Hardness Experiment Report

8/9/2019 Hardness Experiment Report

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Kasırga,

Instructor: Prof. Dr. Ahmet ARAN

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HÜSEYİN KASIRGA

03004033GR!"P

#

$A%ERIA& %ES%ING &A#!RA%!RY REP!R%


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%A#&E !' (!N%EN%S

I. Intro)uct*on1. Hardness2. Hardness Methods

a. Brinell Hardness b. Rockwell Hardnessc. Vickers Hardness

II. E+,er*ment- Proce)ure1. Objectie2. !"a#ination

a. Brinell Hardness $esti. !%&i'#entsii. !"'eri#ent

b. Rockwell Hardness $est

i. !%&i'#entsii. !"'eri#entc. Vickers Hardness $est

i. !%&i'#entsii. !"'eri#ent

III. D-t- An-/s*s1. Brinell Hardness $est

a. (rinci'le ) *or#&la b. +esignation o Brinell Hardness -ber

2. Rockwell Hardness $est

a. (rinci'le ) *or#&la b. +esignation o Rockwell Hardness -ber . Vickers Hardness $est

a. (rinci'le ) *or#&la b. +esignation o Vickers Hardness -ber

I. Resuts1. Brinell Hardness $est Res&lts2. Rockwell Hardness $est Res&lts. Vickers Hardness $est Res&lts

. D*scuss*on

1. Brinell and Rockwell $ests2. /i#itation on $hickness. /i#itations or +istances. &race onditions3. 4ield tress ) Mean (ress&re5. 6dantages o Vickers $est to Brinell $est

I. (oncus*on

II. References

III. A,,en)*+

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I. IN%R!D"(%I!N

1. HARDNESS

i#'l7 stated, hardness is the resistance o a #aterial to 'er#anent indentation. 8tis i#'ortant to recogni9e that hardness is an e#'irical test and thereore hardness is not a#aterial 'ro'ert7. $his is beca&se there are seeral dierent hardness tests that will eachdeter#ine a dierent hardness al&e or the sa#e 'iece o #aterial. $hereore, hardness is test#ethod de'endent and eer7 test res&lt has to hae a label identi7ing the test #ethod &sed.

Hardness is, howeer, &sed e"tensiel7 to characteri9e #aterials and to deter#inei the7 are s&itable or their intended &se. 6ll o the hardness tests inole the &se o as'eciicall7 sha'ed indenter, signiicantl7 harder than the test sa#'le, that is 'ressed into thes&race o the sa#'le &sing a s'eciic orce. !ither the de'th or si9e o the indent is #eas&redto deter#ine a hardness al&e.

$he #ost co##on &ses or hardness tests is to eri7 the heat treat#ent o a 'art

and to deter#ine i a #aterial has the 'ro'erties necessar7 or its intended &se. !stablishing acorrelation between the hardness res&lt and the desired #aterial 'ro'ert7 allows this, #akinghardness tests er7 &se&l in ind&strial a''lications.

. HARDNESS $E%H!DS

$here are three general t7'es o hardness #eas&re#ents de'ending on the #anner in which the test is cond&cted. $hese are:

• scratch hardness•

indentation hardness, and• rebo&nd, or d7na#ic, hardness.

cratch hardness is o 'ri#ar7 interest to #ineralogists. ;ith this #eas&re o hardness, ario&s #inerals and other #aterials are rated on their abilit7 to scratch one another.cratch hardness is #eas&red according to the Mohs< scale. $his consists o 10 standard#inerals arranged in the order o their abilit7 lo be scratched. $he sotest #ineral in this scaleis talc =scratch hardness 1>, while dia#ond has a hardness o 10. $he Mohs< scale is not wells&ited or #etals since the interals are not widel7 s'aced in the high?hardness range. Mosthard #etals all in the Mohs< hardness range o to @.

8n d7na#ic?hardness #eas&re#ents the indenter is &s&all7 dro''ed onto the #etals&race, and the hardness is e"'ressed as the energ7 o i#'act. $he hore selerosco'e, whichis the co##onest e"a#'le o a d7na#ic?hardness tester, #eas&res the hardness in ter#s o the height o rebo&nd o the indenter.

