TECHNICAL REPORT NO. loo5o

* 14iKFUALS MATFRIALS EM INGIW~ U* IN TANK-AUTONDTIVE FTJIPCIN

Mvarch 1968

PERMANENT ? i ERMANENTFILE COPY IFILE COPY .

TCm

I0

REFERENCE COPY IRAECJ

by VICTOR H. PAGAo0 0Materials Division

lietribuL--.n of ais doQLUmOUlT-AO Nli unlimited,_-' "-" _

VEHICULAR COMPONENTS & MATERIALS LABORATORYU.S ARM TAKATMTV£OMADWreMcia

The findings in this report are not to be construed as anofficial Department of the krmy position, unless so designatedby other authorized documents.

The citation of commercial productsin this report does not constitutean official indorsement or approvalof such products.

CITATION OF EQUIPMENT IN THIS REPORTDOES NOT CONSTITUTE AN OFFICIALINDORSEMENT OR APPROVAL OF THE USE OFSUCH COMMERCIAL HARDWARE.

Distribution of this document is unlimited.

METALS MATMrIALS ENGINEERING

IN TANK-AUTOMOTIVE EQUIPMWT

by

Victor H. Pagano

AMCMS: 5025.11.268.03

Approved R&D Project: 1-G-O-24401-A-105

VEHICULAR COMPONENTS & MATERIALS LABORATORY

ABSTRACT

A special presentation was made before the Saginaw Valleychapter of The American Society For Metals on 12 March 1968. Thepaper presented materials engineering requirements peculiar totank-automotive equipment which can be related to significant basicapplication factors to judge material suitability. These factorsinclude weight, service durability, utilization, cost and ballisticintegrity. acamples of prior and current development and applicationprograms are described to demonstrate the importance of totalmaterials analysis in tank-automotive equipment for achieving greaterreliability, manufacturing simplicity and lower cost. Some of thetopics covered are aluminum armor, explosive welding, explosive forming,application of leaded steels, and design around brittle fracture.

iii

TABLE OF CONTENTS

A b s t r a c t * * e e o o o e e o o o o o o * * o e • • • • • • • • • • • i i i

Table of Contents.. . ....... . . . .o - . . • . • . . .iv

List of Figures. .. . . . . . . . . . . o .. . • • . • 0 0 q * V

Introduction. . . . . .e .o a o • o * # • e o • o o oI

Material Design Considerations . . . * . . . . . . . . . .. . . . 1

Increased Mobility Through Lightweight Metals Design . . . . . . . 2

Increased Service Performance - Wear Resistance.. . . . . . . . . 3

Improved Utilization Through New Manufacturing Methods . . . . . . 4

Low Temperature Performance and Design Around Brittle.Fracture . . o . . o • . a # . o * o * o o o o o o o e e * • 5

Improved Utilization Through Better Definition ofMaterial Properties. . .. . . . . . . . . . . . . . . . . . . . . 6

Proven Materials and Methods - Not Always A Production

Reality . . o . . . o . . . . . . . . . . . . . * * o o e o * 7

References * o e o o o o * • e a o e e * a e o i o o # • • • * • • 9

Distribution List.. . o .. .. ... . . . . . . .. . . . . .26

iv

LIST OF FIGURES

Figure No. Title Page No.

1 Aluminum Road Wheel For M60 Tank 10

2 Aluminum Fuel Tank For M60 Tank 11

3 Forged Titanium Escape Hatch Cover 12

4 Forged Titanium Tank Road Wheel Arms 13

5 Aluminum Turret Ring 14

6 Aluminum Wheel Design With Bolted Wear Plate 15

7 Illustration of Plate Collision Process and 16Resultant Jetting Phenomenon During Explo-sive Bonding

8 Enlarged View of Mbplosive Welded Joint 17

9 Manufacturing Process/Techniques For 18Hard Face Coating of Steel Components

10 Forming Large Armor Sections 19

11 Effect of Mechanical,and Metallurgical 20Properties on the Fracture Characteristicsof Steel

12 The Relationship of Fracture Strength-to- 21Crack Size For Different Levels ofFracture Toughness

13 Engineering Tensile Properties of Leaded 22

L20 Material

14 Tank Final Drive Gear 23

15 Enlarged Gear Cross Section (Nital Etch) 24

16 Graphite Mold Precision Casting of Final 25Drive Sprocket

.v

v

INTRODUCT ION

In the past year, Materials Engineering has-become a topic formuch discussion by many society members.

