PAGE5附錄AThesignificanceoflightweight

Automotivelightweightmainguidingprinciple:toensurestabilityonbasisofimprovedperformance,energy-savingdesignoftheassemblypartscontinuousoptimizationmodelspectrum.

Thelightweightcar,thecaristoensurestrengthandsecurityofthepremise,asfaraspossibletoreducethecar'scurbweight,therebyenhancingthecar'spower,reducingfuelconsumptionandreduceexhaustpollution.Experimentsshowthatif10%ofautomobileweightreduction,fuelefficiencycanbincreasedby6%-8%;vehiclecurbweightisreducedby100kghundredkilometerscanbereduced0.3-0.6liters;1%ofvehicleweightreduction,fuelconsumptioncanbereduced0.7%.Atpresent,duetotheneedforenvironmentalprotectionandenergysaving,lightweightcarhasbecometheworldtrendofautomobiledevelopment.

Lightweightcaristhemainway:

①mainstreamcarmodelscontinuetooptimizethesize,specificationsizetoretainthemainparametersofthepremise,toenhancethestructuralstrengthofthevehicle,reducingtheamountofsupplies;

②useoflightweightmaterials.Suchasaluminum,magnesium,ceramic,plastic,fiberglassorcarbonfibercompositematerials;

③Thecomputerdesign.Suchasfiniteelementanalysis,localreinforcementdesign;

④theuseofload-bearingbody,thinningthethicknessofthebodysheetmetal.

Amongthem,thecurrentmajorautomotivelightweightmeasuresmainlytheuseoflightweightmaterials.forautomotivelightweightdesignofthemetalmaterial

Themainvehiclethroughthecar'slightweightmaterialstoimproveeconomytocontribute.Theoreticalanalysisandexperimentalresultsshowthlightweightistoimprovevehiclefueleconomyandeffectiveway.Inordertoequirementsoflightweightvehicles,somenewmaterialemergedandexpandedthescopeofapplication.

NonferrousAlloys

Topassengercars,the1973vehicleusedbythenon-ferrousalloyofthetotaltimberweightratioof5.0%in1980to5.6%,whilein1997itreachNon-ferrousalloysinautomotiveapplicationsistherapidgrowthtrendofdevelopmentofautomotivematerials.

Aluminum

Steelaluminumdensityofabout1/3isthemostwidelyusedlightmaterials.UnitedStatesproductionofautomotiveproducts,forexample,aluminumalloy1976pervehicleisonly39kg,1982reached62kg,whilein1998itreach100kg.

(1)castaluminumalloy

Manyelementscanbeusedascastaluminumalloyelements,onlySi,Cu,Mg,Mn,Zn,Liinthemassproductionofgreatsignificance.Ofcourse,widelyusedinthecarisnotthesimplebinaryalloybutalsoavarietyofelementsaddedtoobtainagoodoverallperformance.

Theautomobileindustryisthemainmarketofaluminumcastings,suchasJapan,76%ofaluminumcastings,aluminumdiecasting77%ofautomotivecastings.Mainlyusedinaluminumalloyengineblockcastings,cylinderheads,pistons,intakemanifold,rockerarms,enginemountbracket,aircompressorconnectingrod,clutchhousings,clutchhousings,wheels,brakeparts,handlesandcovershell-typepartsandsoon.

Aluminumcastinginevitablyflawed,castingcannotbeheattreatedproducearesultintheuseofhigherstrengthaluminumalloycastingsislimited.Onthecastingforthisproductionprocesshasbeenimproved,semi-solidcastingforgingformingmethodandmethodwillbeusedtocraftthefuturemore.

(2)deformationofaluminumalloy

Referstodeformationofaluminumalloyaluminumalloyplateandextrusionsandforgingmaterials,mainlyusedinautomotivebodypanelsontheboengineradiators,airconditioningcondenser,evaporator,wheels,trimandsuspensionparts.

Astheeffectisobviouslightweight,aluminumalloycarbodyapplicationsisexpanding.September1990astheJapanesestartedsellingcarswithaHondaNSXUnibodyaluminum,coldrolledsteelplatethaninthesamelight200kgbodyattractedworldwideattention.NSXtotheentirevehiclewithaluminum31.3%,asinthealuminumcarbody,usingthe6000seriesalloyouterplate,innerplatewith5052-0alloy,mostusethe5182-0alloyframe;thatthesidedoorofthestrengthandstiffnessrequirementsarehigh,theuseofthe6N01alloy-based,appropriateadjustmentstotheMgandSicontentofthealloy.AlsousefulinEuropeandAmericafor2036and2008alloyplatesinsideandoutsidethebody.

AluminumradiatororiginatedinEuropeandthenthroughouttheworld.InEurope,afterthe1980s,aluminumradiatorhasoccupied90%ofthemarket.With?Carairconditioning,oilcoolers,etc.Theextensiveuseofaluminumheatexchangersmarketisrapidlyexpanding.Fromthematerialpointofview,aluminumheatexchangersinawiderangeofcoatingmaterialappliedtoalargeextentduetoaluminumandaluminumcladdingsuccessfuldevelopment.

