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简介:Anovelprocesstechnologytoprepareglass-ceramicsdirectlyfrommoltensteelslag(MSS)isproposedinthestudy.Theliquid-solidmixingmethodwasusedtoadjustthecomponentsoftheMSSandglass-ceramicswasobtained.Theeffectsofheat-treatmentconditionsonthemicrostructure,physicalandmechanicalpropertiesofsampleswerestudied.Economicalbenefitsofthenovelprocesswereanalyzed.Theresultsshowthatheat-treatmentisaveryeffectiveapproachtoachievingcrystallization.Thedominantcrystalphaseinproductsisdiopside[(Mg6Al2Fe2)Ca(Si1.5Al5)O2].Theshapeofthecrystallizationislikeagranule.Theglass-ceramicsamplesexhibitedgoodmechanicalpropertiesandpresentedchemicalstability.Theeconomicbenefitsoftheprocessareremarkableduetolessenergyconsumptioncomparedwithconventionalglass-ceramicsproductionmethods.
简介:Anewmicromechanicsconstitutivemodelforpuredilatanttransformationplasticityofstructureceramicsisproposedinthispaper.Basedonthethermodynamics,micromechanicsandmicroscalet→mtrans-formationmechanismanalysisoftheTZPandPSZZrO2-containingceramics,ananalyticexpressionsoftheHelmholtzandcomplementaryfreeenergyoftheconstitutiveelementforthecaseofpuredilatanttransforma-tionisderivedforthefirsttimeinaself-consistentmanner.Bytheanalysisofenergydissipationinthefor-wardandreversetransformations,themieromechanicsconstitutivelawisderivedintheframeworkofHill-Rice’sinternalvariableconstitutivetheory.
简介:煤苍蝇灰是为精力生产在煤的燃烧期间产生的一个工业副产品。由于增加煤电源的年度消费和煤苍蝇灰的严肃的潜在的环境威胁,关于煤苍蝇灰的利用的研究的可观的数量全球被承担了。玻璃化似乎是为再使用这工业废物的最有希望的选择之一。这篇论文作为原料用煤苍蝇灰给出唯一的高效眼镜陶艺的生产的短概述。对为从煤苍蝇灰和主要水晶阶段,相应性质和那些材料的可能的用法的眼镜陶艺的合成的方法论的详细描述被介绍。调查揭示了那变换的煤苍蝇灰进高效眼镜陶器的材料是一条有希望的新途径改进这个工业副产品的利用。这变换不仅与处理减轻这些问题而且把废物材料变换成高增值可销售的商品。
简介:DenseSi3N4BNcompositeceramicswerefabricatedbysparkplasmasinteringat1500,1600and1650℃under50MPafor5minusingSi3N4andBNpowdersasstartingmaterialsand2mass%Al2O3and6mass%Y2O3assinteringadditives.ThevolumefractionofBNinSi3N4BNcompositepowderswaschosenas10%,20%,and30%,respectively.TheresultsofXRDandSEMshowthatα-Si3N4completelyturnsintoβ-Si3N4whenthecompositeceramicsaresinteredat1650℃;theadditionofBNhindersthegrowthofSi3N4grains,refiningthestructure;VickershardnessandfracturetoughnessofthecompositeceramicsdecreasewiththeincreaseofBNcontent.
简介:PorousSi3N4self-reinforceceramicswerepreparedbygelcastingusingagarosesolutions.Bychangingtheagarosecontentintheslurries,theporoussiliconnitrideceramicswithdifferentporosities,α→β-Si3N4phasetransformation,andmechanicalpropertieswereobtained.Whentheagarosecontentchangedfrom0.2%to0.8%(w/w,basedonpowder),theporositiesincreasedfrom10.3%to21.4%,whilethefracturestrengthdecreasedfrom455to316MPaandthefracturetoughnessdecreasedfrom6.6to5.5MPa·m1/2.Manyfibrousβ-Si3N4grainsgrownfromtheinternalwalloftheroundporesisthetypicalmicrostructureofthegelcastingporoussiliconnitrideceramic.Bothelongatedβ-Si3N4grainsandsuitableinterfacialbondingstrengthcontributestohighfracturetoughnessbyfavoringcrackdeflectionandbridging.Thegrowthmechanismsoffibrousgrainsresultedfromthesynergyofsolution-diffusion-reprecipitationandvapor-liquid-solid(VLS).
简介:Nd:钇铝柘榴石先锋粉末被同类的降水,和Nd综合:钇铝柘榴石透明陶艺被真空sintering为5h在1700°C作好准备。陶器的材料被轻发射度和地排放枪环境扫描显微镜描绘。用统计和立方米科学理论,学习在在轻发射度和立体声之间的量的关系上被执行在三维的欧几里德几何学的空格的逻辑参数。这被发现Nd的发射度:有在厚度的1公里的钇铝柘榴石分别地在可见、在红外线附近的波长是大约45%和58%。发射度线性地与增加相等的范围直径增加并且当相等的范围直径是20μm时,到达单个水晶的理论价值。有每统一谷物和分离谷物的体积增加吝啬的特定的区域的发射度减少,和有增加的发射度减少在Nd意味着谷物的免费距离:钇铝柘榴石陶艺。
简介:Seaurchinspineswerechosenasamodelsystemforbiomimeticceramicsobtainedusingstarch-blendedslipcasting.Porousaluminaceramicswithcap-shapedlayerswithdifferentalternatingporositieswerefoundtohavesuperiorfracturebehaviorunderbulkcompressioncomparedtoceramicswithuniformporosity.Theyfailinacascadingmanner,absorbinghighamountsofenergyduringextendedcompressionpaths.TheporosityvariationinanotherwisesinglephasematerialmimicksthearchitecturalmicrostructuredesignofseaurchinspinesofHeterocentrotusmammillatus,whicharepromisingmodelmaterialsforimpactprotection.