Although gradual, the transition from a society concerned withmetals processing and application metallurgy to one concerned withoverall materials engineering has been a very positive one as wellas a logical one. Laboratory organizations have passed by naturalcourse of events over the past 10-20 years from a testing and postmortem engineering group into a well knit group of specialistsinvolved in basic equipment design.

The major function adopted by such laboratory groups has beenthat of material selection as part of the engineering design cycle.

Responsibilities have broadened also in areas of analysis andtesting due to greater sophistication in materials know-how andlaboratory tools.

A well organized and staffed group together with some orientedmaterials development activity can help effect optimum equipmentdesign for maximum performance and reliability through properselection of materials. Knowledgeable material selection can also leadto lower cost through lighter weight design together with simplicityof manufacture.

Thus, a materials engineering group is an operational activityresponsible for the selection and application of proper materialsand/or processes to provide functional, reliable and economic usagein all equipment design.

MATERIAL DESIGN CONSIDERATIONS

Tank-automotive equipment offers a challenging array ofoperational and environmental considerations for the materialsengineer to cope with. For the tank, primary component areas includeengine and power train, track and suspension, armament, and the hulland turret armor shells. For the logistic vehicle, there are theengine, power train, wheels and suspension, body and frame. Both typesof equipment, because of cross country operational requirements,undergo severe conditions of loading for prolonged periods of time.

Aside from being subject to high dynamic and cyclic loads,military equipment must also sustain the effects of temperatureextremes, corrosion, errosion and ballistic attack (projectilepenetration and explosive shock) - under special circumstances, alsoradiation.

In the material to follow, a description of current efforts andcase histories is made to show how various materials, processes anddesign methods are being investigated to overcome some of the operationalproblems associated with tank-automotive equipment.

INCREASED fBILITY THROUGH LIGHTWEIGHT METALS DESIGN

Materials investigation for reducing equipment weight is aperpetual one in order to keep up with modern mobility concepts.This is especially true in tank design with its additional need forarmor plating to protect against projectile attack and explosiveblast. Successful application of lightweight metals for major vehiclecomponents and for armor has helped the Army field improved combatand tactical vehicles.

Of significant importance has been the development and applicationof aluminum alloy armors.' The first type Used was work-hardened 5083Mg-Al alloy applied to the M113 Personnel Carrier - a real workhorsein the current Vietnam conflict. Besides proven ballistic capability,aluminum armor has provided for easier fabrication by welding andhigher integrity structural design.

A higher strength heat treatable aluminum armor has since beendeveloped possessing improved ballistic properties with essentiallythe same ease of welded fabrication. The material is a Mg-Zn aluminumalloy identified as 7039. This material was primarily developed toovercome the special weight problems associated with the M551 SheridanVehicle. The 16-1/2 ton vehicle was designed for air drop operationand high degree of mobility with good small arms and fragmentationprotection. It has an all aluminum armor hull and a steel turret.Use of aluminum armor on this vehicle was not without problems.The 7039 alloy is prone to stress corrosion cracking in the thicknessor short transverse direction. Thus, usage required an appreciationof special design procedures to avoid application problems.

Besides lightweight metals for armor, similar use has been madeto other component areas. As an example,-consider the aluminum alloyforged road wheel (Figure 1) used on the M60EI Medium Tank. The wheelis a 2014 composition aluminum alloy forging and weighs about 105pounds, a saving of 50 pounds over the steel wheel for a total of1400 pounds for the entire vehicle. Another significant area oflight metal application was in the fuel tank (Figure 2). The tank ismade from 1/4 hard temper 5086 aluminum alloy. This applicationsaved 500 pounds over the old steel tanks. These weight savingsapplications were greatly responsible for making an improved and higherperformance vehicle over the older M48 Medium Tank at the same 50 tonweight.

