洛陽理工專業(yè)英語課件

1.4.1.5ModulusofElasticityThemodulus

[‘m?djul?s]

模量，模數(shù)ofelasticity,orYoung’smodulus,istheslope

[sl?up]

斜率

ofthestress-straincurveintheelasticregion.ThisrelationshipisHooke’slaw.Themodulusiscloselyrelatedtotheforcesbonding

原子間的結(jié)合theatomsinthematerial.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII11.4.1.5ModulusofElasticityAsteepslopeintheforce-interatomic

[,int?r?‘t?mik]原子間的spacing

間距graphattheequilibriumspacingindicates暗示（formulate闡述）thathighforcesarerequiredtoseparatetheatomsandcausethemetaltostretch

拉長elastically.Thus,themetalhasahighmodulusofelasticity.Bindingforces

結(jié)合力,andconsequently[’k?nsikwentli]結(jié)果，因此

themodulusofelasticity,arehigherforhighmeltingpointmetals.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII21.4.1.5ModulusofElasticityThemodulusisameasureofthestiffness

剛度ofthematerial.Astiff

硬的material,withahighmodulusofelasticity,maintainsitssizeandshapeevenunderanelasticload.Ifwearedesigningashaft[?ɑ:ft]軸andbearing

軸承（beer啤酒）,wemayneedveryclosetolerances公差.Butiftheshaftdeformselastically,thoseclosetolerancemaycauseexcessiverubbing

[‘r?bi?]摩擦,wear磨損,orseizing

刮痕.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII31.4.1.5ModulusofElasticity

Keywords:yieldstrength屈服強(qiáng)度proportionallimit比例極限tensile

[‘tensail]

拉力的

strength抗拉強(qiáng)度percentelongation延伸率gauge[geid?]

標(biāo)準(zhǔn)尺寸，標(biāo)準(zhǔn)規(guī)格

length標(biāo)距Brinellhardness布氏硬度indentor[in‘dent?(r)]壓頭；訂貨商ENGLISHINMATERIALSSCIENCEANDENGINEERINGII41.4.1.5ModulusofElasticity

Keywords:Rockwellhardness洛氏硬度modulusofelasticity彈性模量Young’smodulus楊氏模量

楊氏模量：是彈性材料承受正向應(yīng)力時會產(chǎn)生正向應(yīng)變，定義為正向應(yīng)力與正向應(yīng)變的比值。是沿縱向的彈性模量，公式記為E=σ/ε其中，E表示楊氏模數(shù)，σ表示正向應(yīng)力，ε表示正向應(yīng)變。楊氏模量越大，越不容易發(fā)生形變shaft軸bearing軸承tolerance公差percentreductioninarea斷面收縮率ENGLISHINMATERIALSSCIENCEANDENGINEERINGIIENGLISHINMATERIALSSCIENCEANDENGINEERINGII52MaterialsENGLISHINMATERIALSSCIENCEANDENGINEERINGII6Emphasis：Medium-carbonSteels

中碳鋼（低碳鋼mildsteels）HighandVery-high-carbonSteels

高碳和超高碳鋼TheeffectsofcommonelementsaddedtosteelCastIrons

鑄鐵Difficulty:Theeffectsofcommonelementsaddedtosteel

ENGLISHINMATERIALSSCIENCEANDENGINEERINGII72.1FerrousAlloy2.1Ferrous[‘fer?s]

鐵的，亞鐵的

AlloyMorethan90%byweightofthemetallic

[mi‘t?lik]

金屬的materialsusedbyhumanbeingsareferrousalloys.Thisrepresentsanimmense

[i’mens]巨大的familyofengineeringmaterialswithawiderangeofmicrostructuresandrelatedproperties.Themajorityofengineeringdesignsthatrequirestructuralloadsupportorpowertransmission

傳送，傳播involveferrousalloys.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII8represent[,repri‘zent]

v.1.代表，代理

TheThreeRepresents

三個代表

2.表示，表現(xiàn)

92.1FerrousAlloyAsapracticalmatter,thesealloysfallintotwobroadcategoriesbasedonthecarboninthealloycomposition.Steelgenerallycontainsbetweenwc=0.05%andwc=2.0%.Thecastironsgenerallycontainbetweenwc=2.0%andwc=4.5%.Withinthesteelcategory,weshalldistinguish

區(qū)別whetherornotasignificantamountofalloyingelementsotherthan

除了carbonisused.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII102.1FerrousAlloyAcomposition

