摩擦学原理(第1章摩擦表面状态)2013

SCHOOLOFMECHANICALENGINEERINGXI’ANJIAOTONGUNIVERSITY徐华[e-mail]82669157AutomotiveTribology在购车经费一定的情况下，你买车时首先考虑的因素有那些？列举三个，各用一句话来说明。3IntroductionTribology:Tribologyisthescience,applicationscience,whichdealswithofthetwosurfaceshavingrelativemovement,ormovingtrend,coversFriction,LubricationandWear.IthassomeresearchfieldrelatedtoPhysics,Chemistry,Metallurgy,MaterialScience,Rheology,Hydromechanics,Elasticity,Viscoelasticity,Thermodynamics,aswellas,MachineryScienceandsoon.“2012中国汽车产业发展高层论坛”2012年10月在钓鱼台国宾馆举行“2012中国汽车产业发展高层论坛”。中国汽车协会副会长董扬在发言中指出，中国汽车市场的发展空间依旧宽广，2020年之前应会保持与GDP增长率一致的发展速度。“中国汽车已经连续两年增长，这个市场到底有多大？2020年之前，中国汽车应该能够在产销数量用大于等于GDP的数额增长，由于当前我国人均的汽车数量还很低，从现代社会大生产的结构要求来讲，需要更多的汽车；第三个原因是现在中国的机动车数量最多的不是汽车，而是摩托车，这其中蕴含着因为升级换代带来的巨大增长空间。“现在我国汽车有1亿辆，摩托车1亿3000万辆。这些摩托司机都有一个梦，梦见两轮变成四轮，摩托车变成汽车。摩托车的升级有着巨大的市场。”中国汽车工业协会2012年中国汽车产销量双双超过了1900万辆，轿车销售达到了1074万辆，其中中德、中日、中美、中韩、中法等合资企业在中国实现汽车销售250万辆、190万辆、196万辆、172万辆，105万辆，和44万辆。中国汽车工业协会统计分析，2013年1-9月，中国品牌乘用车共销售512.50万辆，同比增长12.14%，德系、日系、美系、韩系和法系乘用车分别销售254.17万辆、198.28万辆、160.46万辆、116.12万辆和40万辆，分别占乘用车销售总量的19.78%、15.43%、12.49%、9.04%和3.11%。中国汽车1-9月产销量1281万辆.2012款奥迪A6L2.5L30FSI手自一体，最大功率140KW140KW*2000万辆=28亿千瓦ThehighestefficiencyofInternal-combustionengineislessthan30%Oilenergyhavemorethan50%wasteasheat，Withtherest,thereare20%energyusedtocontrolthedevices.thereareabout30%energyusedforovercomethefriction，2%gears,5%bearingsandsoon。9TheWheelisthemostsuccessfulexampleofTribologicaldesign.Andlubricanthasbeenusedformorethanthreethousandyears.Byestimate，1/3~1/2energysources,consumedbyhuman,owingtofrictionandwear。FromLeonardodaVinci(1452-1519)toSirJostreportin1960’s.Tribologyfromsingle,isolatedstudybecomesaresearchfieldofsystematicallystudyoffriction,lubricationandwear10MainAreasinTribologyFriction(摩擦)Wear(磨损)Lubrication(润滑)LeonardodaVinci秦始皇兵马俑铜车马的1号车Research——texturedsurfaceSampleoftexturedsurfaceundermicroscopeWithouttexture，frictioncoefficient0.06910v15min,Withtexture，deepness3μmfrictioncoefficient0.031squaretextureDoublelayer1Doublelayer2Surfacetexture表面织构SurfacetexturebylaserTypeoftexture，a-triangle，b-square，c-circle；1-convexly，2-concaveSurfacetextureBearings,piston—rings17Partone,Theoryoftribology.Introduction、solidsurface,frictionandwearIncludingsurfacetopographyparameters,surfacestructure,surfaceproperties.lubricantandit’sproperties,basicfrictiontheoryandwearmeasuringmethods。wearmechanism、lawofwear,wearmeasurementandanti-weardesign，weartypeclassify,wearmechanism,wearingprocedureandpattern,conversionofwear,calculationofwear,andexperimentalmethodofwearandfriction,aswellastestingdevice。Generalmethodsofthefrictionstateanalysis,wear-outfailureanalysis,antifriction,antiwearanalysis.Maincontentsof《AutomotiveTribology》18Parttwo,lubricationtheoryIncludingReynoldsequation,lubricationdesignoftypicalelements,Generalnumericalmethodsforlubricationcalculation,conversionoflubricationstate，namely：fromfluidlubricationtoelasto-hydrodynamiclubrication,fromelasto-hydrodynamiclubricationtothin-filmlubrication,effectsofrarefiedgas,failureoflubricationandboundarylubrication。Maincontentsof《AutomotiveTribology》19Frictionisoneofthreemajorpartsoftribology.Frictionphenomenonisalsotheearliestphenomenonobservedbyhumanbeings。thefrictiontheorystudiesthefrictionsurfacemorphology(形态),texture,contactstatus,layeroffrictionsurface.Introductionofthefrictiontheory20Chapterone--frictionsurfaceanalysisSurfacetopographypropertiesandstatisticalapproach.Surfaceerroringeometricalform,surfaceroughnessandsurfacetopographystatisticalparameter。Analyzingthefrictionsurfaceproperties,suchas,wettingangle,surfaceenergyandsurfaceadsorption。Analyzingthecontactproblemofroughenedsurface。Byintroducecontactarea,contactmodel，toanalyzethecontactstress,contactdeformationinthecontactelementsalongit’sdeepness，whichinvolvestatistics,Physicalchemistry,materialsscienceandelasticity.Introductionofthefrictionstatusandthemethodsofhowtodistinguishthedifferentfrictionstatus.21RealsurfaceairBasemetalBasemetalWork-hardenedlayerAdsorbedgasBiebylayerOxideinclusion22Chapterone,Analysisoffrictionsurface1.1Surfacetopographyparametersandstatisticssurfacetopography（表面形貌）surfacetopography，alsoknowas,surfacegeometrycharacteristic，itindicatethemicro-,unregulargeometricalshapeofthecomponentssurface,suchas,roughness粗糙度,waviness波度、formerror形状误差,texture纹理,andsoon。231.1.1geometricalformerrorofsurface24(a)formerror(形状偏差)(b)waviness(波纹度)(c)roughness(粗糙度)图1.1RealSurfaceprofile(实际表面轮廓)Thesurfacegeometricalcharacteristicpayimportantroleinthefriction,wearandlubricationundermixturelubrication(混合润滑)anddrycontactcondition（干摩擦）roughnesswavinessformerrorRealSurfaceprofilePartialenlargedview(realsurfaceprofile)(geometricalprofile)261．Macro-geometricalformerror（宏观几何形状误差）Macro-geometricalformerror又称为surfaceformerror（表面形状偏差），主要是用不直度、不平度表示平面几何形状误差。不直度是指在指定方向上，其实际的轮廓线与理论直线的直度偏差，当用刀形样板平尺进行校验时，刀口与被检表面的最大空隙b，即为所检范围内的不直度。不平度是指整个平面各方向上所存在的最大不直度，如图1.1a所示。波距l大于10mm的偏差属于形状偏差。271．Macro-geometricalformerror（宏观几何形状误差）对圆柱形表面，在垂直于轴线的横剖面内最典型的误差有椭圆度，通过轴线的纵剖面内，最典型的误差