Dab tsi yog microstructure?
Microstructure hais txog kev npaj thiab koom haum ntawm cov ntaub ntawv sab hauv ntawm lub micrometcic, feem ntau pom ntawm 1 nanometer thiab 1000 micrometers. Cov yam ntxwv ke no suav nrog cov ciaj ciam nplej, theem faib tawm, crystal kev cob qhia, thiab tsis zoo uas cuam tshuam nrog cov khoom siv tshuab hluav taws xob, hluav taws xob, thiab cov khoom siv hluav taws xob.
Nplai thiab cov cim ntawm microstructure
Microstructure tshwm sim hauv qhov loj me me uas yuav tsum tau magification kom soj ntsuam. Feem ntau cov microstructural nta poob ntawm 0.1 thiab 100 micrometers, ua qhov muag thiab hluav taws xob microscopy lub hom phiaj tseem ceeb rau kev kuaj mob.
Cov teeb meem teev vim tias nws zaum ntawm cov qauv atom (nanoscale) thiab macroscale (pom nta). Ntawm qib nrab no, cov ntaub ntawv tsim lawv cov xeeb ceem yam ntxwv. Ib qho kev sib xyaw hlau yuav zoo saib rau lub qhov muag liab qab, tab sis nws cov microstructure qhia cov qauv, thiab cov ciam teb ntau uas txiav txim siab seb nws muaj nkig lossis coorcious.
Cov khoom sib txawv ntawm cov qauv sib txawv Microstration nta nta. Cov nplej ua cov nplej thiab cov ciaj ciam nplej. Ceramics Muab cov theem crystalline thiab porosity. Polymers qhia cov kab hlau molecular kev npaj thiab cov teb crystalline. Kev sib xyaw ua ke ntau microstructures tsis pub dhau ib qho system khoom siv.
Qhov tseem ceeb ntawm microstructure
Nplej thiab Nplej Ciam Teb
Nplej yog cov cheeb tsam crystalline nyob rau hauv cov khoom siv polycrystalline. Txhua cov xaw muaj cov atoms teem rau hauv cov qauv crystal, tab sis cov kev taw qhia txawv ntawm cov nplej sib sib luag. Cov interfaces ntawm nplej -}}} ua raws li cov nyom rau kev tshem tawm cov khoom siv zog.
Lis loj ncaj ncaj qha cuam tshuam nrog cov khoom siv neeg kho tshuab los ntawm kev pab - petch kev sib raug zoo. Cov nplej me me muaj ntau thaj chaw thaj tsam, uas ntxiv dag zog rau cov khoom siv tshem tawm. Cov khoom siv nrog rau 10-cov nplej ua kom muaj zog yuav tsis muaj zog tshaj cov khoom siv nrog 1-micrometer nplej.
Cov qoob loo nplej tseem cuam tshuam corrosion tsis kam, hluav taws xob conductivity, thiab tawg tawm. Cov ntaub ntawv nrog cov hmoov nplej siab sib txawv tuaj yeem tiv taus tawg tab sis tej zaum yuav muaj kev cuam tshuam ntau dua los txhawb kev txhim kho hauv qee qhov chaw ib puag ncig.
Theem faib
Ntau cov ntaub ntawv engineering muaj ntau nqe -} Cov cheeb tsam nrog cov chaw sib txawv lossis cov qauv sib txawv. Steel muaj ferrite thiab xis masite theem. Txhuas alloys muaj cov kauj ruam premases uas muab kev ntxiv dag zog. Kev faib tawm, qhov loj me, thiab morphology ntawm theem no txiav txim siab ua tau zoo.
Theem kev hloov pauv thaum lub caij sov kho tsim cov microstructures txhua yam. Quenching steel ua rau martensite, yog qhov nyuaj heev tab sis loj heev rau theem. Tempering converts converts converts converts qee martensite rau tempered martensite nrog kev nruj dua. Lub txiaj ntsig microstructure nyob ntawm cov kev hloov pauv kinetics thiab cov nqi cua txias thov.
Crystal Orientation thiab Kev ntxhib los mos
Cov neeg nplej muaj cov txheej txheem crystallographic. Thaum muaj ntau cov nplej sib qhia cov kev taw qhia zoo ib yam li, cov khoom tsim kev ntxhib los mos. Qhov kev qhia no nyiam tshaj plaws cuam tshuam rau anisotropic cov khoom- cov khoom siv sib txawv ntawm cov lus qhia sib txawv.
