证券行业分析报告200304

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GlassItiswellknownthatglassesplayanimportantroleasoneofbuildingmaterialsordinarylivingproducts.Advancedandspecialtyglassesalsoplayimportantrolesinseveralindustries.Inthelastseveralyears,thesematerialshavecontinuedtofindnewapplicationsintheareasoftelecommunications,electronics,andbiomedicaluses.Glasscompositionsandprocessingtechniquescontinuetoevolvetosuittheincreasingnumberofapplications.Someoftheglasscompositionshavedistinctivepropertiesthatmakethemthemostpreferredmaterialsforcertainapplications,suchasopticalfibers,electronicdisplays,biocompatibleimplants,dentalposteriormaterials,andhigh-performancecomposites.众所周知，玻璃作为建筑材料普通生活产品之一起着重要的作用。先进和特种玻璃也在许多行业也起着重要作用。在过去几年中，这些材料继续在电讯，电子，生物医学领域发现新的应用。为适应日益剧增的应用，玻璃的组分和加工技术不断发展。一些玻璃成分具有独特的性质，使得它们成为某些应用中最优选的材料，例如光纤，电子显示器，生物相容性植入物，后牙材料和高性能复合材料。Anumberofceramicprocesseshavebeensuccessfullyappliedinglassprocessingtomakeadvancedglasses.Theseincludesinteringofpremeltedandpulverizedglass,sinteringofpremeltedchemicallytreatedglasses,sol-geltechnology,andvaporphasedeposition.Glassceramicswithcomplicatedshapescanbeproducedbythesinteringofglasspowders,similartoaceramicsinteringprocess,andthenapplyingadditionalheattreatmenttoformceramiccrystals.Novelprocessescontinuetobedeveloped.已经有许多陶瓷工艺成功应用于玻璃加工中来制作先进玻璃，包括预熔玻璃粉末烧结，化学处理预熔玻璃烧结，溶胶-凝胶技术以及气相沉积。具有复杂形状的玻璃陶瓷可以通过类似于陶瓷烧结工艺对玻璃粉末进行烧结来制造，然后再进行额外的热处理以形成陶瓷晶体。新工艺在继续发展。Theemergenceoftheseadvancedglasseshassignificantlychangedseveralmajorindustries,includingthetelecommunicationsindustrywherefiberopticcablesrevolutionizedthetechnologyoftransmittinginformation.Otherareaswhereadvancedandspecialtyglassesandglassceramicsfindincreasingusageareelectronicsapplications,suchaselectronicdisplays,substratesforpackaginganddatastorage,andphotoblanksforlithography. 这些先进玻璃的出现极大地改变了几个主要行业，其中包括电信业，光纤光缆彻底改变了这一行业的传输信息技术。先进特种的玻璃和玻璃陶瓷有着越来越多使用的另一领域是电子应用，例如电子显示器，用于包装和数据存储的基板，以及用于光刻的照相机。High-performanceglassandglassceramicsarealsobeingusedasreinforcementsormatricesforadvancedcompositesforstructuralandaerospacematerials.Becausesomeadvancedglassesandglassceramicsarebiocompatible,theycanbeusedasimplantsanddentalposteriormaterials.Glassbeadsarealsobeingusedinradiationtherapytotreatcertainkindsofcancer.AnotherimportantapplicationisglasssubstratesforDNAanalysis.高性能玻璃和玻璃陶瓷也被用作结构和航空用先进复合材料的增强材料或基体。因为一些先进的玻璃和玻璃陶瓷具有生物相容性，它们可以用作植入物和后牙材料。玻璃微珠也被用于放射治疗来治疗某些种类的癌症。另一个重要的应用是玻璃基材可用于DNA分析。FabricsBesidescontinuousanddiscontinuousreinforcements,textilereinforcementsprovidealternativesthatmayincreaseperformancewhilereducingmanufacturingcost.Alargevarietyoftextilefabricformscanbeusedasreinforcementsforcompositematerials.Thissimplest,theleastelaboratedandleastexpensiveonesarethenonwovenfabrics.Anonwovenfabricisusuallycalledamat,whichismadebyrandomlyorientedchoppedfiberssuchaschoppedstrandmat,randomlyorientedshortfibers,orswirledtowsorrovings.Fabricreinforcementsoffermechanicalpropertiessomewhatlowerthanunidirectionalcontinuousfibers.除了连续和不连续的增强外，纺织增强提供了替代品，在可以提高性能的同时降低制造成本。