31 Canadian Materials Science Conference Preliminary Program

58800_7Preliminary_Program_May_16.pdf 1       31
st

CanadianMaterialsScienceConference

PreliminaryProgram

2

Monday,June10



15:00Ͳ18:00Registration



18:00StudentMixer



Tuesday,June11



9:00MaterialsPhysicsLecture

DeformationandFatigueofMagnesiumAlloys:Twinninganddetwinning

DaolunChen,RyersonUniversity

Lightweightingisoneofthemosteffectivestrategiestoreducefuelconsumptionandanthropogenic CO 2 emissions,sincea10%weightreductionbringsabouta6~8%fuelͲefficiencygain.Ithasrecently beendepictedasthe"stormoflightweighting"-arevolutioninmaterials,processes,andbusiness models-whichisbrewingonthehorizonoftheautomotiveindustry.Magnesiumalloy,asanultraͲ

lightweightmetallicmaterial,hasrecentlyreceivedsignificantattentionduetoitssuperiorstrengthͲtoͲ

weightratio.However,thehexagonalcloseͲpackedcrystalstructureofmagnesiumalloyslimitsthe availabilityofslipsystemsandleadstostrongmechanicalanisotropyandtensionͲcompressionyield asymmetryowingtothepresenceofcrystallographictextureandtherelateddeformationtwinning.For thecomponentssubjectedtodynamicloading,suchasymmetrycouldexertanadverseeffectonthe materialperformanceandcompromisethestructuralintegrity,safety,anddurabilityofhighlyͲloaded structuralcomponents.Thisissuecouldbeconqueredthroughweakeningthebasaltextureviathe additionofrareͲearth(RE)elementsandotheralloyingelementstorefinegrainsandgeneratenanoͲ sizedprecipitates.Tosafeguardthestructuralintegrity,durability,andsafetyofloadͲbearingstructural components,understandingthecharacteristicsandmechanismsofdeformationandfatigueof magnesiumalloysisofvitalimportance.Inthispresentation,severalexamplesonthecyclicdeformation behaviorofextrudedmagnesiumalloyswithandwithoutREelementswillbepresented.Moreover, twinning,twingrowth,andtwinͲtwininteractionsduringuniaxialcompressionintheextrusiondirection anddeͲtwinninginthetransversedirectionwillalsobediscussed. 

10:20-12:00EmburySymposiumI

StructuralandChemicalPhaseTransitionsatGrainBoundaries

ChadSinclair

TheUniversityofBritishColumbia

Withthegrowingrangeofexperimentalandsimulationtoolsatourdeposalweareexpandingour appreciationfortherichnessofthechemicalandstructurallandscapeoccupiedbygrainboundaries.In thistalkIwill surveyourresearchcomputationalworkseekingtounlocksomeofthekineticand 3 thermodynamicfactorsthatdeterminechemicalandstructuralequilibriumatgrainboundaries.These resultswillbelinkedbacktopossibleeffectsonplasticityandfractureobservedatamacroscopicscale. Phasetransitions,stresses,andthephysicalpropertiesofsolids

GaryPurdy

McMasterUniversity

DavidEmbury's80

th birthdaywillbecelebratedwithasymposiumofgreatbreadthaswellasdepth. Thisisappropriate:David'sinterestsandcontributionshavespannedagoodportionsofthescopeof MaterialsScience.Thistalkwillrecountsomemutualinterests,beginninginthe1960'swhenDavidfirst cametoMcMasterfrom

USSteellaboratoriesandcontinuingtothepresentday.

Alandscapecanbedefinedthatincludestheoriginsofdifferentscalesofstructure,theinteractionsof appliedstresswithstructuredevelopment,and,finally,theresultingphysicalproperties.Atonelimit, theprocessofstructuredevelopmentreducestothestudyofphase transitions;attheother,tothe effectsofexistingstructureonthephysicalresponseofthematerial.Theinterveningterritory,the effectsofappliedstressontheprocessesofstructuredevelopment,isalsoofinterest.

PrecipitationinAluminiumalloys

1

ChristopherHutchinson,

1

WenwenSun,

1

QiZhang,

1

YumanZhu,

2

RossMarceau,

1

LingyuWang,

1 Xiang Gao 1

MonashUniversity,AUSTRALIA

2

DeakinUniversity,AUSTRALIA

HighstrengthAlalloysexploitsolidstateprecipitationtotailortheirmechanicalresponse.This precipitationrequirestwoingredients:athermodynamicdrivingforceandatomicmobility.Foragiven alloy,theheattreatmenttemperatureischosenasacompromisebetweenhavingsufficientdriving forceforprecipitationandsufficientatomicmobilityso thattheprecipitationreactionoccursina reasonabletimeframe.Itisthiscompromisethatframesthecompetitionbetweennucleation,growth andcoarseningthatconstrainsthepossibleprecipitatedistributionsandhencemechanicalresponses. Wedemonstrateanewapproachtoprecipitationhardeningthatdoesnotusethermaltreatments.The approachusessmall amplitudecyclicplasticityatroomtemperatureasameansofpumpingvacancies intothesystemunderconditionsofhighdrivingforce.Theapproachcanbeusedasanewprocessing routeforhighstrengthAlalloys,orasa'training'routinetoimprovethehighcyclefatiguepropertiesof precipitate strengthenedAlalloys.Bothexampleswillbeshowninthispresentation. OpportunitiesfortheDevelopmentofCompositionallyͲGradedSteels

BoscoYu,HamidAzizi,DavidEmbury,HatemZurob

McMasterUniversity

CompositionallyͲgradedsteelsprovideanextradegreeoffreedomforoptimizingmaterial properties.Recenteffortstocommerciallyproducegradedmaterialswithgradientsofsubstitutional andinterstitialelementswillbereviewed.Thedeformationandfracturebehaviourofselected compositionallygradedmaterialswillbediscussed. 4

13:00-14:20EmburySymposiumII

Understandingthefracturebehaviourofadvancedhighstrengthsteelsthroughthe applicationofinsitumethodologies DavidWilkinson,JavadSamei,LinfengZhou,DiyarSalehiyanandConcettaPelligra

McMasterUniversity

ThedamageprocessesthatleadtofractureinmaterialswithmultiͲphasemicrostructures,suchas advancedhighstrengthsteels,arecomplex.Afullunderstandingoftheunderlyingphenomenarequires acarefulassessmentofthestrainpartitioningamongstthephasesandacrossthematerial,howthe microstructureevolveswithstrainandhow damage,intheformofvoidsandmicrocracks,nucleatesand grows.Thiscanonlybeaccomplishedbyapplyingarangeofmethodologies,includingmicroscopic

digitalimagecorrelation(µͲDIC),xͲraycomputedtomography(XCT)andxͲraydiffraction,allofwhich

canbetrackedasdeformationproceeds.Thisissupplemented withnanonindentationandelectron backscattereddiffraction(EBSD).Therichdatabasethatresultsfromsuchstudiesprovidekeyinsights intotheunderlyingmechanisms.Whencoupledwithmodelsfordeformationanddamageapproaches todevelopingdamageͲtolerantmicrostructurescanbedeveloped.Iwillillustratethiswithexamples fromseveraldualphase(DP) andQuenchandPartitioning(QP)steels. TemperatureInducedSofteningEffectsduringHighRate(10 3 s Ͳ1 )FractureofUltraHigh

StrengthSteelSheets

ArminAbedini,CliffButcher,MichaelWorswick

UniversityofWaterloo

Theeffectofstrainrate(upto10

3 s Ͳ1 )onthefractureofhotstamped,ultraͲhighstrengthsteels(UHSS) usedinautomotiveapplicationsisexamined.ThefracturebehaviourofthematerialsunderquasiͲstatic conditionsisrelativelywellunderstood,atleastundermonotonicstrainpaths,withfracturelocioften expressedintermsoffracturestrainasafunction ofstresstriaxialityandLodeparameter,forexample. Theeffectofdeformationrateonfracturestrainisnotwellestablished,however,anditisnotclear whetherfracturestrainincreasesordecreasesatelevatedstrainratesforagivenstressstate.At dynamicrates,theplasticworkthatisconverted toheatdoesnothavesufficienttimetofullydissipate fromthedeformingarea,resultinginsignificanttemperatureriseandthermalsoftening.Thiseffectis amplifiedwithincreasesinstrengthduetothehigherrateofplasticwork.Thus,therolesofstrainrate andlocaltemperatureriseandtheircomplex thermoͲmechanicalinteractionsneedtobebetter understoodforUHSS. ThecurrentworkconsidersdynamicfractureofhotstampedUsibor®1500ͲAS,Ductibor®1000ͲASand Ductibor®500ͲASwithnominaltensilestrengthsof1,500,1,000and500MPa,respectively.CouponͲ levelminiatureshearandplanestrainnotchtensionspecimens wereadoptedtostudytheinfluenceof stresstriaxialityandstrainrateonhardeningbehaviourandfracturestrain.Insitudigitalimage correlationtechniquesareappliedwithhighspeedopticalimagingtomeasurefracturestrain,while highspeedthermalmeasurementsareusedtocharacterizetemperatureriseduringelevatedrate testing.Measured fracturestrainsareextractedasafunctionofstresstriaxialityforeachstrengthlevel atquasistaticanddynamicrates. Elevatedstrainratecanpromoteincreasedfracturestrainundertensiledominatedtriaxialityconditions, whereassignificanttemperatureriseandadiabaticshearlocalizationmaybeoperativeunderhighstrain rateshearloading, leadingtoearlieronsetoffracture,atleastintermsofmacroscopic(farͲfield)strain 5 measurements.Theeffectofmaterialstrengthontemperatureriseandtheresultinghighstrainrate fractureisexamined. ThermodynamicmodellingofstackingfaultenergyinFeͲMnͲCsteelsforalloydesignand mechanicalpropertypredictions