Rolled hlau ntawv feem ntau loj hlob cov textures los ntawm kev deformation yas. Kev sib sib zog nqus - Daim duab hlau nplaum xav tau cov duab tshwj xeeb kom tsim cov duab nyuaj tsis muaj kev tawg. Hluav taws xob hluav taws xob yuav tsum muaj cov kab mob tshwj xeeb los txo cov magnetic poob. Nkag siab thiab kev tswj hwm kev ntxhib los yog qhov tseem ceeb rau kev ua kom ua tau zoo cov khoom siv hauv kev siv.
Cov tsis xws luag thiab tsis txaus ntseeg
Zoo meej crystal qauv tsis muaj nyob rau hauv cov ntaub ntawv tiag tiag. Microstructures muaj ntau yam: Taw teeb meem: Chaw seem tsis xws luag (cov kab ke thiab cov pob zeb tsis xws luag (cov teeb meem nplej), thiab ntim qhov tsis xws luag (pores thiab suav nrog).
Cov kev tsis txaus siab no tsis yog qhov phem. Dislocations pab tau cov khoom tawg yooj yim, tso cai hlau kom khoov tsis muaj tawg. Kev tswj cov porosity hauv Ceramics muab cov rwb thaiv tsev thermal. Qhov tseem ceeb yog kev nkag siab uas tsis xws luag pab lossis ua kom cov kev siv tau zoo.
Yuav ua li cas Microstructure cov ntaub ntawv
Ua ntej keeb kwm kev txiav txim siab microstructure. Solidification los ntawm cov txiv qhuav tsim cov qauv nplej ua ntej. Tom ntej kev ua haujlwm ua haujlwm ua haujlwm rov qab ua kom paub qab zib thiab qhia txog cov khoom tawm suab. Kev Kho Mob Thaum Tshav Kub Kub ua rau theem hloov pauv thiab cov nyom sib deev.
Tus nqi txias txias thaum lub sijhawm Sandicification tsis kam lees qoob loo loj. Sai sai txias ua cov nplej zoo nrog lub sijhawm tsawg rau kev loj hlob. Qeeb txias txias tso cai rau cov nplej loj dua los txhim kho. Xuab zeb casting tsim cov coarser microstructures dua li tuag casting vim muaj cov nqi sib txawv.
Yas deformation los ntawm dov, forging, lossis extrusion tsoo thiab elongates nplej thaum tsim cov khoom lag luam loj. Qhov haujlwm no ua rau muaj zog ntxiv cov khoom tab sis txo cov qauv sib xws. Tom qab Annealing rau Recrystallization - New strel {3} ucleate thiab loj hlob, rov kho dua.
Cov txheej txheem kev ua tiav zoo liHlau Txhaj MoldingTsim cov microstructures los ntawm kev sib txuas hmoov metallurgy nrog yas molding. Sintering txheej txheem consolidates hlau hmoov sau, ua kom zoo - ni}} duab precision rau cov khoom nyuaj.
Soj Ntsuam Xyuas Thiab Txheeb Rau Micrettructure
Daim Hlau Teeb Meem
Qhia txog kev tsim kho microstructure yuav tsum tau npaj ua qauv. Txiav, Mounting, sib tsoo, thiab Polishing ua ib lub tiaj, kos -} dawb saum npoo. Tshuaj lom neeg lossis electrochemical tawm tsam cov ciaj ciam av thiab theem cuam tshuam, ua rau pom nyob hauv kev magnification.
Sib txawv li qub piv tau nthuav tawm cov yam ntxwv sib txawv. Tseem ceeb (nitric acid hauv cawv) qhia cov txhuv nplej hauv cov hlau. Keller tus reagent qhia cov qauv nplej hauv txhuas alloys. Qhov kev xaiv ntawm Etchant nyob ntawm cov khoom siv thiab cov yam ntxwv ntawm kev txaus siab.
Cov txheej txheem me me
Optical tsom kwm muab cov kev ua kom muaj zog txog li 1000 × rau kev soj ntsuam qhov yooj yim micritioning. Nws yog nrawm, kuj pheej yig, thiab txaus rau ntau yam kev tswj hwm zoo. Grain loj, theem cim kev cim, thiab cov ntsiab lus muaj feem tuaj yeem raug ntsuas qhov muag.