(3)aluminummatrixcomposites

Lowdensityofaluminummatrixcomposites,strengthandhighmodulus,goodthermalfatigueproperties,butinautomotiveapplicationsbythepriceandproductionqualitycontrolandotherconstraints,havenotformedalargescale.Currently,aluminummatrixcompositesintheconnectingrod,piston,cylinderbodyholes,brakediscs,brakecalipersandotherpartsofthedriveshafttubetestorshowingsuperiorperformance,suchasdevelopedbyHondadoesnot?Enhancedaluminummatrixcompositewirerodsteelroddownmorethan30%weightonthe1.2Lgasolineenginecanincreasefueleconomy5%;usingchilledaluminumpowderandSiCpowder(weightpercentageof2%)andmixedextrudedintorods,forgedwiththeshapeofthepistonrodforhighstrengthcanbe20%lowerweight,enginepowerhasincreasedsignificantly;compositeenhancedwithaluminumpistonheadtocancelthefirstringgrooveofausteniticcastironinsertscandropweight20%;aluminummatrixcompositebrakediscsreduceweightthancastironbrakedisc50%.

Magnesium

Aluminummagnesiumdensityofabout2/3,inthepracticalapplicationofthemetalisthelightest.Vibrationabsorptionofmagnesiumalloycuttingabilityisgood,metalcastingperformance,itissuitableformanufacturingautomotiveparts.

Mostofthediecastingmagnesiumalloyintheformofapplicationsinthecar,magnesiumdiecastingaluminumproductionefficiencythanthe30%to50%.Thenewlydevelopednon-porouscastingmethod(PoreFreeDiecast)canproducenoholesandcanbeheat-treatedmagnesiumdiecastings.

Magnesiumcastingsusedinthecartheearliestexamplesisthewheelrim.Inthecaronthetrialorapplicationinstancetheremagnesiumalloyclutchhousing,clutchpedal,brakepedalmountingbracket,dashboardframe,seat,steeringcolumnparts,steeringwheelroundcore,transmissionhousing,enginemounts,cylinderheadandcylinderheadcoverandsoon.Withthetraditionalsystemofthesteeringcolumnbracketcomparedtothezinc,magnesiumandheavypartsdown65%;withtraditionalsteelsteeringwheelcorecomparedto45percentweightreductionofmagnesiumparts;comparedwiththealuminumcylinderhead,magnesiumparts30%weightreduction;traditionalstampingandweldingstructuralsteelbrakepedalbracketcomparedtotheoverallweightofmagnesiumcastingsdown40%,whileitsrigidityisalsoimproved.

Magnesiummatrixcompositeshasalsomadeprogress,withSiCparticlesasreinforcement,mixingtechnologyistheuseofliquidmagnesium-basedcompositematerialswithgoodperformanceandlowerproductioncosts.IntheAZ91alloybyadding25%SiCparticlereinforcedcompositesthanthematrixalloywith23%highertensilestrength,yieldstrengthincreased47%,elasticmodulusincreased72%.

Titanium

Titaniumdensity4.5g/cm3,withhighstrength,hightemperaturestrengthandcorrosionresistanceandsoon.Becausetitaniumisexpensive,sinceIsawthecarintheluxurycarandasmallamountofindividualapplications.However,theapplicationoftitaniuminthetestcarhasalotofresearchwork.Forexample,withα+βtitaniumalloyoftheengineconnectingrodsystem,theequivalentstrengthquenchedandtemperedsteel45levels,andweightcanbereduced30%;βoftitanium(Ti-13V-11Cr-3Al,etc.)andtimebythestrongcoldtreatment,intensityofupto2000MPa,canbeusedtomanufacturesuspensionsprings,valvespringsandvalves,etc.,andthetensilestrengthof2100MPaofhighstrengthsteelthantitaniumspringscanbe20%lowerweight.

Thebiggestobstacletotheapplicationoftitaniumfromitshighprice,ToyotaCentralResearchInstitutehasdevelopedalow-costtitaniummatricomposites.ThecompositematerialtoTi-6Al-4Valloymatrixtothereinforcementspowdermetallurgymethodofproduction,hasbeenappliedintheengineconnectingrod.

