简介：ThepurposeofthisstudywastodeterminetheinffuenceofheattreatmentcycleongraphitephaseformationonCK45steel.Thepresenceofwelldistributedgraphiteinthematrixisresponsibleforthegoodmechanicalandthermalpropertiesofthiskindofalloy.Suchpropertiesincludeexcellentwearresistance,higherresistancetothermalshock,andhigherresistancetooxidationathightemperature.Anumberofspecimensweremadeupofappropriatedesigntoprovidetheexperimentalmaterials.Thetransformationphasetoafreecarbonmicrostructureduringgraphitizationunderdifferentconditionswasthenexaminedforthemostsuccessfulexperimentalsteels.Austenitisingtemperatureof920°Candthefollowingisothermalheattreatmentof750°Catdifferentholdingtimeswereused.MicrostructureswereexaminedbyOM(opticalmicroscopy)andSEM(scanningelectronmicroscopy).Furthermore,itwasfoundthatisothermaltransformationat750°Cfordifferentsoakingtimesproducedatypicalmicrostructure.Also,theamountofgraphiteincreasedwithincreasingisothermalheattreatmenttime.Heattreatmentleadingtosupersaturationofironwithcarbonwasdescribedandsomeoftheconsequencesofthesupersaturationwerepresented.Finally,theformationofthethermodynamicallystablestateofthegraphitetakenfromthesupersaturatedsolidsolutionwasdiscussed.

简介：半导体芯片（集成电路）是信息产业的基础，也是一国或地区科技竞争力的象征。目前全球大多数芯片制造企业一般处于90／65纳米的技术工艺水平。而中芯国际65纳米的产品销量已经实现近1亿美元收入；45纳米产品工艺已经完成了完整的工艺流程研发并通过了国际主流客户的验证，年末有望量产；32纳米产品工艺已经开始了实质性的研发工作，其中关键工艺已在少量芯片上得到验证。

简介：<正>日本已正式启动以氨(NH3)为燃料的新型燃料电池的开发。这是日本文部科学省与日本科学技术振兴机构(JST)推进的"尖端低碳化技术开发(ALCA)特別重点技术领域能源载体"项目中的一项内容,由京都大学研究生院工学研究系教授江口浩一主导。

简介：

简介：利用XRD、SEM等分析手段，对含微量Zr、Ti的Cr35Ni45Nb合金的力学性能和微观组织相互关系进行了研究。结果表明，该合金组织为奥氏体基体和枝晶间骨架状碳化物，碳化物类型为富铬的M23C6和含铌等强碳化物元素组成的MC；微量Zr、Ti可细化二次析出的Cr35Ni45Nb合金中的碳化物，使其呈粒状较均匀地分布在晶内，从而提高合金的力学性能。

简介：Ag-TiAlintermetallicalloy,Tie45Ale2Nbe2Mn(at.%)e0.8vol.%TiB2,hasbeenprocessedfromgasatomizedprealloyedpowderbyfieldassistedhotpressing(FAHP).Aninitialanalysisoftheprealloyedpowderhelpedontheunderstandingoftheintermetallicsinteringbehavior.Atomizedpowderconsistedofametastablephasethattransformedintoa2tgequilibriumphasesbythermaltreating.Differentpowderparticlemicrostructureswerefound,whichinfluencethemicrostructuredevelopmentoftheFAHPg-TiAlmaterialdependingonthesinteringtemperature.Duplex,nearlylamellarandfullylamellarmicrostructureswereobtainedatthesinteringtemperaturesabove1000C.Lowerconsolidationtemperatures,below1000C,ledtotheformationofanAlrichphaseatpowderparticleboundaries,whichisdeleterioustothemechanicalproperties.Highcompressiveyieldstrengthof1050MPawasobservedinsampleswithFAHPduplexmicrostructuresatroomtemperature.Whereasnearlylamellarandfullylamellarmicrostructuresshowedyieldstrengthvaluesof655and626MPaatroomtemperatureand440and425MPaat750C,respectively,whicharesuperiorincomparisontosimilaralloysprocessedbyothertechniques.Theseexcellentpropertiescanbeexplainedduetothedifferentvolumefractionsofthea2andgphasesandtherefinementofthePMmicrostructures.