KevinP.Boyle

CanmetMATERIALS

ManytechnologicallyimportantsteelsarebasedontheternaryFeͲMnͲCsystem,including

transformationͲinducedplasticity(TRIP)steels,twinningͲinducedplasticity(TWIP)steels,Hadfieldsteels

andsomethirdgenerationadvancedhighͲstrengthsteels.Theutilityofthesesteelslargelyderivesfrom theabilitytoinfluencetheiroperativedeformationmechanismsandworkhardeningbehaviourthrough alloymodification.Alloyingmaycriticallyimpactstackingfaultenergy(SFE),whichcanberelatedtothe dislocationandaustenitephasestabilityandtotheresultingworkhardeningbehaviour.Inorderto developworkhardeningmodelswhichareinformedbyalloychemistry,thecurrentstatusof thermodynamicmodellingofSFEinFeͲMnͲCusingtheCALPHADmethodiscriticallyassessed.Particular attentionisgiventotheinfluenceofmagneticordering,thethermoelasticconstants,grainsizeandthe surfaceenergyofthestackingfault.Experimentalresultsfromtheliteraturearealsoassessedinorder toobtainamoreconsistentdatasetforcomparisonwiththemodellingresults.Ourassessmentleadsto anupdatedmappingofalloychemistryandtemperaturetoSFE.Thesignificanceoftheresultswith respecttotheoperativedeformationmechanismsandworkhardeninginFeͲMnͲCsteelswillthenbe discussed.

14:40-17:00EmburySymposiumIII

MeasurementofBackStressEvolutionDuringDeformationofDualͲPhaseSteels DougBoyd,HosseinSeyedrezai,NickSchwenger,KeithPilkey

Queen'sUniversity

InplasticallydeformeddualͲphase(DP)steels,adirectionalbackstress(ʏ B )developswithincreasing strain.ʏ B contributessignificantlytotheflowstressandproducesaBauschingereffect,whichis importantinsheetͲformingmodelsforDPsteels.Inthecurrentstudy,ʏ B hasbeenmeasuredinseveral

DPsteelsbyreverseinͲplanesheartests.ʏ

B initiallyincreaseswithincreasingpreͲstraininagreement withtheBrownandStobbsmodel.ʏ B dependsstronglyonthevolumefractionofmartensite(M),butis lessdependentonmicrostructuralparameterssuchasferritegrainsize,orMsize,shapeorspatial distribution.AthighpreͲstrain,ʏ B becomesconstant('saturates'),owingtodamage (decohesion/fracture)ofMparticles. CrystalPlasticityModellingofLargeStrainBehaviourofMetals

PeidongWu

McMasterUniversity

WefirstintroducevariouspolycrystalplasticitymodelsincludingtheViscoͲPlasticSelfͲConsistent(VPSC)

model,theElasticͲPlasticSelfͲConsistent(EPSC)model,andtheElasticViscoͲPlasticSelfͲConsistent

(EVPSC)model,aswellastwinningmodelsincludingthePredominantTwinReorientation(PTR)model andtheTwinningandDeͲTwinning(TDT) model,withemphasizingoncharacteristicdifferencesbetween thesemodels.Then,wedemonstratethattheEVPSCͲTDTmodelisabletocapturekeyfeaturesoflarge 6 strainbehaviourofmetalsundervariousdeformationprocesses. InͲsituhighresolutionTEMondeformationtwinningprocessinBCCcrystals

ScottXMao

DeptofMechanicalEng.andMaterialsScience

UniversityofPittsburgh

Twinningisafundamentaldeformationmodethatcompetesagainstdislocationslipincrystallinesolids. Inmetallicnanostructures,plasticdeformationrequireshigherstressesthanthoseneededintheirbulk counterparts,resultinginthephenomenonthatthesmalleris thestronger.Suchhighstressesare thoughttofavourtwinningoverdislocationslip.Deformationtwinninghasbeenwelldocumentedin faceͲcentredcubic(FCC)nanoscalecrystals.However,itremainsunexploredinbodycentredcubic(BCC) nanoscalecrystals.Here,byusinginsituhighͲresolutiontransmissionelectronmicroscopyandatomistic simulations, weshowthattwinningisthedominantdeformationmechanisminnanoscalebiͲcrystalsof BCCtungstenandtantalum.Suchdeformationtwinningisfoundtobepseudoelastic,manifested throughreversibledetwinningduringunloading.Wefindthatthecompetitionbetweentwinningand dislocationslipcanbemediatedbyloadingorientation,whichisattributed tothecompetingnucleation mechanismofdefectsinnanoscaleBCCbiͲcrystals.Ourworkprovidesdirectobservationsof deformationtwinningaswellasnewinsightsintothedeformationmechanisminBCCnanostructures. InͲsituobservationonatomicscaledtwinningnucleationandgrowthprocessesandmodelsintheBCC crystalswill bepresented.

Theroleofsimpleshearinmaterialprocessing

TayfurOzturk

MiddleEastTechnicalUniversity,Ankara06800,Turkey

Simplesheardiffersfromotherformsofdeformationwithregardtorigidbodyrotationwithwhichitis associated.Thisiswiththeresultthatwhilegrainsinpolycrystalsnormallyfollowasteadylattice rotationpaths,finallyreachingthestableendorientations,thisisnotthecasewithsimpleshear. With largeassociatedmacroscopicrotations,grainsinsimplesheararesubjecttofasterlatticerotations,but thenreachorientationsthatare,atbest,metastable.Oftenlatticerotationsovershootsthese orientations,andthuswithcontinueddeformation,thetextureisrenewedwithoutmuchfurther intensification.Theabsenceoftrulystableendorientationsin simpleshearhasmicrostructural implications.Withsteadylatticerotationsinconventionalprocessing,uponreachingthestableend orientations,thealterationssoondecelerate,formingadeformedmicrostructurehavingcellsor subrainsofsmallmisorientations.Initiallyrapidaccumulationofdislocationssoonslowsdownreaching oftenasaturationpoint.Withsimpleshear,as thetextureisrenewed,soisthedeformed microstructure.Asaresult,undercomparableconditions,cellsorsubgrainsindeformedstructureare oftensmallerandhavehighermisorientationsacrossthem.Clearlywiththesefeatures,thesimpleshear processedmaterialsarecapableofaccommodatingmoredislocationsintheirstructure.Inthiswork, firstwewillcomparesimpleshearwithpureshearincopperandalphabrassinspeciallydesigned experiments.Weshowthatthetextureinsimpleshearisindeedlessseverethanthepureshear.This differencewhilequitenoticeableindeformationshowsupextremelywellinthesubsequentannealing. Here thepureshearproducesanextremelysharptextures,especiallyincopper,whilethetexturein simpleshearisratherdiffuse.Wethenmakereferencetoequalchannelangularpressingwherethereis avoluminousdatainliteraturewithregardtoadvantagesofsimpleshearinobtaininghighstrengthina variety ofmaterials.Wethenlookatcaseswherethesimpleshearisbroughtintooperationin conventionalprocessingasanadditionalprocess,i.e.strainlocalization.Firstexamplewewilldealtwith 7 willbeheavilyrolledbrasswherethesimpleshearisoperativeintheformofshearbands.Wewillthen examineshearbandformationinhexagonalmetalswheretherelativehardnessofgrainsissubstantially differentfromeachother,often,acauseofstraininstabilityleadingtoshearband formation.Thesimple shearisalsoanaidingprocessindeformationofmultilayermetalliccompositesespeciallywhenthe relativehardnessoftheconstituentlayersdiffersfromeachotherbyafactorofmorethanthree.The lastexamplewewilldealwithwillbeballmillingofelementalpowderswherethe processmakesuseof simpleshearasawayofformingstructurewithdensedislocationsleadingtoamorphization. Onthe'assemblagemechanics'associatedwithmaterialsoptimization

GlennHibbard

UniversityofToronto

Ourabilitytomakethebestuseoutofamaterialsystemisbasedonourabilitytosolveinverse materialsdesignquestionsandtoovercometheassociated'informationbarriers'.Propertiesarebased oninternaldynamicsunfoldingoverarangeofdifferentlengthandtimescales,withdifferentmaterial 'things' takentoexistateachdifferentorganizationalscale[e.g.1],whileaninverseproblemisonein whichtheoutput(maximizingaspecificmaterialperformance)isspecifiedandonetriestofindthe input(aninternalmaterialstructure)thatbestmeetstheoptimizationcriterion[2].

