简介：ThepropertiesofFeMnSiCrNishapememoryalloywereinvestigated.TheresultsshowthatthebestshapememoryeffectofFel4Mn6Si9Cr5Nialloyis85%.Thetransformationamountoftheε→γtransformationisnotcompleteafterheatingthealloyto1000K,AsandAfpointsdropwithincreasedtransformationenthalpy(△Hγ→ε)bythermalcyclingandincreasedprestrain.Thealloyshowsalsogoodcreepandstressrelaxationresistance.Inaddition,thealloyhavingatensileforceof20kNandasealingpressureof6MPacansatisfyrequirementsforpossibleindustrialapplicationonpipejoints.

简介：Thepaperpresentsadetailedanalysisofexperimentaldatainordertocharacterizetheelasticpropertiesofarteries.Suchanalysiswouldprovideagoodbasisforevaluationofbiomimeticvasculargrafts.Sincethelatterneedstoexhibitsimilarpropertiesofnativetissue,itisimportanttoaccuratelycharacterizethebiomimeticsampleinalargerangeofappliedstresses.Thestress-strainpropertiesvaryaccordingtothespecificpathology(e.g.arteriosclerosis,aneurism)andthetissuegraftmustbechosencorrectly.Twomodelsareproposedinthispaperonthestress-straincharacteristics.Anextensionforfrequency-domainanalysisisprovidedforoneofthemodels.Thecomparisonbetweenvasculargraftsandnativetissueforcarotidandthoracicarteriesinpigsareingoodagreementwithresultsfromliterature.Theproposedexperimentalmethodofferssuitableparametersforidentifyingmodelswhichcharacterizebothelasticityandstiffnesspropertiesoftheanalyzedtissues(stress-strain).Theproposedmodelsshowgoodperformanceincharacterizingtheintrinsicmaterialproperties.

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简介：Thefracturetoughnessofhardbiomaterials,suchasnacre,bovinehoofwallandbeetlecuticle,isassociatedwithfibrousorlamellarstructuresthatdeflectorstopgrowingcracks.Theirhardnessandreducedmodulusweremeasuredbyusingananoindenterinthispaper.Micro/nanoscalecracksweregeneratedbynanoindentationusingaBerkovichtip.Nanoindentationofnacreandbovinehoofwallresultedinpile-uparoundtheindent.Itwasfoundthatthefracturetoughness(KC)ofbovinehoofwallisthemaximum,thesecondisnacre,andtheelytracuticleofdungbeetleistheleastone.

简介：Thestudyoffrictionalpropertiesofhumanskinisimportantformedicalresearch,skincareproductsandtextileexploi-tation.Inordertoinvestigatetheinfluenceofnormalloadandslidingspeedonthefrictionalpropertiesofskinanditspossiblemechanism,testswerecarriedoutonamulti-specimenfrictiontester.Whenthenormalloadincreasesfrom0.1Nto0.9N,normaldisplacementandthefrictioncoefficientofskinincrease.Thefrictioncoefficientisdependentontheload,indicatingthatbothadhesionanddeformationcontributetothefrictionbehaviour.Thedeformationfrictionwasinterpretedusingtheploughmodeloffriction.Whenslidingspeedincreasesfrom0.5mm·s?1to4mm·s?1,thefrictioncoefficientincreasesand'stick-slip'phenomenaincrease,indicatingthathystereticfrictioncontributestothefriction.Thehystereticfrictionwasin-terpretedusingschematicofenergytranslationduringtherigidsphericalprobeslidingonthesoftskinsurface,whichprovidesanexplanationfortheinfluenceoftheslidingspeedonthefrictionalcharacteristicsoftheskin.

简介：UltraHighMolecularWeightPolyethylene(UHMWPE)hasbeenwidelyusedasabearingmaterialforartificialjointreplacementoverfortyyears.Itisusuallycrosslinkedbygammaraysirradiationbeforeitsimplantationintohumanbody.Inthisstudy,UHMWPEandUHMWPE/nano-hydroxyapatite(n-HA)compositewerepreparedbyvacuumhot-pressingmethod.Thepreparedmaterialswereirradiatedbygammaraysinvacuumandmoltenheattreatedinvacuumjustafterirradiation.Theeffectoffillingn-HAwithgammairradiationontribologicalpropertiesofUHMWPEwasinvestigatedbyusingfrictionandwearexperimentalmachine(modelMM-200)underdeionizedwaterlubrication.Micro-morphologyofwornsurfacewasobservedbymetallographicmicroscope.Contactangleandhardnessofthematerialswerealsomeasured.Theresultsshowthatcontactangleandhardnessarechangedbyfillingn-HAandgammairradiation.Frictioncoefficientandwearrateunderdeionizedwaterlubricationarereducedbyfillingn-HA.Whilefrictioncoefficientisincreasedandwearrateisreducedsignificantlybygammairradiation.Thewornsurfaceofunfilledmaterialismainlycharacterizedasadhesivewearandabrasivewear,andthatofn-HAfilledmaterialismainlycharacterizedasabrasivewear.Aftergammairradiation,thedegreesofadhesiveandabrasivewearforunfilledmaterialandabrasivewearofn-HAfilledmaterialaresignificantlyreduced.Unfilledandfilledmaterialsafterirradiationaremainlyshownasslightfatiguewear.TheresultsindicatethatUHMWPEandUHMWPE/n-HAirradiatedatthedoseof150kGycanbeusedasbearingmaterialsinartificialjointsforitsexcellentwearresistancecomparedtooriginalUHMWPE.