各种形式的纺织织物可用作复合材料的增强材料。最简单、最精密、最便宜的形式是非织造布。非织造织物通常称为毡，它是由随机取向的短切纤维如玻璃纤维短切毡、随机取向的短纤维丝束，或盘旋的纤维或粗纱制成。织物增强材料的力学性能略低于单向连续纤维。Ifreinforcementisdesiredinonlyonedirection,butmaintainingtheeaseofhandlinganddrapepropertiesofwovenfabrics,thesolutioniscalleduniaxialwovenfabric.Inthiscase,normalyarnsareusedalongthewarpdirectionbutonlythinyarnsthatcanbemadefromanotherlowcost,lowqualitymaterialareusedalongthefulldirection,theirrolebeingtokeepthewrapyarnstogether.Bycontrast,ifamultiaxialreinforcementeffectisdesired,thesolutionisatriaxialwovenfabric,whichisobtainedbyinterlacingthreesetsofyarnsatdifferentangles. 如果仅在一个方向上需要增强，但却保持了处理的容易性和织物的悬垂性，这种编织物称为单轴织物。它是通过在经度方向上用普通纱线，然后使用另一种低成本、低质量的细纱线在纬度方向上将经度方向上的纱线包裹在一起。相反，如果需要多维增强效果，则这种编织物是三轴织物，它是通过在不同的角度交织三组纱线而获得。Yetmoretypesoftextilesusedforreinforcementsexist.Allthelongnarrow,2Dtextile(mat,fabric,knit,braid)aredescribedbytheirfiberarchitectureandtheirweightperunitofsurfaceareain[g/m2].Thefiberarchitecturereferstotheorientationandweightofeachcomponentofthefabrics.现在还有更多类型的纺织品用于增强体。所有长的狭窄的2D纺织品（毡，织物，针织物，编织物）都以其纤维结构及其单位面积的重量[g/m2]来描述。纤维结构是指织物各组分的取向和重量。Byspecialmanufacturingmethods,itispossibletoobtainanewcategoryof3Dtextilearchitecturecalled3Dtextiles.Theseareinfiltratedwitharesintoobtaincompositematerialswithreinforcingfibersinallthreedirections.Theresultingcompositematerialcanbeprocessedasasolid3Dbulkmaterialthatisthenmachinedtoshapeorprocesseddirectlyintothefinalshapeofthedesiredproduce.3Dtextilescanbemadeas3Dweavesor3Dbraids.通过特殊的制造方法，可以获得新类别的3D纺织品架构称为3D纺织品。它们被树脂浸润，可以获得在三个方向具有增强纤维的复合材料。所得到的复合材料可以作为固体3D体材料加工，然后将其加工直接成型或加工成所需产品的最终形状。3D织物可制成3D织物或3D编织物。PolymerPolymersvarywidelyintheirmechanicalbehaviordependingonthedegreeofcrystallinity,degreeofcrosslinking,andthevaluesofTgandTm.Elastomersarethegroupofpolymersthatcaneasilyundergoverylarge,reversibleelongationsatrelativelylowstresses.Thisrequiresthatthepolymerbecompletelyamorphouswithalowglasstransitiontemperatureandlowsecondaryforcessoastoobtainhighpolymerchainmobility.Somedegreeofcrosslinkingisneededsothatthedeformationisrapidlyandcompletelyreversible.Mostelastomersobtaintheneededstrengthviacrosslinkingandtheincorporationofreinforcinginorganicfillers.Someelastomersundergoasmallamountofcrystallizationduringelongation,especiallyatveryhighelongations,andthisactsasanadditionalstrengtheningmechanism.TheTmofthecrystallineregionsmustbebelowtheusetemperatureoftheelastomerinorderthatthecrystalsmeltanddeformationbereversiblewhenthestressis removed.聚合物的机械性能有很大的不同，这取决于结晶度、交联程度以及Tg和Tm的值。弹性体是聚合物的一类，它可以在相对低的应力下很容易地进行非常大的、可逆的延展。这要求聚合物具有完全的非晶态，具有低的玻璃化转变温度和弱的次价键，从而获得高分子链的流动性。并且需要一定程度的交联，使变形迅速且完全可逆。大多数弹性体通过交联和加入无机填料来获得所需的强度。一些弹性体特别具有非常高的伸长率的弹性体在延展时进行少量的结晶，这也是一个额外的增强机制。结晶区的Tm必须低于弹性体的使用温度，以便在应力消除时晶体熔化和变形是可逆的。