简介:异构或合成的材料的有效热传导性为在科学和工程的特定的功能是材料选择和设计的一个必要物理参数。有效热传导性重重地在部分和每个阶段的空间分发上被依靠。在这个工作,基于图象的有限元素方法(女性)被用来与不同毛孔结构计算多孔的陶艺的有效热传导性。与象理论(EMT)方程和平行建模的有效媒介那样的以前的理论模型相比,基于图象的女性的罐头与相对稳定的偏差被用于材料系统的一个大变化。基于图象的女性的计算的偏差主要来自之间的差别二维(2D)想象并且三维(3D)真实系统的结构,和一个实验被执行证实这个假设。因素影响2D和3D有效热传导性被学习由对女性说明精确性和申请条件基于图象女性。
简介:Developmentofhighenergylasersourceswithnanosecondpulsesatseveralhertzvaluesforrepetitionratehasbeenveryattractiveinrecentyearsduetotheirgreatpotentialforpracticalapplications.Withtherecentadvancementinfabricatinglargesizelaserqualitytransparentceramics,diodepumpedsolid-statelasergeneratingpulseenergyof100Jat10HzhasbeenrecentlyrealizedatHiLASEcenterusingYb:YAGceramicwithCr:YAGcladding.ThisreviewdiscussesYbbasedhighenergylasers,specificlasergeometriesforefficientthermalmanagementandtheroleoftransparentceramicsinsuchdiodepumpedhigh-energy-classsolid-statelasersaroundtheworld.
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简介:ForimprovingthepropertiesofSiC-mullitecompositeceramicsusedforsolarsensiblethermalstorage,MnO_2wasintroducedassinteringadditivewhenpreparing.ThecompositeceramicsweresynthesizedbyusingSiC,andalusite,α-Al_2O_3asthestartingmaterialswithnon-contactgraphite-buriedsinteringmethod.PhasecompositionandmicrostructureofthecompositeswereinvestigatedbyXRDandSEM,andtheeffectofMnO_2onthepropertiesofSiCcompositeswasstudied.ResultsindicatedthatsamplesSM1with0.2wt%MnO_2additionachievedtheoptimumproperties:bendingstrengthof70.96MPa,heatcapacityof1.02J·(g·K)-1,thermalconductivityof9.05W·(m·K)-1.ProperadditionofMnO_2wasfoundtoweakenthevolumeeffectofthecompositesandimprovethethermalshockresistancewithanincreasedrateof27.84%forbendingstrengthafter30cyclesofthermalshock(aircoolingfrom1100℃toRT).
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简介:Thepreparationofcalciumphosphate(CP)coatingonaluminaceramicsusingelectricpulsestimulatingmethodhasbeeninvestigated.Thecup-shapedaluminaceramicsweresoakedinasimulatedbodyfluid(SBF),andasquarepulsepotentialwithfrequencyof1Hzandvoltageof110Vwasappliedbetweentheinnerandoutersurfacesofthealuminacup.SurfacemorphologyofCPcoatingsduringdifferentdepositionperiodswasobservedbyaPhilipsXL-30scanningelectronmicroscope(SEM).CompositionalanalysiswasexaminedbyEDAX.ThemechanismofnucleationandgrowthofCPcoatingwasdiscussed.SEMresultindicatesthatthecoatingcomprisesofalargenumberoftinyneedle-likegrainsandhasaporousmicrostructure.ThereisastrongbondbetweenthedepositedlayerandAl2O3substrate,whichmaybeduetothegentlegrowthofthebiomimeticmethod.TheEDAXanalysisindicatesthatmaincompositionofthecoatingiscalciumandphosphor.TheformationofCPcoatingmaybecontributedtothestimulationofelectricpulseandthehighionsconcentrationwhichis1.5timesoftheconcentrationofSBFsolution(1.5SBFsolution).SuchsurfacefunctionalizationmethodbyelectricpulsepotentialcanbeusedtoprepareCPcoatingonvariouselectric-insulatingbioinertmaterialsforimprovingtheirbioactivecharacter.
简介:三新奇Ba_5RNiNb_9O_(30)(R=La,Nd和Sm)陶艺在BaO-R_2O_3-NiO-Nb_2O_5系统被准备并且描绘。所有三混合物areparaelectjicphasesadopting。在房间温度的充满的四角形的钨铜(TB)结构。在1MHz,Ba_5RNiNb_9O_(30)陶艺有高电介质在范围193-245.3,在范围0.0059-0.0087的低绝缘的损失,和在范围的绝缘的常数(tau_e)的温度系数的常数-1140-1310X10~(-6)中心点degC。他们绝缘的常数的温度系数显著地Ba_5RNiNb_9O_(30)与那些相比被减少(R=La,Nd,Sm)陶艺。