简介：Themolluskshellmobilizescalciumfromenvironmentforskeletalmineralization.Thisoccursthroughsynthesizingsolidsinsolutioninthepresenceoforganicmoleculesofspecificinteriorregionsoftheconchshell.TheultrastructureandmicrohardnessoftheHemifusustubaconchshelllivingintheHuang/Boseaareaareinvestigatedinthepaper.Itisshownthatthecompositionandmicrostructureofthemolluskshellvaryindifferentpositions.Theprodissoconchshellconsistsonlyofaragonitewiththecrossed-lamellarmicrostructure.WhilethespiralshellandthebodyshelloftheHemifusustubaconchshellarecomposedofonecalcitelayerandseveralaragonitelayers.Thecalcitelayerconsistsofcylindricalgrains,butthearagonitelayersarecrossed-lamellarultrastructureatthreesizescales.Theminimumstructuresize(thethird-orderlamella)isatabout20nm-80nm.Themarginofshellapertureisonlycomposedofcalcitewithcylindricalgrains.ThisnaturaloptimizationoftheshellmicrostructureisintimatelyduetothegrowthoftheOrganicmatrix.Atdifferentpositionsthemicrohardnessofmolluscshellisdifferentduetodifferentcrystalstructuresandcrystalarrangements.Thegrowthprocessofshellsallowsaconstantrenewalofthematerial,thusenablingtheirfunctionaladaptationtoexternalenvironments.

简介：Poly(vinylalcohol)(PVA)/hydroxyapatite(HA)compositehydrogelspecimenswerepreparedwith15%PVAand1%,2%,3%,4%and5%HAbyrepeatedfreezing-thawing.ThetestsofstaticanddynamicmechanicalpropertieswerecarriedouttodiscusstheinfluenceofdifferentcontentsofHAandfreezing-thawingcyclesonthemechanicalpropertiesofPVA/HAcompositehydrogel.TheresultsofstaticmechanicaltestsshowedthatthePVA/HAcompositehydrogelwith3%HAandninefreezing-thawingcycleshadexcellentstressrelaxationproperties,higherrelaxationratio,lowerstressequilibriumvalueandpresentedbetterpropertiesofcreepandrecovery.TheresultsofdynamicmechanicaltestshowedthatthePVA/HAcompositehydrogelwithninefreezing-thawingcycleshadhigherstoragemodulusandlossmodulus,sowasthePVA/HAcompositehydrogelwith3%HA.

简介：Beetlewingsareveryspecializedflightorgansconsistingoftheveinsandmembranes.Thereforeitisnecessaryfromabionicviewtoinvestigatethematerialpropertiesofabeetlewingexperimentally.Inthepresentstudy,wehaveusedaDigitalImageCorrelation(DIC)techniquetomeasuretheelasticmodulusofabeetlewingmembrane.Specimenswerepreparedbycarefullycuttingabeetlehindwinginto3.0mmby7.0mmsegments(thegagelengthwas5mm).Weusedascanningelectronmicroscopeforaprecisemeasurementofthethicknessofthebeetlewingmembrane.Thespecimenwasattachedtoadesignedfixturetoinduceauniformdisplacementbymeansofamicromanipulator.WeusedanARAMISTMsystembasedonthedigitalimagecorrelationtechniquetomeasurethecorrespondingdisplacementofaspecimen.Thethicknessofthebeetlewingvariedatdifferentpointsofthemembrane.Theelasticmodulusdifferedinrelationtothemembranearrangementshowingastructuralanisotropy;theelasticmodulusinthechordwisedirectionisapproximately2.65GPa,whichisthreetimeslargerthantheelasticmodulusinthespanwisedirectionof0.84GPa.Asaresult,thedigitalimagecorrelation-basedARAMISsystemwassuc-cessfullyusedtomeasuretheelasticmodulusofabeetlewing.Inadditiontomembrane’selasticmodulus,weconsideredthePoisson’sratioofthemembraneandmeasuredtheelasticmodulusofaveinusinganInstronuniversaltensilemachine.TheresultrevealsthePoisson’sratioisnearlyzeroandtheelasticmodulusofaveinisabout11GPa.