2

Also made and tested were parts from titanium alloy. Itemsincluded an escape hatch cover (Figure 3) and road wheel arms(Figure 4). Other items made were track parts, torsion bars, driveshafts and tow bars. From a weight standpoint, all were a success -40% savings. Poor galling and wear characteristics have discourageduse in track part application.

Titanium has shown its best potential as armor. Based onprojectile penetration tests of various kinds, titanium providesweight savings of about 20 to 25% over conventional armor type steels.As is true with the previously mentioned applications, the biggestbarrier to the use of titanium is its high cost - $4.00 to $5.00 aDound - not currently recondilable to need.

In an effort to further reduce the weight of vehicles, work iscontinuing on other components. Typical of this is the concept foran all aluminum turret ring (Figure 5). This is the part whichgives the turret directional control. In doing so, it helps carrythe weight of the turret and related G-loads from gun firing andvehicle operation. The 80" diameter ring is made from a 7075-T6aluminum alloy with an insert of hardened steel to form a non-brinelling surface for the ball bearings. The aluminum assemblyweighs 274 pounds as compared to the steel assembly which weighs667 pounds. Iktensive road and firing tests at Yuma, Arizona, haveindicated excellent application potential. Similar tests are,currently planned for evaluating a 104" diameter aluminum turret ring.

Worthy of mention in solving the weight problem has been theapplication of magnesium alloys. Although limited, such materialsare effectively being used to save weight. Particular use is beingmade in housings (transmissions and fans) and as floor decking. Forexample, a 55 to 60 pound AZ91C-T6 magnesium casting is used for thetransmission housing in the Sheridan vehicle.

INCREASED SERVICE PERFORMANCE - WEAR RESISTANCE

In many of the light metal applications, wear resistance isusually an associated problem which crops up - for example, thealuminum road wheel. Steel wear plates are bolted to wheel innerflange surfaces to protect the aluminum against the sliding actionof track center guides (Figure 6). Methods of dissimilar metaljoining or bonding could help improve this design by eliminating theuncertainty of fastener failures or loosening. Explosive weldingwas selected and investigated for this application. Several wheelswere successfully made for field testing. A new effort is currentlyin the making to optimize critical design features of the wheelforging consistent with efficient explosive welding.

3

In principal, the mechanism of explosive welding is a uniquecombination of physical phenomens involving high pressure mechanicsand hydrodynamic flow. This phenomena is illustrated in Figure 7.Simply stated, bonding is accomplished when the high pressure developedby explosion is used to impinge metal surfaces in such a way thatthe metal surface can hydrodynamically flow as a spray of metal fromthe apex of the angled collision. This flow process and explosionof the metal surface is known as jetting. The severe shearing defor-mation and extension of the colliding surfaces by hydrodynamic flowand the resulting jet act to break up and dispense the bond inhibitingsurface films, leaving film-free surfaces pressed into atomic contact,thus, constituting a metallurgical bond.

Figure 8 is a picture of explosively bonded steel toaluminum showing the wavy interface resulting from the metal jettingcondition.

Another materials approach to achieving wear resistance invarious metals is through hard coating or fuse coating (Tungstencarbide) processes. The merits of such a process is now beingevaluated on selected wear areas found on steel track shoes used onthe M113 vehicle (see Figure 9). If successful, it is believed thatcracking problems associated with current induction hardening. ofselected part surfaces can be avoided. Tests required to insure acrack free product will also be eliminated. Use of lower carbonsteels is also feasible.

IMPROVED UTILIZATION THROUGH NEW MANUFACTURING NMTHODS

Somewhat along the same line of explosive welding, since theenergy sources are both from explosives, is our investigation onexplosive forming of large armor components. The item chosen fordemonstrating manufacturing adaptability is the steel turret of theSheridan vehicle shown earlier. The intent of this effort is shownin Figure 10, i.e., simply to reduce the fabrication costs involvedin the manufacture of this item. As currently planned, the turretwill be made from two explosively formed parts - an upper and a lowerhalf. The upper half presents the more difficult of the two halvesdue to several irregular shaped and variable thickness areas. Workis being conducted for us by both Aerojet General and North American.Based on work conducted so far, forming of the sections from higherstrength armor steel should be fairly routine. A cost effectivenessanalysis will be made of explosive forming and compared with thepresent method of welded fabrication.