附錄B輕量化的意義汽車(chē)輕量化主要指導(dǎo)思想：在確保穩(wěn)定提升性能的基礎(chǔ)上，節(jié)能化設(shè)計(jì)各總成零部件，持續(xù)優(yōu)化車(chē)型譜。汽車(chē)的輕量化，就是在保證汽車(chē)的強(qiáng)度和安全性能的前提下，盡可能地降低汽車(chē)的整備質(zhì)量，從而提高汽車(chē)的動(dòng)力性，減少燃料消耗，降低排氣污染。實(shí)驗(yàn)證明，若汽車(chē)整車(chē)重量降低10%，燃油效率可提高6%—8%；汽車(chē)整備質(zhì)量每減少100公斤，百公里油耗可降低0.3—0.6升；汽車(chē)重量降低1%，油耗可降低0.7%。當(dāng)前，由于環(huán)保和節(jié)能的需要，汽車(chē)的輕量化已經(jīng)成為世界汽車(chē)發(fā)展的潮流。汽車(chē)輕量化的主要途徑是：①汽車(chē)主流規(guī)格車(chē)型持續(xù)優(yōu)化，規(guī)格主參數(shù)尺寸保留的前提下，提升整車(chē)結(jié)構(gòu)強(qiáng)度，降低耗材用量；②采用輕質(zhì)材料。如鋁、鎂、陶瓷、塑料、玻璃纖維或碳纖維復(fù)合材料等；③采用計(jì)算機(jī)進(jìn)行結(jié)構(gòu)設(shè)計(jì)。如采用有限元分析、局部加強(qiáng)設(shè)計(jì)等；④采用承載式車(chē)身，減薄車(chē)身板料厚度等。其中，當(dāng)前的主要汽車(chē)輕量化措施主要是采用輕質(zhì)材料?？捎糜谄?chē)輕量化設(shè)計(jì)的金屬材料車(chē)用材料主要通過(guò)汽車(chē)的輕量化來(lái)對(duì)燃料經(jīng)濟(jì)性改善作出貢獻(xiàn)。理論分析和試驗(yàn)結(jié)果都表明，輕量化是改善汽車(chē)燃料經(jīng)濟(jì)性的有效途徑。為了適應(yīng)汽車(chē)輕量化的要求，一些新材料應(yīng)運(yùn)而生并擴(kuò)大了應(yīng)用范圍。有色合金以乘用車(chē)來(lái)說(shuō)，1973年每輛車(chē)所使用的有色合金占全部用材的重量比為5.0%1980年增至5.6%，而1997年則達(dá)到了9.6%。有色合金在汽車(chē)上應(yīng)用量的快速增長(zhǎng)是汽車(chē)材料發(fā)展的大趨勢(shì)。鋁合金鋁的密度約為鋼的1/3，是應(yīng)用最廣泛的輕量化材料。以美國(guó)生產(chǎn)的汽車(chē)產(chǎn)品為例，1976年每車(chē)用鋁合金僅39kg，1982年達(dá)到62kg，而1998年則達(dá)到了100kg。（1）鑄造鋁合金許多種元素都可以作為鑄造鋁合金的合金元素，但只有Si、Cu、Mg、Mn、Zn、Li在大量生產(chǎn)中具有重要意義。當(dāng)然，在汽車(chē)上廣泛應(yīng)用的并不是上述簡(jiǎn)單的二元合金而是多種元素同時(shí)添加以獲得好的綜合性能。汽車(chē)工業(yè)是鋁鑄件的主要市場(chǎng)，例如日本，鋁鑄件的76%、鋁壓鑄件的77%為汽車(chē)鑄件。鋁合金鑄件主要應(yīng)用于發(fā)動(dòng)機(jī)氣缸體、氣缸蓋、活塞、進(jìn)氣歧管、搖臂、發(fā)動(dòng)機(jī)懸置支架、空壓機(jī)連桿、傳動(dòng)器殼體、離合器殼體、車(chē)輪、制動(dòng)器零件、把手及罩蓋殼體類(lèi)零件等。鋁鑄件中不可避免地存在缺陷，壓鑄件還不能熱處理，因此在用鋁合金來(lái)生產(chǎn)要求較高強(qiáng)度鑄件時(shí)受到限制。為此在鑄件生產(chǎn)工藝上作了改進(jìn)，鑄造鍛造法和半固態(tài)成型法將是未來(lái)較多用的工藝。（2）變形鋁合金變形鋁合金指鋁合金板帶材、擠壓型材和鍛造材，在汽車(chē)上主要用于車(chē)身面板車(chē)身骨架、發(fā)動(dòng)機(jī)散熱器、空調(diào)冷凝器、蒸發(fā)器、車(chē)輪、裝飾件和懸架系統(tǒng)零件等。由于輕量化效果明顯，鋁合金在車(chē)身上的應(yīng)用正在擴(kuò)大。如1990年9月開(kāi)始銷(xiāo)售的日本本田NSX車(chē)采用了全鋁承載式車(chē)身，比用冷軋鋼板制造的同樣車(chē)身輕200kg引起全世界的矚目。NSX全車(chē)用鋁材達(dá)到31.3%，如在全鋁車(chē)身上，外板使用6000系列合金，內(nèi)板使用5052－0合金，骨架大部使用5182－0合金；由于側(cè)門(mén)框?qū)?qiáng)度和剛度要求很高，使用以6N01合金為基礎(chǔ)、適當(dāng)調(diào)整了Mg和Si含量的合金。在歐美也有用2036和2008合金作車(chē)身內(nèi)外板的。鋁散熱器發(fā)源于歐洲而后遍及全世界。在歐洲，到20世紀(jì)80年代后期鋁散熱器已占領(lǐng)市場(chǎng)的90%。隨?車(chē)用空調(diào)、油冷卻器等的大量使用，鋁熱交換器的市場(chǎng)迅速擴(kuò)大。從材料的角度看，鋁在熱交換器上的廣泛應(yīng)用在很大程度上歸功于包覆料覆層鋁板和鋁帶的成功開(kāi)發(fā)。（3）鋁基復(fù)合材料鋁基復(fù)合材料密