Chapter 1. Engineering Materials

7/26/2019 Chapter 1. Engineering Materials

http://slidepdf.com/reader/full/chapter-1-engineering-materials 1/31

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C l a s s i f c a t i o n o E n g i n e e r i n g M a t e r i a l s

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S e l e c t i o n o M a t e r i a l s o r E n g i n e e r i n g P u r p o s e s

P r o p

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P r o p e r t i e s o E n g i n e e r i n g M a t e r i a l s

REPUBLIC OF THE PHILIPPINES

BTN PENINSUL STTE UNI!ERSIT" MIN CMPUS# PRO!INCE OF BTN# CIT" OF BLN$ C%&'((COLLE$E OF EN$INEERIN$ N) RCHITECTURE

)EPRTMENT OF MECHNICL EN$INEERIN$

C*apter '+ Engineering Materials

The engineering materials are mainly classified as:

1. Metals and their alloys, such as iron, steel, copper, aluminum, etc.

2. Non-metals, such as glass, rubber, plastic, etc.

The metals may be further classified as:a) Ferrous metals and

b) Non-ferrous metals.

The ferrous metals are those which have the iron as their main constituent, such as cast

iron, wrought iron and steel.The non-ferrous metals are those which have a metal other than iron as their main constituent,

such as copper, aluminum, brass, tin, zinc, etc.

The selection of a proper material, for engineering purposes, is one of the most difficult

problems for the designer. The best material is one which serves the desired obective at theminimum cost. The following factors should be considered while selecting the material:

1. !vailability of the materials,

2. "uitability of the materials for the wor#ing conditions in service, and

3. The cost of the materials.The important properties, which determine the utility of the material, are physical, chemical

and mechanical properties.

P*,sical Properties o Metals

The physical properties of the metals include luster, color, size and shape, density,

electric and thermal conductivity, and melting point. The following table shows the important physical properties of some pure metals.







The important physical properties are:

Density

$ensity is defined as mass per unit volume for a material. The derived unit

usually used by engineers is the #g%m&. 'elative density is the density of the materialcompared with the density of the water at ()*. The formulae of density and relative

density are:

density ( ρ )= mass (m)volume (V )

Relativedensity (d )=density of t h e material

density of water at 40

C

Mec*anical Properties o Metals

The mechanical properties of the metals are those which are associated with the ability

of the material to resist mechanical forces and load. These mechanical properties of the metalinclude strength, stiffness, elasticity, plasticity, ductility, brittleness, malleability, toughness,

resilience, creep and hardness. +e shall now discuss these properties as follows:

1. Strength. t is the ability of a material to resist the eternally applied forces without

brea#ing or yielding. The internal resistance offered by a part to an eternally applied

force is called stress.

Table 1.1 Physical properties of metals.







2. Stiffness. t is the ability of a material to resist deformation under stress. The modulus

of elasticity is the measure of stiffness.

3. Elasticity. t is the property of a material to regain its original shape after deformation

when the eternal forces are removed. This property is desirable for materials used in

tools and machines. t may be noted that steel is more elastic than rubber.

4. Plasticity. t is property of a material which retains the deformation produced under

load permanently. This property of the material is necessary for forgings, in stamping

images on coins and in ornamental wor#.

5. Ductility. t is the property of a material enabling it to be drawn into wire with the

application of a tensile force. ! ductile material must be both strong and plastic. Theductility is usually measured by the terms, percentage elongation and percentage

reduction in area. The ductile material commonly used in engineering practice in order of diminishing ductility/ are mild steel, copper, aluminum, nic#el, zinc, tin and lead.

Note : The ductility of a material is commonly measured by means of percentage

elongation and percentage reduction in area in a tensile test.

6. Brittleness. t is the property of a material opposite to ductility. t is the property of

brea#ing of a material with little permanent distortion. 0rittle materials when subected

to tensile loads, snap off without giving any sensible elongation. *ast iron is a brittlematerial.

7. Malleability. t is a special case of ductility which permits materials to be rolled or

hammered into thin sheets. ! malleable material should be plastic but it is not essentialto be so strong. The malleable materials commonly used in engineering practice inorder of diminishing malleability/ are lead, soft steel, wrought iron, copper and

aluminum.

8. Toughness. t is the property of a material to resist fracture due to high impact loadsli#e hammer blows. The toughness of the material decreases when it is heated. t is

measured by the amount of energy that a unit volume of the material has absorbed after

being stressed up to the point of fracture. This property is desirable in parts subected toshoc# and impact loads.

9. Machinability. t is the property of a material which refers to a relative case with which

a material can be cut. The machinability of a material can be measured in a number of

ways such as comparing the tool life for cutting different materials or thrust re1uired toremove the material at some given rate or the energy re1uired to remove a unit volume

of the material. t may be noted that brass can be easily machined than steel.

10. Resilience. t is the property of a material to absorb energy and to resist shoc# andimpact loads. t is measured by the amount of energy absorbed per unit volume within

elastic limit. This property is essential for spring materials.







11. Creep. +hen a part is subected to a constant stress at high temperature for a long

period of time, it will undergo a slow and permanent deformation called creep. This property is considered in designing internal combustion engines, boilers and turbines.

12. Fatigue. +hen a material is subected to repeated stresses, it fails at stresses below the

yield point stresses. "uch type of failure of a material is #nown as fatigue. The failure iscaused by means of a progressive crac# formation which are usually fine and of

microscopic size. This property is considered in designing shafts, connecting rods,

springs, gears, etc.

13. ar!ness. t is a very important property of the metals and has a wide variety of

meanings.t embraces many different properties such as resistance to wear, scratching,

deformation and machinability etc. t also means the ability of a metal to cut another metal. The hardness is usually epressed in numbers which are dependent on the

method of ma#ing the test. The hardness of a metal may be determined by the following

tests:

a) 0rinell hardness test,

b) 'oc#well hardness test,

c) 2ic#ers hardness also called $iamond 3yramid/ test, and

!) "hore scleroscope.

C*e-ical Properties

Metals are usually inclined to form cations through electron loss, reacting with oygenin the air to form oides over various timescales iron rusts over years, while potassium burns

in seconds/. 4amples:

( Na 5 67 8 7 Na76 sodium oide/7 *a 5 67 8 7 *a6 calcium oide/

( !l 5 & 67 8 7 !l76& aluminum oide/.

The transition metals such as iron, copper , zinc, and nic#el/ are slower to oidize

because they form passivating layer of oide that protects the interior. 6thers, li#e palladium, platinum and gold, do not react with the atmosphere at all. "ome metals form a

barrier layer of oide on their surface which cannot be penetrated by further oygen moleculesand thus retain their shiny appearance and good conductivity for many decadesli#e aluminum, magnesium, some steels, and titanium/. The oides of metals are

generally basic, as opposed to those of nonmetals, which are acidic.

*hemical properties are any of the properties of matter that may only be observed and

measured by performing a chemical change or chemical reaction.

http://en.wikipedia.org/wiki/Cations


http://en.wikipedia.org/wiki/Oxide

http://en.wikipedia.org/wiki/Rust

http://en.wikipedia.org/wiki/Potassium

http://en.wikipedia.org/wiki/Transition_metal

http://en.wikipedia.org/wiki/Iron


http://en.wikipedia.org/wiki/Copper

http://en.wikipedia.org/wiki/Zinc

http://en.wikipedia.org/wiki/Nickel


http://en.wikipedia.org/wiki/Passivation_(chemistry)

http://en.wikipedia.org/wiki/Palladium


http://en.wikipedia.org/wiki/Platinum

http://en.wikipedia.org/wiki/Gold


http://en.wikipedia.org/wiki/Aluminium

http://en.wikipedia.org/wiki/Steel


http://en.wikipedia.org/wiki/Titanium



http://en.wikipedia.org/wiki/Base_(chemistry)

http://en.wikipedia.org/wiki/Acid



http://en.wikipedia.org/wiki/Rust

http://en.wikipedia.org/wiki/Potassium

http://en.wikipedia.org/wiki/Transition_metal


http://en.wikipedia.org/wiki/Copper

http://en.wikipedia.org/wiki/Zinc


http://en.wikipedia.org/wiki/Passivation_(chemistry)


http://en.wikipedia.org/wiki/Platinum

http://en.wikipedia.org/wiki/Gold


http://en.wikipedia.org/wiki/Aluminium


http://en.wikipedia.org/wiki/Titanium


http://en.wikipedia.org/wiki/Base_(chemistry)





A I S

I &

S A E

S p e

c i f

c a t i

o n

N u

m b

e r

A I S I & S A E S p e c i f c a t i o n N u m b e r





1. Reacti"ity# t refers to the rate at which a chemical substance tends to undergo

a chemical reaction in time

2. To$icity# t is the degree to which something is able to produce illness or damage to an

eposed organism.

