Document x1r0a973QJpbeXnny5wpJXJGE

/ , rf ./ - r /f Infra Company .March 23, 1970 Mr. B. D. Harande ec Gaalar S. Gratch 7. Hospadaruk H. Tlflchor T. Vhalon Subject: Monthly Highlights for March, 1970, Chemical Engineering Department na l :> Sodium-Sulfur Battery Milled, 0.2% LljO saaplea, containing S10a from 0.005 to 0.08$ have been sintered, although the 0.08$ saaplea sintered to a lover density than the other silica-containing materials. Preliminary results reported last month indicated a decrease in strength with increase in silica content after i/ static testing in sodium at 300C after four weeks. More extensive results V indicate that no significant loss In strength is observed In samples containing up to 0.02$ Si04 after six weeks in sodium, and samples containing 0.04$ SiOa vara unaffected after four veeka in sodium. The remaining samples are still in test, with the test duration limited to six weeks. Samples containing 0.005 to 0.06$ Si02 were subjected to the standard, 10-olnute, sodium nitrate-mercury electrolysis test and no detrimental effect of the silica content was observed over this range of silica. Samples containing 19 to 0.2$ SiOj will be tested as they are prepared. A wfiHwg study designed to improve homogeneity of the 0.2$ LijO material was completed. By milling four hours before and after the reaction step with a high-purity alumina mill and grinding media, a uniform, fine grained mierostructure was produced. Whan tested in the 10-olnute electrolysis PLAINTIFF'S EXHIBIT COATES PLAlNTU-r o EXHIBIT irr WV-06143 I PRODUCED BY FORD IN SCF-FORD-0635 PRODUCED BY FORD IN Mr. E. D. Marande Page 2 March 23, 1970 teat, the material v&a consistently stronger vlth a smaller scatter of the data than those samples processed without milling. A mill log study designed to refine grain size as veil as Improve homogeneity of the 0.7? Li*0 material vas continued. The sintered product had a low density, and chemical analysis indicated an unexpected loss of Na40 during sintering. This material la being resintered and will be tested mechanically and electrically. Degradation of the ceramic at high current densities up to 1.5 A/cm2 has been attributed to the discharge of liquid sodium at rapid rates in the microcr&cka present at the ceramic surface. The pressure created by the rapid discharge of liquid sodium in a confined volume may be great enough to fracture the ceramic and extend the microcracks. If this is true, then discharging of solid sodium should cause cracking and degradation at much lover current densities. To test this hypothesis sodium vas discharged into mercury at a 0.2? Li*0 ceramic surface at temperatures above 120C and below room temperature, the melting point of sodium at a low current density, 10 mA/cm2. At room temperature th- ceramic exhibited extensive degradation, vhsreas at 120C no degradation vt>- observed. This result supports ths hypothesis since solid sodium voult be expected to exert greater pressures in microcracks than would liquid r.-.Uum, thus causing microcrack extension and degradation enhancement. Oexsil coatings contaii- /Of graphite on 446 stainless steel ulc....v.i.. iuiVs succession^ pass? six-month test in moxveu at 300C at 200 oi/cm2. Corrosion tests on niobi-.u; show that it is corroded rapidly by the sodium polysulfide melt. jj C-TPS PRODUCED BY FORD IN v FCR0 " 00*3 ---- 1 I I ' Hr. E. D. Karu^e Page 3 March I'J'V P'grer Tnak Fcree Scientific Research Staff parsonnol, In cooperation with Monroe Process Control and Quality Control, have determined tho opcrati:g ccnditlcnj in the white brass plating process responsible for producing the majority of warranty failures. These failures involving zinc-rich bands are asaocletod with current variations and interruptions occurring during machine stoppage. Appropriate steps are to be taken during future breakdown to avoid the production of these failure-prone bumpers. Attention is now being focused on the overall plating process. An investigation has begun with Hcnrce Process Control to determine in some detail the nature of the excessive polarization present in a large mezber of tho plating cells. Cell voltages ranging from 7.5 to 15 volts were recorded. The current variation among the anode baskets within a cell was large. Those conditions indicate inadequate bath composition stability or control, poor current distribution at the racked bunpera and inefficient power consumption. A program will be initiated, with laboratory research support, to determine tc what extent various factors such ss bath