.897

19.3

2.17

122.

2550

1.914

61.9

120

2.0

632

66.6

69.8

55.4

54.9

61.7

14.9

49.4

New

Sam

ple

1 Cyc

le 5

1333

.347

36.8

9719

.32.

1379

2.22

04

1.885

21.8

827

2.03

1658

.264

.460

.261

.161

.06.

244

.6

New

Sam

ple

1 Cyc

le 5

1333

.347

36.8

9719

.32.

1488

2.23

171.8

949

1.892

32.

041

964

.868

.856

.658

.962

.312

.247

.2

New

Sam

ple

1 Cyc

le 5

1333

.347

36.8

9719

.32.

1431

2.22

581.8

899

1.887

32.

0365

62.4

70.2

55.5

60.1

62.1

14.7

46.9

Avg

1333

.347

36.8

9719

.32.

1503

2.23

321.

8962

1.89

362.

043

363

.068

.356

.958

.861

.712

.047

.0

Rang

e-

--

0.03

330.

0346

0.02

940.

0294

0.03

178.

45.

84.

86.

21.

38.

74.

8

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 10: Porosity & Brake Pads Modulus - imsysinc.com

10 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

TAB

LES

1-1

-4 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of C

oppe

r Fre

e 13

% p

oros

ity s

ampl

es.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 5

0 b

ar

CF_

13%

New

Sam

ple

Cyc

le 1

1649

.156

1411

157.

92.

7030

2.72

942.

5556

2.66

392.

6630

80.6

75.1

84.0

83.0

80.7

8.9

68.5

New

Sam

ple

Cyc

le 1

1649

.156

1411

157.

92.

7034

2.73

01

2.55

612.

6643

2.66

3583

.980

.074

.575

.978

.69.

467

.6

New

Sam

ple

Cyc

le 1

1649

.156

1411

157.

92.

6984

2.72

492.

5513

2.65

962.

6586

82.5

79.9

74.5

83.6

80.1

9.1

65.5

New

Sam

ple

Cyc

le 1

1649

.156

1411

157.

92.

7167

2.74

342.

5687

2.67

742.

6766

80.6

76.8

80.6

86.3

81.1

9.5

75.6

Avg

1649

.156

14.0

1115

82.

7054

2.73

192.

5579

2.66

632.

6654

81.9

78.0

78.4

82.2

80.1

9.2

69.3

Rang

e-

--

0.01

830.

0185

0.01

740.

0179

0.01

803.

34.

99.

510

.42.

50.

610

.1

CF_

13%

New

Sam

ple1

Cyc

le 2

1649

.156

1411

052

.62.

7077

2.73

442.

5599

2.66

862.

6676

84.0

79.7

85.2

94.7

85.9

15.0

68.8

New

Sam

ple1

Cyc

le 2

1649

.156

1411

052

.62.

7073

2.73

392.

5595

2.66

822.

6672

88.4

81.0

76.1

72.6

79.5

15.8

67.0

New

Sam

ple1

Cyc

le 2

1649

.156

1411

052

.62.

7312

2.75

792.

5821

2.69

172.

6907

82.7

81.5

87.7

80.9

83.2

6.8

64.7

New

Sam

ple1

Cyc

le 2

1649

.156

1411

052

.62.

7179

2.74

452.

5694

2.67

832.

6775

87.1

75.6

78.7

74.0

78.9

13.1

66.2

Avg

1649

.156

14.0

110

532.

7160

2.74

272.

5677

2.67

672.

6758

85.6

79.5

81.9

80.6

81.9

12.7

66.7

Rang

e-

--

0.02

400.

0240

0.02

260.

0235

0.02

355.

75.

911

.622

.17.

19.

04.

1

CF_

13%

New

Sam

ple

1 Cyc

le 3

1649

.156

1411

052

.62.

7084

2.73

512.

560

62.

6691

2.66

8382

.779

.682

.088

.883

.39.

270

.6

New

Sam

ple

1 Cyc

le 3

1649

.156

1411

052

.62.

7095

2.73

622.

5615

2.67

02

2.66

9377

.685

.483

.777

.581

.17.

967

.6

New

Sam

ple

1 Cyc

le 3

1649

.156

1411

052

.62.

730

52.

7574

2.58

162.

6910

2.69

0181

.482

.710

0.0

91.4

88.9

18.6

64.8

New

Sam

ple

1 Cyc

le 3

1649

.156

1411

052

.62.

7217

2.74

842.

5730

2.68

222.

6813

76.3

78.7

73.1

79.9

77.0

6.8

69.1

Avg

1649

.156

14.0

110

532.

7175

2.74

432.

5692

2.67

812.

6773

79.5

81.6

84.7

84.4

82.6

10.6

68.0

Rang

e-

--

0.02

210.

0224

0.02

100.

0219

0.02

196.

46.

726

.913

.911

.911

.85.

8

CF_

13%

New

Sam

ple

1 Cyc

le 4

1649

.156

1411

052

.62.

7134

2.74

00

2.56

512.

6740

2.67

3182

.682

.782

.990

.184

.67.

571

.9

New

Sam

ple

1 Cyc

le 4

1649

.156

1411

052

.62.

7134

2.74

00

2.56

512.

6740

2.67

3187

.192

.083

.973

.584

.118

.569

.2

New

Sam

ple

1 Cyc

le 4

1649

.156

1411

052

.62.

7366

2.76

352.

5872

2.69

712.

6961

77.1

78.3

78.9

78.8

78.3

1.866

.4

New

Sam

ple

1 Cyc

le 4

1649

.156

1411

052

.62.

7240

2.75

06

2.57

502.

6844

2.68

3583

.397

.082

.274

.884

.322

.271

.2

Avg

1649

.156

14.0

110

532.

7218

2.74

862.

5731

2.68

242.

6815

82.5

87.5

82.0

79.3

82.8

12.5

69.7

Rang

e-

--

0.02

330.

0235

0.02

210.

0231

0.02

3010

.018

.75.

016

.66.

320

.45.

5

CF_

13%

New

Sam

ple

1 Cyc

le 5

1649

.156

1411

052

.62.

6991

2.72

562.

5520

2.66

00

2.65

9285

.982

.183

.583

.283

.73.

868

.3

New

Sam

ple

1 Cyc

le 5

1649

.156

1411

052

.62.

7018

2.72

832.

5547

2.66

272.

6619

88.1

86.5

78.0

78.0

82.7

10.1

67.8

New

Sam

ple

1 Cyc

le 5

1649

.156

1411

052

.62.

720

62.

7473

2.57

232.

6813

2.68

04

95.4

89.9

94.7

79.5

89.9

15.9

64.2

New

Sam

ple

1 Cyc

le 5

1649

.156

1411

052

.62.

7091

2.73

552.

5615

2.67

00

2.66

9078

.782

.690

.272

.481

.017

.865

.7

Avg

1649

.156

14.0

110

532.

7076

2.73

412.

5601

2.66

852.

6676

87.0

85.3

86.6

78.3

84.3

11.9

66.5

Rang

e-

--

0.02

150.

0217

0.02

030.

0212

0.02

1216

.77.

816

.710

.88.

914

.04.

1

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 11: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 11

TAB

LES

1-1

-5 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of C

oppe

r Fre

e 18

% p

oros

ity s

ampl

es.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 5

0 b

ar

CF_

18%

New

Sam

ple

Cyc

le 1

150

8.8

5263

.210

526.

32.

00

842.

1989

2.39

902.

5521

2.28

9654

.361

.455

.857

.357

.27.

169

.3

New

Sam

ple

Cyc

le 1

150

8.8

5263

.210

526.

32.

090

72.

2889

2.49

722.

6565

2.38

3353

.863

.262

.761

.560

.39.

473

.3

New

Sam

ple

Cyc

le 1

150

8.8

5263

.210

526.

32.

044

12.

2380

2.44

162.

7562

2.37

00

76.4

64.3

56.4

60.2

64.3

20.0

78.5

New

Sam

ple

Cyc

le 1

150

8.8

5263

.210

526.

32.

040

02.