Onl7 indentation hardness is o #ajor engineering interest or #etals. $here areie #ajor indentation hardness scales:

• Brinell ? HB

• Knoo' ? HK

• Rockwell ? HR

• hore ? H

• Vickers ? HV

Brinell, Rockwell, and Vickers test are the #ost co##on three #ethods a#ongthe#, and in this re'ort these #ethods will be e"'lained.

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-. #RINE&& HARDNESS

$he Brinell hardness test #ethod consists o indenting the test #aterial with a 10## dia#eter hardened steel or carbide ball s&bjected to a load o 000 kg. *or soter

#aterials the load can be red&ced to 1300 kg or 300 kg to aoid e"cessie indentation. $he&ll load is nor#all7 a''lied or 10 to 13 seconds in the case o iron and steel and or at least0 seconds in the case o other #etals. $he dia#eter o the indentation let in the test #aterialis #eas&red with a low 'owered #icrosco'e. $he Brinell hardness nber is calc&lated b7diiding the load a''lied b7 the s&race area o the indentation =ee *ig&re 8.1>.

$he dia#eter o the i#'ression is the aerage o two readings at right angles andthe &se o a Brinell hardness nber table can si#'li7 the deter#ination o the Brinellhardness. 6 well str&ct&red Brinell hardness nber reeals the test conditions, and looks likethis, A3 HB 10C300C0A which #eans that a Brinell Hardness o 3 was obtained &sing a10## dia#eter hardened steel with a 300 kilogra# load a''lied or a 'eriod o 0 seconds.On tests o e"tre#el7 hard #etals a t&ngsten carbide ball is s&bstit&ted or the steel ball.

o#'ared to the other hardness test #ethods, the Brinell ball #akes the dee'est and widestindentation, so the test aerages the hardness oer a wider a#o&nt o #aterial, which will#ore acc&ratel7 acco&nt or #&lti'le grain str&ct&res and an7 irreg&larities in the &nior#it7o the #aterial. $his #ethod is the best or achieing the b&lk or #acro?hardness o a#aterial, 'artic&larl7 those #aterials with heterogeneo&s str&ct&res.

Figure I.1 – Brinell Hardness Measurement

2. R!(KE&& HARDNESS

$he #ost widel7 &sed hardness test is the Rockwell hardness test. 8ts generalacce'tance is d&e to its s'eed, reedo# ro# 'ersonal error, abilit7 to disting&ish s#allhardness dierences in hardened steel, and the s#all si9e o the indentation, so that inishedheat?treated 'arts can be tested witho&t da#age.

$his test &tili9es the de'th o indentation, &nder constant load, as a #eas&re o hardness. 6 #inor load o 10 kg is irst a''lied to seat the s'eci#en. $his #ini#i9es thea#o&nt o s&race 're'aration needed and red&ces the tendenc7 or ridging or sinking in b7the indenter. $he #ajor load is then a''lied, and the de'th o indentation is a&to#aticall7recorded on a dial gage in ter#s o arbitrar7 hardness nbers. =ee *ig&re 8.2>

$he dial contains 100 diisions, each diision re'resenting a 'enetration o 0.0000@ in =0.002 ##>. $he dial is reersed so that a high hardness, which corres'onds to a

s#all 'enetration, res&lts in a high hardness nber. $his is in agree#ent with the other


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hardness nbers, b&t &nlike the Brinell and Vickers hardness designations, which hae &nitso kgC##DE the Rockwell hardness nbers are '&rel7 arbitrar7.

Figure I.2 – Principle of Rockwell Hardness Test

Major loads o 50, 100, and 130 kg are &sed. ince the Rockwell hardness isde'endent on the load and indenter, it is necessar7 to s'eci7 the co#bination which is &sed.

