Document nNQxgXyOLxnZJbNkGV9KmpVj6

PLAINTIFF'S EXHIBIT To: Mr* J. C. Garward From: W. K. Skuba cc: J. L. Rich ' ' Subject: FAST evaluation of eleven Australian Ford brake linings The friction and wear characteristics of eleven Australian Ford brake linings supplied by Mr. F. P. Hill of your department were investigated using Ford's FAST procedures. We would like to include correlation (or lack^of correlation) with vehicle test experience in the report to be issued on this investigation. Specifically, we would like vehicle test information (quantitative, where possible) on the wear rates and friction characteristics of each material for conditions of braking severity ranging from light to very heavy. Enclosed is a copy of the report with the exception of a discussion of vehicle correlation for which we would appreciate your suggestions. We are enclosing also a copy of report ARM 66-7, April 1, 1966,"Instruction Manual for the FAST Machine", which gives in detail the procedure used in our studies. Also enclosed is a tentative distribution list for the report. We would appreciate your suggestions for any changes. W. K. Skuba 000* l"9 SCF-FORD-0018 PRODUCED BY FORD TITLE: FAST Procedure Friction and Wear Studies of Australian Ford Brake Linings Author: J. L. Rich Department: Chemical Processes and Devices 'SUMMARY Ford FAST (Friction Assessment and Screening Test) procedures were used to evaluate friction and wear characteristics of eleven Australian Ford brake .lining materials (five drum brake lining materials and six disc brake pad materials) under different conditions of temperature, lining unit pressure and input power density. The effect of water vapor or humidity on the friction level of each material was also investigated. (Mr. Garward - we would appreciate your suggestions for a summary on the comparison with vehicle experience) 8002 1^50 PRODUCED BY FORD -1 - INTRODUCTION Friction and wear studies of five Australian Ford drum brake lining materials and six disc brake pad materials were undertaken to: . 1. assess the usefulness of FAST as a friction material screening tool, 2. enlarge our knowledge of friction materials to include some of those manufactured and used outside of the United States. Two samples of each material were subjected to FAST Light and Heavy Duty procedures (see Appendix). Three of the disc brake materials were also subjected to the FAST Extra Heavy Duty Procedure (see Appendix). Water vapor sensitivity tests were performed on all samples during the Heavy Duty Procedure (see appendix). . All Australian vehicles presently use a nine-inch rear drum brake with a disc or drum front brake. The following interpretation of FAST results takes vehicle use into consideration. Discussion of Results A summary of FAST results, and an evaluation of those results according to vehicle use follows: (Hr. Garward: we would appreciate any comments you may be able to add concerning correlation with vehicle performance). 8002 *951 PRODUCED BY FORD -2- Hardie-Ferodo E113 drum brake friction material is the current production primary and secondary lining for rear brakes when front disc brakes (with Ferodo DS-31) are used on the Falcon. FAST laboratory results indicate very good wear life for both light and heavy duty conditions (Table 1) with a friction level that is virtually independent of unit pressure but vMch rolls off slightly with increase in temperature above k75F (Figures land 2). ' This appears to be the best drum lining of those tested for use with Ferodo DS 31 on the front disc brake. However, the near absence of friction rolloff of DS 31 would lead to a variation of braking effort (toward the front) as braking severity increases. Hardie-Ferodo ELIO drum brake friction material is the current production primary and secondary lining for the four wheel drum brake Falcon. FAST laboratory tests indicated good friction (Figures 1 and 2) and wear characteristics under light duty conditions but high wear (Table 1) and a pronounced friction rolloff above 310F on the heavy duty tests (Figure 1). The friction was erratic above 450F. This material should be satisfactory for light duty conditions but result in high pedal efforts, high