2335

2.43

672.

5922

2.32

5665

.761

.267

.862

.064

.26.

687

.2

Avg

150

8.8

5263

.210

526

2.0

458

2.23

982.

4436

2.63

932.

3421

62.6

62.5

60.7

60.3

61.5

10.8

77.1

Rang

e-

--

0.0

822

0.0

900

0.0

982

0.20

410.

093

722

.63.

112

.04.

77.

113

.417

.9

CF_

18%

New

Sam

ple1

Cyc

le 2

150

8.8

5263

.210

526.

32.

035

82.

2286

2.43

122.

5860

2.32

04

57.6

56.6

74.1

61.3

62.4

17.5

63.6

New

Sam

ple1

Cyc

le 2

150

8.8

5263

.210

526.

32.

088

42.

2863

2.49

402.

6529

2.38

04

53.2

65.8

66.4

73.5

64.7

20.3

65.6

New

Sam

ple1

Cyc

le 2

150

8.8

5263

.210

561.4

2.0

419

2.23

542.

4384

2.59

372.

3274

71.7

77.0

62.0

60.6

67.8

16.4

70.0

New

Sam

ple1

Cyc

le 2

150

8.8

5263

.210

526.

32.

045

22.

2388

2.44

232.

5980

2.33

1167

.064

.067

.164

.465

.63.

182

.4

Avg

150

8.8

5263

.210

535

2.0

529

2.24

732.

4515

2.60

772.

3398

62.4

65.9

67.4

65.0

65.1

14.3

70.4

Rang

e-

--

0.0

526

0.0

577

0.0

628

0.0

669

0.0

600

18.5

20.4

12.1

12.9

5.4

17.2

18.8

CF_

18%

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

526.

32.

035

82.

2286

2.43

122.

5860

2.32

04

65.0

63.3

57.6

63.8

62.4

7.4

63.4

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

526.

32.

092

22.

290

42.

4985

2.65

762.

3847

57.0

70.6

64.6

77.8

67.5

20.8

64.4

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

568.

02.

021

92.

2135

2.41

462.

5684

2.30

4676

.382

.294

.566

.079

.828

.568

.4

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

526.

32.

059

22.

2542

2.45

912.

6156

2.34

7069

.978

.969

.468

.871

.810

.179

.2

Avg

150

8.8

5263

.210

537

2.0

523

2.24

672.

450

82.

6069

2.33

9267

.173

.871

.569

.170

.416

.768

.9

Rang

e-

--

0.07

020.

0769

0.0

839

0.0

892

0.0

801

19.3

18.9

36.9

14.0

17.3

21.1

15.8

CF_

18%

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

526.

32.

041

92.

1543

2.50

492.

4161

2.27

9371

.867

.660

.162

.765

.611

.763

.1

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

526.

32.

092

32.

2073

2.56

642.

4757

2.33

5483

.063

.362

.766

.969

.020

.365

.8

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

561.4

2.0

485

2.16

132.

5128

2.42

392.

2866

70.4

71.6

73.8

67.1

70.7

6.7

70.9

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

526.

32.

049

82.

1626

2.51

452.

4254

2.28

8171

.271

.360

.465

.667

.110

.983

.4

Avg

150

8.8

5263

.210

535

2.0

581

2.17

142.

5246

2.43

532.

2974

74.1

68.5

64.3

65.6

68.1

12.4

70.8

Rang

e-

--

0.0

503

0.0

530

0.0

616

0.0

596

0.0

561

12.6

8.3

13.7

4.4

5.2

13.6

20.3

CF_

18%

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

526.

32.

035

62.

2284

2.43

08

2.58

542.

320

071

.165

.365

.460

.165

.511

.063

.3

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

526.

32.

092

92.

2910

2.49

892.

6580

2.38

5272

.766

.860

.368

.167

.012

.468

.1

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

561.4

2.0

369

2.22

972.

4322

2.58

692.

3214

72.7

71.1

75.1

68.8

71.9

6.3

70.3

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

526.

32.

028

02.

2365

2.43

952.

5948

2.32

4772

.771

.175

.168

.871

.96.

382

.7

Avg

150

8.8

5263

.210

535

2.0

484

2.24

642.

450

42.

6063

2.33

7872

.368

.669

.066

.569

.19.

071

.1

Rang

e-

--

0.0

649

0.0

626

0.0

682

0.07

260.

065

21.

65.

814

.88.

76.

56.

119

.4

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 12: Porosity & Brake Pads Modulus - imsysinc.com

12 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

TAB

LES

1-1

-6 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of C

oppe

r Fre

e 22

% p

oros

ity s

ampl

es.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 5

0 b

ar

CF_

18%

New

Sam

ple

Cyc

le 1

1438

.650

17.5

1017

5.4

2.0

485

2.23

961.9

921

2.25

702.

1343

50.6

52.1

44.2

49.8

49.2

7.9

63.0

New

Sam

ple

Cyc

le 1

1438

.650

17.5

1017

5.4

2.0

369

2.22

691.9

808

2.24

422.

1222

54.6

55.5

50.1

48.9

52.3

6.6

63.1

New

Sam

ple

Cyc

le 1

1411

.449

5799

48.4

2.0

166

2.20

481.9

611

2.22

192.

1011

42.2

46.3

50.4

32.1

42.8

18.3

65.8

New

Sam

ple

Cyc

le 1

1438

.650

17.5

1017

5.4

2.0

183

2.20

651.9

627

2.22

372.

1028

55.5

46.2

50.3

48.8

50.2

9.3

66.8

Avg

1431

.850

02.4

1011

92.

0301

2.21

941.

9742

2.23

672.

1151

50.7

50.0

48.8

44.9

48.6

10.5

64.7

Rang

e-

--

0.03

190.

0348

0.03

100.

0351

0.03

3213

.39.

36.

217

.79.

511

.73.

8

CF_

18%

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

1017

5.4

2.0

336

2.22

572.

024

72.

1952

2.11

9849

.855

.248

.650

.251

.06.

654

.3

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

1017

5.4

2.0

131

2.20

322.

00

422.

1730

2.0

984

49.8

58.8

52.1

46.9

51.9

11.9

60.4

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

9964

.91.9

975

2.18

621.9

887

2.15

632.

082

245

.245

.150

.236

.844

.313

.459

.3

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

1017

5.4

1.990

22.

1782

1.981

42.

1483

2.07

4550

.149

.850

.647

.149

.43.

558

.8

Avg

1438

.650

17.5

1012

32.

00

862.

1983

1.99

982.

1682

2.0

937

48.7

52.2

50.4

45.3

49.1

8.9

58.2

Rang

e-

--

0.0

434

0.0

475

0.0

432

0.0

469

0.0

453

4.9

13.7

3.5

13.4

7.6

9.9

6.1

CF_

18%

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

1017

5.4

2.0

559

2.24

821.9

992

2.24

472.

1370

56.8

54.2

40.8

53.0

51.2

16.0

50.3

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

1017

5.4

2.0

422

2.23

321.9

859

2.22

972.

1227

58.6

60.9

45.1

49.6

53.6

15.8

58.6

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

9948

.62.

024

32.

2136

1.968

52.

210

22.

1042

47.5

45.0

39.8

34.8

41.8

12.7

56.4

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

1017

5.4

2.0

518

2.24

361.9

952

2.24

02

2.13

2756

.957

.052

.348

..355

.44.

758

.2

Avg

1438

.650

17.5

1011

92.

043

62.

2347

1.98

722.

2312

2.12

4255

.054

.344

.545

.850

.512

.355

.9

Rang

e-

--

0.03

160.

0346

0.03

070.

0345

0.03

2811

.115

.912

.518

.213

.611

.38.

3

CF_

18%

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

1017

5.4

2.0

516

2.24

331.9

951

2.23

992.

1325

58.9

58.2

59.6

50.8

56.9

8.8

52.5

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

1017

5.4

2.0

396

2.23

02

1.983

42.

2267

2.12

00

54.3

60.7

52.5

50.5

54.5

10.2

59.5

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

9964

.92.

019

72.

