简介:Aninnovativeapproachhasbeendevelopedtofabricatereticulatedporousceramics(RPCs)withuniformmacrostruc-turebyusingthepolymericspongeasthetemplates.Inthisapproach,thecoatingprocesscomprisesoftwostages.Inthefirststage,thethickerslurrywasusedtocoatuniformlythespongesubstrate.Thegreenbodywaspreheatedtoproduceareticulatedperformwithenoughhandlingstrengthafterthespongewasburnedout.Inthesecondstage,thethinnerslurrywasusedtocoatuniformlytheperform.Thepopulationofthemicroscopicandmacroscopicflawsinthestructureisreducedsignificantlybyrecoatingprocess.Afewfilledcellsandcellfacesoccurinthefabricationandthestrutswerethickened.AstatisticalevaluationbymeansofWeibullstatisticswascarriedoutonthebendstrengthdataofRPCs,whichwerepreparedbythetraditionalapproachandinnovativeapproach,respectively.TheresultshowsthatthemechanicalreliabilityofRPCsisimprovedbytheinnovativeapproach.Thisinnovativeapproachisverysimpleandcontrolledeasily,andwillopenupnewtechnologicalapplicationsforRPCs.
简介:Byanalogueexperimentofexhaustgas,thesensitivecharacteristicsoftitaniatoair/fuelratiowasinvestigated.Theeffectsofsomeimpuri-tiesontheelectricconductivityofTiO2,thedeviationof(A/F)cfrom(A/F)sinnonequilibriumgassystemandtheself-catalyticoxidationofTiO2wereexplainedrespectively.Theeffectsofca-talyst,porosityandthicknessofsensorelementontheresponsetimewasalsoanalyzed.
简介:Samplesofacobalt-basedalloythatunderwentasurfacetreatmentwereevaluated.Thesamples,whichwereobtainedbycastingalloyASTMF75,weregroundandpolishedononesideuntilamirrorfinishwasobtained.Thesampleswereencapsulatedinwollastonite(W)usinguniaxialpressure,treatedat1220℃for1handsubsequentlytemperedinwater.Thecharacterisationofthesampleindicatedthatpartoftheceramicencapsulatingmaterialwasmechanicallyincorporatedonthemetallicsurfacebygrowthoftheoxidelayerofthealloy.Afterthermaltreatment,aseriesofspecimensweresubmergedinasolutionwith5-foldsimulatedbodyfluid(5SBF)for3,5and21days.Characterisationbyscanningelectronmicroscopy(SEM),energydispersivespectroscopy(EDS)andX-raydiffraction(XRD)indicatednucleationandgrowthofahomogenouslayerofapatite,beginningonthethirddaywhenthesamplewassubmerged.