Fibersarepolymersthathaveveryhighresistancetodeformation—theyundergoonlylowelongationsandhaveveryhighmoduliandtensilestrengths.Apolymermustbeveryhighlycrystallineandcontainpolarchainswithstrongsecondaryforcesinordertobeusefulasafiber.Mechanicalstretchingisusedtoimpartveryhighcrystallinitytoafiber.Thecrystallinemeltingtemperatureofafibermustbeabove200℃sothatitwillmaintainitsphysicalintegrityduringtheusetemperaturesencounteredincleaningandironing.However,Tmshouldnotbeexcessivelyhigh—nothigherthan300℃.Thepolymershouldbesolubleinsolventsusedforsolutionspinningofthefiberbutnotindry-cleaningsolvents.Theglasstransitiontemperatureshouldhaveanintermediatevalue;toohighaTginterfereswiththestretchingoperationaswellaswithironing,whiletoolowaTgwouldnotallowcreaseretentioninfabrics.纤维是具有非常高的抗变形性的聚合物-它们受力伸长率很低并具有非常高的模量和拉伸强度。用作纤维的聚合物必须非常高度结晶，并且含有具有强次价键的极性链。机械延展赋予了纤维很高的结晶度。纤维的结晶熔融温度必须在200度以上，以便在使用温度下清洗和熨烫过程中保持其物理完整性。然而，Tm不应过高—不高于300℃。聚合物应溶于用于溶液纺丝的溶剂，但不溶于干洗溶剂。玻璃化转变温度应该有一个中间值；过高的Tg会影响拉丝操作和熨烫，而过低的Tg则不能保证织物的防皱。StainlesssteelsThestainlesssteelsarehighlyresistanttocorrosion(rusting)inavarietyofenvironments,especiallytheambientatmosphere.Theirpredominantalloyingelementischromium;aconcentrationofatleast11wt%Crisrequired.Martensiticstainlesssteelsarecapableofbeingheattreatedinsuchawaythatmartensiteistheprimemicroconstituent.Forausteniticstainlesssteels,theaustenitephasefieldisextendedtoroomtemperature.Ferriticstainlesssteelsarecomposesoftheferritephase.Austeniticandferriticstainlesssteelsarehardenedand strengthenedbycoldworkbecausetheyarenotheattreatable.Theausteniticstainlesssteelsarethemostcorrosionresistantbecauseofthehighchromiumcontentsandalsothenickeladditions;andtheyareproducedinthelargestquantities.Bothmartensiticandferriticstainlesssteelsaremagnetic;theausteniticstainlessesarenot.不锈钢在各种环境中特别是环境大气中具有很高的耐腐蚀性（防锈性）。它们的主要合金元素是铬，铬的含量至少需要11wt%。马氏体不锈钢由于马氏体是主要的微观组织成分，因此可以进行热处理。对于奥氏体不锈钢，奥氏体相领域延伸至室温。铁素体不锈钢由铁素体相组成。奥氏体不锈钢和铁素体不锈钢由于不可热处理而被冷加工硬化和加强。奥氏体不锈钢由于铬含量高，镍添加量高，因此耐腐蚀性最强，生产量也最大。马氏体和铁素体不锈钢都是磁性的;奥氏体不锈钢则不是。Ferriticstainlesssteelscontain12to18%chromiumandverylittlecarbon.Austeniticstainlesssteelscontainenoughnickelsothattheyhaveafcccrystalstructureatalltemperaturesbelowmelting.Theyaremoreexpensivethanferriticstainlesssteelsandarenonmagnetic.Thethirdmainclassofstainlesssteelsismartensitic.Martensiticstainlesssteelshavecompositionssimilartoferriticstainlesssteels,butwithenoughcarbonsothatwhenheatedtheytransformtoaustenite.Thehardenabilityissohighthattheyformmartensiteevenwithslowcooling.铁素体不锈钢含有12～18%的铬和极少的碳。奥氏体不锈钢中含有足够的镍，使其在低于熔点的所有温度下都具有fcc晶体结构。它们比铁素体不锈钢更贵，并且是非磁性的。第三类不锈钢是马氏体。马氏体不锈钢具有类似于铁素体不锈钢的组成，但含有足够的碳，使得当加热时它们转变为奥氏体。可淬性如此之高，即使在缓慢冷却下也能形成马氏体。Austeniticstainlesssteelsaresignificantlymorecomplexinnaturethantheferriticsandmartensiticsinthattheyhaveatleasttwomajoralloyingelements:chromiumandnickel.Austeniticstainlesssteelshaveastrongtendencytoworkharden.Theenergyofdeformationpromotesthetransformationofthemetastableaustenitetomartensite.Austeniticstainlesssteelsareincontrovertiblyausteniticinmostcommercialforms.Theaustenitestructureisbroughtaboutbynickeladditionsorinsomecasesbynickelandmanganeseadditions.Manganeseisalsoanaustenitizer.奥氏体不锈钢在本质上比铁素体和马氏体显着更复杂，因为它们具有至少两种主要的合金元素：铬和镍。奥氏体不锈钢有较强的可加工性，它的变形能力促进了亚稳态的奥氏体向马氏体的转变。奥氏体不锈钢在大多数的商业形式中无疑是奥氏体。奥氏体结构是由添加镍元素或在某些情况下添加镍和锰元素带来的。锰也是奥氏体。 