2084

1.964

02.

2050

2.0

993

49.6

48.6

41.4

40.2

45.0

9.4

55.8

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

1017

5.4

2.0

185

2.20

711.9

628

2.20

362.

098

050

.156

.152

.054

.453

.26.

058

.1

Avg

1438

.650

17.5

1012

32.

0323

2.22

221.

9763

2.21

882.

1124

53.2

55.9

51.4

49.0

52.4

8.6

56.5

Rang

e-

--

0.03

320.

0363

0.03

230.

0362

0.03

459.

312

.118

.214

.211

.94.

27.

0

CF_

18%

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

1017

5.4

2.0

482

2.23

941.9

918

2.23

602.

1288

57.6

52.4

42.6

45.4

49.5

15.0

50.8

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

1017

5.4

2.0

361

2.22

631.9

801

2.22

282.

1163

54.4

60.2

52.1

49.8

54.1

10.4

58.9

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

9964

.42.

016

32.

2045

1.960

82.

2011

2.0

957

50.2

42.1

42.3

40.2

43.7

10.0

53.1

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

1017

5.4

2.0

134

2.20

141.9

580

2.19

802.

092

752

.150

.249

.850

.150

.62.

357

.6

Avg

1438

.650

17.5

1012

32.

0285

2.21

791.

9727

2.21

452.

1084

53.6

51.2

46.7

46.4

49.5

9.4

55.1

Rang

e-

--

0.03

480.

0380

0.03

380.

0380

0.03

627.

418

.19.

89.

910

.412

.78.

1

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 13: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 13

Ap

pen

dix

1-2

: Phy

sica

l Pro

per

ties

of

Low

-Co

pp

er a

nd C

op

per

-Fre

e N

AO

Pad

s: 1

00

B

ars

Co

mp

ress

ion

TAB

LES

1-2

-1 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of l

ow c

oppe

r 13%

por

osity

sam

ples

.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

LC_1

3%N

ew S

ampl

e C

ycle

116

1454

38.7

1073

6.9

3.17

983.

2893

3.16

923.

010

73.

1623

91.5

91.8

88.5

92.6

91.1

4.1

111.6

New

Sam

ple

Cyc

le 1

1614

5438

.710

736.

93.

190

33.

1957

3.16

903.

4398

3.24

8782

.592

.984

.891

.688

.010

.493

.5

New

Sam

ple

Cyc

le 1

1614

5438

.710

736.

93.

2190

3.35

953.

5093

3.39

453.

370

693

.795

.188

.887

.391

.27.

889

.2

New

Sam

ple

Cyc

le 1

1614

5438

.710

736.

93.

3099

3.47

453.

5678

3.23

743.

3974

87.6

93.8

93.8

93.4

92.2

6.2

85.0

Avg

1614

5438

.710

737

3.22

473.

3297

3.35

383.

270

63.

2947

88.8

93.4

89.0

91.2

90.6

7.1

94.8

Rang

e-

--

0.13

010.

2788

0.39

880.

4291

0.23

5111

.23.

39.

06.

14.

26.

326

.6

LC_1

3%N

ew S

ampl

e1 C

ycle

216

1454

03.

510

526.

33.

2034

3.34

203.

1980

2.96

03

3.17

5986

.990

.782

.096

.188

.914

.199

.7

New

Sam

ple1

Cyc

le 2

1614

540

3.5

1052

6.3

3.18

503.

1797

3.13

243.

3913

3.22

2184

.291

.778

.294

.087

.015

.887

.1

New

Sam

ple1

Cyc

le 2

1614

540

3.5

1052

6.3

3.21

713.

3622

3.51

123.

4030

3.37

3492

.397

.782

.192

.991

.315

.683

.2

New

Sam

ple1

Cyc

le 2

1614

540

3.5

1052

6.3

3.28

783.

5044

3.59

833.

2656

3.41

4096

.097

.277

.996

.691

.919

.379

.4

Avg

1614

5403

.510

526

3.22

333.

3471

3.36

00

3.25

513.

2964

89.9

94.3

80.1

94.9

89.8

16.2

87.4

Rang

e-

--

0.10

280.

3247

0.46

590.

4427

0.23

8111

.87.

04.

23.

74.

95.

220

.3

LC_1

3%N

ew S

ampl

e 1 C

ycle

316

1454

03.

510

526.

33.

1863

3.36

893.

2455

2.98

893.

1974

93.4

92.0

82.1

86.8

88.6

11.3

97.9

New

Sam

ple

1 Cyc

le 3

1614

540

3.5

1052

6.3

3.20

743.

1967

3.18

073.

4869

3.26

7992

.495

.693

.096

.794

.44.

385

.2

New

Sam

ple

1 Cyc

le 3

1614

540

3.5

1052

6.3

3.22

03

3.36

523.

5448

3.48

343.

4034

95.0

93.4

79.7

89.7

89.5

15.3

81.3

New

Sam

ple

1 Cyc

le 3

1614

540

3.5

1052

6.3

3.35

133.

5174

3.57

973.

3285

3.44

4297

.294

.489

.793

.493

.77.

576

.5

Avg

1614

5403

.510

526

3.24

133.

3620

3.38

773.

3219

3.32

8294

.593

.986

.191

.791

.59.

685

.2

Rang

e-

--

0.16

500.

3207

0.39

900.

4979

0.24

694.

83.

613

.39.

95.

811

.021

.4

LC_1

3%N

ew S

ampl

e 1 C

ycle

416

1454

03.

510

526.

33.

2381

3.41

353.

2876

3.0

359

3.24

3889

.491

.778

.893

.488

.314

.699

.3

New

Sam

ple

1 Cyc

le 4

1614

540

3.5

1052

6.3

3.27

553.

2317

3.18

883.

4659

3.29

05

92.2

90.6

88.0

86.3

89.3

5.9

86.5

New

Sam

ple

1 Cyc

le 4

1614

540

3.5

1052

6.3

3.28

113.

4124

3.55

183.

5331

3.44

4697

.094

.686

.589

.491

.910

.581

.6

New

Sam

ple

1 Cyc

le 4

1614

540

3.5

1052

6.3

3.39

413.

5952

3.62

723.

3252

3.48

5479

.896

.689

.096

.490

.516

.887

.1

Avg

1614

5403

.510

526

3.29

723.

4132

3.41

383.

340

03.

3661

89.6

93.4

85.6

91.4

90.0

12.0

88.6

Rang

e-

--

0.15

610.

3634

0.43

830.

4972

0.24

1717

.26.

010

.210

.13.

510

.917

.7

LC_1

3%N

ew S

ampl

e 1 C

ycle

516

1454

38.7

1073

6.9

3.25

813.

3476

3.22

00

2.98

593.

2029

91.5

95.2

81.3

94.5

90.6

13.9

98.6

New

Sam

ple

1 Cyc

le 5

1614

5438

.710

736.

93.

2317

3.17

293.

1572

3.45

393.

2539

91.6

96.2

92.6

90.4

92.7

5.8

86.9

New

Sam

ple

1 Cyc

le 5

1614

5438

.710

736.

93.

2143

3.37

603.

5317

3.51

323.

4088

96.0

93.0

94.0

91.1

93.5

4.9

82.1

New

Sam

ple

1 Cyc

le 5

1614

5438

.710

736.

92.

9886

3.18

673.

1923

2.98

353.

087

889

.993

.590

.494

.892

.24.

979

.8

Avg

1614

5438

.710

737

3.17

323.

270

83.

2753

3.23

413.

2384

92.3

94.5

89.6

92.7

92.3

7.4

86.9

Rang

e-

--

0.26

950.

2031

0.37

450.

5297

0.32

106.

13.

212

.74.

42.

99.

018

.8

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 14: Porosity & Brake Pads Modulus - imsysinc.com

14 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

TAB

LES

1-2

-2 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of l

ow c

oppe

r 18%

por

osity

sam

ples

.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

LC_1

8%N

ew S

ampl

e C

ycle

114

03.

551

22.8

1017

5.4

2.50

522.

7318

3.13

642.