wear, and perhaps some "pulls" under heavy braking conditions. Hardie-Ferodo B001 drum brake friction material was formerly used for both primary and secondary linings on heavy duty Police and Taxi vehicles. It is not currently in use. FAST laboratory tests indicated good wear life (Table 1) under light and heavy duty conditions, but a pronounced friction rolloff above 200F (Fig ure 3). This would be expected to result in high pedal efforts tinder heavy duty conditions. Hardie-Ferodo B120 drum brake friction material is a proposed primary lining for the 1967 Falcon, to be used with E 308 as the secondary lining. FAST laboratory results indicate a moderate wear rate for light conditions, but a high wear rate for heavy duty conditions (Table 1). With E 308 this should result in balanced wear for light duty conditions, but unbalanced (high primary lining) wear under heavy .. ^. *002- 1952 PRODUCED BY FORD fx&'Jii -3- duty conditions. The friction level rolls off slowly with increasing temperature v and decreases with increasing unit pressure (Figures 3 and k). Hard!e-Ferodo E-3o8 drum brake friction material is a proposed secondary lining for the 19&7 Falcon, to be used with D-120 as the primary. FAST laboratory results indicate low wear rates for light and heavy braking conditions (Table 1). The friction of this lining is sensitive to water vapor, dropping about 30jS in the water vapor test. Furthermore, the friction of this lining drops about 30$ between 400F and 500F, presumably from water vapor evolved from a mineral filler material (Figure 3)* In service this material could be expected to result in "pulls" and/or poor front-to-rear braking balance under heavy duty conditions. Ferodo PS 31 disc brake friction material is currently used on Falcon disc brakes. FAST laboratory results indicate low wear rates for light and heavy duty conditions (Table 1) with a near-constant friction coefficient that rolls off only slightly at elevated temperatures (Figures 5 and 6). It has a moderate (for disc materials) 27jf drop of friction with water vapor. This material should result in substantially increased lining and rotor wear (and some rotor scoring) when used in dusty conditions. This was revealed by the cracking of the cashew friction particles (Figure 10) with heat. Kdntex M-33 disc brake friction material is an alternate material for DS 31* FAST laboratory results indicate a wear rate similar to DS 31 for light duty conditions, but about 40j6 higher wear rate for heavy duty conditions (Table 1). The friction level of M-33 is somewhat lower than DS 31* and also i3 nearly constant, even to elevated temperatures (Figures 5 sad 6). Don 212 disc brake friction material is the production material on the Cortir. FAST laboratory results `indicate that DON 212 has a very flat friction level (Figures 5 and 6) which is higher than either DS 31 or M-33, hut the wear rate for light duty conditions is about two-and one-half times that of the above disc 8002 1953 PRODUCED BY FORD materials. The heavy duty wear rate is about equal to that of M-33, or about 40^ above that of DS-31 (Table 1). The higher wear rate of DON 212 for light duty conditions should be its principal drawback. : Ferodo DS5S disc brake friction material is being considered for 1967 Falcon front disc brakes. FAST laboratory results indicate a low wear rate for light duty conditions and an exceptionally low wear rate for heavy duty conditions (Table 1). However, the friction level of this material is subject to substantial variations (Figures 7* 8, and 9) The effectiveness (friction ) of this material should be relatively low when cold, increasing with temperature to nearly double the initial level, then falling off at the higher temperatures. This material should exhibit a rapid drop in friction above 500? under very heavy braking conditions (Figure 9). The relatively low fade temperature and' large friction level variations should make this a less desirable disc brake material despite its outstanding wear characteristics. Mintex M-69 is a prototype disc brake friction material. FAST laboratory results indicate a high wear rate under both light and heavy duty conditions. The