Lab 1 - Brinell Hardness Test PDF

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Summary

As part of the first lab, Brinell Hardness test will be used to determine the level of hardness
applied from a 10 mm steel ball indenter onto a steel and aluminum disc under different
applied force....

Description

Lab$Report$1$ !

BRINELL$HARDNESS$TEST$ ! ! Engr!244!! Winter!2021! Professor!Mehdi!Eshaghi! Concordia!university! Montreal,!Qc! !Canada! !

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Table of Contents " LAB$REPORT$1$.........................................................................................................................................................................$0! BRINELL'HARDNESS'TEST'.....................................................................................................................................................................'0! NOMENCLATURE$.....................................................................................................................................................................$2! LIST$OF$FIGURES$.....................................................................................................................................................................$3! OBJECTIVE$................................................................................................................................................................................$4! INTRODUCTION$.......................................................................................................................................................................$5! EQUIPMENT$&$PROCEDURE$................................................................................................................................................$6! RESULTS-$CALCULATION$FOR$STEEL$...............................................................................................................................$7! RESULTS$FOR$STEEL$..............................................................................................................................................................$8! RESULTS$–$CALCULATION$FOR$ALUMINUM$...................................................................................................................$9! RESULTS$FOR$ALUMINUM$.................................................................................................................................................$10! DISCUSSION$...........................................................................................................................................................................$11! CONCLUSION$.........................................................................................................................................................................$12! BIBLIOGRAPHY$....................................................................................................................................................................$13! APPENDICES$..........................................................................................................................................................................$14!

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NOMENCLATURE$ "

Greek%Letters% 𝜋 ""

Pi"

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Roman%Letters% HB!!

Brinell!Hardness!Number!

P!

Load!Applied!!

t!

Depth!of!indentation!

A!!

Area!of!indentation!

D!

Diameter!of!ball!(indenter)!

d!!

Average!Diameter!of!indent!!

mm!!

Millimeter!

mm2!

Millimeter!!square!

N!!

Newton!!

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LIST$OF$FIGURES$$$ !

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Figures"above"are"taken"from"lab"handout"of"Engr"244"

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OBJECTIVE$ "

As!part!of!the!first!lab,!Brinell!Hardness!test!will!be!used!to!determine!the!level!of!hardness! applied!from!a!10!mm!steel!ball!indenter!onto!a!steel!and!aluminum!disc!under!different! applied!force.!! !

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INTRODUCTION$ ! In!the!engineering!world,!materials!have!many!properties!including!ductility,!strength,! resilience,!resistance!and!many!more.!Among!these!properties,!hardness!of!a!material!plays! an!important!role!in!determining!if!a!material!is!suitable!to!serve!its!purpose.!! Hardness!is!one!of!the!properties!of!a!material!which!helps!resist!deformation,!breaking! and!indentation.!Therefore,!a!hardness!test!is!conducted!through!experiments,! observations!and!basic!theory.!In!order!to!successfully!conduct!a!hardness!test,!there!are! four!different!type!of!tests.!There!is!the!Brinell!Hardness!Test,!Rockwell!Hardness!Test,! Knoop!Hardness!Test!and!Vickers!Hardness!test!(HARDNESS!TESTING,!n.d.).!! Before!selecting!one!of!these!tests,!it!is!recommended!to!consider!the!following:!! o o o o o o

The!size!of!the!sample!! Surface!of!the!material! Material!type!! Number!of!trials!required! Accuracy!and!precision!of!result!! Compatibility!of!materials!with!its!mounting!piece!!!

In!the!given!lab!experiment,!conducted!by!Concordia!University,!for!Winter!semester!of! 2021,!The!Brinell!Hardness!test!is!used!to!determine!the!hardness!of!an!indenter!-!10mm! steel!ball,!pressed!against!a!steel!and!aluminum!disc!under!a!given!force.!! ! ! !

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EQUIPMENT$&$PROCEDURE$ ! EQUIPMENT:! § § § §

Compression!machine! 10!mm!steel!ball-!known!as!the!indenter! Microscope-!Optical!instrument!to!measure!the!diameter!! Finished!surface!of!Steel!and!aluminum!discs!