9568

2.83

2581

.274

.565

.669

.772

.815

.694

.6

New

Sam

ple

Cyc

le 1

140

3.5

5122

.810

175.

42.

6488

2.58

113.

070

63.

025

62.

8315

78.8

86.8

67.3

73.1

76.5

19.5

94.3

New

Sam

ple

Cyc

le 1

140

3.5

5122

.810

175.

42.

6942

2.74

483.

065

52.

9478

2.86

3179

.190

.073

.569

.678

.120

.491

.2

New

Sam

ple

Cyc

le 1

140

3.5

5122

.810

175.

42.

8622

2.86

682.

5718

2.61

112.

7280

69.4

69.8

70.0

77.7

71.7

8.3

98.1

Avg

1403

.551

22.8

1017

52.

6776

2.73

112.

9611

2.88

532.

8138

77.1

80.3

69.1

72.5

74.8

16.0

94.6

Rang

e-

--

0.35

700.

2856

0.56

460.

4145

0.13

5111

.820

.27.

98.

16.

312

.16.

9

LC_1

8%N

ew S

ampl

e1 C

ycle

214

03.

551

22.8

1017

5.4

2.48

762.

6787

3.12

822.

9730

2.81

6982

.185

.985

.971

.981

.514

.086

.7

New

Sam

ple1

Cyc

le 2

140

3.5

5122

.810

175.

42.

6193

2.54

503.

095

02.

9610

2.80

5180

.784

.489

.972

.581

.917

.487

.4

New

Sam

ple1

Cyc

le 2

140

3.5

5122

.810

175.

42.

6566

2.72

303.

015

02.

9472

2.83

5478

.490

.760

.469

.374

.730

.385

.5

New

Sam

ple1

Cyc

le 2

140

3.5

5122

.810

175.

42.

8395

2.83

952.

5486

2.55

252.

6950

82.7

78.9

61.1

79.5

75.6

21.6

82.4

Avg

1403

.551

22.8

1017

52.

650

82.

6966

2.94

672.

8584

2.78

8181

.085

.074

.373

.378

.420

.885

.5

Rang

e-

--

0.35

190.

2945

0.57

960.

420

50.

140

44.

311

.829

.510

.27.

216

.35.

0

LC_1

8%N

ew S

ampl

e 1 C

ycle

314

03.

551

22.8

1017

5.4

2.51

812.

6789

3.18

483.

016

02.

8494

82.0

77.2

64.0

79.8

75.8

18.0

84.4

New

Sam

ple

1 Cyc

le 3

140

3.5

5122

.810

175.

42.

6848

2.57

673.

093

73.

00

872.

8410

79.2

85.4

62.7

81.3

77.2

22.7

84.0

New

Sam

ple

1 Cyc

le 3

140

3.5

5122

.810

175.

42.

6861

2.69

443.

1623

2.97

592.

8797

82.5

93.3

66.5

78.4

80.2

26.8

81.0

New

Sam

ple

1 Cyc

le 3

140

3.5

5122

.810

175.

42.

8566

2.84

752.

5749

2.53

652.

7039

68.4

69.8

80.0

84.3

75.6

15.9

79.4

Avg

1403

.551

22.8

1017

52.

6864

2.69

943.

003

92.

8843

2.81

8578

.081

.468

.381

.077

.220

.982

.2

Rang

e-

--

0.33

850.

270

80.

6099

0.47

950.

1758

14.1

23.5

17.3

5.9

4.6

10.9

5.0

LC_1

8%N

ew S

ampl

e 1 C

ycle

414

03.

551

22.8

1017

5.4

2.52

352.

6850

3.19

823.

028

32.

8588

87.3

89.7

61.9

84.2

80.8

27.8

88.7

New

Sam

ple

1 Cyc

le 4

140

3.5

5122

.810

175.

42.

6857

2.56

593.

1521

3.0

149

2.85

4686

.989

.071

.677

.981

.417

.483

.8

New

Sam

ple

1 Cyc

le 4

140

3.5

5122

.810

175.

42.

720

02.

7454

3.13

673.

020

32.

9056

84.5

89.3

76.4

78.3

82.1

12.9

80.0

New

Sam

ple

1 Cyc

le 4

140

3.5

5122

.810

175.

42.

9038

2.89

462.

6123

2.58

482.

7489

80.7

73.5

76.3

86.0

79.1

12.5

78.7

Avg

1403

.551

22.8

1017

52.

7083

2.72

273.

0248

2.91

212.

8420

84.9

85.4

71.6

81.6

80.8

17.7

82.8

Rang

e-

--

0.38

030.

3287

0.58

590.

4435

0.15

676.

616

.214

.58.

13.

015

.310

.0

LC_1

8%N

ew S

ampl

e 1 C

ycle

514

03.

551

22.8

1017

5.4

2.53

282.

6953

3.16

373.

016

02.

8520

84.4

90.0

64.3

74.5

78.3

25.7

85.5

New

Sam

ple

1 Cyc

le 5

140

3.5

5122

.810

175.

42.

6250

2.57

783.

1467

3.0

00

22.

8374

84.1

86.6

85.0

71.0

81.7

15.6

84.8

New

Sam

ple

1 Cyc

le 5

140

3.5

5122

.810

175.

42.

6971

2.73

913.

087

83.

098

02.

9055

78.0

86.5

85.2

87.4

84.3

9.4

80.2

New

Sam

ple

1 Cyc

le 5

140

3.5

5122

.810

175.

42.

8813

2.88

132.

5773

2.57

342.

7283

88.5

72.3

85.4

92.2

84.6

19.9

78.3

Avg

1403

.551

22.8

1017

52.

6840

2.72

332.

9939

2.92

192.

830

883

.883

.980

.081

.382

.217

.782

.2

Rang

e-

--

0.34

850.

3035

0.58

650.

5246

0.17

7210

.517

.721

.121

.26.

316

.37.

2

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 15: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 15

TAB

LES

1-2

-3 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of l

ow c

oppe

r 22%

por

osity

sam

ples

.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

LC_2

2%N

ew S

ampl

e C

ycle

113

33.3

4738

.696

49.1

1.760

61.9

601

2.28

672.

1396

2.03

6767

.359

.840

.557

.056

.226

.813

8.3

New

Sam

ple

Cyc

le 1

1333

.347

38.6

9649

.11.7

224

1.532

32.

3693

2.0

963

1.93

0170

.469

.232

.745

.654

.537

.712

7.9

New

Sam

ple

Cyc

le 1

1333

.347

38.6

9649

.11.9

288

1.614

32.

2798

2.0

611

1.97

1062

.069

.455

.661

.962

.213

.813

3.2

New

Sam

ple

Cyc

le 1

1333

.347

38.6

9649

.11.6

702

1.651

42.

3498

1.970

71.

910

570

.070

.743

.346

.757

.727

.413

2.5

Avg

1333

.347

38.6

9649

.11.7

705

1.68

952.

3214

2.0

669

1.96

2167

.467

.343

.052

.857

.626

.413

3.0

Rang

e-

--

0.25

870.

4278

0.0

896

0.16

880.

1262

8.4

10.9

22.9

16.3

7.8

23.9

10.4

LC_2

2%N

ew S

ampl

e1 C

ycle

213

33.3

4738

.696

49.1

1.712

21.9

599

2.20

652.

060

31.

9847

62.4

64.8

50.9

51.6

57.4

13.9

126.

5

New

Sam

ple1

Cyc

le 2

1333

.347

38.6

9649

.11.6

429

1.516

62.

3290

2.0

677

1.88

9078

.465

.932

.641

.054

.545

.811

7.0

New

Sam

ple1

Cyc

le 2

1333

.347

38.6

9649

.11.8

863

1.599

12.

2853

2.0

143

1.94

6274

.669

.254

.658

.564

.220

.012

2.1

New

Sam

ple1

Cyc

le 2

1333

.347

38.6

9649

.11.6

404

1.612

02.

3065

1.864

61.

8558

69.7

69.3

49.6

51.0

59.9

20.1

122.

9

Avg

1333

.347

38.6

9649

.11.7

204

1.67

192.