4

LOW TEMPERATURE PERFORMANCE & DESIGN AROUND BRITTLE BEHAVIOR

The U.S. Army has had a long historical interest in the effectof cold environments on materials used in military equipment.

Most engineering materials show a substantial loss of usefulproperties at sub-zero temperatures. Although wood, ceramics andglass are virtually unaffected by extreme cold, the more importantclasses of engineering materials; namely, metals, rubber and plasticsare indeed subject to mechanical failure.

The complexities of the brittle fracture problem and controllingfactors can be shown to some degree in the concept of transitiontemperature. This is the temperature below which a material behavesin a brittle manner. The commonly used test method for determiningtransition temperatures and evaluating toughness of metals is theV-notch Charpy impact test. The transition temperature depends ona variety of metallurgical and mechanical factors; however, somequalified generalities can be seen in Figure 11 regarding susceptibilityto brittle behavior.

The application of the transition temperature approach to designis more complex than for just simple comparison of materials.- Indesign, the ultimate question evolves around the load bearing capacityof the structure or member for the prevailing circumstances and ,therelationship of transition temperature to load bearing capacity. Ageneral concept, which has come into wide acceptance, is that 4ortemperatures above the transition temperature, stresses of the orderof the yield stress may be tolerated, and below the transitiontemperature, the applied stress must be kept to some unknown low level.

A more definitive approach which is growing in acceptance andactual use is the fracture mechanics or fracture toughness approachdeveloped from the Griffith concept by Irwin and associates. Itapplies to design situations involving sharp notches or defects whichwould not be detected by normal inspection-procedures. The essenceof the concept is to relate the stress for fracture and the materialproperties to the size of a sharp notch or defect. Figure 12 providesa graphical illustration of the relationships of stress, defect size,and toughness for the case of a small disk shaped crack embedded in alarge tensile stress field. By inserting the toughness (GIc - criticalcrack extension force, in lbs/in2 or KIC - critical stress intensityfactor, psi hln) and the defect size numbers in the appropriatemathematical expressions one can solve for the critical value of thestress which will cause catastrophic fracture. Conversely, knowingthe toughness and applied stress, it is possible to estimate the

5

critical defect sizes that are required for catastrophic failure.Design based on the assurance of at least some degree of notchtoughness is far better than design based on the assumption that astructure is completely devoid of defects.

Efforts both under contract and in-house have Peen implementedby USATACOM to accelerate the appreciation of this approach forapplication in design of equipment. In the near future, it shouldeventually be possible to select materials which are adequate for acritical structural application in a given climatic environment, orto specify a minimum acceptable value of toughness for marginalmaterial.

IMPROVED UTILIZATION THROUGH BETTER DEFINITION OF MATERIAL PROPERTIES

Resolving questions of utilization are often necessary throughspecial studies especially where differences in material performancehave been recorded. This has been the case with leaded steels.

In the thirty years since the beginning of quantity productionof leaded, free-machining steels, their use in low strength applica-tions has grown steadily. However, a number of service failures wereencountered during the developmental period for leaded steel meltingpractice, which were traced to a metallographically "dirty" structure.In one instance, the presence of a lead inclusion near the surfaceof a diesel injector nozzle resulted in failure due to the meltingof the inclusion. Current practices for adding lead have essentiallyeliminated the early processing difficulties caused by gross leadsegregations.

The use of lead in alloy steel is relatively recent, and thenumber of applications for this material is increasing. There hasbeen, however, some resistance to their use in high strength applica-tions because of catastrophic failures which have occurred duringheat treatment or subsequent processing. Several exa=les will serveto illustrate this situation.

A heat treating firm, experirncing heretofore unknown crackingin a spindle subjected to warm-punch straightening after heattreatment, determined that the only change in practice was that aleaded 4140 type had been substituted for the non-leaded alloy usedpreviously.