PROCEDURE:! Using!the!illustration!(Fig.!1)!on!page!3,!proceed!with!the!steps!below.!! Step%1.!Place!the!steel!disc!on!the!bottom!plate!illustrated!in!figure!1.!In!order!to!not!distort! the!indentation!upon!pressure,!ensure!that!there!is!a!minimal!contact!between!the!steel! disc!and!the!indenter.!! Step%2.%Adjust!the!pressure!load!to!10!x!10! !N!for!Steel!plate!and!5!x!10!!N!for!Aluminum! and!apply!the!load!for!15!seconds.!! Step%3.%After!15!seconds!has!elapsed,!lift!the!load!and!measure!the!indent!using!the!optical! microscope,!as!illustrated!in!figure!4!on!page!3.!When!measuring,!dimensions!will!be!in!X! and!Y!direction,!calculate!its!average!to!get!its!diameter.!If!while!measuring,!the!diameters! are!off!by!more!than!0.1!mm,!make!a!new!indentation!and!do!another!reading.!! Step%4.%Repeat!three!times!–!step!1!to!3,!with!the!given!load!of!steel!and!aluminum.!Ensure! to!properly!space!the!indent!to!prevent!error-!refer!to!figure!3!on!page!3.!Note!the! measured!diameter!(x!and!y!direction)!and!proceed!with!calculating!the!following:!! • • • • •

Mean!of!diameter! Brinell!Hardness!! Depth!of!indentation! Area!of!indentation! Average!Brinell!number!for!steel!and!aluminum!!

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RESULTS-$CALCULATION$FOR$STEEL$$

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DATA"TAKEN"FROM"HANDOUT"OF"LAB"MANUAL"ENGR"244"

! Note:%Refer%to%appendices%on%page%14%to%complete%the%calculation%below! A%calculation%sample%is%given%for%Trial%1%and%have%been%used%to%calculate%for%trial%2% and%3.%% 1. Calculate!mean!diameter:!! !

!.#$%% &!.'$%%$

!d!=!

(

= 3.65!𝑚𝑚!!

2. Calculate!Depth!of!indentation:! !!!!!!!!!!𝑡 = !

)*+√)*! +!.'-! (

= 0.344962406! ≈ 0.35!mm!!

3. Calculate!area!of!indentation:!! !!!!!!!!!!!!!!!A!=!𝜋 ∙ 10 ∙ 0.345 ≈ 10.84!𝑚𝑚(! 4. Calculate!Brinell!Hardness!number:! )**#*$.

!!!!!!!!HB!=!(

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/.0)$ ! #

)

) ∙ )*.01 = 94.719!≈ 94.72!

5. The!hardness!for!trial!1!is!94.72HB/10/10.07/15!! ! ! ! ! ! ! ! ! 7"

RESULTS$FOR$STEEL$$ ! The!table!below!shows!data!gathered!after!calculating!mean!diameter,!depth!of! indentation,!area!of!indentation!and!Brinell!Hardness!test!for!trial!1,!2!and!3.!! !

STEEL%-%BRINELL%HARDNESS%TEST%RESULTS%

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! After!compiling!the!data,!the!average!Brinell!number!is!95.40!for!steel.!! !

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RESULTS$–$CALCULATION$FOR$ALUMINUM$

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DATA"TAKEN"FROM"HANDOUT"OF"LAB"MANUAL"ENGR"244"

! Note:%Refer%to%appendices%on%page%14%to%complete%the%calculation%below! A%calculation%sample%is%given%for%Trial%1%and%have%been%used%to%calculate%for%trial%2% and%3.%% 1. Calculate!mean!diameter:!! !

!.'$%% &!.-$%%$

!d!=!

(

= 3.55!𝑚𝑚!!

2. Calculate!Depth!of!indentation:! !!!!!!!!!!𝑡 = !

)*+√)*! +!.--! (

= 0.325668497! ≈ 0.33!mm!!

3. Calculate!area!of!indentation:!! !!!!!!!!!!!!!!!A!=!𝜋 ∙ 10 ∙ 0.33 ≈ 10.23!𝑚𝑚(! 4. Calculate!Brinell!Hardness!number:! )**#*$.

!!!!!!!!HB!=!(

"

/.0)$ ! #

)

) ∙ )*.(! = 50.703!≈ 50.70!

5. The!hardness!for!trial!1!is!50.70HB/10/5.09/15!! !

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RESULTS$FOR$ALUMINUM$ ! The!table!below!shows!data!gathered!after!calculating!mean!diameter,!depth!of! indentation,!area!of!indentation!and!Brinell!Hardness!test!for!trial!1,!2!and!3.!! !

ALUMINUM%-%BRINELL%HARDNESS%TEST%RESULTS%

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! After!compiling!the!data,!the!average!Brinell!number!is!50.31!for!aluminum.!! !