2818

2.0

017

1.91

9071

.367

.346

.950

.559

.025

.012

2.1

Rang

e-

--

0.24

590.

4433

0.12

240.

2031

0.12

8916

.04.

522

.017

.59.

731

.99.

5

LC_2

2%N

ew S

ampl

e 1 C

ycle

313

33.3

4738

.696

49.1

1.732

11.9

637

2.26

162.

093

02.

0126

70.9

57.4

51.1

65.2

61.2

19.8

122.

3

New

Sam

ple

1 Cyc

le 3

1333

.347

38.6

9649

.11.6

986

1.519

72.

3834

2.0

699

1.91

7975

.172

.931

.251

.557

.743

.911

3.3

New

Sam

ple

1 Cyc

le 3

1333

.347

38.6

9649

.11.9

158

1.615

32.

7238

2.0

490

2.07

6074

.079

.453

.164

.067

.626

.311

8.1

New

Sam

ple

1 Cyc

le 3

1333

.347

38.6

9649

.11.6

808

1.610

92.

3240

1.90

461.

8801

71.3

72.9

55.5

47.6

61.8

25.3

120.

4

Avg

1333

.347

38.6

9649

.11.7

568

1.67

742.

4232

2.02

911.

9716

72.8

70.7

47.7

57.1

62.1

28.8

118.

5

Rang

e-

--

0.23

500.

4440

0.46

220.

1884

0.19

594.

222

.024

.317

.610

.024

.19.

0

LC_2

2%N

ew S

ampl

e 1 C

ycle

413

33.3

4738

.696

49.1

1.733

72.

00

402.

2679

2.10

732.

0283

72.4

62.1

55.6

67.6

64.4

16.8

121.7

New

Sam

ple

1 Cyc

le 4

1333

.347

38.6

9649

.11.7

180

1.554

82.

3836

2.0

963

1.93

8270

.574

.539

.940

.556

.434

.611

6.1

New

Sam

ple

1 Cyc

le 4

1333

.347

38.6

9649

.11.9

242

1.633

92.

3165

2.0

612

1.98

3976

.070

.767

.462

.969

.313

.111

7.1

New

Sam

ple

1 Cyc

le 4

1333

.347

38.6

9649

.11.6

865

1.642

62.

3473

1.916

71.

8983

75.2

79.9

67.2

50.8

68.3

29.1

118.

6

Avg

1333

.347

38.6

9649

.11.7

656

1.70

882.

3288

2.0

454

1.96

2273

.571

.857

.555

.564

.623

.411

8.4

Rang

e-

--

0.23

770.

4493

0.11

570.

1907

0.13

00

5.5

17.8

27.5

27.1

12.9

21.5

5.6

LC_2

2%N

ew S

ampl

e 1 C

ycle

513

33.3

4738

.696

49.1

1.729

61.9

189

2.24

202.

092

91.

9959

75.0

61.1

64.8

65.5

66.6

13.9

121.8

New

Sam

ple

1 Cyc

le 5

1333

.347

38.6

9649

.11.6

876

1.499

52.

3651

2.0

608

1.90

3270

.076

.049

.553

.662

.326

.511

3.0

New

Sam

ple

1 Cyc

le 5

1333

.347

38.6

9649

.11.8

828

1.765

22.

2921

2.0

551

1.99

8868

.872

.270

.370

.170

.43.

411

7.4

New

Sam

ple

1 Cyc

le 5

1333

.347

38.6

9649

.11.6

526

1.628

02.

3088

1.918

91.

8771

70.2

79.1

50.6

57.3

64.3

28.5

119.

3

Avg

1333

.347

38.6

9649

.11.7

381

1.702

92.

3020

2.03

191.

9437

71.0

72.1

58.8

61.6

65.9

18.1

117.

9

Rang

e-

--

0.23

030.

4193

0.12

310.

1741

0.12

176.

218

.020

.816

.58.

125

.18.

8

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 16: Porosity & Brake Pads Modulus - imsysinc.com

16 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

TAB

LES

1-2

-4 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of C

oppe

r Fre

e 13

% p

oros

ity.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

CF_

13%

New

Sam

ple

Cyc

le 1

1649

.152

98.2

1070

1.82.

1190

2.19

492.

9267

2.47

562.

4291

72.3

75.0

66.0

69.7

70.8

9.0

150.

0

New

Sam

ple

Cyc

le 1

1649

.156

1410

807

2.86

712.

8110

2.80

712.

7155

2.80

0280

.673

.771

.176

.075

.49.

512

8.6

New

Sam

ple

Cyc

le 1

1649

.156

1410

807

3.0

848

3.0

324

2.92

183.

00

673.

0115

70.6

74.8

67.3

72.1

71.2

7.5

96.5

New

Sam

ple

Cyc

le 1

1649

.156

1410

807

2.54

952.

600

12.

5646

2.70

662.

6052

77.2

77.2

73.0

80.0

76.9

7.0

154.

9

Avg

1649

.155

35.1

1078

12.

6551

2.65

962.

8050

2.72

612.

7115

75.2

75.2

69.4

74.5

73.5

8.3

132.

5

Rang

e-

--

0.96

580.

8376

0.36

210.

5311

0.58

2410

.03.

57.

010

.36.

12.

558

.4

CF_

13%

New

Sam

ple1

Cyc

le 2

1649

.155

43.9

1070

1.82.

240

82.

3390

2.81

812.

4326

2.45

7672

.077

.758

.870

.969

.918

.915

2.8

New

Sam

ple1

Cyc

le 2

1649

.156

1411

017

.52.

9133

2.87

492.

860

62.

6978

2.83

6774

.266

.671

.474

.771

.78.

112

6.4

New

Sam

ple1

Cyc

le 2

1649

.156

1411

017

.53.

045

32.

9687

2.89

02

2.94

382.

9620

78.2

73.2

77.1

76.8

76.3

5.0

90.5

New

Sam

ple1

Cyc

le 2

1649

.156

1411

052

.62.

560

12.

5964

2.58

422.

7147

2.61

3976

.078

.968

.881

.376

.312

.515

2.1

Avg

1649

.155

96.5

1094

72.

6899

2.69

482.

7883

2.69

722.

7175

75.1

74.1

69.0

75.9

73.5

11.1

130.

5

Rang

e-

--

0.80

450.

6297

0.30

590.

5112

0.50

446.

212

.318

.310

.46.

513

.962

.3

CF_

13%

New

Sam

ple

1 Cyc

le 3

1649

.155

43.9

1070

1.82.

2597

2.30

352.

7894

2.43

912.

4479

69.3

76.5

69.3

71.4

71.6

7.2

151.2

New

Sam

ple

1 Cyc

le 3

1649

.156

1410

982.

52.

9496

2.87

202.

8911

2.69

08

2.85

08

74.5

73.3

71.4

79.2

74.6

7.8

127.

3

New

Sam

ple

1 Cyc

le 3

1649

.156

1410

982.

53.

0715

2.98

382.

8568

2.92

412.

9590

79.0

75.0

78.7

79.0

77.9

4.0

88.4

New

Sam

ple

1 Cyc

le 3

1649

.156

1410

947.

42.

5566

2.63

412.

560

62.

7372

2.62

2176

.881

.572

.479

.277

.59.

115

1.4

Avg

1649

.155

96.5

1090

42.

7093

2.69

832.

7745

2.69

782.

720

074

.976

.673

.077

.275

.47.

012

9.6

Rang

e-

--

0.81

180.

6803

0.33

05

0.48

510.

5111

9.7

8.2

9.4

7.8

6.3

5.1

63.0

CF_

13%

New

Sam

ple

1 Cyc

le 4

1649

.155

43.9

1070

1.82.

2431

2.32

762.

7533

2.40

222.

4316

80.8

85.5

64.0

83.1

78.4

21.5

151.3

New

Sam

ple

1 Cyc

le 4

1649

.156

1410

982.

52.

900

42.

8386

2.83

862.

6644

2.81

05

75.4

71.8

66.2

84.0

74.4

17.8

124.

