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ScienceDirect学科指南PorousAluminaCeramicsFabricatedbySparkPlasmaSintering多孔氧化铝陶瓷的放电等离子烧结技术制备WANGKun,FUZheng-yi*,PENGYong,WANGYu-cheng,ZHANGJin-gong,ZHANGQing-jie王坤，福郑毅，彭勇，王宇城，张晋宫，张庆街StateKeyLabofAdvancedTechnologyforMaterialsSynthesisandProcessing,WuhanUniversityofTechnologyWuhan,430070,China国家重点实验室先进的材料合成与加工技术，武汉理工大学，武汉，430070，中国Received10August2006;accepted6November20062006年8月10收到；2006年11月6日接受Abstract摘要Porousaluminaofregularsphericalparticleswasfabricatedwiththesparkplasmasintering(SPS)andthencomparedtothoseobtamedthroughconventionalhotpressing(HP).Theeffectsoftheparametersoftheheatingprocessonporositywerealsoinvestigated.Microstructuralstudiessuggestthatporousingotsincludingregularporesbemadeoutofregularsphericalaluminaparticlesduetotheclosespherepackages.AcomparativestudyontherelativenecksofthespecimensproducedbySPSandHPindicatesanenhancementofneckgrowthwithSPS.Contrastingthetheoreticalvaluestotheexperimentalresultsovertherelativenecksindicatesthataproperrelationshipbetweentherelativenecksandtheporositycanbeestablishedbyasinteringmodel.多孔氧化铝为规则的球形颗粒与放电等离子烧结（SPS）制备，然后比较分析通过常规热压（惠普）。同时考察了加热过程的参数对孔隙率的影响。微观结构研究表明，多孔硅锭包括定期毛孔被制造出来的规则的球形氧化铝颗粒由于接近球包。在SPS和惠普生产的标本，相对的脖子比较研究表明SPS颈部生长的增强。对比理论值的实验结果表明，在相对的脖子相对的脖子和孔隙度之间的关系可以通过烧结模型的建立。Keywords:sparkplasmasintering(SPS);porousaluminaceramics;sinteringneck关键词：放电等离子烧结（SPS）；多孔氧化铝陶瓷；烧结颈1Introduction1引言Porousaluminaceramics,whichhavebothfunctionalandstructuralproperties,havebeenwidelyappliedinthechemicalindustries,metallurgicalindustries,medicalindustries,andmanyotherfieldsofengineering[1].Thevariousdesignandperformancecharacteristicsofporousaluminaceramicsareprincipallyconcentratedaboutcontrolledporosityandpore-size,highstrength,heatandcorrosionresistance,durability,shockresistance,andgoodpermeability.Therearemanytechniquestofabricateporousaluminaceramics,butthemajorityofthoseneedtoaddorganicpolymersasporeformingmaterials[2].However,sparkplasmasintering(SPS)issuggestedtobeeffectiveonthefabricationofporousaluminaceramicsbecauseitmakespossiblesinteringandbondingatlowtemperatureandshorttimebychargingtheintervalsbetweenpowderparticleswithelectricalenergyandeffectivelyapplyingahightemperaturesparkplasmageneratedmomentarily[3-5].Comparedwithhotpressing(HP)sintering,porousaluminaceramicscanbemanufacturedbySPSatlowerheatingtemperature,shortholdingtimewithoutanyaddictive.多孔氧化铝陶瓷，具有的功能和结构特性，已被广泛应用于化学工业，冶金工业，医疗业，以及其他许多领域工程[1]。各种设计和多孔氧化铝陶瓷的性能特点，主要集中在受控的孔隙率和孔径，高强度，耐热性和耐蚀性，耐久性，耐冲击性，和良好的渗透性。有许多技术制备多孔氧化铝陶瓷，但大多数人需要添加有机聚合物材料的孔隙形成[2]。