简介：Usingeucollagensolutionsfromoxhide,wecastcollagenfilmstoassesstheinfluenceofcalciumandsilicaonthere-constitutionofthefibrousstructureofcollagen.Thetensilestrengthandthebreakingelongationofthereconstitutedcollagenfilmsweremeasuredandanalysed.Significantdifferenceswereobservedbetweenreconstitutedcollagenfilmswithandwithoutcalciumandsilica.Thebreakingelongationofthefilmsobtainedinthepresenceofsilicawassignificantlygreater,andthedegradationwaslowerthanotherfilmsofreconstitutedcollagen.Collagenandchitosandonotexisttogetherasblendsinnature,butthespecificpropertiesofeachmaybeusedtoproduceinbiomimeticwayman-madeblendswithbiomedicalapplications,thatconferuniquestructural,mechanical(detail)andinvivoproperties.

简介：MedicalforgedCoCrMoalloywastreatedbyplasmanitridingprocess.Themicrostructureswerecharacterizedby3Dprofiler,SEMandXRD.Thetribologicalpropertieswereinvestigatedunderlubricationof25%bovineserumsolution.Resultsshowthatplasmanitridingisapromisingprocesstoproducethick,hard,andmorewearresistantlayersonthesurfaceofCoCrMoalloy.AllnitridedsamplesshowedanimportantincreaseinthesurfacehardnessduetotheformationofharderCrNandCr2Nphaseswithcompactnano-crystallinestructures.ThetypicalhardnessvaluesofHV0.05increasedalmosttwotimesthanuntreatedone.Underbovineserumlubrication,atlownitridingtemperaturetheCoefficientofFriction（COF）ofnitridedsamplewaslowerthanthatofuntreatedsample,butathighnitridingtemperaturetheCOFwasalmostthesameastheuntreatedone.Comparedwiththeuntreatedsample,thenitridedsamplesshowedlowerwearratesandhigherwearresistanceunderdifferentnitridingtemperatures.TheadhesivewearisthemainmechanismforuntreatedCoCrMoalloyandthewearmechanismsofnitridedonesarethefatiguewearandslightadhesivewear.ItisconcludedthattheimprovementofwearresistanceisascribedtothehardnitrideformationofCrNandCr2Nphasesatthenitridedsurfaces.

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简介：Poly(vinylalcohol)/hydroxylapatite(PVA/HA)compositehydrogelwaspreparedbyrepeatedfreezingandthawing.Thewaterlosspropertiesoftheresultanthydrogelwereinvestigatedbyusingopticalmicroscope.LongtimeimmersiontestsofPVA/HAcompositehydrogelwerecarriedoutinthedilutedcalfserumsolutiontostudythechangelawsofswellingpropertieswiththefreezing-thawingcyclesandHAcontent.Themicro-morphologiesofPVA/HAcompositehydrogelafterlongtimeimmersionwereobservedbymeansofthehigh-accuracy3Dprofiler.TheresultsshowthattheswellingprocessofPVA/HAcompositehydrogelistheconverseprocessofitswaterloss.LongtimeswellingratiocurvesofPVA/HAcompositehydrogelinthecalfserumsolutionaremanifestedasfourstagesofquickincrease,decrease,slowdecreaseandstablebalance,anditsequilibriumswellingratiodecreaseswiththeincreaseoffreezing-thawingcyclesandHAcontent.ItisrevealedthatthenetworkstructureofthecompositehydrogelimmersedforalongperiodissignificantlyimprovedwiththeincreaseofHAcontent.PerfectnetworkstructuresofPVA/HAcompositehydrogelaswellasfullandequilibriumtissuesafterswellingequilibriumareobtainedwhentheHAcontentis3%andthenumberoffreezing-thawingcyclesis7.

简介：Lasermultipleprocessing,i.e.lasersurfacetexturingandthenLaserShockProcessing(LSP),isanewsurfaceprocessingtechnologyforthepreparationofbionicnon-smoothsurfaces.Basedonengineeringbionics,samplesofbionicnon-smoothsurfacesofstainlesssteel0Crl8Ni9weremanufacturedintheformofreseaustructurebylasermultipleprocessing.Themechanicalproperties(includingmicrohardness,residualstress,surfaceroughness)andmicrostructureofthesamplestreatedbylasermultipleprocessingwerecomparedwiththoseofthesampleswithoutLSPTheresultsshowthatthemechanicalpropertiesofthesesamplesbylasermultipleprocessingwereclearlyimprovedincomparisonwiththoseofthesampleswithoutLSPThemechanismsunderlyingtheimprovedsurfacemicrohardnessandsurfaceresidualstresswereanalyzed,andtherelationsbetweenhardness,comnressiveresidualstressandroughnesswerealsopresented.

简介：Fivekindsof45#steelsampleswithconcavefeaturesonthesurfaceweremanufacturedusingLaserTexturingTechnology(LTT).Optimumdesigntheorywasusedtodesigntheexperiment,andatwo-levelorthogonaltable-L16(215)designwasadopted.Micro-wearandmicro-frictionexperiencedbysampleswithconcavesurfacefeaturesandsampleswithsmoothsurfaceswerecomparedexperimentally.Thewearresistanceofsampleswithconcavesurfacefeatureswasincreasedmost,anddifferentsurfacemorphologieshaddifferenteffectsonfrictionandwearproperties.