Manufacturers of heat treated gears with flame or inductionhardened teeth found extensive radial cracking in a leaded alloysteel grade after the hardening treatment. Expansion of the teethduring the surface hardening subjected a region just below the surfaceto high tensile stresses. This, coupled with a "forbidden" range oftemperature, caused the failure. Failure point was found to originateat the site of a lead inclusion.

6

The failures all had a common factor; at some time duringprocessing or service the leaded part is subjected to stress at anelevated temperature.

Although the effect of lead on mechanical properties seemsrelatively minor, the disparity between the mechar4cal properties ofleaded alloy steels reported in the literature on the one hand, andthe service failures traced to changeover to a leaded steel type onthe other, suggested a closer look at the elevated temperatureproperties of a leaded and non-leaded grade of 4145 steel. Such aneffort was undertaken under contract with Illinois Institute ofTechnology.

At approximately the lead melting point (6210F) or somewhat above,the leaded steels (140 KSI) showed 50 to 60% less ductility than thenon-leaded material. Even more spectacular is the complete loss ofductility at strength levels of 200,000 psi between 6000 to 800OF (seeFigure 13).

Design application must, therefore, consider this embrittlementcondition if practical usage is to be made of these steels.

PROVEN MATERIALS & METHODS - NOT ALWAYS A PRODUCTION REALITY

There are times, too, where proven materials cost savings effortsdo not materialize for lack of adequate response from industry; Twodevelopments stand out as good examples. The first was the satisfactorydevelopment of induction hardening procedures for heavy duty tankgearing (Figure 14). The hardening profile pattern for the gear isshown in Figure 15. Besides offering a tenfold increase in productionrate, induction hardening improved dimensional stability and eliminatedneed for high alloy steels. Since its addition to drawings in 1957 forboth process and materials as an alternate method to carburizing, notone production gear has been made by the induction hardening method.

A similar situation was experienced with the precision castingof the M48 tank drive sprocket by the graphite mold process in lieuof fabricating from steel plate. A comparison of both methods ofmanufacture is summarized in Figure 16. The differences are obviousand the savings quite significant. However, the molded part stillremains to be made under a production order.

In conclusion, functional equipment of any kind is best evolvedout of a combined consideration of good design and modern materials.

7

Where this fundamental thesis is practiced to the fullest, functionalAnd reliable products will be found along with good economy.

8

REFERENCES:

1. J. S. Rinehart and J. Pearson, "Behavior of Metals Under Impulsive Loads",American Society for Metals, Cleveland, Ohio, 1954, pp 256.

2. J. G. Stefanich, "Utilization of Titanium for Tank-Automotive Components",Paper 459, SAE Automotive Ordnance Day Meeting, Cent:erline, Michigan,February 1955.

3. J. G. Stefanich, "Titanium Wins New Acclaim in Tough Ordnance Trials",The Iron Age, September 1958, pp 90-91.

4. V. H. Pagano and C. J. Kropf, "Case History on Induction HardeningLarge Drive Gear", Metals Progress, September 1958, pp 86-90.

5. J. W. Schuster, "Aluminum-Plastic Bearing Rings", Metals Progress,July 1963, pp 109-110.

6. M. M. Jacobson, "Materials Engineering for Cold Regions and the BrittleFracture Problem", U.S. Army Materials Research Agency Monograph Report,ANRA MS 65-05, August 1965.

7. E. T. Wessel, W. G. Clark and W. K. Nilson, "Engineering Methods forthe Design and Selection of Materials Against Fracture", WestinghouseElectric Corporation, Final Report, June 1966, USATACOM Contract No.DA-30-069-AMC-602 (T).

8. A. Doherty, E. K. Henriken and L. Knop, "Determine Feasibility ofExplosively Bonding Wear Resistant Materials to Aluminum", Aerojet-General Corporation Final Report, July 1966, USATACOM Contract No.DA-O4-495-AM-787(T5.

9. S. Carpenter, R. H. Wittman and R. J. Carlson, "The Relationship ofcxplosive elding Parameters to Material Properties and Geometry

Factors" ., The First International Conference of the Center for HighFhergy Forming, lstes Park, Colorado, June 1967.