3. Flammability# t is defined as how easily something will burn or ignite, causing fire or combustion.

4. %$i!ation# t is the interaction between oygen molecules and other substances.

5. Chemical Stability# Tendency of a material to resist change or decomposition due to

internal reaction, or due to the action of air, heat, light, pressure, etc.

6. Corrosion# t is the gradual destruction of material, usually metals, by chemicalreaction with its environment.

There are numerous 9standard materials specifications. The two most widely used arethe !merican "ociety of Testing Materials !"TM/, the "ociety of !utomotive 4ngineers

"!4/, and the !merican ron and "teel nstitute !"/. The !" and "!4 specification

numbers for steel are almost ali#e ecept that the !" uses prefies 0, *, $, and 4 to indicate

the method of manufacturing the carbon grades.

n general, the first two digits of the number represent a type of steel. !nd the last twodigits in four digit numbers invariably give the approimate or average carbon content in

9points or hundredths of per cent.

The first digit ;/, of this designation indicates the maor alloying element. The "!4-!" system then classifies all other alloy steels using the same four digit inde as follows:

1 < *arbon "teels= 5 - *hromium steels=



A I S I

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o

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l s

A I S I a n d S A E D e s i g n a t i o n o S t e e l s





2 - Nic#el steels= 6 - *hromium-vanadium steels=

3 - Nic#el-chromium steels= 7 - Tungsten-chromium steels=

4 - Molybdenum steels= 9 - "ilicon-manganese steels.

The second digit of the series indicates the concentration of the maor element in

percentiles ; e1uals ;>/. The last two digits of the series indicate the carbon concentration to?.?;>.

For 4ample, "!4 @;&? indicates a chromium steel alloy, containing ;> of chromium

and ?.&?> of carbon.

!dditional letters added between the second and third digits include 0 when boron is

added between ?.???@ and ?.??&>/ for enhanced hardenability, and A when lead is addedbetween ?.;@ and ?.&@>/ for enhanced machinability. The prefi M is used to designate

merchant 1uality steel the least restrictive 1uality descriptor for hot-rolled steel bars used innoncritical parts of structures and machinery/. The prefi 4 electric-furnace steel/ and the

suffi B hardenability re1uirements/ are mainly applicable to alloy steels

The "ociety of !utomotive 4ngineers "!4/ designates "!4 steel grades. These are

four digit numbers which represent chemical composition standards for steel specifications.The !merican ron and "teel nstitute !"/ originally started a very similar system. 6ver

time they used the same numbers to refer to the same alloy, but the !" system used a letter

prefi to denote the steelma#ing process. The prefi C!C denotes alloy basic open-heart. The prefi C0C denoted carbon acid 0essemer. The prefi C*C denoted open-hearth furnace, electric

arc furnace or basic oygen furnace. The prefi C$C denotes carbon acid open-heart while C4C

denoteselectric arcfurnacesteel.f the prefi is omitted, the steel is assumed to be open hearth. 4ample: !" *;?@?

indicates a plain carbon, basic-open hearth steel that has ?.@? > *arbon content./

!nother letter is the hardenability or B-value. 4ample: (&(?B/

SAE Designation Type

1xxx *arbon steels

2xxx Nic#el steels

3xxx Nic#el-chromium steels

4xxx Molybdenum steels

5xxx *hromium steels

Table. 1.2 Major Classification of Steels







6xxx *hromium-vanadium steels

7xxx Tungsten steels

8xxx Nic#el-chromium-vanadium steels

9xxx "ilicon-manganese steels

86XX

Triple !lloy steels which include Nic#el Ni/, *hromium

*r/, and Molybdenum Mo/.

These steels ehibit high strength and also high strength to

weight ratio, good corrosion resistance.

87XX

93XX

94XX97XX

98XX

From the figure above showing that the first digit indicates the type of steel. Then the

second one is the modification in alloys. Aastly, the two digits remainingDs show the carbon

content in percentage.3rior to ;EE@ the !" was also involved, and the standard was designated the

!"%"!4 steel grades. The !" stopped being involved because it never wrote any of thespecifications.

Table. 1.3 Classification of steel according to AISI standard

!" Types of "teel !lloy 4lements >

10 3lain *arbon ?.( Mn

11 Free machining ?. Mn, ?.;7 "

13 Bigh Manganese ;.G - ;.E? Mn

2 Nic#el "teels &.@ - @.? Ni

3 Nic#el *hromium ;.? - &.@ Ni, ?.@ -;.@ *r 40 Molybdenum ?.;@ - ?.& Mo

41 *hrome-Molybdenum ?.H? -;.; *r, ?.;@ - ?.7@ Mo

43 Nic#el - *hrome - Molybdenum ;.G@ - 7.? Ni, ?.( - ?.E *r, ?.7 - ?.& Mo

46 Nic#el - Molybdenum ;.G@ Ni, ;.G@ Mo

5 *hromium ?.( *r

61 *hromium - 2anadium ?.@ - ;.; *r, ?.; - ?.;@ 2a

81 Nic#el - *hrome - Molybdenum ?.7 - ?.( Ni, ?.& - ?.@@ *r, ?.?H - ?.;@ Mo

86 Nic#el - *hrome - Molybdenum ?.( - ?.G Ni, ?.( - ?.G *r, ?.;@ - ?.7@ Mo

92 "ilicon ;.H - 7.7 "i







AS!SAE Designation

N"#$e%

Type

&a%$on stee's

10xx 3lain *arbon Mn. ;.??> ma./

11xx 'esulfurized

12xx 'esulfurized and rephosphorized

15xx 3lain *arbon ma. Mn. range ;.??-

;.G@>/

(anganese stee's

13xx Mn ;.@

Ni)*e' stee's

23xx Ni &.@?

25xx Ni @.??

Ni)*e'!)+%o#i"# stee's

31xx Ni ;.7@= *r ?.G@, ?.H?

32xx Ni ;.@= *r ;.?

33xx Ni &.@?= *r ;.@?, ;.@

34xx Ni &.??= *r ?.(o'y$,en"# stee's

40xx Mo ?.7?, ?.7@

44xx Mo ?.(?, ?.@7

&+%o#i"#!#o'y$,en"# stee's

41xx *r ?.@?, ?.H?, ?.E@= Mo ?.;7, ?.7?, ?.7@,

?.&?

Ni)*e'!)+%o#i"#!#o'y$,en"# stee's

43xx Ni ;.H7= *r ?.@?, ?.H?= Mo ?.7@

43-xx Ni ;.H7= *r ?.@?= Mo ?.;7, ?.7@= 2 ?.?&

min.

47xx Ni ;.?@= *r ?.(@= Mo ?.7?, ?.&@

81xx Ni ?.&?= *r ?.(?= Mo ?.;7

86xx Ni ?.@@= *r ?.@?= Mo ?.7?