additives, complex!ng lens, agitation, etc., are responsible for the difficulties. A study is also underway to determine the influence of agitation, cathodic current density and other factor on the composition and phase structure of the deposit. These data will be especially valuable in relating these parameters to the anodic behavior of the brasses deposited. Technical assistance is being given MDC in their evaluation of a brass bath adjusted to & higher copper-to-zinc ratio. Of special Interest at this time is the Investigation of factors that will assure uniform anode corrosion and the study of the anodic reactivities of deposits obtained from the bath. COATES PRODUCED BY FORD IN V FORD - 0369 COA FES Mr. E. D. Marande Pag* 4 March 23, 1970 fual Tanka An investigation is being undertaken at the request of Dearborn Engine Plant and Chassis Materials Engineering to determine the cause for the early rusting of a large number of fuel tank interiors prior to car assembly. The corrosion proceeds through galvanic cell action between cathodic terne coating and anodic steel exposed at pore sites. This condition is present due to moisture condensation and acid flux residue in tank interiors. Steps have been taken to combat the corrosion through a better wash procedure ami the use of corrosion inhibitors. However, for a more positive solution to the problem the objective is to determine whether there is a marked variation in the quality of the terne coating as Indicated by the corrosion failures. The investigation indicates that the terne coating on the atanping shests supplied by Axmco, a major supplier, are substantially more porous than the a coatings on sheets obtained from U.S. Steel, Republic or Wheeling. Armco has recently modified the hot-dip proceas by substituting an air-jet finishing technique for the more conventional grease-pot roller step for coating thickness control. The results to date indicate that high porosity is in part related to insufficient coating weight. Substantial differences in costing thickness for both aider of the sheets have been found. Revisions to the specifications are indicate-.-. since they refer to only a total coating weight--not weight per side. The raishing or brushing operation used hr Armco on the coatings (0.1 to 0.i i. average thickness) in an attempt to rei-ue the porosity count mey, at -.mee, aggravate the situation* The investigation is continuing and test procedures for Improving quality oontrol inspection will be :eoonaended. COATES PRODUCED BY FORD IN c a iw m K D Hr. E. D. Marande \ s/ Page b March .\, 1*\ \ Air Pollution frcSL Brake Lining Asbestos In order to assess the possible contribution of brake lining wj debris to environmental pollution, an estimate was made of the amount of asbestos which is worn away during braking. Data obtained from Ford Test Track Brake Life tests were used. The result--about 100 g of asbestos per car per year--indicates that approximately 11,000 tons per year cf brake lining asbestos would be worn away in the U.S. (about 1 Billion tons of asbestos per year are consumed in the U.S. for all applications). A report by J. R. Lynch of the Tubllc Health Service indicates that less than lit of the brake lining wear debris generated during normal braking is fibrous asbestos--the remainder of tho asbestos is decomposed into nonfibrous dust particles. However, a question has been raised by I. J. Sollkoff, an expert in the field, regarding the adequacy of the electron microscope magnification used to observe the fibers. Dr. Lynch's samples are S' being checked in Dr. SelikofF1 a laboratory. Asbestos has been duplicated as a carcinogen, and it is suspected that this carcinogenic effect is associated with tho fibrous nature of asbestos. The chronic effect of asbestos decoapoaition products is not known; however, some work has been reported in which asbestos decomposition products produced an acute toxic effect when injected into the peritoneal cavities of mice. Because of the possible hazard associated with inhalation or Ingestion of asbestos, study was suds of personnel exposure to asbestos dust during compounding, sample preparation, and frietlon machine testing of brake lining formulations In our laboratory. The evaluation was conducted by Mr. H. B. Lick, Industrial Hygiene Department. Air samples taken during all operations were below the threshold limit value for asbestos dust recommended by the American Lv * COATES V FORD " 0071 PRODUCED BY FORD IN ^aTes Mr. E. D. Maraade Page 6 March 23, 1970 Conference on Governmental