简介：Thelargesize,crack-freeZr55Cu30Al10Ni5bulkmetallicglass(BMGs)withthediameterof54mmandtheheightof15mmwasbuiltbylasersolidformingadditivemanufacturingtechnology,whosesizeislargerthanthecriticaldiameterbycasting.Themicrostructure,tensileandcompressivedeformationbehaviorsandfracturemorphologyoflasersolidformedZr55Cu30Al10Ni5BMGswereinvestigated.Itisfoundthatthecrystallizationmainlyoccursintheheat-affectedzonesofdepositionlayers,whichconsistofAl5Ni3Zr2,NiZr2,ZrCu,CuZr2phases.Thecontentofamorphousphaseinthedepositisabout63%.Underthecompressiveloading,thedepositpresentsnoplasticitybeforefractureoccurs.Thefractureprocessismainlycontrolledbytheshearstressandthecompressiveshearfractureanglesofabout39.Thecompressivestrengthreaches1452MPa,whichisequivalenttothatofas-CastZr55Cu30Al10Ni5BMGs,andthereexistvein-likepatterns,river-likepatternsandsmoothregionsatthecompressivefractography.Underthetensileloading,thedepositpresentsthebrittlefracturepatternwithoutplasticdeformation.Thefractureprocessexhibitsnormalfracturemodel,andthetensileshearfractureangleofabout90°.Thetensilestrengthisonlyabout609MPa,andthetensilefractographymainlyconsistsofmicro-scaledcoresandvein-likepatterns,dimple-likepatterns,chocolate-likepatternsandsmoothregions.Theresultsfurtherverifiedthefeasibilityandlargepotentialoflaseradditivemanufacturingonfabricationandindustrialapplicationoflarge-scaleBMGsparts.

简介：AdditivelymanufacturedTi-6Al-4Vlatticestructureshavefoundimportantnicheapplications.However,theyoftenshowinsufficientcompressiveductilityorinsufficientstructuralintegrity.Inthisstudy,abatchof45octahedralTi-6Al-4Vlatticestructureswasmanufacturedinthreedifferentstrutdiameters(0.5,1.0,1.5mm)byselectiveelectronbeammelting(SEBM).Theinfluenceofpost-SEBMannealingonthecompressivedeformationcharacteristicsofthelatticestructurewasinvestigated.Theas-builtTi-6AI-4Vlatticesfragmentedwhenthecompressivestrainreached13%-23%dependingonstrutdiameter.Annealingat950℃(Ptransustemperature:995℃)onlyslightlyimprovedthecompressiveductilityofthelatticestructures.However,annealingat1050℃(p-annealing)fundamentallychangedthecompressivedeformationmodeofthelatticestructures.Theresultantcompressivestress-straincurvewasfeaturedbyalongsmoothplateauandnofactureoccurredevenaftersignificantdensificationofthelatticestructurehadtakenplace(>50%ofcompressivestrain).