$his is done b7 'rei"ing the hardness, nber with a letter indicating the 'artic&lar co#bination o load and indenter or the hardness scale e#'lo7ed. 6 Rockwell hardnessnber witho&t the letter 'rei" is #eaningless. Hardened steel is tested on the scale withthe dia#ond indenter and a 130?kg #ajor load. $he &se&l range or this scale is ro# abo&tR 20 to R 0. oter #aterials are &s&all7 tested on the B scale with a 1C15?in?dia#eter steel ball and a 100?kg #ajor load. $he range o this scale is ro# RB 0 to RB 100. $he 6scale =dia#ond indenter, 50?kg #ajor load> 'roides the #ost e"tended Rockwell hardnessscale, which is &sable or #aterials ro# annealed brass to ce#ented carbides. Man7 other scales are aailable or s'ecial '&r'oses:

• HRA : e#ented carbides, thin steel and shallow case hardened steel• HR# : o''er allo7s, sot steels, alin allo7s, #alleable iron, etc.• HR( : teel, hard cast irons, 'earlitic #alleable iron, titani, dee' case hardened

steel and other #aterials harder than B 100• HRD : $hin steel and #edi case hardened steel and 'earlitic #alleable iron• HRE : ast iron, alin and #agnesi allo7s, bearing #etals• HR' : 6nnealed co''er allo7s, thin sot sheet #etals• HRG : (hos'hor bron9e, ber7lli co''er, #alleable irons• HRH : 6lin, 9inc, lead• HRK & $ P R S : Bearing #etals and other er7 sot or thin #aterials,

incl&ding 'lastics.

c. I(KERS HARDNESS

$he Vickers hardness test #ethod consists o indenting the test #aterial with as%&are?base dia#ond '7ra#id indenter with an angle o 15 degrees between o''osite acess&bjected to a load o 1 to 120 kg. =ee *ig&re 8.>. $he &ll load is nor#all7 a''lied or 10 to13 seconds. Beca&se o the sha'e o the indenter, this is re%&entl7 called the dia#ond?

'7ra#id hardness test. $he dia#ond?'7ra#id hardness nber =+(H>, or Vickers hardnessnber =VH-, or V(H>, is deined as the load diided b7 the s&race area o the indentation.

8n 'ractice, this area is calc&lated ro# #icrosco'ic #eas&re#ents o the lengths o thediagonals o the i#'ression. =*or#&las or calc&lations is gien in the +ata 6nal7sis section>


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$o 'eror# the Vickers test, the s'eci#en is 'laced on an anil that has a screwthreaded base. $he anil is t&rned raising it b7 the screw threads &ntil it is close to the 'oint o the indenter. ;ith start leer actiated, the load is slowl7 a''lied to the indenter. $he load isreleased and the anil with the s'eci#en is lowered. $he o'eration o a''l7ing and re#oingthe load is controlled a&to#aticall7. eeral loadings gie 'racticall7 identical hardness

nbers on &nior# #aterial, which is #&ch better than the arbitrar7 changing o scale withthe other hardness #achines.

$he adantages o the Vickers hardness test are that e"tre#el7 acc&rate readingscan be taken, and j&st one t7'e o indenter is &sed or all t7'es o #etals and s&racetreat#ents. 6ltho&gh thoro&ghl7 ada'table and er7 'recise or testing the sotest and hardesto #aterials, &nder ar7ing loads, the Vickers #achine is a loor standing &nit that is rather #ore e"'ensie than the Brinell or Rockwell #achines.

Figure I. – Indenter of t!e "ickers Hardness Test

II. E5PERI$EN%A& PR!(ED"RE

1. !#6E(%IE

$o e"a#ine the 'rinci'les, li#itations and signiicances o dierent indentationhardness testing #ethods.

. E5A$INA%I!N

-. #RINE&& HARDNESS %ES%

i. E7u*,ments:

8n this e"'eri#ent a Brinell hardness tester carr7ing a scale ill&strating the#agnit&de o a''lied load is &sed. $he tester o'erates according to the 'rinci'le o thetrans#ission o orce b7 the #echanis# o a ale and 'iston. 8t is controlled #an&all7. 6 10## dia#eter hardened steel ball is &sed as indenter obe7ing the standards o Brinell hardnesstest. 6 low?'ower #icrosco'e and a 'ortable light are e#'lo7ed or the #eas&re#ent o the

dia#eter o indentation.