and Industrial Hygienists, es aeaeured by a light field count technique. However, it is likely that the smallest fibers would not be observed by this technique. Ae an added precaution, we have obtained approved dust masks for use during these operations. In view of the questions which remain regarding the fiber content and respirability of wear dust, and the possible hazard from even the decomposed asbestos, we are giving thought to what we might do to help to answer these questions. V. Petrocelll pevn COATES V FORD - 0C7 2 PRODUCED BY FORD IN COATES R-12G R FRICTION MATERIALS AND SYSTEMS The objective of this project Is to develop and^ evaluate friction materials and to establish effective test methods and standards. This includes Investigations of heat transfer, vibration, and other phenomena which affect the application of friction materials. This program Is pursued cooperatively with the Chemical Engineering Department. Progress is reported Jointly. 1. New Materials Friction test (FAST) results have shown that additives such as NaF, Na^AlFj (cryolite), IF, KF, or BaS04 play a dominant role in altering the characteristics of the interface between the friction material and the mating surface. Thus, for a given brake lining formulation, the FAST friction level for a particular additive was the same on copper, steel and cast iron surfaces. 4 In many cases this friction level was different for different lining additives. The test samples had essentially the same weight loss on the steel and cast iron surfaces but a much greater wear on the copper surface. The copper rub* bing surfaces became much rougher with use than those of cast iron or mild steel. The roughness change with use of each metal surface was affected to varying degrees by the different additives. Studies are In progress to determine if the wettability of the mating surfaces by the additives at their melting point may be Important. The studies of the wetting of the copper surface show that KF, NaF, Na,A2Fa and PbF# vet the copper surface In approximately the some order as the additives Improve the friction and wear characteristics of the friction nnterlsl. Tests are in progress to study the vetting of the additives on the cast iron and steel surfaces. To obtain a better understanding of the Interface phenomenon, friction and wear characteristics of samples of friction material without additive COATES \i c.j5: PRODUCED BY FORD IN COAIES wprv mtiHuntil In tJu- mu in Jc firm M' (.ho FAFT rnchVxo vhi.lv unal.v ca:.-. -` Vng Ali* nddlLtvr until* t* A-uilv v.nv Vvl.l in -in :f.L\ T. vuy rtn mv! .'iv..ci*. t.ho wxvir tract. The reoult.: of thla dual arm approach indicate that the additive applied to the vear track in this vay does influence the interface characteristics for the main ana sample, probably either by adhesion to the mating surface or by transfer through the vear debris that has entered the interface. Studies are in progress to ascertain the underlying mechanism. Attempts to develop a secondary lining vtth the desired low vear and low friction coefficient are continuing. As suggested by results from dual-arm FAST tests, linings were prepared with a higher resln-to-asbestos ratio than the linings previously tested. During the break-la period on the Dynamometer, cracks were again observed in the lining. This vas probably due to poor kneading of the mix during the cold pressing operation. Preliminary experiments indicate that this difficulty could be overcome by a< preforming and repressing operation. Once this processing problem has been resolved nev mixes with additives such as M3Sa, coal and graphite vill be evaluated in order to obtain the optimum secondary lining to match the superior drum primary and disc linings that have been found and reported. Dual arm FAST tests will be made to help ascertain the compatibility of the secondary and primary linings before full brake tests are performed. A patent application has been filed on our alkaline fluoride filled friction materials. 2. Test Methods A small laboratory shear test fixture has been designed and built vhlch should provide valuable Information on the structural strength of linings. This device la somewhat unique in that It uses small (.2 x .3 x .6 inch) samples, thereby permitting samples to be prepared vitb the shear plane at various angles to the asbestos fibers. Preliminary tests have shovn good stability of results from several consistent lining formulations. A lining which PRODUCED BY FORD IN 3 provided Inconsistent results also vaj founa *.c nave lar^c variation.