87xx Ni ?.@@= *r ?.@?= Mo ?.7@

88xx Ni ?.@@= *r ?.@?= Mo ?.&@

93xx Ni &.7@= *r ;.7?= Mo ?.;7

94xx Ni ?.(@= *r ?.(?= Mo ?.;7

Table. 1. Steel Alloy !esignation System







97xx Ni ;.??= *r ?.7?= Mo ?.7?

98xx Ni ;.??= *r ?.H?= Mo ?.7@

Ni)*e'!#o'y$,en"# stee's

46xx Ni ?.H@, ;.H7= Mo ?.7?, ?.7@

48xx Ni &.@?= Mo ?.7@

&+%o#i"# stee's

50xx *r ?.7, ?.(?, ?.@?, ?.G@

51xx *r ?.H?, ?.H, ?.E7, ?.E@, ;.??, ;.?@

50xxx *r ?.@?= * ;.?? min.

51xxx *r ;.?7= * ;.?? min.52xxx *r ;.(@= * ;.?? min.

&+%o#i"#!/ana,i"# stee's

61xx *r ?.G?, ?.H?, ?.E@= 2 ?.;?, ?.;@

T"ngsten!)+%o#i"# stee's

72xx + ;.@= *r ?.@

Si'i)on!#anganese stee's

92xx "i ;.(?, 7.??= Mn ?.G@, ?.H7, ?.H@= *r

?.??, ?.G@

ig+!st%engt+ 'o!a''oy stee's

9xx 2arious "!4 grades

-o%on stee's

xx-xx 0 denotes boron steels

ea,e, stee's

xxxx A denotes leaded steels

TE DES&TN

Carbon Steels

• The first digit is C;C as in ;?, ;;, and ;7.

• The second digit describes processing: C;C

is resulfurized and C7C is resulfurized

and rephosphorized.

• The first digit is C;C as in ;& and is, indeed, a

carbon steel. Bowever, since manganese is a

Table. 1." Type and !escription

http://www.kanabco.com/vms/glossary/r/resulfurizing.html


http://www.kanabco.com/vms/glossary/r/rephosphorize.html

http://www.kanabco.com/vms/glossary/m/manganeses.html


http://www.kanabco.com/vms/glossary/r/rephosphorize.html

http://www.kanabco.com/vms/glossary/m/manganeses.html







Manganese Steel normal by-product of carbon steel ma#ing the

!"%"!4 has decided not to classify it as an

alloy steel.

• The second digit is always C&C.

&ic'el Steel

• The first digit is C7C as in 7& and 7@.

• The second digit designates the percentage

of nic#el in the steel.

&ic'el-Chromium Steel

• The first digit is C&C as in &;, &7, and &&,

• The second digit designates the percentage of

nic#el and chromium in the steel.

Molyb!enum Steels

• The first digit is C(C as in (? and ((.


of molybdenum in the steel.

Chromium Steel

• The first digit is C@C as in @; and @7.


chromium in the steel.Chromi#m$%anadi#m

Steel

• The first digit is CGC as in G;.


chromium and vanadium in the steel.

T#ngsten$Chromi#m

Steel

• The first digit is CC as in 7.


of tungsten and chromium.

Silicon$Manganese

Steel

• The first digit is CEC as in E7.


of silicon and manganese in the steel.

Triple (lloy Steels

• These steels contain three alloys.

• The first digit can be C(C, CHC, or CEC dependingon the predominate alloy.


the reaming two alloys.

!s shown, the !" % "!4 steel designation system gives information about thechemical composition of the steel alloy type and carbon content/. Bowever, in many cases,

http://www.kanabco.com/vms/glossary/n/nickle.html


http://www.kanabco.com/vms/glossary/c/chromium.html

http://www.kanabco.com/vms/glossary/m/molybedum.html


http://www.kanabco.com/vms/glossary/v/vanadium.html

http://www.kanabco.com/vms/glossary/t/tungsten.html


http://www.kanabco.com/vms/glossary/s/silicon.html



http://www.kanabco.com/vms/glossary/c/chromium.html


http://www.kanabco.com/vms/glossary/v/vanadium.html









this is not enough information for the purchasing company to procure the steel. The !"TM

specification of fabrication methodology will often be added to the material specificationsdemonstrated but fabrication methods will not be discussed here. t remains to be seen how the

IN" will designate manufacturing specifications.

Following are two eamples of IN" designators and how they relate to !"4%"!4designations:

1. 'esulfurized carbon steel containing ?.7;> carbon would be IN" J;;7;? or

!"%!"4 ;;7;.

2. "teel alloyed with 7?> chromium and vanadium and containing ?.@> carbon would

be IN" JG7@? or !"%"!4 G7@.

Ta$'e 1.6!1Stain'essStee' Designation

SAE

,esignation

NS

,esignatio

&

%Ni & (n Si S N t+e%

A"steniti)

201"7?;?? ;G<

&.@<

@.@ ?.;@ @.@< ?.@ ?.?G ?.?& ?.7@ !202 "7?7?? ;< (<G ?.;@ .@< ?.@ ?.?G ?.?& ?.7@ -

205"7?@??

;G.@

< ;<

?.;7

< ;(< ?.@ ?.?G ?.?&

?.&7<

?.(? !

254 8

"&;7@( 7? ;H?.?7ma - - - - ?.7?

6 (o; 0.75

&";

<S"pe%

a"steniti)<;A''

/a'"es no#ina'

301 "&?;?? ;G< G<H ?.;@ 7 ?.@ ?.?( ?.?& - -

302 "&?7?? ;< H<;? ?.;@ 7 ?.@ ?.?( ?.?& ?.; -

302- "&?7;@ ;< H<;? ?.;@ 7 7.?<&.? ?.?( ?.?& - -

303 "&?&??;<

;E

H<;? ?.;@ 7 ; ?.7?.;@

min

-(o 0.60

=optiona'>303Se "&?&7& ;< H<;? ?.;@ 7 ; ?.7 ?.?G - 0.15

304 "&?(??;H<

7?

H<

;?.@??.?H 7 ?.@

?.?(

@?.?& ?.; -

304 "&?(?& ;H< H<;7 ?.?& 7 ?.@ ?.?( ?.?& ?.; -

304&" "&?(&? ;< H<;? ?.?H 7 ?.@ ?.?( ?.?& - &<( *u

304N "&?(@;;H<

7?

H<

;?.@??.?H 7 ?.@

?.?(

@?.?&

?.;?

< -

305 "&?@?? ;<

;E

;?.@?

<

?.;7 7 ?.@ ?.?(

@

?.?& - -

Table. 1.& Stainless Steel !esignation

http://en.wikipedia.org/wiki/SAE_steel_grades#cite_note-ni-7









308 "&?H?? ;E< ;?<;7 ?.?H 7 ; ?.?( ?.?& - -

309 "&?E?? 77< ;7<;@ ?.7 7 ; ?.?( ?.?& - -

309S "&?E?H 77< ;7<;@ ?.?H 7 ; ?.?( ?.?& - -

310 "&;??? 7(< ;E<77 ?.7@ 7 ;.@ ?.?( ?.?& - -

310S "&;??H 7(< ;E<77 ?.?H 7 ;.@ ?.?( ?.?& - -

314 "&;(?? 7&< ;E<77 ?.7@ 7 ;.@<&.? ?.?( ?.?& - -

316 "&;G?? ;G< ;?<;( ?.?H 7 ?.@ ?.?( ?.?& ?.;? 2.0?3.0

316 "&;G?& ;G< ;?<;( ?.?& 7 ?.@ ?.?( ?.?& ?.;? 2.0?3.0

316@ "&;G7?;G< ;H

;?<;( ?.?H 7 ; ?.7?.;?min

-1.75?2.50

(o

316N "&;G@;;G<

;H;?<;( ?.?H 7 ?.@

?.?(

@?.?&

?.;?