Thereareseverallayersto

anoptimizationquestion.Forexample,itisnotsimplyenoughtoknowhow tobuildaparticularmaterialͲstructure(theprocessͲstructurerelationship),onealsoneedstopredict thebehavior(thestructureͲpropertyrelationship)andtoknowpreciselywhichconfigurationsto fabricatefromtheaccessiblestatespace(theoptimizationstep).These arequestionsinvolvinglarge parameterspaceswithnogeneralsolution.Inallcaseshowever,thekeyissueisspecifyingtheinternal structure. In1976theMITMaterialsScientistMorrisCohenwrotethat'thestructuralladderembodiesmachinery withinmachinerywithinmachineryuntilthemindrunsoutofcomprehension'[3].Formalizing our understandingofthisdomainwouldbeahelpfulsteptowardstherealizingthepotentialofmaterials optimization.Accordingly,thistalkwillbeginfromthe1964book'MathematicalFoundationsof Thermodynamics'byRobinGiles[4].Gilesbelievedthattherewerethreeessentialelementstothe idealtheoreticalframeworkofthermodynamics:states, theunionofstates,andthetransitionbetween states.WewilluseacasestudyapproachtoexamineGiles'sideainthecontextofmultiͲscalematerial dynamics. [1]G.B.Olson,Science277(1997)1237 [2]M.F.Ashby,MaterialsScienceandTechnologyFebruary8(1992)102 [3]M.Cohen,Materials

ScienceandEngineering25(1976)3

[4]R.Giles,MathematicalFoundationsofThermodynamics,PergamonPress(1964)

MaterialsScienceandMaterialsSystems

MikeAshby(1)andMarcFry(2)

1) UniversityofCambridge,UK

2) ANSYSGRANTAEducationDivision,Cambridge,UK

Materialssciencehasalongpedigreewithrootsintheabilitytomanipulateceramics(10,000BC),to alloymetals(2,500BC)andpolymersynthesis(1839).Thegreatdevelopmentofthesecondhalforthe 20 th centurywastheblendingoftheseintoascienceofmaterialsthatenabledlinkswiththepure sciences(physics,chemistry)andtheapplied(design). WhenIjoinedtheEngineeringDepartmentinCambridgesomeyearsago,myremitwastoupgradethe teachingofMaterialstoEngineeringstudents.Thestudentsdid notrespondwelltothetraditional 8 physicsͲorientedbottomͲup("atomsͲtoͲartefacts")approachthatwasthencurrentandhadnomental mapofthematerialsuniverseortoolsforselectingthemtomeetdesignspecifications.Ourapproach wastoreversethesequence,takingatopͲdownapproachandtoprovidestudentswithmapsof materialproperties,softwaretomakethemandtechniquesforselection.Fromateachingperspective, thissucceededprettywell.Whatwehadnotanticipatedwasthesubsequentcommercialisationthrough aUniversityspinͲoff,GrantaDesign,nowANSYSGRANTA. Understandingmaterials,improvingthemanddevelopingnewonesremainprincipalconcernsof

MaterialsScientists.

ButtheGrantaexperiencehighlightedthattheroleofthematerialsexpertinthe commercialworldcanberatherdifferent.Materialsaretradedglobally,butthetradeisnot"free". Materialpricestability,supplychainsecurity,restrictionsandreportingrequirements,theenvironment, circularityandsocialresponsibilitycanbegreaterconcerns -anditisthejobofthematerialsexpertto adviseandguidedecisionͲmakinginthematerialsͲaspectsofallofthese.Aproperscientific understandingofmaterialfamiliesandofsinglematerialsremainessentialcoreskills,buttheabilityalso tothinkintermsofmaterialssystems- thecontextinwhichmaterialsaresourced,usedandreͲ circulated,andtheinfluenceofgeopoliticalandtradeconstraintsonthese,becomeimportanttoo. Doweteachourstudentsaboutthesebroaderaspectsofmaterials?Materialscoursesarealready overloaded-addingmorelayersseemsimpractical.Butatleaststudents shouldbemadeawarethat theseissuesexist.Ashort,wellͲdesignedpresentationcanatintroducethem,atthesimplestlevel,in lessthan30minutes.Thepresenttalkisa(truncated)versionofanattempttodoso.

10:20Ͳ12:00AdvancedCharacterizationofMaterialsI

Understandingmaterialswithadvancedelectronmicroscopy (INVITED)

GianluigiBotton

CanadianLightSourceandMcMasterUniversity

Electronmicroscopeshavebecomeverypowertoolstostudythestructureofmaterialsat unprecedentedresolution.Fromtheirinvention,thesetoolshaveprovidedessentialinformationonthe structureandpropertiesofthebroadestrangeofmaterialsusedtodayinstructuralandfunctional applications.However,electronmicroscopesprovidemuchmorethan images.Inthispresentation,the majorbreakthroughsinthefieldofelectronmicroscopyofthelastfewdecadeswillbepresented.Itwill beshownthat,inadditiontoimages,electronmicroscopesprovidemuchmorethanstructural informationwithtechniquessuchaselectronenergylossspectroscopyandscanningtransmission electronmicroscopy. Severalexamplesrelatedtotheanalysisofnanoscaleenergystorageand conversionmaterials,semiconductorsandalloyswillbepresented.Thisworkdemonstratesthatonecan studywhereatomsareinasolid,orinadefect,withexceptionalprecisionandaccuracysothateventhe strainfieldatinterfaces,in devicesandarounddefectscanbeobtained.Examplesalsoshowthat spectroscopicinformationonthevalenceofatoms,evenincomplexmaterialssuchashighͲtemperature superconductorscanbeobtainedatatomicresolution.Theuseofcomplementarycharacterization tools,suchasfocusedionbeamsand3DͲatomprobetomographyandvarious synchrotronsbeamlines, highlightsthepowerfularsenalavailabletomaterialsscientistsandengineerstounderstandthe behaviorandpropertiesofmaterials. 9

MaterialCharacterizationonVESPERSbeamlineatCLS

RenfeiFeng

CanadianLightSource

CanadianLightSourceistheonlysynchrotronradiationfacilityinCanada.VESPERSbeamlineisahardXͲ

raymicroprobebeamlinetherededicatedtoXͲraymicroͲdiffraction(ʅXRD),XͲraymicroͲfluorescence

(ʅXRF),andmicroXͲrayabsorptionspectroscopy(ʅXAS)studies.Thebeamlineoffersfourwidely differing bandwidths,~0.01%,~1.6%,~10%,andfullypolychromaticbeam,whichallowstosimplifythe Lauediffractionanalysis,tooptimizeXRFexcitation,andtoenableXͲrayabsorptionspectroscopy measurement.Thesetoftechniquesprovidedbythebeamlineenablesthedeterminationofelements, materialphases,andchemicalspeciationsforalocalmicronͲ sizedarea,whichisparticularlyusefulfor theinhomogeneoussample.ThemappingcapabilityisavailableusingbothXRFandXRD,especially microͲLaueͲdiffraction,simultaneouslyorconsequently,toobtainthespatialdistributionofelements, phases,andspeciations.Thebeamlinehasbeeninoperationformorethan10years.Thebeamline capabilities, togetherwithsomecasestudiesinmaterialcharacterization,willbepresented. MaterialsResearchUsingSynchrotron:FromGoodtoBetter,ImpossibletoPossible

FeizhouHe

CanadianLightSource

Synchrotronlightsourceisaversatile,andoftenindispensabletoolformaterialsresearch.Eachyear, thousandsofresearchersfromCanadaandothercountriescometotheCanadianLightSource,the nationalsynchrotronfacilityofCanada,tocharacterizeawidevarietyofmaterials,includingengineering materials,nanoͲcatalyst,biologicalmaterials,and novelelectronicmaterials,etc.Thistalkwillprovide anoverviewoftheresearchactivitiesatasynchrotronfacility,withafewresearchhighlights,suchas nonͲdestructivemicroͲCTimaging,inͲsitumeasurementsofbatterymaterialsinoperation,and understandingthepropertiesofmaterialsatfundamentallevel.Theseadvancedimaging,spectroscopic anddiffractiontechniquesareeitherimpossibleorverydifficultwithoutasynchrotronsource.The researchesenabledbysynchrotronsareconstantlypushingboundariesofmaterialsscienceand engineering. StudyoftheformationofadiabaticshearbandsinAZ31Magnesiumalloyduringimpact

FrancisTettehandSolomonBoakyeͲYiadom

YorkUniversity

Materialsandstructuresarebeingconsideredforuseinincreasinglyextremeconditionswithrespectto extremesinappliedpressures,strainͲrates,strainsandtemperatures.Thesemechanicalextremesand highrateofdeformationeventsincludecarframesduringcollisions,crushtubesunderimpact,ballistic impacts(aprojectilehittingatarget)and shock/impulsiveloading.Duringdeformationunderthese extremes,thematerialsandstructuresrelyontheirabilitytodistributeloadastheydeformplastically vianucleationandpropagationofdefects,aswellasactivationoffailuremechanismssuchasstrain localization,cracknucleationandgrowthinordertoaccommodatetheexcessivedeformation. Magnesium(Mg)isthelighteststructuralmetalusedforlightweightapplicationsduetoitslowdensity. However,mechanismofdeformationanddamageaccumulationinMgalloysduringhighstrainrate loadingconditionssuchasimpactarenotfullyunderstood.Inthisstudy,AZ31Mgalloysweresubjected tohighstrainrate loadingusingtheDirectImpactHopkinsonPressureBar(DIHPB)underdifferent impactmomentumtounderstandthemechanismofstrainlocalizationandformationofadiabaticshear bands.ThepreͲandpostͲimpactAZ31Mgalloysweremounted,groundpolishedandetchedfollowed 10 bymicrostructuralcharacterizationtechniquesincludingelectronmicroscopyandmicroanalysisto determinewhereAdiabaticShearBands(ASBs)nucleatewithinthemicrostructureandthedominant damagemechanismsunderdynamicshockloading.Microstructuralanalysisindicatesthatathighstrain rates,ASBsevolvedwithfinenarrowregionsprolongingalongregionsofpropagatingcracks. MicrohardnessmeasurementsindicatedthattheASBsregionswerehardandbrittlecomparedto regionsawayfromtheASBs.InadditiontotheevolvedASBsandcracks,itwasobservedthattherewas selectivegrainrefinementbothwithintheregionsoftheshearbandsandawayfromtheASBs.Thus, therewere regionswithsomegrainsextensivelyrefinedsurroundinggrainsthathadnotundergoneany extensiverefinement.Inaddition,highvolumefractionsoftwinsandmicrotwinsevolvedbothwithin theregionsoftheASBsandawayfromtheASBs.Itisinferredthatthecrystalstructureandactivationof slipsystems inadditiontomechanicalgrainrefinementresultinthestructureoftheevolvedASBs. LiquidMetalEmbrittlementDuringLaserBeamWeldingofZnͲcoatedAdvancedHighStrength