friction level drops over one-third with water vapor and has a "humped" variation of friction much like Ferodo DS5S. The performance of this material in a car could be expected to be marginal at best. Mintex M-78 is a prototype disc brake friction material. FAST laboratory results indicate slightly higher wear rates for M-78 than M-69, the same kind of friction variation, but much less water sensitivity. Like M-69, the performance of this material in a car could be expected to be marginal, at best. 8002 1954 PRODUCED BY FORD CONCLUSIONS L, (Mr. Garvard: we are deferring any conelusigns until we have the benefit of your ' comments) 8002 1955 PRODUCED BY FORD \ Procedure Duration Friction Force Shear Stress min. psi Light Duty Heavy Duty Extra Heavy Duty 60 90 60 8.7 17.4 26.1 35 69 104 Final Disc Bulk Temperature op 210 560 690 802 195* -7- APPENDIX FAST PROCEDURES A complete description of tbe FAST machine, sample and disc preparation and basic testing procedures may be found in the Instruction Manual for the FAST machine (ARM 66---7* April 1, 1966). The comparative severity of the three FAST procedures employed in this study is summarized in the following table: Procedure Duration, Friction Force/ Shear Stress Final Disc Bulk Temperature Light Duty Heavy Duty Very Heavy Duty 60 min 90 min 60 min 8.7 lbs 17.4 lbs 26.1 lbs 35 psi 69 psi 104 psi 210F 560F 690oF In all three procedures the sliding velocity is constant at 23 fps. WATER VAPOR SENSITIVITY TEST The effect of water vapor on friction properties is a qualitative indication of the type of resin binder used in the friction material. For example, a straight phenolic resin binder material loses friction with application of water vapor while the friction level of an oil-modified phenolic or a rubber binder material increases. The friction level of a cashew material 1b unaffected by water vapor. For the sake of standardization, the test is run at tbe 3506F point of the FAST heavy duty procedure since at this disc bulk temperature the coefficient.of friction of most lining materials is fairly constant. A low velocity (2-3 fps from lA" dia. orifice) stream of water vapor is played on the friction track just above the sample for a period of one minute. The amount applied must be sufficient to insure maximum effect but not large enough for condensation to fonn on_the loading arm. The 6002 1957 -Bpercent change of friction and the direction of that change, if any, are then recorded. EVALDATION OF LINING UNIT PRESSURE SENSITIVITY Evaluation of the sensitivity of the coefficient of friction to lining unit pressure is based upon comparison of the friction levels exhibited by a material during the light and heavy duty procedures for the same temperature range. 8002 1958 -9 - TEST RESULTS ^ a Drum Brake Lining Materials : Hardie-Ferodo E1I3. The wear rates of this material for both duty cycles are among the lowest of the drum brake lining materials tested (Ref. Table 1). The friction level varies little with temperature (Ref. Fig, 1), rolling off slightly above V?5F under heavy duty conditions. Comparison of light and heavy duty test curves for the same temperature range shows the fraction level of E113 to be essentially independent of unit pressure for the temperature range available (below 210F). The friction level' drops about 20? with application of water vapor. Microscopic examination (7X-30X) reveals large crudes of asbestors, black particles which appear to be an oil modified phenolic, and small particles of a white crystallin< mineral. The general appearance of the material suggests a dry-mix process. On the basis of the test procedures employed, E113 is a very good drum brake lining material. Hardie-Ferodo Blip. Under light duty conditions the E110 material exhibits a good friction level (Figure 2) and a low wear rate (Table 1). Under heavy duty conditions, however, its friction level rolls off from p a .51 at 310F to u = .27 at 175F (Figure 1). In addition, the variation of friction with temperature becomes very erratic at 450F, indicating possible degradation of one or more of the lining constituents. It also possesses a very high wear rate under heavy duty conditions (Table 1). The