10. S. Mostovoy and N. N. Breyer, "The Effect of Lead on the MechanicalProperties of 4145 Steel", Illinois Institute of Technology, Phase I,Final Report, January 1968, USATACOM Contract No. DA-20-113-AMC-10820(T).

11. Various In-Progress Contract Work (1968) by USATACOM:

a. Explosive Forming Large Armor Components, Aerojet-General Corporation& North American Aviation, Incorporated, Contract Nos. DAAE-7-67-C-2405and DAAE-7-67-C-5727 respectively.

b. Hard Coating of T130 Track Shoes, Contract No. DAAE07-67-C-5592.

9

z

I-W

01

4C

I.-

FORGED TITANIUM ESCAPE MATCH COVER

WT. STEEL APPROX. 130 lbs-WT. TITANIUM APPROX. 78 bs.

WT. SAVINGS 52 lbs.

FIGURE 312

uiIA I

cr.~ UA

00

110

LU~j ~ L

I-0

Ln g

0n%EL.u

im z

Cie-I 42-

13Z

0UL

z1

UU

IU I k'LUi

aft

mo

15.

zz wU0

VA U) 0

mmZ 4

0 j

UlU

I-W

Ck

-J W6

216

LU>

uj~ 0

'UU

LU4

-I ~~ r U6

U.

>

0J'Ui

17

ii i ii 1112

IM1I

OZ

-0-6

11.1k

108

C,)zz

0nLU-L

0L

'U

IL0

w LL.

NJ 2(

U-0

-C

ILd

19

42

$4

00

000

S. $4

41.

4a .-4 0 .f4

4. '

Lmn

4. I6

0 ~20

C.4 0

ElE

u =m/7/7 7/(A

b- a.)

20 .2 C

LAJ CD

z C..)

CD cm 0=4=c

(!S 001 'PGInsalLL. I-! a

(U (~Fu

In IM

In W6

21U

200L2

L 20

-""

I UTS

160 004A

120-

0j of t 14-80 _ __ _II

60 _ __ _-o

40_ RA_ __ 20

~20 _ _1__0_

0 200 400 60 1000

Test- Temperature 0 F

FIGURE 13 Engineering Tensile Properties of Leaded L20

22

TANK FINAL DRIVE GEAR

01

FIGURE 14

23

ENLARGED GEAR CROSS SECTION (NITAL ETCH)

(SECTION TAKEN ACROSS TEETHMIDWAY BETWEEN GEAR FACES)

FIGURE 15

24

F 0ui z 0

0 0

0ZZ z oP"1

0L 41wx

0. > z 0

_j Xj i@ W

~3Wz -J 0 W4

0 xw 4 . 0 lo ,

wI w

4w U) i~~An4 0 z W, a

U. IL 0

Iz z i -9L ca a W U,

S~~ Z-0bu): I-

w xw LK

aa

00

PI) IW0L w 0 j I

049 ZIA) FZC IL

w~

w2

TECHNICAL REPORT DISTRIBUTION LIST

Report No. 10050No. of

Address

Commnding General, U.S. Army Tank-Automotive Command, Warren,Michigan 4809oAls AMSTA-B, Vehicular Components/Materials Laboratr.y ..... 060009 -.1

AMSTA-BS, Laboratory Support Division.. • •.2AMSTA-BSL, Research Library Branch• •. . ................ .• • • 03A1MTA-BH, Materials Division... .... ... ...... .. o..°o•1lAMSTA-QK, Key Inspection Division1... ••• ••• ••• .• .•• . .iANSTA-RR, Systems Concept Division.. ........... • . .•...AMSTA-RRD, Systems Evaluation Branch•..•.•••.•..00•,••.•••09.AMTA-RRD, Mr. H. Nadler.....•..°...... •...•••.....••.•..••.••..o.1

AMSTA-RRE, Economic Engineering Branche. •.o .0.0*60860 ........ •1iSAETA-ERR, Systems Requirements Branch*e..,*,eoo,,&,.99.o•. . •AMSTA-RP, Operations Support Division.................. ..... 2

AMTA-RS, Engineering Control Systems Division* ... • . • •• •••••2AMSTA-RSR, Engineering Requirements Branch*... **..... ****e9eo2AMSTA-REA, Vehicle Systems Support Brancho,,oooooo**...e.........