Steels

MohammadHadiRazmpoosh,Prof.E.BiroandProf.Y.N.Zhou

UniversityofWaterloo

Despitefrequentreportsofliquidmetalembrittlement(LME)duringresistancespotwelding,littlework hasbeendonetoinvestigatetheLMEsensitivityinlaserbeamwelding(LBW)ofZnͲcoatedadvanced highstrengthsteels(AHSS).BydevelopinganewtechniquetoapplyexternalloadingduringLBW,LME sensitivityasa functionofappliedstressandheatinputhasbeeninvestigated.Theembrittlement behaviorinthreelowͲMn(1wt.%)22MnB5pressͲhardeningsteel,mediumͲmanganese(10wt.%) transformationinducedplasticity(MMnͲTRIP),andhighͲManganese(14wt.%)twinninginduced plasticity(TWIP)steelgradeshavebeenstudied.Theeffectsofweldingparametershavebeen investigatedbymeansofGleeblesimulations.Electronbackscatterdiffraction(EBSD)inconjunction withelectronprobemicroͲanalyzer(EPMA)resultsreflectedthemajorroleofprioraustenitegrain boundariesandpreͲexistinghighͲanglegrainboundarieswithintheheatͲaffectedͲzone(HAZ)inthe embrittlement.

13:00Ͳ17:00AdvancedCharacterizationofMaterialsII

Soluteclusteringanditshardeningeffectinferrousalloys (INVITED)

GoroMiyamotoandTadashiFuruhara

TohokuUniversity

Inthenitridingofferrousalloyscontainingstrongnitrideformingelement(M),ithasbeenrecognized thatsurfacehardeningoccursbyprecipitationoffinenitrides.Thepresentauthorsdirectlyobserved thatsurfacehardeninginthenitridingofTiorVͲaddedspecimensoccursnotbytheprecipitationof stablealloy nitridesbutbymetaͲstablemonoͲlayerMͲnitrogen(N)clustersbymeansofhighresolution transmissionelectronmicroscopy.Ontheotherhand,clusteringwasnotobservedinAlorCrͲadded specimens.ThoseclusteringandprecipitationbehaviorscanbeunderstoodbyMͲNinteractioninbcc phase,whichinducesphaseͲseparation betweenMͲNrichandpoorregionsinbcclattice.Furthermore,

innitridingofternaryalloyscontainingclusterͲformingandnonͲformingelements,suchasFeͲAlͲ(V,Ti)

alloys,VͲNclusteringinducesnucleationofAlNparticlesandrefinesdistributionofthem,whichresults insignificantsurfacehardening.This indicatespreͲcursorsoluteclusteringcanbeusedtocontrol precipitationreactioninferrousalloys. 11 LowͲcyclefatiguebehaviourofglassfiber/epoxylaminatesmodifiedwithreducedͲgraphene oxide

MohammadRafiee,F.NitzscheandM.Labrosse

UniversityofOttawaandCarletonUniversity

Multiscalelaminatedfiberglass/epoxycompositesmodifiedwithreducedͲgrapheneoxide(rGO)were examinedforlowcycleuniaxialtensilefatiguelifeassessment.Simultaneousreinforcementofmatrix andfiberswascarriedoutviaanovelmethodthatcombinesnanoparticlesprayingand nanoparticle/epoxymixturetoincorporatenanoparticlesfortheenhancementoffatiguepropertiesof multiscalelaminatedfiberglass/epoxycomposites.Thetensileandfatigue,aswellasmorphological, propertiesoftheglassfiberͲreinforcedmultiscalecompositeswereinvestigated.Theexperimental resultsrevealedthatallrGOconcentrationssuccessfullyledtosignificantimprovementsinfatiguelifeof reinforcedcomposites.Theseimprovementscanbeascribedtobondingbetweenthe nanoparticlesand theglassfiberͲreinforcedpolymer(GFRP). AnalyzingtheFractureBehaviourofToolSteelsinVariousStressTriaxialities AlexandraRose,I.SariSarraf,R.Marentette,A.T.Alpas,D.E.Green

UniversityofWindsor

Thewearoftrimmingdiescausesscratches,burrs,reducededgestretchabilityandsliversintrimmed parts.Thus,predictingtheusefullifeoftoolsteelssuchasD2,ahighchromium,highcarbonsteel, throughnumericalsimulationcanhelptoimprovepartquality.Besidescompressiontests,arangeof mechanicaltests withdifferentstresstriaxialitiesarerequiredtofullycharacterizethedominant damagemechanismsintoolsteels.Inthisstudy,uniaxialtension,shearandcompressiontestswere conductedusingminiaturetension,miniatureshear,andcylindricalcompressionspecimens.Digital imagecorrelation(DIC)wasusedtomeasurestrains.Scanningelectronmicroscopy(SEM)wasused to characterizethefracturesurfacesoftestspecimens.Althoughsomeplasticdeformationwasobserved incompressiontests,apparentfacetsandcleavagestepsshowedthatthedominantfracturemodeis brittlewithasmallamountofductilefractureinbothtensionandcompression. AdvancedCharacterizationTechniquesforUnderstandingtheEffectofNonͲframework CationFieldStrengthontheStructureof(NaͲMg)AluminosilicateGlasses HarisankarNellattukuzhiSreenivasan,PaivoKinnunen,ElijahAdesanya,MinnaPatanen,AnuM. Kantola,VilleͲVeikkoTelkki,MarkoHuttula,WeiCao,JohnL.Provis,MirjaIllikainen OuluUniversity,FinlandandUniversityofSheffield,UnitedKingdom Aluminosilicateglassesarematerialswithwidetechnologicalapplications.Duetotheirdesirable properties,theyarecommerciallyusedasglassͲceramics,containerglasses,liquidcrystaldisplay(LCD) substrates,opticalandlasermaterials,andsoon.Theyarealsoconsideredaspotentialsupplementary cementitiousmaterialswithreducedCO2emissionswhencomparedto ordinaryPortlandcement(OPC). Consideringsignificanceofaluminosilicateglasses,thereisagreaterneedtounderstandtheirstructure. Oneofthekeyparametersaffectingtheirstructureisthecationfieldstrength(definedtobecation chargedividedbythesquareofthecation-oxygenionicbonddistance)ofthenonͲframework cation. Hereinthiswork,westudytheeffectofcationfieldstrengthofnonͲframeworkcation(NaandMgin thiscase)onthestructureof((Na2O)2Ͳx(MgO)x(Al2O3)0.5(SiO2)2.5)glassesusingadvanced characterizationtechniqueslikeincludingSiKͲedgeEXAFS/XANES,27AlMASNMR,29SiMASNMR,XPS, XRD, andSEM.Resultsindicatethatduetothehighcationfieldstrengthofmagnesiumoversodium, 12 magnesiumispreferredfornetworkmodification,whilesodiumispreferredforchargecompensation. TheaforementionedpreferenceamongnonͲframeworkcationsisfoundtohaveacrucialrolein determiningglassstructure. Comparativestudiesoftheeffectofwarmandhighrollingtemperaturesonthe microstructureandtextureofAPIX70pipelinesteel

JosephOmaleandProf.JerzySzpunar

UniversityofSaskatchewan

TheevolutionofmicrostructureandtextureofAPI5LX70pipelinesteelafterwarmandhigh temperaturerollinghasbeenstudiedusingXͲraydiffractionandelectronbackscatterdiffraction(EBSD). EBSDinvestigationsrevealedthatthemicrostructureaftertheroughrollingstageconsistofcoarse largeͲgrainedferrites.Thewarmrolled showedmainlydeformedandelongatedferritesintherolling directionwhilehightemperaturerolledspecimenshowedrecrystallizedandequiaxpolygonalshaped ferritegrains.EBSDinvestigationsconfirmedthatbothrecoveredanddeformedgrainsweremostly dominantatwarmrolledspecimenwhilehightemperaturerollingproducedhigherfractionof recrystallizedgrainswith fewdeformedandrecoveredgrains.XͲraymacroͲtexturemeasurement showedthatthefinishrollingtemperaturesplayedakeyroleinthedevelopmentofthetexture. InsituElectronMicroscopyStudyoftheStructuralEvolutionofNanostructuredPalladium duringElectrodeposition

JieYang,LeylaSoleymaniandGianluigiA.Botton

McMasterUniversity

Palladiumnanostructuresarewidelyusedinapplicationsrelatedtobiosensingandenergyconversion. Thefunctionalitiesofthesematerialsarehighlydependentonthemorphologyandsizedistributionof thenanostructures.Tofurtherunderstandthemechanismofpalladiumnanostructureformationunder variouselectrochemicalconditions,insituscanningtransmissionelectronmicroscopy(STEM) hasbeen applied.Inthiswork,theeffectofasupportingelectrolyte(HCl)onpalladiumdepositionhasbeen studied.AliquidcellwasusedinsideaTEMandtheelectrochemicalresponseandstructuralevolution ofpalladiumparticlesweresimultaneouslyacquired.Insitucyclicvoltammetryandchronoamperometry wereperformedtostudythe palladium/hydrogencoͲdepositionandtheeffectofchlorideionson palladiumstructureformation.ItwasfoundthatduringinsitucyclingaddingHClenhancedaggregation anddetachmentofdepositedpalladium,correspondingtothecharacteristicsofhydrogen adsorption/absorption/evolutionanddesorption.Furthermore,undertheelectrodepositionpotentialat whichhydrogenadsorption/absorptionoccurred,porous andnonͲsphericalstructureswereformed. ThroughthisworkwehaveshownthattheinsituTEMtechniqueprovidesdirectexperimentalevidence ofintermediateproductsduringtheearlystageofelectrochemicalprocessesintheirnative environment,whichgivesinsightsintodevelopmentofnanostructuredmaterialsbytuning electrodepositionconditions.