friction level of E110 is not sensitive to changes in lining unit .pressure (Figures 1 and 2) but drops 8? upon application of water vapor. Microscopic examination reveals large asbestos crudes, brown resin particles (probably phenolic) and appears to be a dry-mix process material. This material should be acceptable for light duty application. Hardie-Ferodo E001. Although this material demonstrates good wear characteristics under both light and heavy duty conditions, (Table 1),_its friction 8002 1959 - 10 - level varies rapidly with temperature. Under heavy duty conditions its friction level drops from p. = .54 at MOO^F to p s .18 at 525F (Figure 3). This rapid friction t rolloff vould probably result in excessive pedal efforts under severe duty conditions. The friction level of this material exhibits essentially no pressure sensitivity (Figures 3 and 4) but drops 1J& upon application of water vapor. Microscopic examination shows that 001 contains what appears to be phenolic resin, large asbestos crudes, approximately % brass, and appears to be a dry-mix process material. The acceptability of this material would depend on the design of the brake in vrhich it is used; In particular, the manner in which the actuation factor of the brake varies with change in lining coefficient of friction would be of critical importance. Hardie-Ferodo E120. This material possesses acceptable friction characteristics under both light and heavy duty conditions (Figures 3 and 4). It exhibits, however, the highest wear rates for both light and heavy duty test procedures of all the drum materials tested (Table 1). Its friction level is essentially insensitive to lining unit pressure and relatively insensitive to water vapor (10jS loss of friction upon application of water vapor). The presence of large asbestos crudes, particles of what appears to be phenolic resin, white crystalline particles and the general appearance of a dry-mix process lining are revealed under the microscope. The high wear rate exhibited by EL20 under all duty conditions makes it less desirable for vehicle application than all the other drum brake materials tested. ' Disc Brake Pad Materials. The six disc brake pad materials may be divided into two groups of three on the basis of friction behavior with temperature. The first group exhibits very little variation of friction over a wide temperature range (75F to 5600?) (Figure ?) while the second group exhibits a pronounced friction buildup with temperature, followed by a marked friction rolloff (Figure 7). Hardie-Ferodo 308. Tho wear rate of this material nearly matches that of 113 under both light and heavy duty conditions (Table 1). Between 400F and L23F, 8002 *980 - 11 - however, it loses 3$6 of its friction very rapidly, remains at this low level through a 100F temperature range, and then recovers to its original level (Figure 3). This *. rapid loss of friction may cause braking imbalance in some instances. Subsequent water vapor tests and microscopic observations lead to the tentative conclusion that the friction loss may be due to a white crystalline mineral contained in the lining which loses water of hydration in this temperature range. Coupled with a high water vapor sensitivity, (28 drop in friction level with water vapor application), this occurrence can easily account for the friction loss. E30S decreases in friction with increase in lining unit pressure (Figures 3 and 4). In addition to the white crystalline mineral, microscopic examination also reveals large asbestos crudes, brown chunks of whst appears to be phenolic resin, and the general appearance of a dry mix process material. If the friction loss described above can be corrected, E308 may match the" performance characteristics of E113. Ferodo PS31. The low wear rates for both test procedures make it the best wearing material of group one (Table 1). It loses 27 of its friction upon application of water vapor and increases in friction somewhat with an Increase in lining unit pressure (Figures 5 and 6). Microscopic examination reveals chunks of resin (probably phenolic) particles, and appears to be a dry-mix process material. This material was one of three disk