<

2.0?3.0

(o

317 "&;??;H<

7?;;<;@ ?.?H 7 ?.@

?.?(

@?.?&

?.;?

Ma

3.0?4.0

(o

317 "&;?&;H<

7?;;<;@ ?.?& 7 ?.@

?.?(

@?.?&

?.;?

Ma

3.0?4.0

(o

321 "&7;??;<

;EE<;7 ?.?H 7 ?.@

?.?(

@?.?&

?.;?

Ma

Ti 5=&N>

#inB

329 "&7E?? 7&< 7.@<@ ?.?H 7 ?.@ ?.?( ?.?& - 1?2 (o

330 N?H&&? ;< &(<& ?.?H 7 ?.@< ?.?( ?.?& - -

347 "&(??;<

;EE<;& ?.?H 7 ?.@

?.?(

@

?.?&

?-

N$ TaB

10 x&

348 "&(H?? ;< ;E

E<;& ?.?H 7 ?.@ ?.?(@

?.?&?

-

N$ TaB

10 x&

#inB1

#axB $"t0.10 Ta

#ax;

0.20 &a

384 "&H(?? ;@< ;<;E ?.?H 7 ; ?.?( ?.?& - -

SAE

,esignatio

NS

,esignatio&

%

N

i& (n Si S N t+e%

@e%%iti)

405 "(?@??;;.@ <

- ?.?H ; ; ?.?( ?.?& -0.1?0.3

A'B0.60

409 "(?E??;?.@ <

?.?@ ?.?H ; ;?.?(

@?.?& -

Ti 6 x&B $"t

0.75#ax

429 "(7E?? ;(< ?.@ ?.;7 ; ; ?.?( ?.?& - -

430 "(&??? ;G< ?.@ ?.;7 ; ; ?.?( ?.?& - -

430@ "(&?7?;G<

;H- ?.;7 ;.7@ ; ?.?G

?.;@

min-

0.60 (o

=optiona'>

430@Se "(&?7& ;G< - ?.;7 ;.7@ ; ?.?G ?.?G - 0.15 Se#in

434 "(&(?? ;G< - ?.;7 ; ; ?.?( ?.?& - 0.75?1.25

436 "(&G?? ;G< ;H

- ?.;7 ; ; ?.?( ?.?& -

0.75?1.25

(o;

N$Ta 5

x&







442 "((7?? ;H< - ?.7 ; ; ?.?( ?.?& - -

446 "((G?? 7&< ?.7@ ?.7 ;.@ ; ?.?( ?.?& - -

SAE

,esignatio

NS

,esignatio&% Ni & (n Si S N t+e%

(a%tensiti)

403 "(?&??;;.@< ;&.?

?.G? ?.;@ ; ?.@ ?.?( ?.?& - !

410 "(;???;;.@< ;&.@

?.@ ?.;@ ; ; ?.?( ?.?& - !

414 "(;(??;;.@<

;&.@

;.7@<

7.@??.;@ ; ; ?.?( ?.?& - !

416 "(;G?? ;7<;( - ?.;@ ;.7@ ; ?.?G?.;@min

-0.060 (o

=optiona'>

416Se "(;G7& ;7<;( - ?.;@ ;.7@ ; ?.?G ?.?G - 0.15 Se#in

420 "(7??? ;7<;( -?.;@

min; ; ?.?( ?.?& - -

420@ "(7?7? ;7<;( -?.;@

min;.7@ ; ?.?G

?.;@

min-

0.60 (o

#ax

=optiona'>

422 "(77??

;;.?<

;7.@

?.@?<

;.?

?.7?<

?.7@ ?.@<;.? ?.@ ?.?7@?.?7

@-

0.90?1.25

(o;

0.20?0.30 ;

0.90?1.25C

431 "(;G7& ;@<;;.7@<

7.@??.7 ; ; ?.?( ?.?& - -

440A "((??7 ;G<;H -?.G?< ?.@

; ; ?.?( ?.?& - 0.75 (o

440- "((??& ;G<;H -?.@< ?.E@

; ; ?.?( ?.?& - 0.75 (o

440& "((??( ;G<;H -0.95?

1.20; ; ?.?( ?.?& - 0.75 (o

SAE

,esignatio

NS

,esignatio

&

%

Ni & (n Si S N t+e%

eat %esisting

501 "@?;?? (<G - ?.;?

min

; ; ?.?( ?.?& - 0.40?0.65

(o

502 "@?7?? (<G - ?.; ; ; ?.?( ?.?& - 0.40?0.65

D"p'ex

22058 "&;H?&

"&77?@

77 @ ?.?&

ma

- - - - ?.;@ 3 (o; A''

a'"es

2304 "&7&?( 7& ( ?.?&ma

- ;.??ma

?.?(ma

?.?(ma

?.;@ 0.10!0.60

(o

S"pe% ,"p'ex





S y s t e m

S p e c i f c a t i o

n N u m b e r

o r S t e e l

( A I S I a n d

S A E )

S y s t e m S p e c i f c a t i o n N u m b e r o r S t e e l ( A I S I a n d S A E )





25078 "&7@? 7@ ?.?&

ma

- - - - ?.7H 4 (o; A''

a'"es

no#ina'

(a%tensiti) p%e)ipitation +a%,ening

630 ";(??;@-

;&-@ ?.? ; ; ?.?( ?.?& -

&" 3!5B

Ta9

!

! number system or series to identify carbon and alloy steel had been developed by "ociety of

!utomotive 4ngineers "!4/ and !merican ron and "teel ndustry !"/. "teel are names based on

their alloying elements and carbon content.The first 7 numbers refer to the alloying elements present in that steel. First number tells the

#ind of steel and the second number shows the approimate percent of alloy elements.

The last 7 numbers shows the carbon content in points ;?? points e1ual ; percent/.

Stee' N"#$e% ange o N"#$e%

a/ *arbon steel*arbon steel "!4-!" ;KKK

3lain *arbon ;?KK

Free machining resulphurized/ ;;KK

'esulphrized, rephosporised ;7KK

b/ !lloy "teel

Manganese ;&KK

Molybdenum (KKK

*-Mo?.7@> Mo/ (?KK

*'-Mo?.?> *r, ?.;@> Mo/ (;KK Ni-*r-Mo;.H> Ni, ?.G@> *'/ (&KK

Ni-Mo;.@> Ni/ (GKK

Ni-*r?.(@> Ni, ?.7> Mo/ (KK

Ni-Mo&.@> Ni, ?.7@> Mo/ (HKK

*hromium @KKK

Table. 1.' Steels and Their (especti)e *#mbers


http://en.wikipedia.org/wiki/SAE_steel_grades#cite_note-8


http://en.wikipedia.org/wiki/SAE_steel_grades#cite_note-8



U

s

es

of

a

l lo

y

st

ee

ls

U s e s o f a l l o y s t e e l s





?.@> *r @?KK

;.?> *r @;KK @;7?-@;@7

;.@> *r @7KK @7?E@-@7;??

*orrosion-heat resistant @;(KK !" (?? "eries/

*hromium-2anadium GKKK

;> *r, 6.;7> 2 G;KK G;7?-G;@7

"ilicon Manganese

?.H@> Mn, 7> "i E7KK E7@@-E7G7

Triple-alloy "teels

?.@@> Ni, ?.@?> *r, ?.7?> Mo, HGKK HG;@-HGG?

?.@@> Ni, ?.@?> *r, ?.7@> Mo HKK H7?-H@?

&.7@> Ni, ;.7> *r, ?.;7> Mo E&KK E&;?-E&;

?.(@> Ni, ?.(> *r, ?.;7> Mo E(KK E(&-E((@

?.(@> Ni, ?.;@> *r, ?.7> Mo EKK E(-EG&

;.?? > Ni, ?.H> *r, ?.7@> Mo EHKK EH(?-EH@?