PlasmonicbehaviorofwrinkledͲgoldsurfaces

S.ShayanMousaviMasouleh,IsobelC.Bicket,EdsonP.BellidoSosa,L.Soleymani,GianluigiA.Botton

McMasterUniversity

Wrinkledgoldsurfaces(WGSs)areknownfortheirexcellentperformanceinfieldssuchas electrocatalysis[1].Recently,WGSshaveattractedmuchattentionastheyshowhighsurfaceplasmon 13 (SP)activity.DifferentexperimentshaveprobedtheopticalandplasmonicpropertiesofWGSsandtheir potentialapplicationinfieldssuchasphotoelectrocatalysis[2].Herewehaveutilizedelectronenergy lossspectroscopy(EELS)toprovidehighspatialandenergyresolutioninformationontheSPactivity.The

2DEELSmapsof

theSPactivityareusedtoinvestigatetheplasmonbehaviorandresonancelocalization. Basedonourobservations,thesestructuresprovidepromisingconditionsforSPspropagation.WGSs showmultiplesurfaceplasmonexcitations,makingthesematerialsstrongcandidatesforplasmon tuningapplications,suchasmultiͲwavelengthphotocatalysisandbroadbandabsorptiondevices. [1]Gabardo, etal.Sci.Rep.7(2017):42543. [2]Zhang,etal.ACSNano5.6(2011):4407Ͳ4413. AtomicandElectronicStructuresofNanoscaleConstituentswithinSolids

GuozhenZhu

UniversityofManitoba

Thediscoveryofdefectswithinsolidsandcorrespondingpropertieshasbeenlargelyacceleratedusing

thestateͲofͲtheͲarttechnologyindirectlyresolvingtheiratomicandelectronicstructures.Herein,Iwill

discussafewuniquenanoscaleconstituentsatdislocationsandboundaries.Thesestructureshave distinctcompositionsandatomicarrangements,and cannotbeisolatedfromabuttingsolids.WithinMgͲ Gdalloys,ahexagonalpatternofGdnanoͲfibers,templatedbydislocations,wasselfͲassembledafter thermalͲmechanicalprocessing.Suchpatternsareabletoregulatetherelativeactivitiesofbasaland nonͲbasalslips,andinturn,improvethestrengthandductility ofMgalloys.Inaddition,interface reconstructions,withasignificantatomicrearrangement,wasdiscoveredbetweengoldandoxides, whichcanprovideawaytotunethemasstransportofoxidesandfurtherthesynthesisofoxide nanostructures.Thedeepunderstandingofsuchstructureswillbeusefultodiscover,predict,and design advancednanostructuredmaterials. Theeffectsofmicrostructureandmicrotexturegeneratedduringsolidificationon deformationmicromechanisminIN713CNickelͲbasedsuperalloy

GangLiuandSoranBirosca

TheUniversityofBritishColumbia

NickelͲbasedsuperalloyIN713Cproducedbyinvestmentcastingmethodareusedforturbinebladeof turbochargerinmodernvehicles.IN713Calloypossessesgoodstrength,fatigue,creepandhigh temperatureoxidationresistancethatmakethealloysuitabletobeusedinharshserviceenvironment suchasintheheatingpartof turbocharger.However,thismaterialsuffersfrommicrostructureand microtextureheterogeneityproducedduringsolidification.Thismicrostructureheterogeneityacrossthe componentwillinevitablygiverisetolocalstressandstrainaccumulationwhichmayfacilitatecrack initiationandaffectcrackpropagation.Fatigue,bothLCF(LowCycleFatigue)andHCF(HighCycle fatigue)are thecommonfailuremodesofturbinebladecomponentinturbocharger.Thenecessityof optimisationoffatiguepropertyforthenewlydevelopedturbochargercomponentpartsisbecoming criticalandafundamentalresearchforunderstandingfatiguedeformationmicromechanismandthe influenceofmicrostructure(dendritestructure,carbides/oxidisedcarbides,grainsize,etc.)and microtexture(individualcrystallographicorientation,clusterofgrains,etc.)isrequired. Inthecurrentinvestigation,LCFandHCFfatiguetestsareconductedonrealturbinebladesaswelason barsproducedviainvestmentcasting.Variousmicrostructurecharacterisationtoolswereusedto identifythedeformationmicromechanicsduringLCFandHCFfatigue conditions.Theresultsshowed thatinrealturbinebladeswheretherearemuchlesscastingdefectsthaninthetestingbar,thefatigue crackinitiatedfrombladesurfaceandcrackpropagationprocesswasmainlydominatedbyoxidationͲ 14 assistedprocesswithoxidisedcarbidesduringLCFtest.Duringthelatestageofcrackpropagation,the interdendriticareawasfoundtodeformdifferentlyfromthesurroundingareatoaccommodate accumulatedstrainheterogeneity.WhilstforHCF,facetwasinitiatedfromslipplaneswiththehighest

Schmidfactorandassistedby

smallporosityinmostcases. Asforthefatiguetestsconductedontestbarsproducedviainvestmentcasting,thedendritestructure playedavitalroleincrackpropagationmechanism.Basedontheobservationsthroughoutthisstudy,a conceptof'crackpropagationunit(CPU)'wasproposed.Fromthisproposedmicrodeformation mechanism, anewperspectiveofHallͲPatcheffectofsmallgrainsizeincastingalloys(containing dendritestructure)wasfurtherelucidatedduirngbothLCFandHCF. EffectofNitrogenIonImplantationontheFatigueLifeofAISI1018andAISI1045Carbon

Steels

EmmanuelAwoyele,Oguocha,I.N.A.,Odeshi,A.G,Bradley,MP

UniversityofSaskatchewan

Plasmaionimmersionimplantation(PIII)isasurfacemodificationtechnique,whichhasprovento improvethehardness,corrosionandwearpropertiesofsteel.Inthisresearch,theeffectofnitrogenion implantationonthefatiguelifeandsurfacepropertiesofAISI1018andAISI1045carbonsteelswas studied.All testspecimenswereimplantedusing5kVbiasvoltageatapressureof15mTorrfortwo hours.Afterthat,surfaceroughnessmeasurement,microandnanohardnesstest,XͲraydiffractionand XͲrayphotoelectronspectroscopywereperformedtoinvestigatetheeffectofnitrogenimplantationon surfacepropertiesofthealloy. Rotatingbendingfatiguetestat50Hzwasperformedonbothtreated andasͲreceivedspecimens.Fatiguelifeofbothsteelsimprovedatlowstressamplitudesbutdecreased athighstressamplitudes.ThiseffectwasmorepronouncedinAISI1045steelcomparedtoAISI1018 steel.Thisandotherfindingsfrom thisworkwouldbepresented. KWNmodelingofprecipitationinafrictionstirweldingprocess OlgaGopkalo,B.J.Diak,FrédéricDeGeuser,AlexisDeschamps Queen'sUniversity,SIMAP,UniversitéGrenobleAlpes,Grenoble,France TheweldingofheatͲtreatablealuminiumalloysgreatlyimpactsthepreͲweldpropertiesbythe modificationofthesizeandfractionofstrengtheningprecipitates,andsoitusefultounderstandand predictthesechanges.TheKampmannandWagnernumerical(KWN)model[Kampmann,Eckerlebe&

Wagner,1987]hasbeenusedto

describetheprecipitationkineticsinthermallyprocessedaluminum alloys[Myhr,Grøng&Andersen,2001].Thesimplestmodelisbasedonthegrowthordissolutionof precipitatesdistributedinsizeclassesandisadaptedheretothesolidstatefrictionstirweldingofanAlͲ

MgͲZnalloy,illustratingthetimeͲdependent

developmentofthedifferentparametersrelatedtothe precipitationkinetics.Thepredictionsofthemodelfromtheevolutionofsizeandvolumefractionof precipitatesarecomparedtosmallangleXͲrayscattering(SAXS)measurements.Modelpredictionsare usedtoenhancephysicalinsightintotherangeofmaterialbehaviorin theobservedexperiments. 15

10:20Ͳ12:00AppliedElectrochemistryandDegradationofMaterialsI

MultiͲLayeredSteelasanAlternativetoFerriticStainlessSteelforAutomotiveExhaust

Systems

Invited

JoeyKish

McMasterUniversity

AfeasibilitystudyisbeingconductedtobenchmarkthecorrosionperformanceofamultiͲlayeredsteel (chromizedIFsteel)againstferriticstainlesssteelscurrentlybeingusedtofabricateautomotiveexhaust systems.Comparativecorrosiontestinginbothsimulated"coldͲend"and"hotend"environmentsis beingperformedforthispurpose.The "coldͲend"corrosionperformanceconcernsthepittingcorrosion susceptibilitywhenexposedinatmosphericnearͲneutralsaline(external)andacidiccondensate (internal)environments.The"hotͲend"corrosionperformanceconcernsthehightemperaturewet oxidationsusceptibilitystartingsimplywithdryversuswethotairexposures.Relativedifferencesinthe corrosionperformanceobservedin bothcasesarebeinglinkedtodifferencesinthestartingsurface microstructuresandhowthesesurfacesevolveduringexposure,asrevealedbyscanningelectron microscopy(andassociatedtechniques)coupledwithAugerelectronspectroscopy.Theresultsare discussedwithinthecontextofthesuitabilityofmultiͲlayeredsteelsforthisapplication andpathways forfuturemultiͲmaterialdevelopment. EffectsofStressIntensityFactorandLoadingSpectraonIntergranularSCCCrackGrowth