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DISCUSSION$ ! After!successfully!conducting!the!Brinell!Hardness!test,!the!average!Brinell!number!for! steel!is!95.40!and!for!aluminum!it!is!50.31.!Compared!to!the!actual!average!Brinell!number,! it!is!found!that!for!steel,!it!has!a!hardness!of!approximately!117!HB!and!aluminum!has!a! hardness!of!approximately!95!HB.!! Many!factors!could!have!challenged!the!results!during!the!experiment,!for!example,!miscalibration!of!the!machine!when!replacing!the!discs,!or!the!setting!of!the!indenter.!There!is! also!a!possibility!that!a!minor!indent!was!already!present,!and!it!was!not!taken!into! consideration!when!setting!up!the!sample!(Newage!Hardness!testing,!n.d.).!! When!conducting!hardness!test,!it!is!important!to!ensure!proper!spacing!from!one! indentation!to!another.!Failure!to!do!so!will!adversely!influence!the!results!obtained.!The! proper!spacing!is!judged!from!being!three!times!the!size!of!the!indentation!diameter!from! the!center!of!the!indentations!(Solution!for!material!testing,!2021).!However,!it!defers! when!considering!the!imprints!from!the!edge!of!the!sample.!According!to!Buehler,!the! safety!line!is!drawn!from!2.5!times!the!size!of!the!diameter!from!the!edge!of!the!disc.!Also,!If! the!indentations!are!too!close!to!other!indentations,!the!material!sample!is!more!prone!to! breaking!and!faulty!results.!! Beside!Brinell!Hardness!Test,!there!are!three!other!types!of!test!that!can!be!useful!in! different!setting.!!Each!test!is!made!to!gather!indentation!of!a!material!differently,!for! example,!the!Brinell!Hardness!Test!is!used!when!an!indenter!is!pushed!with!a!given!force! onto!a!plate!for!a!certain!time!(in!seconds)!then!using!an!optical!measurement!and!Brinell’s! equation,!we!solve!for!its!hardness.!The!other!test!also!known!as!The!Rockwell!Hardness! test!is!widely!used!when!testing!material!because!it!is!easier!to!conduct!and!generally!more! accurate!data-wise.!In!such!setting,!it!is!used!when!the!indentation!mark!is!too!large!or! simply!because!the!sample!is!bigger.!On!the!other!hand,!the!Knoop!Hardness!test!is!used! mainly!for!smaller!sample,!and!for!indents!that!are!closer!to!the!edge.!Similarly,!an!optical! measurement!is!used!to!measure!the!indentation!and!successively!calculated!using!its! respective!equation.!Finally,!the!fourth!test!is!Vickers!hardness!test.!It!is!used!in!situation! where!the!testing!material!is!wider!than!most!materials.!! ! !

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CONCLUSION$ ! Despite!having!other!tests!to!compute!the!hardness!of!a!material,!Brinell!Hardness!test!was! used!in!this!lab.!After!calculating!the!hardness!number,!it!is!found!that!the!average!number! for!steel!is!95.40!and!that!for!aluminum!is!50.31.!Many!factors!could!have!challenged!the! results.!As!a!possibility,!a!mis-calibration!or!unpolished!surface!could!have!led!to!this! disagreement!from!its!actual!number,!being!117!and!95!respectively.!However,!while! keeping!this!aside,!the!objective!of!this!lab!was!achieved,!by!using!Brinell’s!Hardness! equation!to!calculate!its!hardness.!! !

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Bibliography " Aldon"Company."(n.d.)."Aluminum'vs'steel."Retrieved"from"Aldon"Company:" https://www.aldonco.com/PDFs/AlumvsSteel.pdf! HARDNESS'TESTING."(n.d.)."Retrieved"from"Struers"Ensuring"Certainty:" https://www.struers.com/en/Knowledge/Hardness-testing#hardness-testing-how-to" Newage'Hardness'testing."(n.d.)."Retrieved"from"Hardness"Testers:" https://www.hardnesstesters.com/test-types/brinell-hardness-testing" Solution'for'material'testing."(2021)."Retrieved"from"Buehler:"https://metallographymatters.buehler.com/2016/04/14/rockwell-hardness-test-indent-spacing/" "

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APPENDICES$ The%data%table%below%is%given%to%complete%the%discussion%questions.%%

! Actual%Hardness%number%for%Steel%and%Alum%

! Equation%reference% Area!of!indentation:!A=!𝜋 ∙ 𝐷 ∙ 𝑡!𝑚𝑚( !

2

Brinell!Hardness!Number=! ! 3

Load!Applied=!!

. #

/.0)$ ! $

Average!Diameter!of!indent:!!

!!

Depth!of!indentation:!t=!!

6+57%89:7;9$&...