PropertyWecanconsiderthepropertiesofamaterialintwocategories—mechanicalandphysical.Themechanicalpropertiesdescribehowthematerialrespondstoanappliedforceorstress.Stressisdefinedastheforcedividedbythecross-sectionalareaonwhichtheforceacts.Themostcommonmechanicalpropertiesarethestrength,ductility,andstiffnessofthematerial.However,weareofteninterestedinhowthematerialbehaveswhenitisexposedtoasuddenintenseblow(impact),continuallycycledthroughanalternatingforce(fatigue),exposedtohightemperatures(stability),orsubjectedtoabrasiveconditions(wear).Themechanicalpropertiesnotonlydeterminehowwellthematerialperformsinservice,butalsodeterminetheeasewithwhichthematerialcanbeformedintoausefulshape.Ametalpartformedbyforgingmustwithstandtherapidapplicationofaforcewithoutbreakingandhaveahighenoughductilitytodeformtothepropershape.Oftensmallchangesinthestructurehaveaprofoundeffectonthemechanicalpropertiesofthematerial.我们可以将材料的性质分为两类-力学性能和物理性能。力学性能描述材料如何对施加的力或应力作出反应。应力定义为单位横截面积的力。最常见的机械性能是材料的强度，延展性和刚度。然而，我们经常感兴趣的是当材料受到突然强烈的撞击（冲击），受到交变力作用（疲劳），受到高温作用（稳定性）或受磨料磨损（磨损）等影响时如何反应。力学性能不仅决定了材料在使用中的性能，而且决定了材料能否形成有用的形状。通过锻造形成的金属部件必须承受力的快速施加而不破裂并且具有足够高的延展性使其能改变为适当的形状。通常，结构的细微变化对材料的机械性能具有深远的影响。Physicalpropertiesincludeelectrical,magnetic,optical,thermal,elastic,andchemicalbehavior.Thephysicalpropertiesdependbothonstructureandprocessingofthematerial.Eventinychangesinthecompositioncauseaprofoundchangeintheelectricalconductivityofmanysemiconductingmetalsandceramics.物理性质包括电，磁，光，热，弹性和化学行为。物理性质都取决于材料的结构和加工。甚至成分的微小变化也会导致许多半导体金属和陶瓷的导电性的深奥变化。Highfiringtemperaturesmaygreatlyreducethethermalinsulationcharacteristicsofceramicbrick.Smallamountsofimpuritieschangethecolorofaglassorpolymer. 高烧结温度可大大降低陶瓷砖的隔热特性。少量杂质会改变玻璃或聚合物的颜色。PLASTICSOrganicpolymersconstitutethethirdgroupofimportantindustrialmaterials.Theseareallbasedonthechemistryofcarbonandtheycontainlargemacromolecules.Thesematerialsareeasytofabricate,aregoodinsulators,arelightandhavegoodcorrosionresistance.However,theirstrengthislowandtheirhightemperatureresistanceispoor.Asthesematerialsarelight,inertandeasytofabricatetheyareusedextensivelyinthetransportindustryforvehicles.Theyhavegoodfabricabilityandinsulatingpropertieshencetheyareusedinelectricalindustry.Becauseoftheirinertcharacteristicstheyarealsousedinthechemicalindustry.Organicpolymersareprimarilysyntheticorganiccompounds.Somelikerubberarenaturalproducts.有机聚合物构成了第三类重要工业材料。它们都是基于碳元素的化学成分，且它们含有大的高分子。这类材料易于制造，绝缘体良好，质轻且具有良好的耐腐蚀性。然而，它们的强度低，耐高温性差。由于这类材料质轻，具有惰性且容易制造，因此它们广泛用于车辆的运输业。而它们具有良好的可制造性和绝缘性，因此它们也用于电气工业中。由于它们的惰性特性，它们也被用于化学工业。有机聚合物主要是人工合成的有机化合物，也有些是天然产物，比如橡胶。Plasticmaterialsdisplaypropertiesthatareuniquewhencomparedtoothermaterialsandhavecontributedgreatlytoqualityofoureverydaylife.Plastics,properlyapplied,willperformfunctionsatacostthatothermaterialscannotmatch.Manynaturalplasticsexist,suchasrubber,asphalt,andcellulose.Plasticsareusedinourclothing,housing,automobiles,aircraft,packaging,electronics,signs,recreationitems,andmedicalimplantstonamebutafewoftheirmanyapplications. 