HamidNiazi,HaoZhangandWeixingChen

UniversityofAlberta

WestudiedtheeffectsofdifferentloadingwaveformsonthefirstandsecondstagesofHighpHStress CorrosionCrackinginpipelinesteel.Obtainedresultsrevealedthatthecorrelationbetweenloading spectraandcrackgrowthkineticishighlydependedonthemagnitudeofthestressintensityfactor aheadofthe cracktipandtheloadfrequency.WhenKmaxKISCC, anditisintheorderof10Ͳ7mm/s.However,underloadcyclesretardthecrackgrowthduetocrack closureeffect,decreaseinmeanstressintensityfactorandreduceinstrain rate. EvaluationofFBEandHPPCcoatingsusingamodifiedcathodicdisbondmenttest

Min(Mina)XuandEdouardAsselin

TheUniversityofBritishColumbia

Tocomparetheperformanceoftwopipelinecoatingsystems,i.e.,fusionbondedepoxy(FBE)andhighͲ performancepowdercoating(HPPC),inbothacidicandalkalineenvironment,amodifiedcathodic disbondmenttest(CDT)wasdesignedandapplied.InthismodifiedCDT,theelectrolytepHwas controlledatspecificvalues(0,1,

4,7,and12).Viaelectrochemicalimpedancespectroscopyaswellas

monitoringofthecoatingthickness,itwasrevealedthatthethickerHPPCcoatingstendtoslowthe migrationofwaterandionicspeciesthroughthecoatingandshowlessdisbondmentthanFBEoverthe entirepHrangestudied.For bothcoatingsystems,aclearcorrelationbetweentheirdisbondmentradius 16 andtheoverpotential(apotentialdifferencebetweentheappliedcathodicpotentialandmeasured opencircuitpotential)wasobserved.Thepresentstudysuggeststhatamorenegativecathodic potentialisneededtoreducecoatingdisbondmentatnearneutralpHcondition. Performanceofsacrificialanodecoupledwithconductivemortarforcathodicprotectionof thereinforcingsteelinthechloridecontaminatedconcretecolumninthesplashzone

XingguoFengandJingͲliLuo

UniversityofAlberta

Forovercomingtheproblemthatthereinforcingsteelinconcretelocatedinthemarinesplashzoneis difficulttobeprotectedbytheconcretecoatingsorbythesacrificialanodeintheseawater,anew systemconsistsofthesacrificialanodeandtheconductivemortarwasdevelopedtoprotectthe rebarin themarinesplashzone.Theprotectionperformanceofthesystemwasestimatedbyvarious electrochemicaltestsinthreeconcretecolumnsinasimulatedsplashzone,andthecorrosionstatusof therebarsinthesplashzonealsowereexamined.Theresultsshowthattherebarsinthesplashzone in theconcretecolumnscanbeeffectivelyprotectedbythesacrificialanodeͲconductivemortarsystem. Moreover,comparedwiththemagnesiumalloyanode,thealuminumalloyanodeismoresuitablefor couplingwiththeconductivemortarlayertoprotecttherebarsinthesplashzone. CorrosionbehaviorofhotͲdipgalvanizedsteelinsimulatedsoilsolution:astatisticalanalysis

DavoodNakhaieandEdouardAsselin

TheUniversityofBritishColumbia

HotͲdipgalvanizedsteelisoftenusedintheelectricpowerutilityindustryforpowertransmissionand distributionstructuresbecauseofitsservicelifeperformanceinmanyatmosphericandunderground conditions.SoilcorrosionofgalvanizedsteellatticetowersinstalledinBritishColumbia,Canada,isof significanttechnicalandeconomic importance.Inthepresentstudy,afulltwoͲlevelfactorialdesignwas employedtoassesstherelativesignificanceofthepossibleinfluencingfactorsonthesoilcorrosionof galvanizedsteel.Aseriesofcorrosionexperimentswereperformedinsimulatedsoilsolutionprepared torepresentsomeaspectsofBritishColumbia'ssoiland climateconditions.Thecorrosioncurrent densitywasthemodel'sresponse.Theinfluenceofchloride,sulfate,bicarbonate,citricacid concentrationandtemperaturewasevaluatedusingstatisticalanalysisoftheresults.ANOVAwas employedtoanalyzethestatisticalsignificanceoftheresults.ANOVAshowedthatthemodelis significant,whilethecurvature isnot,suggestingthatthemodelaccuratelyfitsthedata,hencecan reliablybeusedtointerpolatetheresponse.Itwasfoundthattemperature,citricacidandchlorideare individuallysignificant.Temperature/citricacidandtemperature/chlorideinteractionswerealsofound tobesignificant. 17

13:00Ͳ14:20AppliedElectrochemistryandDegradationofMaterialsII

UsingIn-SituSurfaceEnhancedRamanSpectroscopytoStudytheEffectofTriazineͲBased H 2 SScavengerontheFilmCompositionandCrackingofCarbonSteel

Invited

VinicioYnciarteLeivaandBrendyRinconTroconis

TheUniversityofTexasatSanAntonio

Thecommonpracticeusedtoreducetheconcentrationofhydrogensulfideinthehydrocarbon productionfluidsistoinjectahydrogensulfidescavengerintothegastransmissionline.However, failuresintheformofstresscorrosioncracking(SCC)ofsteelpipeshavebeenreportedwhenusing certaintriazinebasedscavengers.

OneofthemostfrequentlyusedH

2

SscavengertriazineishexahydroͲ

1,3,5Ͳtris(hydroxyethyl)Ͳtriazine,whichisamonoethanolaminederivedtriazine(MEAͲtriazine).Its

reactionswithH 2 Sarewelldocumented.OnemoleoftriazinewillgenerallyreactwithtwomolesofH 2 S fromthegasstreamandliberatetwomolesofamine.TheMEAbyͲproductsthatformduringthe scavengingprocess,havebeenhypothesizedtocauseSCC. AvastamountofinformationisavailableinregardstothecorrosionproblemsassociatedtoMEAͲCO 2 andMEAͲH 2 Ssweeteningreactionsthroughouttheyears.However,thecorrosiveeffectsofMEAͲ triazinebyproductsisstillunknown.Inaddition,thereisnoinͲsitustudyrelatedtothistopic.Basedon theliterature,itissuggestedthatSCCisgovernedbycorrosionprocessesandspecificallybyapossible transitionfroma passivesurfacetoanactivesurface.Thistransitionisacomplicatedfunctionofacidgas concentration(CO 2 /H 2 S)andamineadsorption.Thereareseveralpossiblemechanismsbywhich crackingcanbeinduced.First,areductioninH 2 ScontentcouldreducethesemiͲprotectiveironͲsulfide film,thuschangingthenatureoftheactive/passivetransitionandmakingcrackingmorelikely.Second, specificadsorptionofaminesontothesurfaceofthesteelcouldresultinachangeintheactive/passive transition.Third,thereactionofMEAwithCO 2 couldformacombinationofcarbamate,bicarbonate, andcarbonate,whichcouldresultinalkalinecarbonatestresscorrosioncracking.Therefore, characterizationoftheMEA/H 2 S/CO 2 reactionprocess,theadsorptionofaminesontosteel,andthe electrochemicalbehaviorofthesteelareimportantfactorsthatneedtobeexplored. Inthiswork,weseektoexploretheroleofMEAͲtriazinebyͲproductsonSCCofcarbonsteel.InͲsitu

Ramanspectroscopywasusedtomeasure

H 2

SandCO

2 intheliquidphase,aswellasidentifyingthe chemicalspeciespresentinthetestsolutionpriortoandfollowingthescavengingprocess.Surface EnhancedRamanspectroscopywasutilizedtomeasurespecificadsorptionofaminebyͲproductsonthe steel,aswellas,changesinthesurfacefilmcompositionbased onpreviouselectrochemicalstudies. Finally,slowstrainratetestingwasperformedtoevaluateSCCsusceptibility. Evaluationofmaterialsusceptibilitytohydrogenembrittlement(HE)basedonexperimental andfiniteelement(FE)analyses

TuhinDas,JunSong,StephenYue

McGillUniversity

HydrogenEmbrittlement(HE)hasbeenaseriousproblemfordecadesinvariousindustriessuchas aerospace,automotive,oilandgas,fasteneretc.HEcausesstructuralmetals,includinghighͲstrength steels,superalloysandaluminumalloystosufferprematureandcatastrophicfailures,threateningtheir reliabilityanddurability.Anumberoffactorssuchas stressgradients,environmentduringapplications etc.areresponsibleforHEfailureofmaterials,butmaterialsusceptibilitycouldbeidentifiedasacritical parameteramongthem.Therefore,inthepresentstudy,acombinedapproachbasedonfiniteelement 18 analyses(FEA)andexperimentalinvestigationshasbeenadoptedtoevaluatematerialsusceptibilityto HE.Thestresscoupledhydrogendiffusionfiniteelementstudyfurtherdevelopsabetterunderstanding ofHEfailureofmaterialsbyaddressingthefundamentalaspectsoftheproblem. Electrochemicalbehaviorofmetallicbipolarplatesunderfluctuatingpotentialconditions