2

AMSTA-RSP, Packaging Engineering & Development Brancho.090....... 61

AMSTA-TD, Technical Data Division..... • • .1AMSTA-USi Scientific Computer Division......... .. 1AMTA-LEL, U.S. Army Electronics Command R&D Liaison Office.oe*.lAMSTA-MC, Combat Vehicle Division........•..•e •8•. •61

Commander, Defense Documentation Center, Cameron Station, Alexandria,Virginia 223.......... ............ .................................. 20

Director, U.S. Army Production Equipment Agency, Rock Island Arsenal,Rock Island, Illinois 61202.. ......................... ,. .. ......

Commanding Officer, Tuma Proving Ground, Tuma, Arizona 85364.. 6 6........1

Commanding General, U.S. Army Aviation School, ATTNt AASPI-L,Office of the Librarian# Fort Racker, Alabam .* ... *0................... 1

Commanding General, U.S. Army Test & Evaluation Comand, ATTUTechnical Librar, Aberdeen Proving Oround, MaAryland 2100e........•.*.2

Comandlng Officer, U.S. Ari Arsenal, Frankford, Bridge & Tacon:treeta, ATTNo Mr. Frank Husey, Philadelphias Pennslvania 19137i......1

26

No. ofAddress

,Conmanding Officer, Harry Diamond laboratories, Connecticut Avenue'& Van Ness Street$ N.W., Washington, D. C. 20480............. ,**01

Conuandig Officer, U.S. Army Materials & Mechanics Researoh Center,Watertown, Massachusetts 02172A T T N : W e .W l l i a m t P e h : o o o . , o o , . ., . . o o o o . . , , , ,

Nre Arthur I .OP9o , . . o .. , . . . o , , . ,, , , , . . , , .

go B. Naval Civil Indnerins Reaoh & Engineering Laboratory,onstruotion Battalion center, Port &senoe, Califonmia...... ......... 0 .1

27

UNCLASSIFIEDSecuifty Clalication

(S.cuNtp ~ ___ OC~~HT CONTROL DATA.- R&D __ we*miacMu1.

-Warren, Michigan 48090

3. REPORT TITLE

Metals Materials Engineering in Tankl-Automtive Equipment

4. DIESCRIPTIVE NOTES (Ti*o-pol OW.,. wi arive doil".)

S. AUTHOR(S) (Last me. flint ame, WdSUal

Pagano, Victor H.

9. REPORT DATE OTOANOOFP09 &N.OrRe

Mvb.ch 1268291go. CONTrRACT OR 41RANT NO. S&. 61111INAToRs REPORT mutisaWl)

SPROJKCT No. 1-G-0-24Ol1-A-105 100,50

10. A V A IL AIIILITY/LIMITATION NOTICES

Distribution of this document Is unlimitedi

It. SUPPLEMENTARY NOTES J12. 41PO01ORING IMLITANY ACTIVITY

1S. AUSTRACT

Materials engineering requirements peculiar to tank-autamotivt equipmenit danlbe related to significant basic application factors wherein material suitoilitycan be judged. These faotors include weight, service durabilitys uti3isation,coat and ballisti c integrity. ExaMples of prior and current developmcanapplication programs are described' to demonstrate the importance of total astrlalsanalysis in tank-automotive equipment,fft achieving greater reliability, manufao*.turing simplicity and lower cost. Some'.6f the topics covered Afe alwaltft aftb~r,explosive welding, explosive forming, application.of leaded stals, arA dea gnaround brittle fracture.