然而，放电等离子烧结（SPS）建议对多孔氧化铝陶瓷的制备是有效的因为它使烧结和粘结在较低的温度和较短的时间间隔，通过充电的电能和有效应用高温放电等离子粉末颗粒之间产生瞬间[3-5]。热压烧结（惠普）相比，多孔氧化铝陶瓷可由SPS在较低的加热温度，保持时间短，无任何添加剂。Inthispaper,porousaluminaceramicswerefabricatedbySPSandcomparedwiththesamplesbyHP;furthermore,theeffectsofthetechniqueparametersonporosityandtheeffectivenessforthesinteringnecksduringSPSprocesswerediscussed.在本文中，SPS制备与惠普的多孔氧化铝陶瓷样品进行了比较；此外，还讨论了对孔隙度的技术参数和在SPS烧结过程的脖子的效果。2ExperimentalProcedures2实验程序RawmaterialsweresphericalparticlesofAl2O3withanadditiveofZrO,ofwhichdiameterswerefrom0.4mmto0.5mm.4gofthesesphericalparticleswereputintoagraphitemoldandsinteredusingasparkplasmasinteringapparatus(modelSPS-1050,Sumi-tomoCoalMiningCo.Ltd.Japan).原材料是球形颗粒的Al2O3withan添加剂ofZrO，diametersofwhichwerefrom0.4毫米至0.5毫米4gofthese球形粒子是putinto石墨模具和使用火花等离子体烧结sintered呼吸器（SPS1050模型，大隅我煤矿业有限公司Japan）Fig.lshowstheschematicdiagramofSPSdeviceemployedintheexperiments图1显示了SPS装置采用的实验原理图SPSprocessingwascarriedoutinavacuum(1=6Pa)byheatingtotherequiredtemperature(1173K-11253K)atheatingrateof50K/min-400K/min,with1min-30minofholdingtimeandanappliedpressureof0kPa-80kPa.Temperaturewasmeasuredbythermocouple.Forcomparison,thesameparticleswerecompactedusingahot-pressing(HP)procedureunderthesametemperaturewith60minand481kPa.SPS处理是在真空中进行（1=6Pa）被加热到所需温度（1173k-11253K）在加热速率为50K/min-400K／min，1min-30分钟的保持时间和0kpa-80千帕施加的压力。使用热电偶测量温度。相比之下，同一颗粒被压实采用热压（惠普）程序相同的温度下60分钟，481kpa。3ResultsandDiscussion结果与讨论3.1Porositymeasurement孔隙度测量ApparentporositymeasurementwasbasedonArchimedeanprincipalmethod.Figs.2-5showthattheeffectofthedifferenttechniqueparametersduringthesinteringprocessonporosity.AscanbeseeninFigs.2-4,apparentporositydecreasesslightlywithincreasingsinteringtemperatureandincreasingholdingtime,whiletheappliedpressurehaslittleinfluenceontheporositybecauseofthehighhardnessandlargedimensionoftherawparticles.InFig.5,thereisaslightdeclineinporositywhentheheatingrategoesupfrom50K/minto100K/min,whichisfollowedbyaroughlyleveloffinporositywhentheheatingratereaches400K/min.Therefore,anappropriateascendofheatingratehasapositiveeffectontheporosityofthesamples,andthereexistsdifferentoptimumheatingratefordifferentsystems.显气孔率的测量是基于阿基米德主要方法。Figs.2-5表明，在烧结过程中对孔隙度的不同工艺参数的影响。如可于图2-4中可以看出，表观孔隙率随烧结温度和增加保持时间略有减小，而所施加的压力有因为高硬度和原料颗粒的大尺寸的影响较小的孔隙率。在图5中，有在孔隙率略有下降，当加热速率上升为50K/分钟至100K/分钟，这之后是在孔隙大致平整时的升温速率达到400K/min的。因此，升温速率适当的递增有对样品的孔隙率有正面影响，并且存在不同的最佳加热速度为不同的系统。Fig.2TheeffectofsinteringtemperatureonporosityforporousAl2O3ceramics(pressure:48kPa;holdingtime:10min;heatingrate:100K/min)图2烧结温度对孔隙度的多孔氧化铝陶瓷的影响（压力48千帕;保温时间