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ii. E+,er*ment:

*irst, the indenter, a 10 ## dia#eter hardened steel ball, is attached to the tester.6ter the s&race o the s'eci#en to be tested is e"a#ined whether it is lat, clean, and reero# an7 o"ide and dirt, a s&itable 'oint is designated or 'enetration. +eter#ining this 'oint,

so#e li#itations or distance ro# s'eci#en edge to the 'oint and the distance ro# an7e"isting indentations #&st be considered. $he s'acing between the indentations sho&ld be#ini# 2.3 ti#es the dia#eter o the indentation, and the 'oint sho&ld be distant to theedges o the s'eci#en as 'ossible. 6ter a s&itable 'oint is deter#ined the s'eci#en is 'lacedon the 'late o the tester, and raised &' b7 rotating a handle &ntil the s'eci#en to&ches to theindenter ball. $hen the ale is t&rned o to let oil go into 'iston and let load to be a''lied.$he load is a''lied on the s'eci#en b7 #oing the handle o the 'iston in hori9ontal 'lane &'and down. *ollowing the scale on the tester, this is contin&ed &ntil the a''lied load reaches toa #agnit&de o 000 kg which is calc&lated kee'ing the ratio o load ( to the s%&are o dia#eter o the ball +D constant =(F6 " +D where 6 is e%&al to 0 or steels and cast irons>.6ter waited or abo&t 13?20 seconds d&e to the 'rinci'le o elastic s'ringback in #etals, the

load is c&t o b7 t&rning the ale on, and then the s'eci#en is taken awa7 or #eas&re#ent.

2. R!(KE&& HARDNESS %ES%

i. E7u*,ments:

8n the e"'eri#ent, a Rockwell hardness tester is &sed. 6 dia#ond cone and a hardsteel ball are e#'lo7ed as indenter. +ia#ond cone is &sed to test the hard s'eci#en and it hasa cone angle o 120G. $o test the soter s'eci#en, the hard steel ball o si9e 1.5 ## =1C5> is&sed.

ii. E+,er*ment:

*irst, the test is started with the scale o Rockwell. Beca&se scale re%&ires adia#ond cone as indenter and 130 kg #ajor load, the dia#ond cone is attached to the tester,and the #ajor load is adj&sted b7 adding the black weight to the tester. 6ter the s&race o thes'eci#en is e"a#ined to deter#ine a s&itable 'oint or the test, the s'eci#en is 'laced on the

'late o the tester. $he 'late is raised &' &ntil the s'eci#en gets in to&ch with the dia#ondcone. $hen the #inor load is a''lied on the s'eci#en b7 co#'ressing it between the rising

'late and the dia#ond cone &ntil the s#all indicator in the dial co#es on the red 'oint on the

scale. $he '&r'ose o a''l7ing a #inor load is to establish a reerence 'osition which#ini#i9es the a#o&nt o the s&race 're'aration needed and red&ces the tendenc7 or ridgingor sinking in b7 the indenter.

$hen the scale is adj&sted to a reerence al&e and the #ajor load is a''lied or abo&t 20 seconds b7 t&rning the ale o. 6ter waited or a while, the #inor load is &nloaded

b7 t&rning the ale on. $hen the hardness o the s'eci#en is read on the o&ter black scale as2 RH. Howeer, beca&se the &se&l range or this scale is ro# 20 to 0 HR, thisdeter#ined al&e, 2 HR, is not considered. $hereore, the e"'eri#ent is contin&ed with asoter scale, B. $o achiee this, the indenter is re'laced with a 1.5 ## dia#eter hard steel

ball, and the #ajor load is red&ced to 100 kg b7 re#oing the black weight ro# the s7ste#.$hen the sa#e ste's are ollowed or this scale. Inlike the scale here the calibrated scale is

adj&sted to a standard reerence 'oint in the inner red scale !$ 0.

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$his 'roced&re is a''lied or two dierent s'eci#ens seeral ti#es. 'eci#en?1 istested once with scale. 'eci#en?2 is tested o&r ti#es: once with scale and three ti#eswith B scale.

c. I(KERS HARDNESS %ES%

i. E7u*,ments:

8n this test, a #icro hardness =Vickers> tester is &sed. 6 s%&are?bas e dia#ond '7ra#id with an angle o 15G between the o''osite aces o the '7ra#id is e#'lo7ed asindenter. $his angle was chosen beca&se it a''ro"i#ates the #ost desirable ratio o indentation dia#eter. Beca&se o the geo#etr7 o the indenter, this test is called as Jdia#ond?