0oron L?.?@> Mn/ KK0KK

(S Designation (pplication

(S *++, +olts, st#ds, t#bing s#bjected to torsional stress

(S *+,-#enched and tempered shafting connecting rods, )ery highly

stresses bolts, forgings

(S *+., igh capacity gears, shafts, hea)y d#ctile machine parts

(S +/+, Shafts, bolts, steering /n#c/les

(S +/, Air craft and tr#c/$engine cran/$shafts, a0els, earth mo)ing

e#ipment

(S +/.,ear$resisting parts in e0ca)ating and farm machinery, gears,

forgings

(S +*, Shafts, highly stressed pins and /eys, gears

(S ++,, series or hea)y parts re#iring deep penetrating of the heat treatment

Table. 1.4 5ses of Alloy Steels



N

o

n

%

f

e

r

r

o

u

s

M

e

t

a

l

s

N o n % f e r r o u s M e t a l s





and high fatig#e strength per #nit 6eight (S ,0+ 7eaf and coil springs

(S /+,1 /, A#tomobile connecting rods and a0els, air craft parts and t#bing

(S +, Cran/shafts, a0els, gears, landing gear parts

(S 0,8ears, splined shafts, hand tools miscellaneo#s hea)y d#ty

machine parts

(S 20+, Connecting rods, bolts shapes, air hardens after 6elding

(S 20,1 23, 8ears, propeller$shafts, /n#c/les shapes

"teel ehibits different colors depending on temperature. Temperatures above H??F

(7*/ produce incandescent colors= the atoms in the steel are so energized by heat that theygive off photons. Temperatures below H??F (7*/ produce oidation colors. !s the steel is

heated, an oide layer forms on the surface= its thic#ness and thus the interference color as

light is reflected/ is a function of temperature. These colors may be used in tempering tool

steel.

7???F 0right yellow

;?E&

* ;???F 2ery slight red, mostly grey @&H*

;E??F $ar# yellow;?&H

* H??F $ar# grey (7*

;H??F 6range yellow EH7* @@F 0lue &?7*

;??F 6range E7* @(?F $ar# 3urple 7H7*

;G??F 6range red H;* @7?F 3urple 7;*

;@??F 0right red H;G* @??F 0rown%3urple 7G?*

;(??F 'ed G?* (H?F 0rown 7(E*

;&??F Medium red ?(* (G@F $ar# "traw 7(;*

;7??F $ull red G(E* ((@F Aight "traw 77E*

;;??F "light red @E&* &E?F Faint "traw ;EE*

*ote9 (emember that, at the critical temperat#re, 6hen the phase change to a#stenite begins,

the steel 6ill become non$magnetic.

Table. 1.: Tool Steel Color )s. Temperat#re



C l a s s

i f c a t

i o n

o

N o n %

F e r r

o u s

M e t a

l s

C l a s s i f c a t i o n o N o n % F e r r o u s M e t a l s





+e have already discussed that the non-ferrous metals are those which contain a metal

other than iron as their chief constituent. The non-ferrous metals are usually employed inindustry due to the following characteristics:

4ase of fabrication casting, rolling, forging, welding and machining/,

'esistance to corrosion,

4lectrical and thermal conductivity, and

+eight.

The various non-ferrous metals used in engineering practice are aluminum, copper,

lead, tin, zinc, nic#el, etc. and their alloys. +e shall now discuss these non-ferrous metals andtheir alloys in detail, in the following pages.

'. lu-inu-t is white metal produced by electrical processes from its oide alumina/, which is

prepared from a clayey mineral called bau$ite. t is a light metal having specific gravity 7.

and melting point G@H*. The tensile strength of the metal varies from E? M3a to ;@? M3a.n its pure state, the metal would be wea# and soft for most purposes, but when mied with

small amounts of other alloys, it becomes hard and rigid. "o, it may be blan#ed, formed,

drawn, turned, cast, forged and die cast. ts good electrical conductivity is an important property and is widely used for overhead cables.

lu-inu- llo,sThe aluminum may be alloyed with one or more other elements li#e copper,

magnesium, manganese, silicon and nic#el. The addition of small 1uantities of alloyingelements converts the soft and wea# metal into hard and strong metal, while still retaining its

light weight. The main aluminum alloys are discussed below:

a) Duralumin. t is an important and interesting wrought alloy. ts composition is as

follows:

*opper &.@ < (.@>= Manganese ?.( < ?.>= Magnesium ?.( < ?.>, and the

remainder is aluminum.This alloy possesses maimum tensile strength up to (?? M3a/ after heat

treatment and age hardening. !fter wor#ing, if the metal is allowed to age for & or (

days, it will be hardened. This phenomenon is #nown as age har!ening .







b) 4-alloy. t is also called copper-aluminum alloy. The addition of copper to purealuminum increases its strength and machinability. The composition of this alloy is as

follows:

*opper &.@ < (.@>= Manganese ;.7 < ;.>= Nic#el ;.H < 7.&>= "ilicon,Magnesium, ron ?.G> each= and the remainder is aluminum.

This alloy is heat treated and age hardened li#e duralumin. The ageing process

is carried out at room temperature for about five days.

c) Magnalium. t is made by melting the aluminum with 7 to ;?> magnesium in avacuum and then cooling it in a vacuum or under a pressure of ;?? to 7?? atmospheres.

t also contains about ;.@> copper. $ue to its light weight and good mechanical properties, it is mainly used for aircraft and automobile components.

!) in!alium. t is an alloy of aluminum and magnesium with a small 1uantity of chromium. t is the trade name of aluminum alloy produced by Bindustan !luminum

*orporation Atd, 'enu#oot I.3./. t is produced as a rolled product in ;G gauges,

mainly for anodized utensil manufacture.

&. Copper

t is one of the most widely used non-ferrous metals in industry. t is a soft, malleable andductile material with a reddish-brown appearance. ts specific gravity is H.E and melting point

is ;?H&*. The tensile strength varies from ;@? M3a to (?? M3a under different conditions. tis a good conductor of electricity. t is largely used in ma#ing electric cables and wires for

electric machinery and appliances, in electrotyping and electroplating, in ma#ing coins and

household utensils.

t may be cast, forged, rolled and drawn into wires. t is non-corrosive under ordinaryconditions and resists weather very effectively. *opper in the form of tubes is used widely in

mechanical engineering. t is also used for ma#ing ammunitions. t is used for ma#ing useful

alloys with tin, zinc, nic#el and aluminum.

Copper llo,sThe copper alloys are broadly classified into the following two groups:

Copper-5inc alloys = Brass>. The most widely used copper-zinc alloy is brass. There are various

types of brasses, depending upon the proportions of copper and zinc. This is fundamentally a binary alloy of copper with zinc each @?>. 0y adding small 1uantities of other elements, the

properties of brass may be greatly changed.







For eample, the addition of lead ; to 7>/ improves the machining 1uality of brass. t has a

greater strength than that of copper, but has a lower thermal and electrical conductivity. 0rassesare very resistant to atmospheric corrosion and can be easily soldered.

Copper-tin alloys = Bron5e>. The alloys of copper and tin are usually termed as bronzes. The

useful range of composition is @ to E@> copper and @ to 7@> tin. The metal is comparativelyhard, resists surface wear and can be shaped or rolled into wires, rods and sheets very easily. n

corrosion resistant properties, bronzes are superior to brasses. "ome of the common types of

bronzes are as follow:

(luminum bron5e. t is an alloy of copper and aluminum. The aluminum bronze with G< H> aluminum has valuable cold wor#ing properties. The maimum tensile strength of this

alloy is (@? M3a with ;;> of aluminum. They are most suitable for ma#ing componentseposed to severe corrosion conditions. +hen iron is added to these bronzes, the

mechanical properties are improved by refining the grain size and improving the ductility.

