简介:Aninnovativeapproachhasbeendevelopedtofabricatereticulatedporousceramics(RPCs)withuniformmacrostruc-turebyusingthepolymericspongeasthetemplates.Inthisapproach,thecoatingprocesscomprisesoftwostages.Inthefirststage,thethickerslurrywasusedtocoatuniformlythespongesubstrate.Thegreenbodywaspreheatedtoproduceareticulatedperformwithenoughhandlingstrengthafterthespongewasburnedout.Inthesecondstage,thethinnerslurrywasusedtocoatuniformlytheperform.Thepopulationofthemicroscopicandmacroscopicflawsinthestructureisreducedsignificantlybyrecoatingprocess.Afewfilledcellsandcellfacesoccurinthefabricationandthestrutswerethickened.AstatisticalevaluationbymeansofWeibullstatisticswascarriedoutonthebendstrengthdataofRPCs,whichwerepreparedbythetraditionalapproachandinnovativeapproach,respectively.TheresultshowsthatthemechanicalreliabilityofRPCsisimprovedbytheinnovativeapproach.Thisinnovativeapproachisverysimpleandcontrolledeasily,andwillopenupnewtechnologicalapplicationsforRPCs.
简介:在亚毫米尺寸的空幸运微范围被准备;作为药交货车辆调查了。LCB(锂钙硼酸盐)微范围,通过火焰水花过程被做,为空幸运微范围被选择为先锋的玻璃。LCB玻璃微范围与磷酸盐缓冲剂(K2HPO4)反应了在37°C的5天的答案。在反应期间,Ca-P-OH混合物在LCB玻璃的表面上猛抛微范围;形成的多孔的壳。然后,微范围转弯了是有象在LCB玻璃以后的微范围在化学反应跑出去的玻璃的一样的直径的空的。在以后在为4h的600°对待热,Ca-P-OH混合物成为了幸运,因此,空幸运微范围被生产。形成空幸运的机制通过在磷酸盐缓冲剂之间的化学反应的微范围;LCB玻璃被XRD分析证实。空、多孔的微范围的微观结构特征被SEM观察。
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简介:Znbasedmetalshaveexhibitedpromisingprospectsasastructuralmaterialforbiodegradableapplications.PureZnporousscaffoldswereproducedbylaserpowderbedfusion(LPBF)basedondatafilesofdesigningandCTseanning.MassiveZnevaporationduringlasermeltinglargelyinfluencedtheformationqualityduringLPBFofZnmetal.Themetalvaporinprocessingchamberwasblownoffandsuctionedoutefficientlybyanoptimizedgascirculationsystem.Numericalanalysiswasusedtodesignandtestifytheperformanceofgasflow.Thesurfaceofscaffoldswascoveredwithnumerousparticlesindifferentsizes.Processingporesoccurredneartheoutlinecontourofstruts.Theaveragegrainsizeinwidthwas8.5μm,andthehardnesswas43.8HV.Chemicalpluselectrochemicalpolishingobtainedunifonnandsmoothsurfacewithoutprocessingpores,butthediameterofstrutsreducedto250μmfromthedesignvalue300μm.Thepoorsurfacequalityandprocessingporeswereresultedbythesplashingparticlesincludedspattersandpowdersduetotherecoilforceofevaporation,andthehorizontalmovementofliquidmetalduetooverheatingandwetting.TheinsufficientmeltingattheoutlinecontourcombinedwithgoodwettingofZnliquidmetalfurtherincreasedthesurfaceroughnessandprocessingpores.
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:Theinternalstressinducedbyaporouslayerorpassivelayercanassisttheappliedstresstopromotedislocationemissionandcrackpropagation,e.g.whenthepipelinesteelisburiedinthesoilcontainingwater,resultinginstresscorrosioncracking(SCC).Moleculardynamics(MD)simulationisperformedtostudytheprocessofdislocationemissionandcrackpropagationinaslabofFecrystalwithandwithoutaporouslayeronthesurfaceofthecrack.Theresultsshowthatwhenthereisaporouslayeronthesurfaceofthecrack,thetensilestressinducedbytheporouslayercansuperimposeontheexternalappliedstressandthenassisttheappliedstresstoinitiatecracktipdislocationemissionunderloweredstressintensityKI,orstress.Torespondtothecorrosionaccelerateddislocationemissionandmotion,thecrackbeginstopropagateunderloweredstressintensityKI,resultinginSCC.