'7ra#id hardness =+(H>< test in so#e so&rces.

ii. E+,er*ment:

Inlike other indentation hardness tests, Vickers test re%&ires a 're'ared s'eci#enhaing a grinded, 'olished and carb&ri9ed s&race or e"a#ination in order to obtainre'rod&cible res&lts. 6ter the 're'ared s'eci#en 'laced on the 'late o the tester, contrastadj&st#ents are #ade b7 the aid o the o'tical #icrosco'e, and then a s&itable 'oint isselected or the test. $hen the tester is t&rned on and when the load is started to be a''lied, thelet la#' on the tester t&rns on. 6ter this 'oint, the load is a''lied on the on the s'eci#en or 20?0 seconds. $hen it is &nloaded and e"a#ined with the o'tical #icrosco'e. $his 'roced&reis a''lied seeral ti#es with 0.2 ## interals a''roaching to the center o s'eci#en.

III. DA%A ANA&YSIS

1. #RINE&& HARDNESS %ES%

-. Pr*nc*,e 8 'ormu-s:

*or the #eas&re#ents o the dia#eters o the indentation a low 'ower #icrosco'eis &sed. 6 'ortable la#' is e#'lo7ed to i#'roe the i#age o the indentation. $wo dia#eter #eas&re#ents o the indentation are done b7 &sing the r&ler on the #icrosco'e. alc&lating

the aerage dia#eter o the indentation d, the Brinell Hardness -ber =BH-> is obtained b7diiding the a''lied orce (, b7 the c&red s&race area o the indentation, which is act&all7 aseg#ent o a s'here =ee *ig&re 888.1>. $h&s, the hardness o the s'eci#en can be deter#inedaccording to the ollowing or#&la.

H#: Brinell Hardness -ber =kgC##D>

': a''lied orce =kg> D: dia#eter o indenter ball =##> ): aerage dia#eter o indentation =##>


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Figure III.1 – Measurements of Brinell Hardness Test

2. Des*9n-t*on of #r*ne H-r)ness Num2er:

calc&lated nber ti#e =s>

dia#eter o ball =##> a''lied load =kg>

. R!(KE&& HARDNESS %ES%

-. Pr*nc*,e 8 'ormu-:

+iering ro# other indentation hardness tests, Rockwell test &tili9es the de'th o indentation &nder constant load as a #eas&re o hardness directl7 b7 the aid o a co#'arator e"isting on the tester. 6ter #inor load is &nloaded, the de'th o additional 'enetration =!?e>d&e to the a''lied #ajor load =ee *ig&re 888.2 > is a&to#aticall7 #eas&red and recorded on adial gage in ter#s o arbitrar7 hardness nbers. $he dial contains 100 diisions, eachdiision re'resenting a s'eciied a#o&nt o 'enetration. $he calibrated dial is reersed so that

a high hardness corres'onding to a s#all 'enetration res&lts in a high hardness nber.;orking on B scale, the inner red scale in the dial is regarded as hardness nber #eas&re#ent, whereas the o&ter black scale corres'onds to scale. Inlike the Brinell andVickers hardness designations, which hae &nits o kilogra#s 'er s%&are #illi#eter =kgC##D>,the Rockwell hardness nbers are di#ensionless.

Figure III.2 – Measurements of Rockwell Hardness Test

2. Des*9n-t*on of Roc;e H-r)ness Num2er:

$he Rockwell Hardness -bers are designated as HR, where indicates thescale &sed =i.e. or B> which declares the geo#etr7 o the indenter and the #agnit&de o the

@

### BHN D P t


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load a''lied. $hereore, a Rockwell hardness nber is #eaningless i the scale is nots'eciied.