7

New

Sam

ple

1 Cyc

le 4

1649

.156

1410

982.

53.

033

32.

9721

2.86

462.

9030

2.94

3370

.870

.268

.783

.273

.214

.588

.2

New

Sam

ple

1 Cyc

le 4

1649

.156

1410

947.

42.

5211

2.55

662.

5486

2.68

492.

5778

85.3

84.0

64.9

80.5

78.7

20.4

151.5

Avg

1649

.155

96.5

1090

42.

6745

2.67

372.

7513

2.66

372.

690

878

.177

.966

.082

.776

.218

.612

8.9

Rang

e-

--

0.79

020.

6446

0.31

600.

500

80.

5117

14.5

15.3

4.7

3.5

5.5

7.0

63.3

CF_

13%

New

Sam

ple

1 Cyc

le 5

1649

.155

43.9

1070

1.82.

2217

2.31

862.

7775

2.39

282.

4276

74.4

75.6

69.3

84.2

75.9

14.9

147.

4

New

Sam

ple

1 Cyc

le 5

1649

.156

1410

982.

52.

9133

2.84

182.

8512

2.67

202.

8196

70.1

76.0

63.1

78.8

72.0

15.7

123.

5

New

Sam

ple

1 Cyc

le 5

1649

.156

1410

982.

53.

066

22.

9687

2.87

102.

9144

2.95

5163

.673

.375

.674

.171

.712

.086

.1

New

Sam

ple

1 Cyc

le 5

1649

.156

1410

947.

42.

5119

2.55

152.

5277

2.65

882.

5625

85.2

75.8

78.8

84.8

81.2

9.4

148.

6

Avg

1649

.155

96.5

1090

42.

6783

2.67

022.

7568

2.65

952.

6912

73.3

75.2

71.7

80.5

75.2

13.0

126.

4

Rang

e-

--

0.84

450.

6501

0.34

340.

5216

0.52

7421

.62.

715

.710

.79.

56.

362

.5

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 17: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 17

TAB

LES

1-2

-5 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of C

oppe

r Fre

e 18

% p

oros

ity.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

NH

ardn

ess

- HRR

Com

pres

sibi

lity

1X

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

CF_

18%

New

Sam

ple

1 Cyc

le 1

150

8.8

5263

.210

842.

11.0

728

1.056

61.0

712

1.067

91.0

671

59.3

60.1

67.3

60.5

61.8

8.0

135.

8

New

Sam

ple

1 Cyc

le 1

150

8.8

5263

.210

842.

11.0

580

1.141

11.1

629

1.150

11.1

280

58.2

55.3

53.4

57.1

56.0

4.8

104.

2

New

Sam

ple

1 Cyc

le 1

150

8.8

5263

.210

912.

31.1

521

1.134

11.1

217

1.128

81.1

342

69.8

64.9

60.4

66.3

65.4

9.4

131.2

New

Sam

ple

1 Cyc

le 1

150

8.8

5263

.210

982.

51.1

300

1.110

01.0

00

01.0

00

01.0

600

57.0

54.9

64.5

66.1

60.6

11.2

157.

6

Avg

150

8.8

5263

.210

912

1.113

41.1

284

1.094

91.0

929

1.107

461

.758

.459

.463

.260

.78.

513

1.0

Rang

e-

--

0.0

941

0.03

100.

1629

0.15

010.

0742

12.8

10.0

11.1

9.2

9.3

6.4

53.4

CF_

18%

New

Sam

ple

1 Cyc

le 2

150

8.8

5263

.210

491.2

1.060

61.0

638

1.068

71.0

494

1.060

662

.462

.956

.857

.259

.86.

112

7.3

New

Sam

ple

1 Cyc

le 2

150

8.8

5263

.210

526.

31.0

724

1.10

921.1

682

1.116

11.1

165

62.8

51.6

61.1

53.5

57.3

11.2

95.8

New

Sam

ple

1 Cyc

le 2

150

8.8

5263

.210

350.

91.1

582

1.165

61.1

206

1.124

11.1

421

62.2

56.8

5457

.457

.68.

212

5.8

New

Sam

ple

1 Cyc

le 2

150

8.8

5263

.210

982.

51.0

816

1.093

40.

9837

0.96

801.0

317

58.9

5465

.971

.462

.617

.414

7.7

Avg

150

8.8

5263

.210

588

1.093

21.1

080

1.085

31.0

644

1.087

761

.656

.359

.559

.959

.310

.712

4.2

Rang

e-

--

0.0

977

0.10

180.

1845

0.15

610.

110

53.

911

.311

.917

.95.

311

.351

.9

CF_

18%

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

350.

91.0

658

1.078

91.0

839

1.056

11.0

711

67.6

70.1

55.9

57.3

62.7

14.2

125.

5

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

526.

31.0

652

1.073

31.1

601

1.122

41.1

053

5755

.263

.151

.356

.711

.894

.6

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

526.

31.1

621

1.156

61.1

367

1.120

81.1

441

68.3

61.4

64.9

70.1

66.2

8.7

124

New

Sam

ple

1 Cyc

le 3

150

8.8

5263

.210

526.

31.1

019

1.090

01.0

028

0.98

811.0

457

60.3

59.4

68.3

69.9

64.5

10.5

146

Avg

150

8.8

5263

.210

482

1.098

71.0

997

1.095

91.0

719

1.091

563

.361

.563

.162

.262

.511

.312

2.5

Rang

e-

--

0.0

969

0.0

833

0.15

730.

1343

0.0

984

11.3

14.9

12.4

18.8

9.5

5.5

51.4

CF_

18%

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

350.

91.0

439

1.066

31.0

811

1.048

61.0

600

64.3

64.8

61.2

59.5

62.5

5.3

130.

7

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

526.

31.0

429

1.035

01.1

462

1.091

91.0

790

58.7

50.2

50.1

61.5

55.1

11.4

95.3

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

526.

31.1

548

1.173

31.1

297

1.119

21.1

443

6378

.789

.967

.674

.826

.912

5

New

Sam

ple

1 Cyc

le 4

150

8.8

5263

.210

526.

31.1

035

1.10

350.

9976

0.97

03

1.043

757

.954

.464

.571

.362

.016

.914

4.2

Avg

150

8.8

5263

.210

482

1.086

31.0

945

1.088

61.0

575

1.081

761

.062

.066

.465

.063

.615

.112

3.8

Rang

e-

--

0.11

200.

1383

0.14

870.

1489

0.10

05

6.4

28.5

39.8

11.8

19.7

21.6

48.9

CF_

18%

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

350.

91.0

711

1.066

21.0

678

1.036

01.0

603

6159

.952

.662

.559

.09.

912

3.6

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

526.

31.0

732

1.083

11.1

729

1.125

81.1

137

53.2

57.5

60.5

52.4

55.9

8.1

92.2

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

526.

31.1

246

1.145

91.1

00

41.1

176

1.122

172

.456

.351

.972

63.2

20.5

120.

7

New

Sam

ple

1 Cyc

le 5

150

8.8

5263

.210

526.

31.0

713

1.071

30.

960

80.

9622

1.016

457

.657

.360

.776

.963

.119

.614

1.3

Avg

150

8.8

5263

.210

482

1.085

01.0

916

1.075

51.0

604

1.078

161

.157

.856

.466

.060

.314

.511

9.5

Rang

e-

--

0.0

535

0.07

980.

2121

0.16

360.

1057

19.2

3.6

8.8

24.5

7.3

12.4

49.1

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 18: Porosity & Brake Pads Modulus - imsysinc.com

18 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

TAB

LES

1-2

-6 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

, 4th

cyc

le a

nd 5

th c

ycle

of C

oppe

r Fre

e 22

% p

oros

ity.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1X

(um

)

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

CF_

22%

New

Sam

ple

Cyc

le 1

1438

.645

61.4

9614

1.993

12.

068

31.8

678

1.913

71.

9607

25.7

35.0

35.2

45.2

35.3

19.5

141.2

New

Sam

ple

Cyc

le 1

1438

.645

61.4

9614

2.0

229

2.17

421.8

012

1.933

51.