与其他材料相比，塑料材料显示出独特的性能，大大有助于我们的日常生活质量。适当的应用塑料，它将以其他材料无法比拟的价格履行职能。有许多天然塑料存在，如橡胶、沥青和纤维素。塑料用于我们的服装，住房，汽车，飞机，包装，电子，标牌，娱乐用品和医疗植入物，这只列举了许多应用中的一些。Occasionallyplasticsarestillimproperlyusedanddrawnegativecomments.Thethousandsofsuccessfulapplicationsthatcontributetothequalityofourlifeareseldomnoticedandaretakenforgranted.Remember,MATERIALSDON'TFAIL,DESIGNSDO.塑料偶尔也有使用不当的地方，并招致了负面评论。成千上万有助于提高我们生活质量的成功应用很少被人注意，这被视为理所当然。记住，材料不会错，但设计会出错。Plasticsencompassalargeandvariedgroupofmaterialsconsistingofdifferentcombinationsorformulationsofcarbon,oxygen,hydrogen,nitrogenandotherorganicandinorganicelements.Mostplasticsaresolidinfinishedform;however,atsomestageoftheirexistence,theyareliquidandmaybeformedintovariousshapes.Theformingisusuallydonethroughtheapplication,eithersinglyortogether,ofheatandpressure.Thereareoverfiftydifferent,uniquefamiliesofplasticsincommercialusetodayandeachfamilymayhavedozensofvariations.塑料包括由碳，氧，氢，氮和其他有机和无机元素的不同组合或配方组成的一类大的且多样化的材料。大多数塑料是成品的固体;然而，在它们存在的某个阶段它们是液体的并且可以形成各种形状。塑料通常通过热、压力或它们的组合来成型。如今，有超过五十种不同的独特的塑料种类在商业中应用，每个种类的塑料可能有几十种变体。OpticalfibersOpticalfibers,usedtotransmitlight,aregainingwideacceptanceinthecommunicationsfieldbecausetheycanbeproducedfromtheplentifulsilicasandtoreplaceheavier,bulkier,andmoreexpensivecopperandaluminumconductors.Opticalfibersofglassandplastichavebeenusedformanyyearsinthemedicalprofessionandbyengineersasinspectiontubes.Flexiblefibersonprobes探针orendoscopes内窥镜areinsertedintothehumanbodyorintoamotorandattachedtoatelevisionsystemormagnifyinglenstoallowviewingoftheseotherwiseinaccessibleplaces. 用于传输光的光纤在通信领域得到广泛的认可，因为它们可以由含量丰富的硅砂生产，以取代更重，体积更大，更昂贵的铜和铝导体。玻璃和塑料的光纤已经在医疗行业和被工程师用作检查管使用了多年。探针或内窥镜上的柔性纤维插入到人体或电动机中，并连接到电视系统或放大镜，以允许这些不可接近的位置可以观察。Asignalopticalfiberthesizeofahairhasthepotentialtotransmitseveralthousandvoicesignals,comparedtothefewerthan50voicesignalsthatcanbecarriedonacopperwireofthesamesize.Forthisreason,telephone,television,computer,andothercommunicationssystemsaremovingtothesmallercoaxial同轴的fiber-opticscabletoreplacecopper-strandedcables.Photonsofelectromagneticradiation(light)replaceelectronsinsignaltransmissionthroughthesetransparentopticalfibers.Thishasincreasedthespeed,thedistance,andtheamountofinformation(density)beyondallimagination.Claddingoffiber-opticcableswithatransparentcovering包层,whoseindexofrefractionislowerthanthatofthefiber,preventsleakageoflight.Becauseofthequalityoftheolderfibersintransmittingsignals,itisnecessarytoboost推进thesignalevery50kmusingrepeaterstations中继站.与相同尺寸的铜线上携带的少于50个声信号相比，信号光纤具有发送几千个声信号的潜力。因此，电话，电视，计算机和其他通信系统正在向较小的同轴光纤电缆转移以取代铜绞线。电磁辐射的光子（光）通过这些透明光纤代替信号传输中的电子。这超出所有想象的增加了运输速度，距离和信息量（密度）。具有透明覆盖层的光纤电缆包层，其折射率低于光纤的折射率，防止了光的泄漏。由于传输信号中较旧的光纤存在质量问题，因此有必要每50km使用中继站将信号提升。Withtheuseoflaserlightandthinnercable(10μmindiameter),litterenergyislostandboostingstationsareseldomneeded.Present-daytechnologylimitsthelasertransmissionofdataoverfiber-opticcabletosome50miusingnumerouslaserstokeepthesignalsstable.Thisrepresentsadatacapacityofabout40gigabitspersecondwiththecable’scapacityof10Tbits/s.随着激光和更薄的电缆（直径为10μm）的使用，能量损失较少，增压站很少需要。