Kev Ntsuas Hluav Taws Xob Hluav Taws Xob Hluav Taws Xob Cov me me (SEM) txuas ntxiv rau kev ua kom 100,000 × nrog qhov tob ntawm teb. SEM qhia tau zoo precipitates, pob txha lov, thiab cov yam ntxwv incographical tsis pom nyob rau hauv tsom iav tsom iav. Zog -}}} - ray teb spectroscopy (EDS) txuas rau SEMS muab cov cim kev sib xyaw ua ke.
Kev Hloov Hluav Taws Xob Cov Khoom Siv Hluav Taws Xob (TEM) nce siab tshaj plaws cov magnifications thiab qhia tawm atomic - nplai nta. Dislocations, daus kev teeb tsa, thiab cov yam ntxwv cuam tshuam los pom. Tem yuav tsum muaj cov qauv kev npaj nrhiav tab sis muab kev daws teeb meem tsis daws tau rau cov kev tshawb fawb microstration.
Microstructure - kev sib raug zoo
Cov Khoom Siv Neeg Kho Tshuab
Lub zog, ductility, kev nruj me ntsis, thiab hardness txhua yam nyob ntawm microstructural. Nplua {{1} nplej cov ntaub ntawv tiv thaiv deformation zoo dua li coarse {2} nplej sawv daws yuav. Zas hau kev faib khoom muaj zog ntxiv rau txhuas thiab nickel {{}} raws li alloys. Theem Morphology txiav txim seb cov hlau yuav tawv lossis nkig.
Ib qho dual -}} phe theem steel muaj cov martensite hauv lub pob zeb muag. Qhov no microstructure sib xyaw ua ke los ntawm Martensite nrog cov qauv zoo los ntawm ferrite {}-} theem steels.
Cov Khoom Siv Lub Cev
Hluav taws xob kev coj ua uas muaj kev nce qib zuj zus vim muaj qoob loo nplej ntau vim muaj ciam chaw rau hluav taws xob. Thermal conductivity ua raws cov qauv zoo sib xws. Cov khoom sib nqus nyob ntawm cov kab zauv hnyav rau cov cim kev qhia thiab tus qauv sau.
Corrosion Kuj
Cov qoob loo nplej feem ntau corrode preferentlyly, tshwj xeeb tshaj yog nyob rau hauv sensentized stainless hlau uas chromium carbonipides nag los ntawm cov ciam teb. Nplua {{{1} nplej cov ntaub ntawv nrog ntau dua thaj chaw tuaj yeem cuam tshuam tau ntau dua los cuam tshuam kev xeb. Theem Kev faib tawm kuj cuam tshuam nrog kev ua kom thaj chaw hauv nroog - sib xyaw thiab thib ob theem tuaj yeem ua raws li Anodic lossis Cathodic Xaib.
Tswj Microstructure rau Kev Siv
Engineers tswj cov txheej txheem ua kom tiav los ua kom tiav cov tswv yim microstructures. Automotive daim ntawv hlau yuav tsum muaj cov ferrite - pearlite micruction microstructures rau kev muaj peev xwm. Aerospace Aluminium xav tau tswj kav dej kub rau kev faib khoom rau lub zog. Turbine tuaj siv ib qho - siv lead ua microstries kom tshem tawm cov qoob loo cov qoob loo sib txuas rau kev ntxhov siab.
Kev tsim ntxiv ntxiv rau cov cim microstration microstration. Kev SolidIfation ceev thiab rov qab caij thermal cycling tsim tsim cov qauv nplej tshwj xeeb thiab theem faib khoom. Nkag siab cov txheej txheem no {{2} Tus qauv kev sib raug zoo yog qhov tseem ceeb rau kev tsim 3D {4} Cov luam tawm cov khoom siv.
Tsim kev tsim qauv microstructural txuas ntxiv mus nce qib. Nanostructured cov ntaub ntawv rub cov khoom sib txuas hauv qab 100 nanometers rau kev muaj zog tshwj xeeb. Gradient microstructures sib txawv ntawm cov khoom siv tuab. Ntau - nplai microstructural ua kom cov qauv zoo ntawm qhov ntev ntev teev ib txhij.