9829

27.7

30.1

37.8

45.2

35.2

17.5

129.

7

New

Sam

ple

Cyc

le 1

1438

.647

01.8

9859

.62.

1793

2.17

591.9

950

1.995

02.

086

333

.926

.949

.061

.642

.934

.713

4.8

New

Sam

ple

Cyc

le 1

1438

.647

01.8

9614

1.945

51.9

455

1.945

51.8

690

1.92

6438

.233

.736

.540

.837

.37.

115

1.0

Avg

1438

.646

31.6

9675

.42.

0352

2.0

910

1.90

241.

9278

1.98

9131

.431

.439

.648

.237

.719

.713

9.2

Rang

e-

--

0.23

380.

230

50.

1938

0.12

600.

1599

12.5

8.1

13.8

20.8

7.7

27.6

21.3

CF_

22%

New

Sam

ple1

Cyc

le 2

1438

.649

47.4

1010

5.3

1.952

82.

031

61.8

573

1.875

81.

9294

24.8

39.2

41.3

50.5

39.0

25.7

129.

7

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

1018

9.3

2.0

177

2.17

481.8

172

1.979

61.

9973

25.9

29.3

32.1

44.2

32.9

18.3

119.

.1

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

1017

5.4

2.12

732.

1664

1.958

01.9

751

2.0

567

32.5

29.1

47.2

61.3

42.5

32.2

128.

0

New

Sam

ple1

Cyc

le 2

1438

.650

17.5

1017

5.4

1.927

01.9

437

1.927

01.8

363

1.90

8542

.031

.843

.237

.238

.611

.413

9.2

Avg

1438

.650

00.

010

161

2.0

062

2.07

911.

8899

1.91

671.

9730

31.3

32.4

41.0

48.3

38.2

21.9

132.

3

Rang

e-

--

0.20

030.

2311

0.14

08

0.14

340.

1482

17.2

10.1

15.1

24.1

9.7

20.8

11.2

CF_

22%

New

Sam

ple

1 Cyc

le 3

1438

.649

47.4

1010

5.3

1.958

92.

050

21.8

603

1.889

61.

9397

26.9

33.9

29.9

43.7

33.6

16.8

127.

8

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

1017

5.4

2.0

189

2.17

611.8

208

1.975

11.

9977

27.1

30.3

33.9

45.8

34.3

18.7

119.

7

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

1017

5.4

2.33

08

2.35

182.

150

32.

1816

2.25

3633

.026

.351

.959

.342

.633

.012

6.8

New

Sam

ple

1 Cyc

le 3

1438

.650

17.5

1017

5.4

1.936

21.9

530

1.930

61.8

447

1.91

6136

.338

.335

.745

.539

.09.

813

8.8

Avg

1438

.650

00.

010

158

2.0

612

2.13

281.

940

51.

9727

2.02

6830

.832

.237

.948

.637

.419

.612

8.3

Rang

e-

--

0.39

460.

3988

0.32

950.

3368

0.33

759.

412

.022

.015

.69.

023

.219

.1

CF_

22%

New

Sam

ple

1 Cyc

le 4

1438

.649

47.4

1010

5.3

1.932

72.

007

31.8

439

1.867

51.

9128

42.9

46.8

39.0

52.0

45.2

13.0

129.

0

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

1017

5.4

2.0

124

2.14

571.8

054

1.986

11.

9874

26.3

26.7

32.2

49.9

33.8

23.6

117.

7

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

1017

5.4

2.13

01

2.15

281.9

607

1.989

42.

058

330

.032

.533

.959

.639

.029

.612

3.5

New

Sam

ple

1 Cyc

le 4

1438

.650

17.5

1017

5.4

1.944

91.9

226

1.925

41.8

323

1.90

6335

.536

.630

.848

.437

.817

.614

1.7

Avg

1438

.650

00.

010

158

2.0

050

2.0

571

1.88

381.

9188

1.96

6233

.735

.734

.052

.538

.921

.012

8.0

Rang

e-

--

0.19

740.

2302

0.15

530.

1572

0.15

2016

.620

.18.

211

.211

.416

.624

.0

CF_

22%

New

Sam

ple

1 Cyc

le 5

1438

.649

47.4

1010

5.3

1.925

92.

038

71.8

428

1.861

11.

9171

34.3

34.7

42.5

55.9

41.9

21.6

125.

2

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

1017

5.4

2.0

061

2.17

151.8

126

1.954

21.

9861

24.9

31.3

45.0

45.8

36.8

20.9

116.

1

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

1017

5.4

2.13

222.

1452

1.965

31.9

739

2.0

541

28.6

37.0

49.5

60.3

43.9

31.7

122.

5

New

Sam

ple

1 Cyc

le 5

1438

.650

17.5

1017

5.4

1.914

41.9

255

1.898

11.7

968

1.88

3733

.247

.337

.346

.041

.014

.113

4.7

Avg

1438

.650

00.

010

158

1.99

472.

0702

1.87

971.

8965

1.96

0330

.337

.643

.652

.040

.922

.112

4.6

Rang

e-

--

0.21

780.

2460

0.15

270.

1771

0.17

04

9.4

16.0

12.2

14.5

7.1

17.6

18.6

© SAE International

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Page 19: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 19

Ap

pen

dix

2: P

hysi

cal P

rop

erti

es o

f Lo

w-C

op

per

and

Co

pp

er-F

ree

NA

O P

ads;

Ag

ed

at R

oo

m T

emp

erat

ure

for

12 M

ont

hsTA

BLE

S 2

-1-1

 1st

cyc

le, 2

nd c

ycle

, 3rd

cyc

le o

f low

cop

per 1

8% p

oros

ity s

ampl

es.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

Old

Sam

ple

Cyc

le 1

1537

.253

96.8

1059

6.5

3.82

713.

730

33.

1770

2.86

623.

4002

78.0

80.2

76.5

73.2

77.0

710

2.2

Old

Sam

ple

Cyc

le 1

1543

.954

03.

510

596.

53.

3233

3.44

03

3.47

05

3.40

463.

4097

73.9

81.9

81.4

81.7

79.7

811

1.0

Avg

1540

.55

540

0.2

1059

6.5

3.57

523.

5853

3.32

383.

1354

3.40

4976

.081

.179

.077

.578

.47.

510

6.6

Rang

e-

--

0.50

380.

290

00.

2935

0.53

830.

00

954.

11.7

4.9

8.5

2.8

1.08.

8

Old

Sam

ple

Cyc

le 2

150

8.8

5368

.410

491.2

3.71

783.

5918

3.0

334

2.70

643.

2623

83.7

82.2

72.0

64.3

75.6

19.4

100.

2

Old

Sam

ple

Cyc

le 2

1543

.954

03.

510

701.8

3.27

793.

3229

3.45

153.

2014

3.31

3476

.083

.581

.684

.881

.58.

899

.8

Avg

1526

.35

5386

.010

596.

53.

4979

3.45

743.

2425

2.95

393.

2879

79.9

82.9

76.8

74.6

78.5

14.1

100.

0

Rang

e-

--

0.43

980.

2689

0.41

820.

4950

0.0

511

7.7

1.3

9.6

20.5

5.9

10.6

0.4

Old

Sam

ple

Cyc

le 3

150

8.8

5368

.410

491.2

3.72

853.

6553

3.0

631

2.76

913.

3040

87.9

86.7

70.9

69.2

78.7

18.7

93.3

Old

Sam

ple

Cyc

le 3

1543

.954

03.

510

596.

53.

3275

3.38

523.

5112

3.31

623.

3850

74.5

85.0

85.5

80.1

81.3

1199

.7

Avg

1526

.35

5386

.010

543.

93.

5280

3.52

023.

2871

3.0

427

3.34

4581

.285

.978

.274

.780

.014

.996

.5

Rang

e-

--

0.40

100.

2701

0.44

810.

5471

0.0

810

13.4

1.714

.610

.92.

67.

76.