/. Magnesiu- llo,sMagnesium alloys are approimately two-thirds as heavy as aluminum alloys. The common

alloys contain from ( to ;7 per cent of aluminum and from ?.; to ?.& per cent of manganese=those with more than G per cent of aluminum can be heat-treated and aged to increase the yield

strength. The alloys are resistant to atmospheric corrosion if #ept dry, but when humidity is

high, corrosion proceeds slowly with a powder forming on the surface.

0. Lea1t is a bluish grey metal having specific gravity ;;.&G and melting point &7G*. t is so

soft that it can be cut with a #nife. t has no tenacity. t is etensively used for ma#ing solders,as a lining for acid tan#s, cisterns, water pipes, and as coating for electrical cables.

The lead base alloys are employed where a cheap and corrosion resistant material is

re1uired. !n alloy containing H&> lead, ;@> antimony, ;.@> tin and ?.@> copper is used for large bearings subected to light service.

2. Tin

t is brightly shining white metal. t is soft, malleable and ductile. t can be rolled intovery thin sheets. t is used for ma#ing important alloys, fine solder, as a protective coating for

iron and steel sheets and for ma#ing tin foil used as moisture proof pac#ing.

! tin base alloy containing HH> tin, H> antimony and (> copper is called babbit

metal . t is a soft material with a low coefficient of friction and has little strength. t is the most

common bearing metal used with cast iron boes where the bearings are subected to high

pressure and load.







Note: Those alloys in which lead and tin are predominating are designated as 6hite metal

bearing alloys. This alloy is used for lining bearings subected to high speeds li#e the bearingsof aero-engines.

3. 4inc Base llo,sThe most of the die castings are produced from zinc base alloys. These alloys can be

casted easily with a good finish at fairly low temperatures. They have also considerablestrength and are low in cost. The usual alloying elements for zinc are aluminum, copper and

magnesium and they are all held in close limits.

The compositions of two standard die casting zinc alloys are as follows:

!luminum (.;>, copper ?.;>, magnesium ?.?(> and the remainder is zinc.

!luminum (.;>, copper ;>, magnesium ?.?(> and the remainder is zinc.

!luminum improves the mechanical properties and also reduces the tendency of zinc todissolve iron. *opper increases the tensile strength, hardness and ductility. Magnesium has the

beneficial effect of ma#ing the castings permanently stable. These alloys are widely used in the

automotive industry and for other high production mar#ets such as washing machines, oil

burners, refrigerators, radios, photographs, television, business machines, etc.

5. Titaniu-There are three structural types of titanium alloys:

a) (lpha (lloys are non-heat treatable and are generally very weld-able. They havelow to medium strength, good notch toughness, reasonably good ductility and

possess ecellent mechanical properties at cryogenic temperatures. The more highly

alloyed alpha and near-alpha alloys offer optimum high temperature creep strengthand oidation resistance as well.

b) (lpha-Beta (lloys are heat treatable and most are weldable. Their strength levelsare medium to high. Their hot-forming 1ualities are good, but the high temperature

creep strength is not as good as in most alpha alloys.

c) Beta or near-beta alloys are readily heat treatable, generally weldable, capable of high strengths and good creep resistance to intermediate temperatures. 4cellentformability can be epected of the beta alloys in the solution treated condition.

0eta-type alloys have good combinations of properties in sheet, heavy sections,

fasteners and spring applications.







8 !obalt"!#romium"$ungsten"%olybdenum ear"'esistant AlloysThese alloys feature a wear resistance which ma#es them ideal for metal-cutting

operations. Their ability to retain hardness even at red-heat temperatures also ma#es them

especially useful for cutting tools.

recious %etalsThese include silver, gold, platinum, palladium, iridium, osmium, rhodium, and

ruthenium, and their alloys. These alloys are produced under technical and legal re1uirements.

Jold alloys used for ewelry are described in #arats. The #arat is the content of gold epressedin twenty-fourths. !n ;H-#arat gold alloy would contain ;H%7( gold @ percent by weight/.

6ther than ewelry, there are many industrial uses for precious metals.

*+$rue ,rassTrue 0rass sin#s or protects bench tops where a large amount of acid is used. Aead-

lined pipes are used in systems that carry. This is an alloy of copper and zinc. !dditional

corrosive chemicals, fre1uently, lead are used in alloyed elements, such as aluminum, lead, tin,iron, manganese, form to increase its low-tensile strength. !lloyed with or phosphorus, are

added to give the alloy specific tin, lead produces a soft solder. +hen added to metal

properties. Naval rolled brass Tobin bronze/ contains alloys, lead improves their

machinability. !bout G?> copper, &E> zinc, and ?.@> tin. This brass is highly corrosion-resistant and is practically impurity free. &ATN: 0rass sheets and strips are available in

several grades: soft, ;%( hard, ;%7 hard, full hard, and spring. +hen wor#ing with lead, you

must ta#e grades. Bardness is created by the process of cold roll-proper precautions becausethe dust, fumes, or ring. !ll grades of brass can be softened by annealing at vapors from it are

highly poisonous. ! temperature of @@?F to G??F then allowing it to cool by itself without

1uenching. 6verheating can destroy the zinc in the alloy.

**,ron-e0rass is a combination of H(> copper and ;G> tin and was the best metal available

before steel-ma#ing techni1ues were developed. Many comple bronze alloys, containing suchelements as zinc, lead, iron, aluminum, silicon, and phosphorus, are now available. Today, the







name bronze is applied to any copper-based alloy that loo#s li#e bronze. n many cases, there is

no real distinction between the composition of bronze and that of brass.

*.!opper"Nic/el Alloys Nic#el is used in these alloys to ma#e them strong, tough, and resistant to wear and

corrosion. 0ecause of their high resistance to corrosion, copper nic#el alloys, containing ?>

copper and &?> nic#el or E?> copper and ;?> nic#el, are used for saltwater piping systems."mall storage tan#s and hot-water reservoirs are con. Oou often see zinc used on iron or steel in

the form of a protective coating called galvanizing. Pinc is also used in soldering flues, die

castings, and as an alloy in ma#ing brass and bronze.

'/.Non%-etallic MaterialsThe non-metallic materials are used in engineering practice due to their low density,

low cost, fleibility, resistant to heat and electricity. Though there are many non-metallic

materials, yet the following are important from the subect point of view.

Plastics. The plastics are synthetic materials which are molded into shape under pressure with

or without the application of heat. These can also be cast, rolled, etruded, laminated andmachined. Following are the two types of plastics:

a) Thermosetting plastics, and

b) Thermoplastic.The thermosetting plastics are those which are formed into shape under heat and

pressure and results in a permanently hard product. The heat first softens the material, but as

additional heat and pressure is applied, it becomes hard by a chemical change #nown as

phenolformaldehyde 0a#elite/, phenol-furfural $urite/, ureaformaldehyde 3las#on/, etc.The thermoplastic materials do not become hard with the application of heat and

pressure and no chemical change occurs. They remain soft at elevated temperatures until they

are hardened by cooling. These can be remelted repeatedly by successive application of heat."ome of the common thermoplastics are cellulose nitrate *elluloid/, polythene, polyvinyl

acetate, polyvinyl chloride 3.2.*./, etc.

The plastics are etremely resistant to corrosion and have a high dimensional stability.

They are mostly used in the manufacture of aeroplane and automobile parts. They are also usedfor ma#ing safety glasses, laminated gears, pulleys, self-lubricating bearing, etc. due to their

resilience and strength.