materials subjected to an additional very heavy duty test (see appendix) at the request of Australian engineering personnel, to acquire information about their friction behavior under higher energy input conditions. DS31 produced a moderate controlled friction rolloff during this test (Fig. 9)* Microscopic examination of the surface of a semple of this material which had completed the FAST heavy duty procedure showed cracks in the cashew friction particles on this surface. A photomicrograph of the used lining surface is included as Figure 10. Preliminary tests run after contaminating the friction surfaces with road dust show that such dust collects in these cracks and increases the wear rate of the sample through abrasive action. ..... .' 8002 1961 - 12 - The cracking of cashew friction particles is known to be due to thermal degradation and it was therefore suggested that a friction particle of higher temperature capability and smaller size be considered to help alleviate the problem. A sample of a commercially available high temperature 60. mesh friction particle (Cardolite NC111-60) was sent to Ford of Australia for evaluation in a production batch of Ferodo DS-31. Mintex M33. This material wears at a rate similar to DS31 under light duty conditions, but at a considerably higher rate under heavy duty conditions (Table 1). . It loses 20 of its friction with application of water vapor and increases in friction with an increase in lining unit pressure (Figures 5 and 6). Visual inspection of the surface under a microscope reveals the presence of graphite, large brass chips, open fiber asbestos, and the general appearance of a dry-mix process material. The material appears acceptable for light duty conditions, but less desirable than DS31 for heavy duty application because of high wear. The friction of M33 remains at a relatively constant level under light, heavy and severe duty conditions (Figs. 5> 6, and 9). DON 212. This material of group one, wears 2.5 times faster than the other two materials under light duty conditions (Table 1). It loses 10% of its friction upon application of water vapor and decreases slightly in friction with an increase in lining unit pressure (Figures 5 and 6). Large amounts of coal and a crudy fibre asbestos were visible under the microscope. It appears to be a dry-mix process material. The second group of three di6C brake materials tested, Ferodo DSpS, Mintex M69, and Mintex M7& exhibit more variation in friction level with temperature. Under heavy duty conditions, all three of these materials possess low friction values at near-aabient temperatures, increase to maximum friction values at approximately 400^, and thereafter gradually decrease in friction with an increase in temperature (Figure 7) 8002 1962 - 13 - Ferodo DS5S possesses far better wear characteristics for both light end heavy duty conditions than either of the other two materials in this group (Table 1). It loses 24? of its. friction with water vapor application and decreases in friction with an increase in lining unit pressure (Figures 7 and 8). Under severe duty con ditions, the friction level of ES5S increases from p = .26 at ambient temperatures to p = .37 at 500DF then decreases rapidly to p = .22 at 525F (Figure 9), thus exhibiting an inability to withstand the high energy input. Visual examination reveals an open fibre asbestos and particles of brass. Large amounts of a coloring agent (probably carbon black) made visual observations difficult. Mlntex M69. wears more than twice as fast as DS5S under light duty conditions and over 3-l/3 times as fast under heavy duty conditions (Table 1). It loses 3656 of its friction with water vapor and decreases in friction with an increase in lining unit pressure (Figures 7 and 8). Microscopic examination shows the presence of large brass chips, some coal and large crudes of asbestos. It appears to be a dry-mix material. Mlntex M-78 exhibits the highest wear rates under both light and heavy duty conditions of all six disc brake materials tested (Table 1). The heavy duty procedure friction curve for this material (Figure 7) shows large variations of friction above 500F, indicative of a rapid deterioration of this lining material above this temperature. It loses 15? of its friction with water vapor and its frictic: level appears to be essentially insensitive to changes in lining unit pressure (Figures 7 end 8). It appears to be a dry-mix material, containing some coal, chunks of resin (probably phenolic), and particles of brass. 