当今技术限制数据在光纤上的激光传输在大约50mi，因此使用许多激光器来保持信号的稳定。这表示电缆容量为10Tbits/s，其数据容量为40Gbits/s。GlassGlasswhennewlyformed,withaperfectsurface,isverystrongaboutfivetimesasstrongassteel.Thismayseemstrange,buttheoreticallyglassshouldbeverystrongbecauseofthenatureofitsinteratomicbonds.Inpractice,thestrengthisverymuchlessthanthetheoreticalvalue.Oneofthemaincausesofthislossofstrengthisthepresenceofsurfacedefects,suchasthosecausedby chemicalcorrosionormechanicalabrasion.Theseflawscanbeverysmallbutbecauseglassisrigidtheyacttoconcentrateanyappliedstressoveronlyafewinteratomicbondsattheapexofthecrack.Undertheseconditionsthestrongbondsbreakandfractureoccurs.Oncestartedithasahighprobabilityofspreadingrightacrossthematerialbecausetherearenointernalgrainboundariestostopit.Thus,apieceofglasswilloftenshattersuddenlywhensubjecttoastress.新形成的玻璃，具有完美的表面，强度是钢的五倍。这似乎看起来很奇怪，但理论上玻璃应该是非常强的，这是因为它的原子间键的性质的缘故。实际上，其强度远远低于理论值。这种强度损失的主要原因之一是存在表面缺陷，例如由化学腐蚀或机械磨损引起的缺陷。这些缺陷可能非常小，但是由于玻璃是刚性的，它们的作用是将任何施加的应力集中在裂缝顶点的仅仅几个原子间的作用力上。在这些条件下，强键断裂导致玻璃出现破裂。一旦开始，由于没有内部晶粒边界阻止它，所以它很可能在材料之间传播。因此，当受到压力时，一片玻璃将经常会突然破碎。Thisconceptofstressisalsoimportantincoolingtheglassduringthemanufacturingprocess.Iftheglassiscooledtoorapidlyitdoesnothavetimetoreleasestressessetupwithinitduringcoolingtheseare"frozen-in"andcancausetheglasstoshatterwhenitbecomesasolid.Thismayoccurspontaneously,orwhenatinyflawisproducedonthesurface.Inordertoavoidtheseinternalstresses,glassarticlesaresubjectedtoacontrolledheattreatmentaftermanufacture,aprocessknownasannealing.Thetemperatureisraisedtothatwhichwillallowinternalstressestoberelaxedbyflowwithintheglass(butnotsohighthatthearticlewilldeform)andheldthereforanappropriatetime.Itisthenslowlyreducedtoapointwellbelowthetransformationrangeandafterwardsmorerapidlytoroomtemperature.这种应力概念在制造过程中对玻璃的冷却也很重要。如果玻璃冷却太快，则在冷却过程中没有时间释放在其内部施加的应力，这些“冷冻”可能导致玻璃在变成固态时破碎。这可能是自发发生的，或者当表面产生微小的缺陷时发生。为了避免这些内应力，玻璃制品在制造之后受到可控的热处理，这个过程称为退火。温度升高到允许内部应力通过玻璃内的流动而松弛的温度（但不会使得物品变形）并将其保持在适当的时间。然后将其缓慢降至远低于转化范围的温度，随后更快地降至室温。Glassisinwidespreaduselargelyduetotheproductionofglasscompositionsthataretransparenttovisiblewavelengthsoflight.Incontrast,polycrystallinematerialsdonotingeneraltransmitvisiblelight.Theindividualcrystallitesmaybetransparent,buttheirfacets(grainboundaries)reflectorscatterlightresultingindiffusereflection.Glassdoesnotcontaintheinternalsubdivisionsassociatedwithgrainboundariesinpolycrystalsandhencedoesnotscatterlightinthesamemannerasapolycrystallinematerial.Theglasssurfaceisoftensmoothsinceduringglass formationthemoleculesofthesupercooledliquidarenotforcedtodisposeinrigidcrystalgeometriesandcanfollowsurfacetension,whichimposesamicroscopicallysmoothsurface.Theseproperties,whichgiveglassitsclearness,canberetainedevenifglassispartiallylight-absorbing.玻璃的广泛使用主要由于生产的玻璃成分对可见光波长是可透过的。相比之下，多晶材料通常不透射可见光。单晶可以是透明的，但它们的面（晶界）反射或散射光导致漫射。玻璃不包含与多晶体中的晶界相关的内部细分，因此不以与多晶材料相同的方式散射光。玻璃表面通常是平滑的，因为在玻璃形成期间，过冷液体的分子不被强制地以刚性晶体几何形状分布，并且可以遵循表面张力，这使其强制形成微观平滑的表面。即使玻璃部分吸光，这些赋予玻璃清晰度的性质也能保留。