hardness scale nber

3. I(KERS HARDNESS N"$#ER

-. Pr*nc*,e 8 'ormu-

Beca&se the indenter is a s%&are?base '7ra#id dia#ond, the geo#etr7 o theindentations a s%&are, too, and thereore, diagonal #eas&re#ents are done in this test or dataanal7sis. (eror#ing the test seeral ti#es ro# the o&ter sections to inner sections o thes'eci#en, dierent al&es o diagonals =d> corres'onding increasing distances ro# s&race=carb&ri9ing de'th> are #eas&red and recorded in a chart. $hen these data are &sed to 'lot aVickers hardness nbers =VH-> ers&s distance ro# s&race => c&re o the carb&ri9eds'eci#en in order to obtain eectie carb&ri9ing de'ths corres'onding to dierent VH-s.$he Vickers hardness nber =VH-> is deined as the load =(> diided b7 the s&race area o indentation. $he VH- can be deter#ined &sing the ollowing e%&ation.

HN: Vickers hardness nber =kgC##D> P: load =kg>

): aerage dia#eter o diagonals

Figure III. – Measurements of "ickers Test

2. Des*9n-t*on of *cers H-r)ness Num2er:

$he Vickers hardness nber is designated with the calc&lated hardness nber

ollowed b7 VH-.

L

### HRX

VHN = 1.844 (P / d²)

d=(d1 + d2)/2


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hardness hardness test nber #ethod

I. RES"&%S

1. #RINE&& HARDNESS %ES% RES"&%S

P < 000 kg BH-F1. kgC##D

D < 10 ##

)1F .3 ##

)2F .5 ##

. R!(KE&& HARDNESS %ES% RES"&%S

• S,ec*men=1: HRF 3 on scale

• S,ec*men=: HRF2 on =not considered>

HRF2HRF30 on B scale

HRF3

3. I(KERS HARDNESS %ES% RES"&%S

+eter#ined ro# the gra'h =ee ra'h 8V.1> eectie carb&ri9ing de'th to 00VH- is L30 N#.

10

### VHN

174 BHN 10 3000 15

35 HRC

46 HRB


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#rap! I".1 – "H$ %ersus &istance from 'urface

. DIS("SSI!N

1. #RINE&& -n) R!(KE&& %ES%S

$his iss&e is e"'lained and disc&ssed in the 'reio&s sections clearl7.

. &I$I%A%I!N !N %HE %HI(KNESS

$he thickness o the s'eci#en sho&ld be considered. $o obtain re'rod&cibleres&lts, botto# resistance to the 'enetration #&st be 'roided s&ch that a #ark or b&lge is not

'rod&ced on the reerse side o the s'eci#en. 8t is reco##ended that the thickness o thes'eci#en sho&ld be at least 10 ti#es the de'th o the indentation =ee *ig&re V.1>. $est sho&ld

be #ade on onl7 a single thickness o #aterial.

Figure ".1 – (imitation on T!ickness of t!e 'pecimen

3. &I$I%A%I!NS '!R DIS%AN(ES

11

(µm)

VHN(kg/mm²)


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Beca&se o the strain hardening #echanis# res&lted ro# the cold or#ing 'rocesso hardness tests, there sho&ld be so#e li#itations or distance between the indentations. $hes'acing between indentations sho&ld be #ini# 2.3 ti#es the dia#eter o the e"istingindentation =ee *ig&re V.2>.

6nother li#itation is or the distance ro# s'eci#en edge to the indentation. $o

'roide eno&gh resistance to 'enetration d&ring the test, the distance between the indentationand the edges o the s'eci#en sho&ld be distant as 'ossible =ee *ig&re V.>

Figure ".2 – (imitation for t!e &istance Between Indentations

Figure ". – (imitation for t!e distance to t!e )dges

4. S"R'A(E (!NDI%I!NS

$he s&race to be tested sho&ld be clean and dr7, s#ooth, and ree ro# an7 o"ideand dirt. 6ltho&gh a ro&gh?gro&nd s&race is &s&all7 ade%&ate or the Rockwell test, Vickers

test re%&ires a grinded and 'olished s&race. 8n all test #ethods, the s&race sho&ld be lat and 'er'endic&lar to the indenter. $ests on c7lindrical s&races will gie low readings, the error de'ending on the c&rat&re, load, indenter, and hardness o the #aterial. $his eect re%&irestheoretical and e#'irical corrections.