YuanyuanHong,JingliLuo,CadienKen

UniversityofAlberta

Degradationofmetallicbipolarplates(BPPs)undertheaggressiveworkingconditionsisaseriousissue impedingthecommercializationofprotonexchangemembranefuelcells(PEMFCs).Fluctuating potentialsgeneratedduringthedynamicoperatingstagesofPEMFCscouldfurtherdegradeitsstability anddurability.Inthisstudy,squarewavepotentialpulsesare appliedto316Lstainlesssteel(316LSS)to simulatethepotentialfluctuationsonBPPs.Resultsshowthattransientpotentialswouldacceleratethe degradationof316LSS.Alargerpotentialfluctuationgeneratesamuchhigherfrequencyofpassivefilm breakdowneventsthanthatgeneratedbyasmallerpotentialfluctuationduringthe cyclicpulsetests, besides,negativecurrentisdetectedatlargepotentialfluctuationconditions.TheMottͲSchottkyresults suggeststhatthebreakdowneventsarecloselyrelatedtothedisorderdegreeofpassivefilmsformedat differentlowerpotentials;aprotectivepassivefilmwithlesslocalizedstatesisbeneficialtomitigatethe dissolution inducedbythetransientpotentials.Thedevelopmentofbipolarplateswithlessdefective surfacestructureandassessmentofitsperformanceundertransientpotentialsarenecessaryfor improvingPEMFCstabilityanddurability. EffectofdepositparticlesizeonthecorrosionbehaviorofAPIͲX100pipelinesteel HongxingLiang,RebeccaFilardoSchallerandEdouardAsselin

TheUniversityofBritishColumbia

Emulsifieddropletscontainingchloridescanbeidentifiedindilutedbitumen(referredtoas"dilbit") pipelines[1].Thechloridedropletscoupledwithsoliddepositsmayaccumulateontheinsidesurfaceof dilbitpipelines[2].Thecorrosionmechanismsofchloridedropletsunderparaffinoil[3]andsimulated dilbit[4]havebeeninvestigatedinourpreviousstudies.Thesolidparticlesdepositedondilbitpipeline havevaryingsizes(fromlessthan40ʅmtomorethan400ʅm)[5].However,toourknowledge,the effectofsandparticlesizeonthedropletcorrosionbehaviorofsteelcoveredbydilbithasnotbeen investigated. Theparticlesizewherethecumulativedistributionis80%ismarkedasparticlediameter(d v,0.8 )[6].The dropletcorrosionbehaviorunder40mesh(d v,0.8 ,540ʅm)and200mesh(d v,0.8 ,43ʅm)silicadeposits onX100pipelinesteelcoveredbysimulateddilbitfor24and240hwasstudiedinorderto understandtheeffectofsandparticlesize.Scanningelectronmicroscopywasusedtomonitorthe corrosiondevelopmentandprofilometrywasusedtocharacterizethecorrosiondepth.After24hof exposure,localizedcorrosioncoupledwithuniformcorrosionoccurredforboththe40and200mesh silicadeposits.After240h,thecorrosionunderbothsizesofsilicacontinuedtodevelop.Themaximum penetrationrateoflocalized corrosionunderthe40meshsilicawasfasterthanunderthe200mesh silica.Thecorrosionproductsformedundertwotypesofsilicaconsistoflepidocrociteandhematite,as indicatedbyscanningelectronmicroscopyandtransmissionelectronmicroscopy.

References

[1]X.Wu,InvestigatingthestabilitymechanismofwaterͲinͲdilutedbitumenemulsionsthroughisolation andcharacterizationofthestabilizingmaterialsattheinterface,EnergyFuels17(2003)179о190. [2]J.Been,Comparisonofthecorrosivityofdilbitand conventionalcrude,Report 19 ofAlbertaInnovatesTechnologyFutures,2011. [3]H.Liang,J.Liu,R.Schaller,E.Asselin,AnewcorrosionmechanismforX100pipelinesteelunderoilͲ coveredchloridedroplets,Corrosion,74(2018)947о957.

4]H.Liang,J.Liu,A.Alfantazi,E.Asselin,CorrosionbehaviourofX100pipelinesteelunder

asaltydroplet coveredbysimulateddilutedbitumen,Mater.Lett.222(2018)196о199. [5]T.D.Place,M.R.Holm,C.Cathrea,T.Ignacz,"UnderstandingandMitigatingUnderͲDepositCorrosion inLargeDiameterCrudeOilPipelines-AProgressReport,"ProceedingsofIPC2008,paper64562(2008). [6]Y.Liu,Y.Yang,S.Mai,D. Wang,C.Song,Investigationintospatterbehaviorduringselectivelaser meltingofAISI316Lstainlesssteelpowder,Materials&Design,87(2015)797Ͳ806.

14:40Ͳ17:00AdditiveManufacturing

FatigueBehaviourofShotͲpeenedAdditiveManufacturedTiͲTiB

LizaͲAnastasiaDiCeccoandAfsanehEdrisy

UniversityofWindsor

ThefatiguebehaviourofanalphatitaniumfeaturinglowamountsofTiB(<1wt%boron)made throughanadditivemanufacturingprocesstermedplasmatransferredarcsolidfreeformfabrication (PTAͲSFFF),wasinvestigated.Thestudyfocusesontheinfluenceofshotpeeningsamplesforfatigue improvement,whichthroughmicrohardnessprofiling hasshownincreasesinhardnessupto1mmdeep insamples.AnRBFͲ200HTrotatingbeamfatiguemachinewasusedtoconductrotatingͲbendingfatigue tests.Priortotesting,tensiletestingwasperformedandusedasabasistobeginthefatiguetests,which beganat1/3theultimatetensile strength.BasedonchangesincyclesͲtoͲfailurewithincreasingload,SͲ Ncurveswereconstructed.Fracturesurfaceswereobservedandcharacterizedbyscanningelectron microscopy(SEM)equippedwithelementaldiffractivespectroscopy(EDS).Modesoffailurewillbe presented,andfatiguebehaviourpatternswillbesummarised. EffectofprintingparametersonporosityandmicroͲHardnessofAISI316LfabricatedbyDMLS

AliEliasu,SolomonBoakyeͲYiadom,AlexCzenkanski

YorkUniversity

Metal3Dprintinghasseenlotsofattentioninthepastfewyearsbuthasnotgottentothesamelevelas otherformsof3Dprintingsincethemechanicalpropertiesofpartfabricatedbysuchaprocesscannot bepredictedduetoseveraldefects.Themajordefectthatinfluence theloadbearingcapabilityof structuralmaterialsislevelandnatureofporositypresent.Theporosityisanalyzedqualitativelyusing areafractionoftheentiresurfaceofthesamples.Theporositylevelsreduceasthelaserenergyinput increasestoapointwiththelowestporosityandthenstartsrising againastheenergydensityexceedsa certainthreshold.DuetothecharacteristicrapidheatingandcoolingcyclesofPowderbedfusion technologies,fineͲsubstructuresarepresentinthemicrostructurethatincreasesthehardnesswithin

209HVͲ241HVwhichishigherthanthehardnessoftheconventionallymanufacturedAISI316L.

20 EffectofHeatTreatmentontheMicrostructuralEvolutionof3DͲprintedWCͲCocemented carbides JosephAgyapong,CzekanskiAlex,BoakyeͲYiadomSolomon

YorkUniversity

TungstenCarbideͲCobalt(WCͲCo)cementedcarbidesarewellknownfortheirhighhardnessandwear resistancewithextensiveapplicationsinmanufacturingandminingindustries.However,thismaterialis verydifficulttoprocessusingmetalͲbasedAdditiveManufacturingprocessesduetohightemperature gradientsresultinginhighresidualstresses,cracks, nonͲequilibriummicrostructuresandunpredictable mechanicalproperties.Inthisstudy,optimizedprocessingparameterswereusedtoproduceWCͲCo (87wt%Ͳ17wt%)usingSelectiveLaserSintering.Thespecimenswereheattreatedtounderstandthe effectofheattreatmentonthemicrostructuralintegrityofthespecimensbycharacterizingthe microstructuralevolutionofthe specimensduringheattreatmentusingScanningElectronMicroscopy andXͲRaydiffraction.ResultsshoweddecompositionofW2CandformationofWͲCͲCophasesinheat treatedsampleswhichcontributedsignificantlytothemechanicalproperties.Inshort,carefulselection forposttreatmentofadditivelymanufacturedWCͲConeedstobe doneinordertoachievebetterand desirableproperties. CharacterizationofMechanicalBehaviorof3DPrintedCompositeParts

MadhukarSomireddyandAlexCzekanski

YorkUniversity

Thepresentstudyinvestigatedthemechanicalbehavioroftheadditivelymanufactured(AM)composite parts.Finalpropertiesoftheprintedpartsweredifferentfromtheirinitialmaterialusedforprinting,the finalpropertieswereinfluencedbyprintingprocess.Reasonsforthisanisotropywereunveiledduring characterizationofmicrostructureoftheparts usingµͲCTscanner.Printingprocessparameterssuchas printingdirection,layerthicknessaffectedtheorientationofreinforcements,bondingbetweenthe extrudedfibers,andadditionallydensityofvoidsinthemesostructureoftheparts.Further,mechanics oftheprintedpartsforcharacterizingtheirmechanicalbehaviorundermechanicalloadswereexplored. Forthis,3Dprintedcompositepartssubjectingtotensileandflexuralloadsweretested,andthenthe laminatemechanicswereemployedforcharacterizingtheirmechanicalbehavior.Resultsconfirmedthat themechanicsoflaminatescanbeemployedforcharacterizingthemechanicalbehavioroftheprinted parts. UsingAdditiveManufacturingtoTailortheDesignofHeterogeneous/GradedArchitected