Hom microstructural hauv cov khoom sib txawv
Tus hlau: Ferrite, Pearlite, bainite, martensite Austen, khaws cia, carbon, thiab grack loj sib txawv nyob ntawm kev sib xyaw thiab kev kho cua sov.
Txhuas Alloys: Koom Haum Kis Kas, Khaub Ncaws Kub, zoo li θ 'hauv 2xxx series lossis' nyob rau hauv 6xxx series), grain Ciam teb tuab, thiab dispersoids.
Titanium alloys: Alpha thiab Beta theem nrog lamellar, equiaxed, lossis bimodal morphologies. Colony qauv hauv + alloys.
Rooj ceramics: Crystalline nplej, iav qoob loo phass, porosity, thiab ob {{0} в}} theem hais. Grain loj heev cuam tshuam rau cov khoom siv kho tshuab.
Polymers: Crystalline thiab amorphous cheeb tsam, spherulitic qauv nyob rau hauv semicrystalline polymers, thiab {}} sib cais nyob rau hauv block copolymers.
Cov Lus Nquag Nug
Vim li cas thiaj lis cov nplej loj cuam tshuam cov khoom siv zog?
Cov hmoov nplej ciam thaiv kev txav mus los, uas yog cov hlau tsis ua kom plormatically. Cov nplej me me txhais tau ntau cov ciaj ciam ib cheeb tsam ntim rau ib lub ntim ntim, tsim ntau cov teeb meem rau kev tshem tawm cov lus tsa suab. Qhov tsis kam cuam tshuam rau kev tshem tawm cov kev tshem tawm nce kev ntxhov siab xav tau los deform cov khoom, ua rau nws muaj zog dua. Lub Hall - petch sib npaug ntawm cov kev sib raug zoo ua lej.
Puas tuaj yeem ob cov ntaub ntawv nrog cov khoom siv tib yam muaj cov khoom sib txawv?
Yog lawm, thiab microstructure yog qhov laj thawj. Hlau nrog 0.4% cov pa roj carbon muaj peev xwm ua tau mos thiab ducab lossis tawv tawv thiab tawv tawv thiab nkig nyob ntawm nws cov microstructure. Kev kho cua sov, ua cov siv tshuab, thiab cov qhab nia txias txhua qhov hloov micrubtructure yam tsis muaj kev hloov pauv. Qhov no yog vim li cas kev ua kom muaj teeb meem ntau npaum li cov khoom xaiv.
Yuav hloov kho microstructure sai npaum li cas?
Nws nyob ntawm qhov kub thiab txias thiab kev siv tshuab. Theem kev hloov pauv thaum lub sijhawm quenching tshwm sim hauv milliseconds. Grain kev loj hlob thaum annealing yuav siv sijhawm ib zaug. Nag lossis daus nyob rau hauv lub hnub nyoog - tawv tawv }loks tshwm sim ntau teev nyob rau hnub. Chav - kub micrervation hloov tau qeeb heev, uas yog vim li cas cov ntaub ntawv feem ntau nyob ruaj khov thaum lub sijhawm ua haujlwm.
Dab tsi yog qhov txawv ntawm microstructure thiab cov qauv siv lead ua?
Crystal piav qhia txog kev tswj hwm atomic nyob rau hauv ib qho zoo nkauj crystal - rov qab cov qauv xov tooj ntawm tes. Microstructure piav qhia seb cov cheeb tsam uas muaj tseeb li cas (nplej) tau npaj, taw qhia, thiab faib nrog nrog ciam teb, theem, thiab tsis xws luag. Cov qauv siv lead ua yog atomic ing ... 3}} nplai; Microstructure yog microscopic - nplai.
The field of microstructure continues evolving with new characterization techniques. 3D microscopy methods now reveal microstructures in three dimensions rather than two-dimensional cross-sections. Tshuab kawm algorithms tshawb xyuas txhiab ntawm cov duab microstructural kom kwv yees kev ua haujlwm lossis qhia cov kev ua kom zoo. Cov kev tawm tsam no tau ua rau microstration tshuab txhim kho ntau yam kev twv ua ntej thiab tsis muaj peev xwm tsawg.
Nkag siab microstructure txuas txuas txuas hniav sib txawv ntawm kev ua thiab cov khoom. Nws piav txog yog vim li cas cov ntaub ntawv coj zoo li lawv ua thiab muab cov kev paub uas xav tau los txhim kho kev ua haujlwm los ntawm kev tswj hwm.