>. YIE&D S%RESS AND $EAN PRESS"RE

Beca&se indentation hardness tests are destr&ctie tests orcing an indenter to 'enetrate the #aterial, the indentation #echanis#s work according to the 'rinci'le o elasticand 'lastic deor#ation. Hardness deor#ations are #ade b7 #eas&ring the si9e or de'th o the indentation, thereore there #&st be so#e 'er#anent deor#ation on the #aterial, and this

is achieed b7 e"ceeding the elastic li#it, 7ield stress, o the #aterial. $his is wh7 the #ean 'ress&re &nder the indenter is greater than the 7ield stress. Howeer, a''l7ing #&ch stress

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oer the elastic li#it 'rod&ces high a#o&nt o elastic s'ringback, dierence between the#ean 'ress&re and the 7ield stress sho&ld not be too #&ch.

?. ADAN%AGES !' I(KERS %ES% %! #RINE&& %ES%

•

&o-): $he load ordinaril7 &sed with Vickers test range ro# 2 to 120 kg. 8t is also 'ossible in Vickers scale to 'eror#ing #icro hardness testing b7 a''l7ing orce between3 gr and 2 kg.

• In)enter: 8n the Vickers test a s%&are?base '7ra#id dia#ond is &sed as indenter, whereasin Brinell test a hardened steel or carbide ball in dierent dia#eters according to thehardness o the #aterial is &sed.

• In)ent-t*on: 8n Vickers test the si9e o the indentation is er7 s#all, #eas&red in#icrons. $hereore it enables the o'erator to 'eror# lots o tests on a #icrosco'ic area.

• A,,*c-t*ons: Vickers test can be 'eror#ed on er7 brittle, hard, and thin #aterials, s&ch

as cera#ics, glasses, and thin sheets, whereas Brinell tests are 'eror#ed on steels, castirons, sot #etals and allo7s.

• E+-m*n-t*on -n) $e-surements: ensitie #eas&re#ents are #ade in Vickers test, s&chas ce#entation de'th and carb&ri9ation de'th. 8n addition, hardness o grain bo&ndariesand an7 'hase incl&ded in #aterial can be e"a#ined and #eas&red in Vickers.

I. (!N(&"SI!N

!"a#ining the 'rinci'les, li#itations, and signiicance o dierent hardness#ethods, engineering and design 'ro'erties o the #aterials can be o'ti#i9ed or their intended &se.

II. RE'ERAN(ES

1P +ieter . !., “Mechanical Metallurgy”, Mcraw?Hill, rd !dition, 1L@5

2P 8nstron, retrieed ro# htt':CCwww.instron.co#.tr , on -oe#ber 15, 2005

P Ke7 to teel, teel +atabase, retrieed ro# htt':CCwww.ke7?to?steel.co#C,

On -oe#ber 15, 2005P ordon !ngland, retrieed ro# htt':CCwww.gordonengland.co.&kC , on -oe#ber 15, 2005

3P +.R. 6skeland, “The Science and Engineering Materials”, (.( (h&le $ho#son (&b., 3th

edition, 2005.

5P !ngineering *&nda#entals, htt':CCwww.e&nda.co#C&nitsChardnessCshowQhardness.c#,On -oe#ber 15, 2005

P Materials !al&ation and !ngineering, 8nc, retrieed ro#htt':CCwww.#ee?inc.co#Crockhar.ht#l , on -oe#ber 1, 2005

@P Ke7 to Metals, Metals +atabase, retrieed ro# htt':CCwww.ke7?to?#etals.co#C, on -oe#ber 1@, 2005

1

http://www.instron.com.tr/http://www.key-to-steel.com/http://www.gordonengland.co.uk/http://www.gordonengland.co.uk/http://www.efunda.com/units/hardness/show_hardness.cfmhttp://www.efunda.com/units/hardness/show_hardness.cfmhttp://www.mee-inc.com/rockhar.htmlhttp://www.key-to-metals.com/http://www.instron.com.tr/http://www.key-to-steel.com/http://www.gordonengland.co.uk/http://www.efunda.com/units/hardness/show_hardness.cfmhttp://www.mee-inc.com/rockhar.htmlhttp://www.key-to-metals.com/


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Hardness Experiment Report

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