Rubber . t is one of the most important natural plastics. t resists abrasion, heat, strong al#alis

and fairly strong acids. "oft rubber is used for electrical insulations. t is also used for power



A A

D e s i g

n a t i o no

A l u m i

n u m

a n d

i t s A l l o y s

A A D e s i g n a t i o n o A l u m i n u m a n d i t s A l l o y s





transmission belting, being applied to woven cotton or cotton cords as a base. The hard rubber

is used for piping and as lining for pic#ling tan#s.

a) &atural an! Synthetic Rubber

(a6, or cr#de, r#bber is obtained by the coagulation of the late or mil#y fluid

obtained by tapping certain tropical trees and shrubs. 'aw rubber is used in the pure state for rubber cements, surgical tape, and similar purposes. Most rubber is vulcanized by adding sulfur

and heating. Bard rubber is used for electric insulation, switch handles, bearings, etc. "emi

hard rubbers are used for rubber belting, fleible tubing, hose, springs, vibration controls, and

many other devices.

b) Synthetic Rubber *eoprene and the +#na rubbers are the synthetics most li#e natural rubber. The cost of

the synthetics has limited their use, ecept when compounded for particular properties such asresistance to oils, heat, cold, and oidation. The properties of a few of the hundreds of

compounded synthetic rubbers are given in Table 7-;G. "ome synthetics, li#e Thio#ol, are

thermoplastic, whereas others, li#e Neoprene and the 0una rubbers, are thermosetting. 0othtypes can be compounded for use in molded products.

!"TM has established a system of employing letters to designate the more commonly

used rubbers. "0' is a styrene- butadiene rubber, formerly #nown as J'-" or 0una ". N0' refers to nitrile-butadiene rubber often called J'-N or 0una N. *hlorophene rubber,

commonly called neoprene or J'-!, designated by *'.

Ceramics# Materials having a high percentage of alumina !l767/ or steatite Mg6"i67/ are#nown as ceramics, particularly if they have been fired. They have high thermal and electricresistivity, good chemical resistance, and relatively high hardness and strength, and can be used

at temperatures much higher than the average metals. They find application in electrical

insulators, bearings, valve seats, pistons, chemical containers, and internal-combustionturbines.

!luminum casting alloys are listed in many specifications of various standardizing

agencies. These include Federal "pecifications, Military "pecifications, !"TM "pecificationsand "!4 "pecifications, to mention some. The numbering systems used by each differ and are

not always correctable. *asting alloys are available from producers who use a numbering

system is the one used in the table of aluminum casting alloys which are given further alongthis section.







! system of four < digit numerical designation for wrought aluminum and wrought

aluminum alloys are adopted by the !luminum !ssociation in ;E@(. This system is used by thecommercial producers and is similar to the one used by the "!4= the differences being the

addition of two prefi letters.

roug#t Alloys+rought alloys fall into two distinct categories:

a) Those which derive their properties from wor# hardening.

b) Those which depend upon solution heat treatment and age hardening.

+e shall first consider the (-digit wrought aluminum alloy identification system.

A''oy Se%ies %in)ipa' A''oying E'e#ent

1000 EE.???> Minimum !luminum

2000 *opper

3000 Manganese

000 "ilicon

"000 Magnesium

&000 Magnesium and "ilicon

'000 Pinc

4000 6ther 4lements

:000 Inused "eries

&%TE7

The first digit QD/ indicates the principal alloying element, which has been added

to the aluminum alloy and is often used to describe the aluminum alloy series. ;0ample91<<< series, 2<<< series, 3<<< series #p to 4<<< series.

The second single digit DD/, if different from ?, indicates a modification of the

specific alloy, and the third and fourth digits DD/ are arbitrary numbers given to identify aspecific alloy in the series. ;0ample9 In alloy "143, the n#mber " indicates that it is of the

Table. 1.1< ro#ght Al#min#m Alloy !esignation System







magnesi#m alloy series, the 1 indicates that it is the 1 st modification to the original alloy "<43

and the 43 identifies it in the "000 series.=The only eception to this alloy numbering system is with the ; series aluminum

alloys pure aluminums/ in which case, the last 7 digits provide the minimum aluminum

percentage above EE>. >;0ample9 Alloy 13"< >::."<? minim#m al#min#m=.=

!ast alloys

The cast alloy designation system is based on a &-digit plus decimal designation

./. ;0ample9 3"&.<=

A''oy Se%ies %in)ipa' A''oying E'e#ent

100.0 EE.???> minimum !luminum

200.0 *opper

300.0 "ilicon 3lus *opper and%or Magnesium

00.0 "ilicon

"00.0 Magnesium

&00.0 Inused "eries

'00.0 Pinc

400.0 Tin

:00.0 6ther 4lements

&%TE7

The first digit QD./ indicates the principal alloying element, which has been added

to the aluminum alloy.

Table. 1.11 Cast Al#min#m Alloy !esignation System







The second and third digits DD./ are arbitrary numbers given to identify a specific

alloy in the series. The number following the decimal point .DD/ indicates whether thealloy is a casting .?/ or an ingot .; or .7/. ! capital letter prefi indicates a modification to a

specific alloy.

Aluminum Alloys and $#eir !#aracteristics

f we consider the seven series of wrought aluminum alloys, we will appreciate their

differences and understand their applications and characteristics.

• /$$$ Series (lloys < non-heat treatable < with ultimate tensile strength of ;? to 7 #si/ this

series is often referred to as the pure aluminum series because it is re1uired to have EE.?>

minimum aluminum.

• *$$$ Series (lloys < heat treatable< with ultimate tensile strength of 7 to G7 #si/ these are

aluminum % copper alloys copper additions ranging from ?. to G.H>/, and are high

strength, high performance alloys that are often used for aerospace and aircraft

applications.

• +$$$ Series (lloys < non-heat treatable < with ultimate tensile strength of ;G to (; #si/

These are the aluminum % manganese alloys manganese additions ranging from ?.?@ to

;.H>/ and are of moderate strength, have good corrosion resistance, good formability andare suited for use at elevated temperatures.

• $$$ Series (lloys < heat treatable and non-heat treatable < with ultimate tensile strength

of 7@ to @@ #si/ these are the aluminum % silicon alloys silicon additions ranging from ?.Gto 7;.@>/ and are the only series which contain both heat treatable and non-heat treatable

alloys. "ilicon, when added to aluminum, reduces its melting point and improves its

fluidity when molten.

• .$$$ Series (lloys < non-heat treatable < with ultimate tensile strength of ;H to @; #si/

These are the aluminum % magnesium alloys magnesium additions ranging from ?.7 to

G.7>/ and have the highest strength of the non-heat treatable alloys.

• 0888 Series (lloys < heat treatable < with ultimate tensile strength of ;H to @H #si/ These

are the aluminum % magnesium - silicon alloys magnesium and silicon additions of around

;.?>/ and are found widely throughout the welding fabrication industry, used

predominantly in the form of etrusions, and incorporated in many structural components.







• 3888 Series (lloys < heat treatable < with ultimate tensile strength of &7 to HH #si/ These

are the aluminum % zinc alloys zinc additions ranging from ?.H to ;7.?>/ and comprisesome of the highest strength aluminum alloys.

HR)NESS TESTIN$9hat is ar!ness:

Bardness is the property of a material that enables it to resist plastic deformation,usually by penetration. Bowever, the term hardness may also refer to resistance to bending,

scratching, abrasion or cutting.

Measurement of ar!ness7

Bardness is not an intrinsic material property dictated by precise definitions in terms of

fundamental units of mass, length and time. ! hardness property value is the result of a definedmeasurement procedure.

Bardness of materials has probably long been assessed by resistance to scratching or

cutting. !n eample would be material 0 scratches material *, but not material !. !lternatively,

material ! scratches material 0 slightly and scratches material * heavily. 'elative hardness of minerals can be assessed by reference to the Mohs "cale that ran#s the ability of materials to

resist scratching by another material. "imilar methods of relative hardness assessment are still

commonly used today. !n eample is the file test where a file tempered to a desired hardness is

rubbed on the test material surface. f the file slides without biting or mar#ing the surface, thetest material would be considered harder than the file. f the file bites or mar#s the surface, the

test material would be considered softer than the file.