- of asbestos fiber orientations. Further shear strength studies will he performed to determine vhich processing and compounding parameters are significant vitb respect to reproducibility of results, strength level, and orientation sensitivity. Air Pollution from Brahe Lining Asbestos In order to assess the possible contribution of brake lining wear debris to environmental pollution, an estimate vas made of the amount of asbestos vhich is vom avay during braking. The estimate vas based on lining volume vorn from various types of brakes using Ford Proving Ground lining life experience. The result -- about 100 g of asbestos per car per year -- indicates that approximately 11,000 tons per year of brake lining asbestos vould be worn avay in the United States (about 1 million tons of asbestos per year are consumed in the U.S. for all applications). Asbestos has been Implicated as a carcinogen, and it is suspected that this carcinogenic effect is associated vlth the fibrous nature of asbestos. Some vork reported In the literature Indicates that less than 1$ of the brake lining vear debris vas fibrous asbestos, vhereas roughly half of the original lining vas asbestos. The remainder of the asbestos is decomposed inton non-ftbroua dust particles. Hovever, there is some controversy on this point. In viev of the questions which remain regarding the fiber content and reapirability of vear dust emitted to the atmosphere, some preliminary measurements are being made of vear dust sampled from a moving air stream downstream of an operating brake dyna mometer. 3. Support to Divisions. FGC and FAST tests were run on samples from 10 batches each of tvo brake lining formulations submitted by Ford of Germany. The objective vas threefold: to demonstrate the applicability of these quality control tests to formulations used In Germany, to provide benchmarks for comparison with test /> U o I< PRODUCED BY FORD IN u result.} which nay bo generated in Germany, und to provide sone Lzfcr-e.z-.zn about the linings. The contained results from the chenical and mechanical tests Indicated that one of the linings, Textar V-1U3IFF, vas quite consistent from batch-to- batch, even though it has scwevhat greater morphological irvhomogeneity vithin a piece than is usually found for U.S. production linings. The other lining, PagId 300/62, was higher in wear rate than the Textar lining and most U.S. disc brake linings. Both FGC and FAST results indicated that the Pagid lining is fairly inconsistent, which may lead to a quality assurance problem. Both linings generated many times more cast iron wear than typical U.S. disc brake linings. Also, in response to their request, some suggestions were given on the application of gas chromatography for the quality control of a particular brake fluid used in Germany. , U. Wet Clutches In order to provide the basis for improved quality control and design of wet clutches, a theoretical model has been developed which simulates the engagement of a pair of ua-grooved wet-type clutches. This is based on a study of squeeze films for porous annular disks. The model provides estimates of fiber thickness, viscous shear torque, oil film temperature, and energy dissipation during the engagement. The method and results have been described la two technical reports. Laboratory apparatus has been developed to measure this squeeze film thickness for two sizes of non-rotating clutch plates. Informal meetings were held with Transmission and Chassis Division personnel who concluded that this nev approach warrants further effort. Future studies win he directed to improving the present model and to correlating the theoretical results with Laboratory measurement of oil film thickness vs. time characteristics of production clutch facings. tOATct produced by ford in 5 5. Analytical Studies Characteristic values for the deflectlots and stresses in. brake drur.c have been obtained for most passenger drum designs vhich are currently ia production. The structural behavior obtained is based upon uniform lining pressure distributions for both the leading and trailing shoes. Some study has been made of the effect of the ring vhich is attached to the drum at the labyrinth seal. The stiffening effect of this ring is so predominant that the analysis of this portion of the drum structure warrants further study. Consideration of the problem of incorporating brake shoe deflections into the calculation of lining pressures indicates that the analytical method vili have to be revised somewhat. -'T s. CCATES PRODUCED BY FORD IN