CellularMetamaterials

BoscoYu

1 ,DerekArangurenvanEgmondandDaliaMahmoud 2 1

McMasterUniversity

2

UniversityofToronto

Cellularmaterialsareaclassofstructuralmetamaterialsthatcanfilltheunattainedregionsinthe "Ashby"materialͲpropertyͲspace.Currently,cellularmaterialsusedforindustrialapplicationsare generallyfabricatedviatraditionalmanufacturingprocessessuchascasting,forming,andmachining.To minimizetheprocessingtiming,thesecellularstructuresarenormally fabricatedtohaveperiodicunit

cells(i.e.lattices).WhilelatticeshavebeenabletoachieveimpressivestiffnessͲtoͲweightratios,their

periodicity(orhomogeneity)imposesalimitationontheirarchitecturaldesign-whichhindersthe developmentofpropertiessuchfracturetoughness,impactenergyabsorption,etc.Wehaverecently 21
demonstratedthatadditivemanufacturingcanbeutilizedtoproducehighlycomplexheterogeneousor gradedarchitectedmaterialswithoutpayingthepenaltyofhighermanufacturingcosts.Through experimentsandsimulation,wehavedemonstratedthattheseheterogeneouscellularmaterialsoffer superiorperformanceinstructural/bioͲimplantapplicationsthatrequirehighfracturetoughness,impact resistance/energyabsorption,andfatiguestrength.Futureresearchopportunitieswillalsobediscussed. TantalumcoatingsbyhighͲpressurecoldsprayforwearandhighͲtemperaturecorrosion protectionapplications

JagannadhSripadaandGobindaSaha

UniversityofNewBrunswick

ColdsprayisarelativelynovelsolidͲstatematerialadditivemanufacturingprocesswhichworksonthe principleoftransformingkineticenergyintohighͲimpactparticlevelocityinasupersonicenvironment. Thinlayersofmaterialsaredepositedintheformofprotectivecoatingsonsubstratesorstandalone3D freeformobjectcreation. Theresultingmaterialstructureisdense,andwithverylimitedporosity presence,makingthetechnologyattractivefordesign,developandtestmanymaterialsystems, includingmetals,ceramics,cermets,polymers,thermallyͲdissimilarmaterials,etc.forcorrosion resistance,wear,highͲtemperatureoxidationprotectionapplications.Inthisresearch,Tantalumis chosentoworkwith highͲpressurecoldsprayprocessanddevelopthincoatingsonAISI1018carbon steelsubstratestoachieveacombinedwearandcorrosionresistancetosubstrate.Tantalumisa refractorymetalwithmeltingpoint2,996oC,andisknownforitssuperiorcorrosionresistanceunder extremeconditions,aswellasgoodmachinability.

Inthiswork,thefeedstockparticle(Ta)ofspherical

morphologywithsizedistribution5Ͳ60micronisusedtodevelopthreedifferentcoatingthicknesses:

100µm,200µm,and300µm.HPCSsprayprocessparametersarestudiedtoachieveadesiredcoating

microstructureanddepositionefficiency(DE).Resultsshowthatthe porositypercentagecanbe suppressedtobelow0.1withthedevelopedparameters,andthereappeartobeanexcellentinterfacial bondingbetweensubstrateandcoatings.FromXRDresults,itisfurtherconfirmedthatthecoatingsare devoidofanynoticeablephaseformation. TheInfluenceofPostͲDepositionHeatTreatmentsontheMicrostructureandMechanical PropertiesofWireͲArcAdditiveManufactured(WAAM)ATI718PlusSuperalloy

OluwasanmiOguntuaseandJonathanBeddoes

UniversityofManitoba

TheinfluenceofpostͲdepositionheattreatmentsonthemicrostructureandmechanicalpropertiesof wireͲarcadditivemanufactured(WAAM)ATI718Plusispresented.Theapplicationofthestandardheat treatmentrecommendedforthewroughtATI718Plusresultsintheformationofexcessiveeta(ɻ)phase particlesalongtheinterdendriticspaces.Thismicrostructuredegradesthetensilepropertiesofthe WAAMalloyandcausesaprofoundanisotropiceffect.Theuseofexperimentalandthermodynamic simulationtoolsenablethedevelopmentofTimeͲTemperatureͲTransformation(TTT)diagramsthat elucidatethestabilityandgrowthkineticsofɻphaseintheWAAMATI718Plusandallowthedesignof newheattreatmentscapableofprecipitatingamoderateamountofɻphase.Thenewlydevelopedheat treatmentssignificantlyimprovethemechanicalpropertiesoftheWAAMalloyandalsoreducethe anisotropiceffect.  22
MicrostructuralEvolutionDuringHeatTreatmentandMechanismofWearofConventional and3DPrintedTi6Al4VTitaniumAlloys

NiyoushaAzgomiandSolomonBoakyeͲYiadom

YorkUniversity

MedicalGradeTi6Al4Visoneofthealloysusedashipandkneeimplantsduetoitsbiocompatibility, strength,toughnessandgoodcorrosionresistance.Recenteffortsduetoadvancementofmetal3D printinghasseenanincreaseinthenumberof3DprintedTi6Al4Vtitaniumalloysusedasimplants.Even thoughmetal3Dprintinghasgreatadvantagesincludingabilitytoeasilyprintcomplexshapesandparts, thepropertiesof3DprintedTi6Al4Vtitaniumalloysarestillunderinvestigation.Theaimofthisstudyis tounderstandtheeffectofheattreatmentonthemicroͲstructuralevolution,hardnessandmechanism of wearofconventionaland3DprintedTi6Al4Vtitaniumalloy.ItisdemonstratedthatthemicroͲ structuralintegrityoftheTi6Al4Valloysisafunctionofboththemanufacturingprocessandthe temperature/durationforheattreatment.

17:00Ͳ19:00PosterSession

23

Wednesday,June12



9:00MaterialsChemistryLecture

 TheDevelopmentofCorrosionͲresistantCopperͲcoatedSteelContainersforthePermanent

DisposalofHighLevelNuclearWaste

DavidShoesmith,UniversityofWesternOntario

 TheproposedlongͲtermmanagementprocedureforusednuclearfuelinCanadaisdisposalinadeep geologicalrepository(DGR)whichhasmultiplebarrierstoensuresafeisolationandcontainment.Within thismultiͲbarriersystem,thekeyengineeredbarrierisarobustcontainerconsistingofacarbonsteel innervesselcoatedwith~3mmofcopperappliedviaelectrodepositionandcoldspraydeposition.Once emplacedintheDGRthecontainerwillbeexposedtoconditionswhichevolvefromwarm,dryandoxic tocool,wetandanoxic.Tojustifytheuseofsuchacontainerrequirestheoptimizationofthecopper coatingproceduresandathoroughevaluationofthepossiblecorrosion/degradationprocessesthat couldoccur.Thispresentationwilldescribethecontainerdesign,discussthekeyissuesinvolvedin achievingadurablecoating,andoutlinesomeofthekeycorrosionprocesseslikelytooccuronthe container. 

10:20-12:00EmburySymposiumIV

NanoscaledstructureandpropertiesofultrafinegrainedAluminumstabilizedbyCagrain boundarysegregationsandintermetallicparticles

XavierSauvage

NormandieUniversité,UNIROUEN,INSARouen,CNRS

ThesolubilityofCainAlisextremelylow,whichmakesthisalloyingelementattractivetostabilizea nanoscaledgrainstructurethankstoGBsegregationsandtoachieveauniquecombinationofhigh strength,lowelectricalresistivity,goodthermalstabilityandlowdensitymaterial.Toachievethisgoal, anAl ͲCametalmatrixcompositewasprocessedbysevereplasticdeformation(SPD),andtheresulting nanoscaledstructureswerecharacterizedwithacombinationofTEMandAPTanalyses.Weshowthat theSPDledtoaprogressivedissolutionofCagrainsandameanAlgrainsizeofonly25nm,whichis stabilizedbyCasegregationatGBsandalowsupersaturatedsolidsolutionofCainAl.Thisgivesrisetoa hardnessupto300HVbutanelectricalconductivitylowerthan10%IACS.Uponaging,thegraingrowth isrelativelylimited,nanoscaledAl4CaparticlesnucleateatGBs,andtheelectricalconductivity is significantlyrecovered. PrecipitationHardeningAssociatedwithHighTemperatureFormingofHeatTreatableAl

Alloys

AtekehAbolhasani,MassimoDiCiano,KaabOmer,MichaelWorswick,MaryA.WellsandShahrzad

Esmaeili

UniversityofWaterloo

AlthoughconventionalmanufacturingroutesforAlpartsarebasedonroomtemperatureforming practices,thedesiretofurtheroptimizeprocessingandpropertiesofthesealloysforautomotive applicationsiscreatingconsiderableinterestintheirhightemperatureforming.Hightemperature 24
formingofprecipitationhardeningAlalloys,however,interferewithand/ormodifyprecipitate dissolutionandformationphenomena.Dependingonthechoiceoftheprocessvariables,such interferencesand/ormodificationsmayresultinenhancementordeclineintheprecipitationhardening capacityofthealloysandthusthefinalpartstrength.For hightemperatureformingprocessestobe fullyadoptedbytheautomotiveindustryformanufacturingAA6xxxandAA7xxxaluminumalloyparts, interactivephenomenarelatedtotheirprecipitationhardeningbehavioursshouldbecomprehensively investigated.Thispresentationfocusesontheevolutionsthatoccurinthemicrostructureandstrength ofwarmformedAA6013anddie ͲquenchedAA7075alloysduringvariousthermalprocess

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