8002 J983 - 14 - TABLE 1 Material Drum Brake Materials Avg. Specific Gravity Avg. Specific Wear . Water Vapor % decrfaie^o^f&ctior Lt. Duty Hvy. Duty Hardie-Ferodo E113 Hardie-Ferodo E110 Hardie-Ferodo E001 Hardie-Ferodo E120 Hardie-Ferodo E308 Disc Brake Materials Ferodo DS31 Mintex M33 DON 212 Ferodo DS5S Mintex K69 Mintex M78 I.85 1.83 1.98 2.00 ' 2.00 2.88 2.65 1.99 2.19 2.69 2.12 2.06 2.75 2.43 4.23 2.00 3.70 9.55 4.11 15.3 3.98 1.29 1.26 3.51 1.55 3.28 3.69 3.72 5.12 4.95 2.55 8.96 9.36 20.0* 8.0* 15.6* 10* 28* 26.8 19.4* 96* 23.7* 35.6* 14.6* 8002 1964 * Y7'/> * 15 I tx~tiI n. ShH.SS-3". P ou (X . "S p 2 o jc -o S. <D tO (8 H *H * > P H fc, P H 0ir\ (04) fH 0)>iCr-- Pg co 0> 3 o> P J3 g cd :* r. p m o m c X> ouv rt p n o 3H Oto-au-v a Bail. CD a> pXo<noCm 3HO O . H SO Ij o i/v p --- >-3" S H P I fO * , C X 3 -rt > JB M 32 f SiiC8 6 P Em J5 H *3 3 3 VK.OCm JS r- itnp vO CM *rt -- J3 IA) M Prt "3. 3 BJ C IX t0 O 3 H -rt >>H H Em m v-* 3 *0 rt O w Eh CX B O o o 34H O, E4 p ^ <8 mg > 5 8. S -S fe ?M Ja jps* sp d co O CO rt O fH cd !*| (X U a p.ro a. XS S3 to OP pH t> H H . as 3 3^ (4 . ^ BI C"M S. cpSn C ,, ^ rt CM rt Cm > c_x < J- too rt Q Eh xpmi H> 33e Eh D O UVP 3 H Cm TBS .8 5 *rt ro p 3` 2 t> c Oh 3W <UM O3 H > tOoT Hto Eri HO 'Eh a ai 'SI <o & (VI o o CO k t(-8 (O H3O 0) ^ o <1 ro 3 l_ 4>'8'5` "Sol H 5* 5- l/VJC >NUV Hto Q\J3 2PX t/v 5al p r- e. JC o to CM *3 HO ha PH.S sc ~ 3 QP (O <8 PJ- E, js a> to CM TJ HO ha > P a~ rO X 60 ___ sc X P 00 3 X On O 2(8 rO* sH-^ SC i? 0J3 pJC CM Hto MJ- X5 pS JS to CM o 0 u Cl. (O 1H V (8 SC o *8 b CM O SS R0) sc ! o *8 X) o c! *Y 8 H 3 *w 11 w ~ 16 - K Zf f sSs I SJJL & N ii aCO 1-3 5C3 0n) PSJ >ws? "Q(4)> >J t4 -C3U5j pJ3 -1A' rH p*J agxP:-Ht>o 3 . 8 S"' p 8.x: t pH e pP * Ch r-t -P iw (0 4* CO T2S 2 4-cH4*d rH Q>* >_ ^ "d ^ UN Ch 3 rH P ax: bD 4> gpji H O -H <H rH P 3---- C X! S4* d X3 P r-, rj r- 88 0.1/N p 11 -CiTU U) *H P d an m p B l/S. co _ x> O dCO Cm u aULoO+> a h p d o p T3 CIXMv d3 Hi4 xi p 8? 8 ..S P Cm " & O ro . * 8.3> P bD W .rt p 0to> OO.CM p d CO p sO a p <oad> < o Cm - ^ li a_o oiirrs\ > M o p p x: p d dp p d 3 vs co a x: 4c>d p LT' 'T**4*. P Cm fn p a o -h " ES *8.5 OaH ^cud Ip J -P 4> O W fOC<(^30i fCl) vO .XHf>i || A P Po CO CO d VCh o >o COm p rC tr\ O o x> s sS3 o CO TABLE IIB VEHICLE CORRELATION i? CM 3 & rAO aj row 33 ro ST X! bHDH < .-3 P ^S S> HCM Vdt. d irsTJ A *, X3 H bD rH w p" "" H & I\s\ h<Jx?rs *Qao $ ~ rH X! P IT\ bD x: h bsro x: _ lAMS gw` & 3! > *? c> 'd pftfe X3 Tl bHD rH 5B J s-r 4? p v> bO dcow X Is 00 bD Sbown.o2w P p \0 X! >rn bD 5a os w*arC i? x Os bO PVfi H x: bO _____ _ rmo ft *3 CoO s *o0 x p8 e eCr4Mg CQO Oo(o4 8Cm Cm vOaOsIN CrO~ s B 5s dHX 6002 1966 r\r>t t>\r r*r\i>r> 8 I .1 id I(Tv>\ 3 ir o ir\o a u\m5 r**> h iO9T9W5O0 O(0* V u\ no r<* d J| rt CM VO H G co o n i0 5v i R i Q & p >d >3 -t urn KSS4 # MOfl to Islasf o r- CM -8 -8 FAST LIG HT DUTY PROCEDURE f**)00 lO i-- r-CO W CXI r~ O VO rr> Tr---'J- CO W CM r- <0D0 .c Cl O' CO M o CD n b- r* Jfl} I * O O "Boo3* C c llll "5$" y -OfO CM**1 oCu -a *> g 8cE. noO ^ 8o *V* II H5 & Jg<J--OJTlBSSJI tonjca 8902 1969 T in e -- M in u te s g 8002 1971 sa & & '3 & R8 fc uo^oTJa JO VX9-PTJJOO0 a B & 30 FAST LIG H T DUTY PROCEDURE rrsO*)oOCONwOOJ * *~ OJ a a wH W CQ O & Of j- f Sr- COD' ro r* JC k#M. wO' ne** OJ oo ao o br *C* Ia) l-s ^ o u * c c c ill! tA <v o r-* OJ 8Ol o ~U\ ct-A-- *3 vO w coMoc o ITS-- -Oro 0) l/N , | W-1 +0>5 -8 iH0) 5 O CO ot"* nV -1 v ST UN ftItj J. O 5H ISi""3JT\a30JJ x^jjoa &3Tun } if'Jy < H 38 no'j^Djj.i jo (A (V) OfO imr O iriior\ vir\v'3Q5 tO- o5 na-pTjj->oD r- g 6M fc 002 1V?3 T>t>r>nnrrn nv tAi>n FAST SEVERE DUTY PROCEDURE Fig. 16 Sample of Ferodo DS31 after heavy duty tet. Note crocks in cashew friction porticles. The light ridge was foimed on the sample surface when a piece of brass lodged in one of the crocks. CALL.W. n Rnss fl-.-A.9i 8002 I**77