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ZrB_2改性CC复合材料微观结构及烧蚀性能的研究(英文).docx

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ZrB_2改性CC复合材料微观结构及烧蚀性能的研究(英文) ResearchonMicrostructureandAblativePropertiesofZrB2-ModifiedCCComposites Introduction Carbon-carbon(CC)compositesarewidelyusedintheaerospaceindustryduetotheirexcellentmechanicalpropertiesandhightemperatureresistance.However,theirpoorablationresistancelimitstheirapplicationsinthefieldofatmosphericreentryvehicles.InordertoimprovetheablationresistanceofCCcomposites,modifyingagentsareoftenaddedtothematerial.Inthisstudy,ZrB2waschosenasthemodifyingagenttoimprovetheablationresistanceofCCcomposites.ThemicrostructureandablationpropertiesoftheresultingZrB2-modifiedCCcompositeswereinvestigated. ExperimentalMethodology ZrB2powderwasaddedtotheCCprecursortoformtheZrB2-modifiedCCcomposite.TheweightpercentagesofZrB2powderaddedwere2%,4%,6%,8%,and10%.TheCCprecursorandtheZrB2-modifiedCCcompositeswerecarbonizedanddensifiedusingahigh-temperaturefurnace.Themicrostructureandablationpropertiesoftheresultantmaterialswereanalyzedusingscanningelectronmicroscopy(SEM)andalaserablationtestsystem,respectively. ResultsandDiscussion MicrostructureAnalysis ThemicrostructureofCCcompositesisdeterminedbythefiberdistributionandpyrolysisprocess.TheadditionofZrB2didnotchangethedistributionofthefiberbutaffectedthepyrolysisprocess.SEMimagesshowedthatthesurfaceoftheZrB2-modifiedCCcompositeswasmuchsmoothercomparedtothatoftheunmodifiedCCcomposites.ThiscouldbeduetothefactthattheadditionofZrB2promotedtheformationofaprotectivelayeronthesurfaceoftheCCcompositesduringcarbonization. AblationProperties TheablationpropertiesoftheZrB2-modifiedCCcompositeswereevaluatedusingalaserablationtestsystem.ResultsshowedthattheablationresistanceoftheZrB2-modifiedCCcompositesimprovedwithincreasingweightpercentageofZrB2powder.TheablationrateoftheunmodifiedCCcompositeswas73.5μm/s,whilethatoftheCCcompositesmodifiedwith10%ZrB2wasonly5.7μm/s.TheadditionofZrB2powdereffectivelyblockedthetransferofheatandmass,leadingtotheimprovementoftheablationresistanceoftheCCcomposites. Conclusion Inthisstudy,ZrB2wasusedas