Therefractiveindexdependsuponthewavelengthoflight,thedensity,temperature,thermalhistory,stress,andcompositionoftheglass.Thechangeofindexwithwavelengthscalleddispersion.Itisbecauseofthischangethatthevariouscoloursaredispersedbyaprism.Glassesofhigherrefractiveindexhavegreaterdispersion,thehighertheindex,themorethedispersiontendstoincreasewithdecreasingwavelength.折射率取决于光的波长，玻璃的密度，温度，热历史，所受应力和组成。折射率随波长变化称为色散。正是由于这种变化，各种颜色被棱镜分散。折射率较高的玻璃具有较大的色散，折射率越高，随着波长的减小，色散倾向程度增加。ElasticandplasticdeformationTwoofthemostimportantpropertiesofmetalsformanufacturingpurposesareelasticdeformationandplasticdeformation.Stressisthematerial’sresistancetotheappliedloadorforce.Whenmetalsareplacedundertensile,torsion,orcompressionstress,aslightelongationorcompressiontakesplaceinthecrystallattice.Thismovementiscalledstrain.Elasticdeformationisnotpermanent.Assoonasthestressisremoved,thestructurereturnstoitsformershape.Also,thiselongationorcompressioninonedirectionwillproduceanoppositechangeat90degreestothatforce.Thatis,apieceofmetalwillbecomethinnerifitisstretchedlengthwise.ThisratioofmovementatrightanglestotheappliedforceiscalledPoisson’sratio.用于制造业的金属的两个最重要的特性是弹性变形和塑性变形。应力是材料对施加的载荷或力的抵抗力。当金属处于拉伸，扭转或压缩应力下时，晶格中会发生轻微的伸长或压缩。这种运动被称为应变。弹性形变不是永久性的。一旦应力消除，其结构就恢复到原来的形状。而且，一个方向上的这种伸长或压缩将产生与该力成90度相反的变化。 这个与所施加的力成直角运动的比例，叫做泊松比。Plasticdeformationisoneofthemostusefulcharacteristicsofmetals.Forging,drawing,forming,extruding,rolling,stamping,andpressingallinvolveplasticdeformation.Plasticdeformationinmetalscantakeplaceonlyatastressorloadhigherthantheelasticlimit.Astheappliedloadisincreased,theatomsmustslideovereachothertoproduceapermanentchangeinshapeorbreaktheatomicbonds,resultingintotalrupture.塑性变形是金属最有用的特征之一。锻造，拉丝，成型，挤压，轧制，冲压和压制都涉及塑性变形。金属中的塑性变形只能在高于弹性极限的应力或负荷下进行。当施加的载荷增加时，原子一定彼此滑动以产生永久形变或破坏原子键，导致完全破裂。FrictionMaterialsGraphiteandcarbonaceousrawmaterialsareusedasfrictionmodifiersforbalancingcohesiveandadhesivefrictionalforces.Thesematerialscushionfrictionparticlestooptimizestoppingperformanceandpedalfeel.Theyalsoofferlubricationagainstthebrakedrum,orrotor,thermalconductivitytodissipateheatduringheavybraking,andoffersincreasedstrengthpropertiestoretainfrictionmaterialintegrity.SuperiorGraphiteoffersanumberofsolutionstomeetthedemandingrigorsoffrictionmaterialapplications.TheFormulaFX™lineofmaterialshasbeendesignedtoofferhighpurity,consistentparticlesizedistributions,anduniquephysicalcharacteristicsneededforgeneralandhighperformanceformulations.石墨和碳质原料用作润滑剂，以平衡粘性和粘着摩擦力。这些材料缓冲摩擦颗粒以优化制动性能和踏板感觉。它们还为制动鼓或转子提供润滑，导热，以便在重型制动过程中散热，并提升强度特性以保持摩擦材料的完整性。优良的石墨提供了许多解决方法，来满足摩擦材料应用中的严格要求。FormulaFX™系列材料的设计旨在提供高纯度，粒度分布一致，以及普通和高性能配方所需的独特物理特性。MagneticpropertyofmaterialsDiamagneticmaterialsaresolidscomposedofatomswithcompletelyfilledelectronshells,sotheinteractionisnil.Someexamplesandcopper(Cu),silver(Ag),gold(Au),andorganicpolymers.反磁性材料是由核外电子是饱和状态的原子组成的固体，因此相互作用为零。比如：铜（Cu），银（Ag），金（Au）和有机聚合物。 