成分（=constituent)of5%totalnoncarbonadditionswillserveasanarbitrary

[‘ɑ:bi,tr?ri]

任意的

boundarybetweenlowalloyandhighalloysteels.Thesealloyadditionsarechosencarefullybecausetheyarejustified

認(rèn)為…是正當(dāng)?shù)膐nlybyessential

實質(zhì)的，基本的improvementsinpropertiessuchashigherstrengthorimprovedcorrosionresistance耐腐蝕性.與耐腐蝕性有類似的構(gòu)詞法的詞有：heatresistance

耐熱性能；wearresistance耐磨性；ENGLISHINMATERIALSSCIENCEANDENGINEERINGII112.1.1IronandSteelTheearthcontainsalargenumberofmetalswhichareusefultoman.Oneofthemostimportantoftheseisiron.Modernindustryneedsconsiderablequantities

數(shù)量.

ofthismetal,eitherintheformofironorintheformofsteel.Acertainnumberofnon-ferrousmetals,includingaluminum[?'lju:min?m]

andzinc,arealsoimportant,buteventodaythemajorityofourengineeringproductsareofironorsteel.Quality

質(zhì)量quantity

數(shù)量例：Qualityoftenmattersmorethanquantity.質(zhì)量往往比數(shù)量更重要。

ENGLISHINMATERIALSSCIENCEANDENGINEERINGII122.1.1IronandSteelMoreover,ironpossesses[p?‘zes]

擁有

magnetic

[m?g’netik]

有磁性的，磁鐵的properties,whichhavemadethedevelopmentofelectricalpowerpossible.Theironore

[?:]

礦，礦石

whichwefindonearthisnotpure.Itcontainssomeimpurities

雜質(zhì)thatmustberemovedbysmelting

熔煉，精煉.Theprocessofsmeltingconsistsofheatingtheoreinablast

(一陣)疾風(fēng)(或氣流等)

furnace

高爐，鼓風(fēng)爐withcoke

[k?uk]焦炭，焦煤andlimestone

[‘laimst?un]石灰石，石灰?guī)r,andreducingittometal.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII132.1.1IronandSteelBlastsofhotairenterthefurnacefromthebottomandprovidetheoxygen

[‘?ksid??n]氧氣

thatisnecessaryforthereductionoftheore.Theorebecomesmolten

熔化的,熔解的

,anditsoxides[’?ksaid]氧化物

combinewithcarbonfromthecoke.Thenon-metallicconstituents成分oftheorecombinewiththelimestonetoformaliquidslag

[sl?g]

爐渣，熔渣.Thisfloats漂浮物ontopofthemolteniron,andpassesout

分流出thefurnacethroughatap

閥門，龍頭.Themetalwhichremainsispigiron(=castiron).

ENGLISHINMATERIALSSCIENCEANDENGINEERINGII142.1.1IronandSteelWecanmeltthisdown

下面的東西againinanotherfurnace―acupola

[‘kju:p?l?]沖天爐，熔鐵爐―withmorecokeandlimestone,andtapitout

敲入intoaladle

[’leidl]鐵水包

ordirectlyintomolds鑄模.Thisiscastiron.Castirondoesnothavethestrengthofsteel.Itisbrittleandmayfractureundertension

張力.Butitpossessescertainpropertiesthatmakeitveryusefulinthemanufactureofmachinery

機(jī)器，機(jī)械.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII152.1.1IronandSteelInthemoltenstateitisveryfluid

流暢的,therefore,itiseasytocastitintointricate(=complicated

復(fù)雜的)shapes.Alsoitiseasytomachineit.Castironcontainssmallproportionsofothersubstances.Thesenon-metallicconstituentsofcastironincludecarbon,siliconandsulphur,andthepresenceofthesesubstancesaffectsthebehaviorofthemetal.ENGLISHINMATERIALSSCIENCEANDENGINEERINGII162.1.1IronandSteelIronwhichcontainsanegligible

[‘neglid??bl]

可以忽略的，微不足道的

quantityofcarbon,forexample,wrought

精細(xì)的iron鍛鐵，熟鐵behavesdifferentlyfromironwhichcontainsalotofcarbon.Thecarbonincastironispresentpartlyasfreegraphiteandpartlyasachemicalcombinationofironandcarbonwhichiscalledcementite

滲碳體.Thisisaveryhardsub