The Brinell ar!ness Test

The 0rinell hardness test method consists of indenting the test material with a ;? mm

diameter hardened steel or carbide ball subected to a load of &??? #g. For softer materials theload can be reduced to ;@?? #g or @?? #g to avoid ecessive indentation. The full load is

normally applied for ;? to ;@ seconds in the case of iron and steel and for at least &? seconds in

the case of other metals. The diameter of the indentation left in the test material is measuredwith a low powered microscope. The 0rinell harness number is calculated by dividing the load

applied by the surface area of the indentation.

;ic'ers ar!ness Test

The 2ic#ers hardness test method consists of indenting the test material with a diamond

indenter, in the form of a right pyramid with a s1uare base and an angle of ;&G degrees betweenopposite faces subected to a load of ; to ;?? #gf. The full load is normally applied for ;? to ;@

seconds. The two diagonals of the indentation left in the surface of the material after removal of







I

)

E

N

T

I

F

I

C

T

I

O

N

I ) E N T I F I C T I O N

the load are measured using a microscope and their average calculated. The area of the sloping

surface of the indentation is calculated. The 2ic#ers hardness is the 1uotient obtained bydividing the #gf load by the s1uare mm area of indentation.

Microhar!ness Test

The term microhardness test usually refers to static indentations made with loads not

eceeding ; #gf. The indenter is either the 2ic#ers diamond pyramid or the Rnoop elongated

diamond pyramid. The procedure for testing is very similar to that of the standard 2ic#ers

hardness test, ecept that it is done on a microscopic scale with higher precision instruments.

<<<<<<<<</#! hard and wear-resistantmaterial that is used to wear, grind or cut

away other material. (brasi"e

<<<<<<<<<*#s a change in a metal by

which its structure recovers from anunstable or metal stable condition that has

been produced by 1uenching or cold

wor#ing. (ge ar!ening

<<<<<<<<<+#Metallic solid or li1uid formed

from an intimate combination of two or more elements. (lloy

<<<<<<<<<#! generic term used to denote

a heat treatment wherein the micro structure

and, conse1uently, the properties of a

material are altered. Fre1uently, refers toheat treatment whereby a cold-wor#ed

metal is softened by allowing it to

recrystallizes. (nnealing <<<<<<<<<..For semiconductors andinsulators, the energies that lie between the

valence and conduction bands. Ban! =ap

Energy

<<<<<<<<<0 .The energy re1uired to

separate two atoms that are chemically

bonded to each other. Bon!ing Energy

<<<<<<<<3 .! copper-rich copper-zinc alloy.

Brass

<<<<<<<<2.! metal oining techni1ue that

uses a molten filler metal alloy having amelting temperature greater than about (7@

*. Bra5ing







<<<<<<<<<>.Fracture that occur by rapid

crac# propagation and without appreciablemacroscopic deformation. Brittle Fracture.

<<<<<<<<</,.! copper-rich copper-tin

alloy. Bron5e.

<<<<<<<<<//.The charge-storage ability of

a capacitor, defined as the magnitude of

charge stored on either plate divided by the

applied voltage. Capacitance

<<<<<<<<</*.The process by which thesurface carbon concentration of a ferrous

alloy is increased by diffusion from thesurrounding environment. Carburi5ing

<<<<<<<<</+.! ferrous alloy with carbon

content between 7 and (.@ wt>. Cast ron

<<<<<<<<</.! substance that can be used

to build together aggregates of sand or stone

into a cohesive structure.May be a singlecompound or a miture.May be hydraulic

set, air set or chemical set. Cement

<<<<<<<<</.. ron carbide Fe&*/Cementite

<<<<<<<<</0 .norganic,nonmetallic

products for which the interatomic bonding

is predominantly ionic. Ceramic

<<<<<<<<</3 .! composite material

consisting of a combination of ceramic and

metallic materials. Cermet

<<<<<<<<</2.The plastic deformation of a

metal at a temperature below that at which

it recrystallizes. Col! 9or'ing

<<<<<<<<</>.! composite materialconsisting of aggregate particles bound

together in a solid body by cement.

Concrete

<<<<<<<<*,.The lowest-lying electron

energy band that is not completely filled

with electrons. Con!uction Ban!

<<<<<<<<*/.$eteriorative loss of a metal as

a result of dissolution environmentalreactions. Corrosion

<<<<<<<<**.! primary interatomic bond

that is formed by the sharing electrons between neighboring atoms. Co"alent

Bon!

<<<<<<<<*+.The state of a solid material

characterized by a periodic and repeating

three-dimensional arrays of atoms, ions, or molecules. Crystalline

<<<<<<<<<*.For polymers, the statewherein a periodic and repeating atomic

arrangement is achieved by molecular chain

alignment. Crystallinity

<<<<<<<<<*.. ! region within a crystalline

polymer in which all the molecular chains

are ordered and aligned. Crystallite

<<<<<<<<<*0 . For crystalline materials, the

manner in which atoms or ions are arrayed

in space. t is defined in terms of the unitcell geometry and the atom positions withinthe cell. Crystal Structure

<<<<<<<<<*3 .! wea# form of induced or

nonpermanent magnetism for which themagnetic susceptibility is negative.

Diamagnetism

<<<<<<<<<*2.!ny material that iselectrically insulating. Dielectric

<<<<<<<<<*>.Mass transport by atomic

motion. Diffusion

<<<<<<<<<+,#The intentional alloying of semiconducting materials with controlled

concentrations of donor or acceptor

impurities. Doping

<<<<<<<<<+/#! measure of a materialSs

ability to undergo appreciable plastic

deformation before fracture. Ductility







<<<<<<<<<+*#! polymeric material that

may eperience large and reversible elasticdeformations. Elastomer

<<<<<<<<<++#Technical ceramics for

structural applications. Engineering

Ceramics

<<<<<<<<<+.Failure, at relatively low

stress levels, of structures that are subected

to fluctuating and cyclic stresses. Fatigue

<<<<<<<<<+..3ermanent and largemagnetizations found in some metals e.g.,

Fe, Ni, and *o/, which result from the parallel alignments of neighboring magnetic

moments. Ferromagnetism

<<<<<<<<<+0 .!ny material that has beendrawn into a cylinder with a length-to-

diameter ratio greater than about ten. Fiber

<<<<<<<<<+3 .! high-temperature heattreatment that increases the density and

strength of a ceramic piece.

@@@@@@@@@34.Mechanical forming of ametal or alloy by heating and hammering.

Forging

<<<<<<<<+>.*ritical value of the stress

intensity factor for which crac# etensionsoccurs. Fracture toughness

<<<<<<<<,#!n inorganic product of fusion

which has cooled to a rigid conditionwithout crystallizing. =lass

<<<<<<<<</.The measure of some

materialsS resistance to deformation by

surface indentation or by abrasion.

ar!ness

<<<<<<<<<*#! nonmetallic material that

has filled valence band at ? R and a

relatively wide energy band gap.

nsulator?electrical)

<<<<<<<<<+.!n acronym for light

amplification by stimulated emission of

radiation. @aser

<<<<<<<<.The temperature at which asolid substance changes to a li1uid state.

Melting Point

<<<<<<<..The electropositive elements

and both edge and screw components.

Metal

<<<<<<<<<0 .The ratio of stress to strain

for a material under perfectly elastic

deformation. Mo!ulus of Elasticity.

<<<<<<<<<3#! solid material in the

primary ingredient of which is an organic

polymer of high molecular wight. Plastic <<<<<<<<<2#$eformation that is permanent or nonrecoverable after release

of the applied load. Plastic Deformation

<<<<<<<<<>#The stress re1uired to produce a very slight yet specified amount

of plastic strain. 4iel! Strength

<<<<<<<<<.,# The ratio of stress to strainwhen deformation is totally elastic.

4oungAs Mo!ulus



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Documents

Chapter 1. Engineering Materials