Paramagneticmaterialscontainunpairedelectronsintheirinnershellsthatformatomicdipolesthatarefreetorotatewithanexternalfield,producingsomeinteractionandrenderingarelativepermeabilityμslightlygreaterthan1.Likediamagneticmaterials,paramagneticmaterialsonlyexhibitmagnetismwheninthepresenceofanexternalmagneticfield.Someexamplesofparamagneticmaterialsarethemetalsaluminum(Al),chromium(Cr),andtitanium(Ti).顺磁性材料在内部壳层中含有未配对的电子，形成原子偶极子，可以自由地与外部磁场旋转，产生一些相互作用，并使相对磁导率μ略大于1。像反磁材料一样，顺磁材料只有在存在外部磁场时才表现出磁性。如金属铝（Al），铬（Cr）和钛（Ti）都是顺磁材料。Ferromagnetismispresentinsomemetallicmaterialsthatpossessapermanentmagneticmoment.Iron(Fe),cobalt(Co),nickel(Ni),andsomemetalalloysexhibitferromagnetism.Themagneticbehaviorcanbeincreasedinmagnitudebystrongmagneticfields.Theexplanationofthistypeofbehaviorusestheworddomain,whichisatinyregionabout1mminlengthorwidth.Eachdomainactslikeatinymagnetwithanorthpoleandasouthpoleandistheresultoftheelectronicstructureofindividualatoms.Theseregionsarevisibleusingpowerfulelectronmicroscopes.Ifthemagneticmaterialisdemagnetized(B=0),asinheating,thedomainsarearrangedinarandomfashion.Thesedomainsarecapableofrotatingaswellaschangingsize.Theywillrotatesoastobemoreparalleltoanexternalfield.Ifaferromagneticmaterialisheated,theincreasedmovementoftheatomsleadstorandomizationoftheirmagneticmoments.Allferromagneticmaterialsbegintolosetheirmagneticpropertiesasthetemperaturesincrease.铁磁存在于一些具有永久磁矩的金属材料中。铁（Fe），钴（Co），镍（Ni）和一些金属合金显示铁磁性。强磁场可以提高磁性能。这可以用领域这一单词来解释，它是一个长度或宽度约1毫米的小区域。每个域的作用就像是一个带有北极和南极的微小磁铁，是单个原子的电子结构的结果。这些区域可以使用强大的电子显微镜观察到。如果磁性材料消磁（B=0），比如加热，域以一个随机的方式排列。这些领域既可以旋转也可以改变大小。它们将旋转以便更平行于外部磁场。如果铁磁材料被加热，则原子的运动加剧导致它们磁矩的随机化。随着温度的升高，所有铁磁材料开始失去磁性。SuperconductingMetalsSilver,copper,andaluminumwiresareallverygoodconductorsofelectricity,butnotperfectconductors.Becauseoftheresistanceofwiretothepassageofelectricity,greatlossesinelectricaltransmissionsystemsareexperienced.Recently,severalsuperconductingmetalsandceramicshavebeendevelopedthatoffernoresistancetotheflowofelectricityatverylowtemperatures.Superconductingmetalsandalloyslosetheirelectricalresistanceonlyatverylowtemperatures. 银，铜和铝丝都是非常好的导体，但不是完美的导体。由于电线有电阻，电力传输系统中电量的损失很大。最近，已经开发了几种超导金属和陶瓷，其在非常低的温度下对电流没有阻力。超导金属和合金仅在非常低的温度下才会失去电阻。In1962,thefirstsuperconductingalloyofniobiumandzirconium(NbZr)wasproduced.Thismetalhadtobecooledto2to5K.Thiswasnotaveryductilemetal,andsurfacehardeningoccurredduringwiredrawingoperations.Aniobium-titaniumalloy(NbTi)waslaterdevelopedandisstillinuse,sinceitismoreductileandmultifilamentscanbemadeofit.Aniobium-tinalloy(NbSn)hastheadvantageofahighercriticaltemperature.However,tokeepthesealloysatthesuperconductingtemperature,theymustbeimmersedinliquidhelium.1962年，制造了第一个由铌和锆组成的超导合金（NbZr）。该金属必须冷却至2至5K。这不是一种很有韧性的金属，在拉丝作业过程中会发生表面硬化。铌-钛合金（NbTi）相继被开发并且目前仍然在使用中，因为它更具延展性并且可以制成多丝。铌锡合金（NbSn）具有较高临界温度的优点。然而，为了将这些合金保持在超导温度，它们必须浸在液氦中。Anewsinteredceramicsuperconductor,composedofY1Ba2Cu3O7,wasdevelopedinthelaboratoriesofTeledyneWahChang.Thisceramicmaterialhastheadvantageofahighertransitiontemperaturewhereitbecomesasuperconductor,about90K.Therefore,liquidnitrogencouldbeusedinsteadofthemorecostlyliquidhelium.TeledyneWahChang在实验室开发了一种由Y1Ba2Cu3O7组成的新型烧结陶瓷超导体。这种陶瓷材料具有较高的转变温度的优点，其在约90K的温度时成为超导体。因此，可以使用液氮代替更昂贵的液氦。