DD IJ~A 41473 UNCLA&MED28 S cud esaseSces"e

UnclassifiedSecurity Classification

14. LINK A LINK 0 LINK CKEY WOROS ROL WT ROLU WT ROLE WT

METALSMATERIALS ENGINEERINGTANK-AUTOMDTIVE EQUIPMENTDESIGN CONSIDERATIONSLIGHTWEIGHT MErALS APPLICATIONIMPROVED WEAR RESISTANCEALUMINUM ARMOREXPLOSIVE FORMINGLEAD ED STEELSBRITTLE FRACTURE

INST-J-CTIONS

1. ORIGINATING ACTIVITY: Enter the name and address 10. AVAILABILITY/LIMITATION NOTICES: Enter any iL.-of the contractor, subcontractor, grantee, Department of De- itationa on further diaemination of _h report, other than thosefone activity or other organization (corporate author) issuing imposed by security classifiction, using stagdard statementsthe report. such as:

2a. REPORT SECURTY CLASSIFICATION: Enter the over- (1) "Qualified requesters may obtain copies of thisall security classification of the report. Indicate whether report from DDC.""Restricted Data" is included. Marking is to be in accord-ance with appropriate security regulations. (2) "Foreign announcement and diesemination of this

report by DDC is not Authbft"

2b. GROUP: Automatic downgrading is specified in DoD Di-rective 5200.10 and Armed Forces Industrial Manual. Enter (3) "U. S. Government agencies may obtain copies ofthe group number. Also, when applicable, show that optional this report directly from DDC. Other qualified DDCmarkings have been used for Group 3 and Group 4 -as author- users shall request throughized. . "

3. REPORT TITLE: Enter the complete report title in all (4) "U. S. military agencies may obtain 00pies of thiscapital letters. Titles in all cases should be unclassified, report directly from DDC. Other qualified usersIf a meaningful title cannot be selected without classifica- shall request throughtion, show title classification in all capitals in parenthesisimmediately following the title.

4. DESCRIPTIVE NOTES If appropriate, enter the type of (S) "All distribution of this report is contolod Qual-report e.g., interim, progress, summary, annual, or final. iflid DDC userm shall request throughGive the inclusive dates when a specific reporting period iscovered. covered.If the report hats been furnished toThoe Office of Technical

5. AUTHOR(S). Enter the name(s) of author(s) as shown on Services. Deport of Commerce, ffr ode to the public, indior in the report. Enter last name, first name, middle initial catse this fact and enter the price, f know t iIf military, show rank and branch of service. , The name ofthe principal author is an absolute minimum requirement. 11. SUPPLEMENTARY NOTM Use fee additional explana-

6. REPORT DATE Enter the date of the report as day, try notea.

month. year. or month, year. If more than one date appears 12. SPONSORING MILITARY ACTIVITY1 Enter the name ofon the report, use date of publication, the departmental project office or laboratory sponsoring (pay

7. TOTAL NUMBER OF PAGES: The total page count ing for) the research and developmentL Include address.

should follow normal pagination procedures, Le., enter the 13. ABSTRACT: Enter an abstract giving a brief and factual

number of pages containing information. summary of the document indicative of the report, even thoughit may also appear elsewhere in the body of the technical re-

7b. NUMBER OF REFERENCES" Enter the total number of port. If additional space is required, a continuation sheetreferences cited in the report. shall be attached.

8. CONTRACT OR GRANT NUMBER: If appropriate, enter It is highly desirable that the abstract of classified re-the applicable number of the contract or gnt under which ports be unclassified. Each paragraph of the abstract shallthe report was writte& end with an indication of the military security blassification

8b, Be, & 8d. PROJECT NUMBER: Enter the appropriate of the information in the paragraph, represented am (TS), (S),

military department Identification, such as project number, (C), or (U).subproject number, system numbers, task number, etc. There Is no limitation on the length of the abstract. How-

9&. ORIGINATOR'S REPORT NUMBER(S): Enter the offi- ever, the suggested length is from 150 to 225 words.

cial report number by which the document will be identified 14. KEY WORDS: Key words are technically mesaingful termeand controlled by the originating activity. This number must or short phrases that characterize a report and may be used asbe unique to this report. index entries for cataloging the report. Key words muset be

9b. OTHER REPORT NUMBER(S): If the report has been selected so that no security classification is required. Idea-

assigned any other report numbers (either by the ordfinator flare, such as equipment model designation, trade name, mill-

or by the eponsor), also enter this ubr(). tary project code name, geographic location, may be used askey words but will be followed by an indication of technicalcontext. The assignment of links, rules, and weights isoptional.

Unclassified

29 Security Classification