4

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 20: Porosity & Brake Pads Modulus - imsysinc.com

20 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

TAB

LES

2-1

-2 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

of l

ow c

oppe

r 22%

por

osity

sam

ples

.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

Old

Sam

ple

Cyc

le 1

1473

.752

44.4

1042

1.13.

1912

3.12

602.

4479

2.75

592.

8802

78.6

69.8

66.6

68.3

70.8

1293

.1

Old

Sam

ple

Cyc

le 1

1473

.752

44.4

1042

1.13.

00

233.

0736

2.87

562.

7966

2.93

7076

.270

.965

.570

.770

.810

.793

.1

Avg

1473

.752

44.4

1042

1.13.

096

83.

099

82.

6617

2.77

632.

9086

77.4

70.4

66.1

69.5

70.8

11.4

93.1

Rang

e-

--

0.18

890.

052

40.

4278

0.0

407

0.0

568

2.4

1.11.1

2.4

0.0

1.3

0.0

Old

Sam

ple

Cyc

le 2

140

3.5

5157

.999

64.9

3.15

02

3.0

921

2.60

982.

6754

2.88

1982

.583

.467

.067

.575

.116

.481

.6

Old

Sam

ple

Cyc

le 2

140

3.5

5157

.999

64.9

2.86

972.

9789

2.93

582.

7885

2.89

3280

.583

.468

.068

.575

.115

.481

.6

Avg

1403

.551

57.9

9964

.93.

010

03.

0355

2.77

282.

7319

2.88

7581

.583

.467

.568

.075

.115

.981

.6

Rang

e-

--

0.28

05

0.11

310.

3260

0.11

310.

0114

2.0

0.0

1.01.0

0.0

1.00.

0

Old

Sam

ple

Cyc

le 3

140

3.5

5157

.995

143.

043

02.

9926

2.59

982.

6140

2.81

2484

.283

.661

.369

.974

.822

.980

.7

Old

Sam

ple

Cyc

le 3

140

3.5

5157

.995

143.

011

62.

9819

2.95

332.

6377

2.89

6182

.883

.263

.469

.674

.819

.880

.7

Avg

1403

.551

57.9

9514

3.02

732.

9872

2.77

662.

6259

2.85

4283

.583

.462

.469

.874

.821

.480

.7

Rang

e-

--

0.03

140.

0107

0.35

340.

0237

0.0

838

1.4

0.4

2.1

0.3

0.0

3.1

0.0

© SAE International

Downloaded from SAE International by Donald Yuhas, Thursday, April 12, 2018

Page 21: Porosity & Brake Pads Modulus - imsysinc.com

Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018) 21

TAB

LES

2-2

-1 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

of C

oppe

r Fre

e 18

% p

oros

ity s

ampl

es.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

Old

Sam

ple

Cyc

le 1

160

456

0.7

110

27.6

3.23

423.

2113

2.91

463.

084

23.

1111

75.2

70.6

74.9

69.5

72.6

5.7

140.

2

Old

Sam

ple

Cyc

le 1

1614

5614

1084

2.1

3.27

563.

3051

2.94

473.

00

573.

1328

77.3

78.9

67.7

61.9

71.5

1713

8.6

Avg

160

930

87.4

1093

4.9

3.25

493.

2582

2.92

973.

045

03.

1219

76.3

74.8

71.3

65.7

72.0

11.4

139.

4

Rang

e-

--

0.0

413

0.0

938

0.03

010.

0785

0.02

172.

18.

37.

27.

61.1

11.3

1.6

Old

Sam

ple

Cyc

le 2

1578

.955

08.

811

052

.63.

084

23.

1058

2.85

172.

9494

2.99

7871

.973

.979

.273

.874

.77.

312

3.0

Old

Sam

ple

Cyc

le 2

1578

.954

73.7

1084

2.1

3.18

463.

1846

2.83

552.

8977

3.02

5674

.479

.173

.462

.072

.217

.112

0.9

Avg

1578

.954

91.3

1094

7.4

3.13

443.

1452

2.84

362.

9236

3.01

1773

.276

.576

.367

.973

.512

.212

2.0

Rang

e-

--

0.10

04

0.07

890.

0161

0.0

517

0.02

782.

55.

25.

811

.82.

59.

82.

1

Old

Sam

ple

Cyc

le 3

1578

.955

08.

811

052

.63.

027

33.

037

72.

8395

2.91

152.

9540

74.9

74.8

71.0

68.3

72.3

6.6

120.

2

Old

Sam

ple

Cyc

le 3

1578

.954

73.7

1091

2.3

3.20

213.

2021

2.84

552.

9525

3.0

506

75.4

73.3

66.4

75.3

72.6

912

2.0

Avg

1578

.954

91.3

1098

2.5

3.11

473.

1199

2.84

252.

9320

3.0

023

75.2

74.1

68.7

71.8

72.4

7.8

121.1

Rang

e-

--

0.17

490.

1645

0.0

061

0.0

410

0.0

966

0.5

1.5

4.6

7.0

0.3

2.4

1.8

© SAE International

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Page 22: Porosity & Brake Pads Modulus - imsysinc.com

22 Sriwiboon et al. / SAE Int. J. Mater. Manf. / Volume 11, Issue 1 (March 2018)

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Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE International. The author is solely responsible for the content of the paper.

TAB

LES

2-2

-1 1

st c

ycle

, 2nd

cyc

le, 3

rd c

ycle

of C

oppe

r Fre

e 22

% p

oros

ity s

ampl

es.

Sam

ples

Nat

Fre

q(kH

z)M

odul

us @

100

N (G

Pa)

Har

dnes

s - H

RRCo

mpr

essi

bilit

y 1 X

Peak

1Pe

ak 2

Peak

3Po

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gPo

sitio

n 1

Posi

tion

2Po

sitio

n 3

Posi

tion

4Av

gRa

nge

@ 10

0 b

ar

Old

Sa

mpl

e C

ycle

1

150

8.8

5112

.810

421.1

2.38

412.

3730

2.26

292.

3511

2.34

2850

.554

.654

.447

.951

.96.

713

3.7

Old

Sa

mpl

e C

ycle

1

150

8.8

5052

.610

175.

42.

1392

2.19

332.

290

42.

2732

2.22

4050

.751

.757

.952

.153

.17.

213

9.7

Avg

150

8.8

5082

.710

298.

32.

2616

2.28

312.

2766

2.31

212.

2834

50.6

53.2

56.2

50.0

52.5

7.0

136.

7

Rang

e-

--

0.24

490.

1797

0.02

750.

0779

0.11

880.

22.

93.

54.

21.

30.

56.

0

Old

Sa

mpl

e C

ycle

2

1432

.651

57.9

1042

1.12.

3051

2.28

432.

230

02.

2167

2.25

9065

.360

.856

.262

.661

.29.

111

7.6

Old

Sa

mpl

e C

ycle

2

1473

.750

87.7

1031

5.8

2.11

00

2.15

04

2.24

162.

3033

2.20

1358

.853

.653

.954

.755

.35.

213

0.0

Avg

1453

.1551

22.8

1036

8.5

2.20

762.

2173

2.23

582.

260

02.

2302

62.1

57.2

55.1

58.7

58.2

7.2

123.

8

Rang

e-

--

0.19

510.

1338

0.01

160.

086

60.

057

76.

57.

22.

37.

96.

03.

912

.4

Old

Sa

mpl

e C

ycle

3

1438

.651

57.9

1042

1.12.

3357

2.30

02

2.25

882.

310

82.

3014

71.3

69.8

66.6

72.6

70.1

611

9.6

Old

Sa

mpl

e C

ycle

3

1473

.750

87.7

1031

5.8

2.0

953

2.13

532.

2621

2.28

262.

1938

60.2

52.3

53.8

58.6

56.2

7.9

138.

4

Avg

1456

.1551

22.8

1036

8.5

2.21

552.

2177

2.26

04

2.29

672.

2476

65.8

61.1

60.2

65.6

63.2

7.0

129.

0

Rang

e-

--

0.24

030.

1650

0.0

033

0.02

820.

1075

11.1

17.5

12.8

14.0

13.9

1.9

18.8

© SAE International

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