Nkag siab Porosity: lub hauv paus ntawm cov khoom siv science

Ua ntej peb tuaj yeem teb tauStainless hlauYog qhov ntxeem tau tiag tiag, peb yuav tsum xub nkag siab qhov porosity uas nyob rau hauv cov ntsiab lus ntawm cov khoom ntawm cov khoom kev tshawb fawb. Pority hais txog qhov muaj cov viny me me, cov khoob, lossis raws li cov qauv qauv. Cov hws no tuaj yeem sib txawv hauv qhov loj me-} los ntawm microscopic (millometers) rau kev cuam tshuam nrog huab cua, roj av, lossis lwm yam tshuaj.

Porosity yog ib qho ntawm feem ntau yog tseem tsis tau to taub cov khoom hauv cov khoom science. Thaum tib neeg hnov ​​lo lus "ntxeem tau," Lawv feem ntau xav txog cov ntxaiv lossis ua npuas - cov khoom siv ntawm cov qhov uas pom cov kua uas pom. Tab sis nyob rau hauv cov ntaub ntawv muaj kev muaj, lub tswvyim ntawm porosity txuas deb, nqis rau theem microscopic ntawm cov atoms thiab lwg me me. Yuav kom nkag siab tiag tiag seb puas muaj feem ntau ntawm cov hlau uas tsis muaj lub ntsej muag txhais tau tias, yuav ua li cas nws ntsuas, thiab yog vim li cas nws tseem ceeb hauv kev ua engineering.

1.1 Porosity yog dab tsi?

Hauv cov ntsiab lus yooj yim,porosityHais txog kev faib ua feem ntawm khoob chaw (voids lossis pores) nyob rau hauv cov khoom siv tau. Nws yog feem ntau qhia raws li aFeem pua ​​ntawm tag nrho cov ntimThiab tuaj yeem tawm ntawm ze li 0% (hauv cov hlau tuab zoo li cov hlau stainless) rau ntau dua 90% (hauv foined lossis sintered cov ntaub ntawv).

Porosity tsis yog qhov puas yog los ntawm lub neej ntawd. Nws yog akev tsim qauv sib txawv{{0- tej zaum tsis xav, qee zaum txhob txwm ua rau engineerally. Piv txwv li:

Porosity hauv kev ua vaj tsecuam ​​tshuam lub zog thiab dej permeability.

Porous Ceramicssiv rau kev lim thiab catalysts.

Cov hlau ntxigZoo li bronze yog qhov tseem ceeb nyob rau hauv lubrication tshuab thiab mufflers.

Txawm li cas los xij, rau cov ntaub ntawv uas xav taulub zog, kev nyiam huv, thiab impermability, zoo li stainless hlau,Tsawg lossis xoom porosityyog qhov tseem ceeb tshaj plaws.

Hauv kev tshawb fawb txog kev tshawb fawb, Porosity (φ) yog xam raws li:

φ=vvoidvTotal × 100% \\ phi {vots {ve {\\}}}}} vtotal vvoid × 100%

Qhov twg vvoidv _ {\\ ntawv nyeem}} vvoid yog qhov ntim ntawm txhua lub pores thiab vtotalv {tag nrho}}}}}}}}}}}}}}}}}

1.2 Hom Porosity

Porosity tsis yog ib qho tshwm sim ib qho; Nws muaj nyob rau hauv ntau hom ntawv nyob ntawm seb yuav ua li cas cov khoom siv thiab siv. Cov kws tshawb fawb feem ntau cais tawm cov porosity mus rau ntau pawg:

Qhib porosity:
Pores txuas nrog thiab siv tau los ntawm cov khoom saum npoo av, tso kua dej lossis roj av nkag mus. Pom nyob rau hauv foams, lim, thiab ceramics.

Kaw Porosity:
Pores raug kaw hauv cov khoom, tsis raug rau saum npoo. Cov voids cuab gases tab sis tsis muaj kev cuam tshuam ib qho kev sib tw. Pom nyob rau hauv qee cov hlau cam khwb cia thiab iav.

Micro - porosity:
Pores me dua ib micron (1 μm), feem ntau ntawm cov ciaj ciam av lossis suav nrog cov hlau.

Macro - porosity:
Pores loj los yog loj pores uas ua los ntawm kev ua tsis tiav fusion lossis roj nkag thaum lub sij hawm ua pov.

Hauvntom, zoo -} Cov txheej txheem stainless hlau, txhua yam zoo tshaj plaws feem ntau yog qhov tsawg rau ib qho kev tsis zoo siab theem, kom ua tiav impermabeability.

1.3 Yuav ua li cas porosity cov ntawv nyob rau hauv cov ntaub ntawv

Porosity tuaj yeem pib thaum muaj cov txheej txheem ntawm cov khoom tsim:

Nrum:Yog hais tias molten hlau soli solietifies sai dhau lawm, gases (oxygen, nitrogen, hydrogen) tuaj yeem raug cuab, tsim cov vuaj me me.

Sintering:Hauv cov hmoov metallurgy, tsis tiav kev lom zem ntawm cov lus ua rau cov khoom siv sib tw pore network.

Vuam:Cov ris tsho nkag lossis cov ntaub thaiv tsis raug yuav ua rau muaj kev puas ntsoog hauv Weld Seams.

Ntxiv (3D Printing):Laser lossis Electron - nqaj larting yuav tsim hluav taws xob yog hmoov ntom lossis lub zog tsis sib xws.

Txawm li cas los xij, siab -} qib qib stainless hlau undergoesKev Tsim Kho{{0 {{}} nruam casting, kub dov, txias ua haujlwm, thiab annealing tshem tawm cov tsis zoo no.

1.4 Porosity yog ntsuas

Cov kws tshaj lij ua haujlwm ntau cov txuj ci kev tshawb fawb los tshawb nrhiav thiab ntau yam porosity. Ntawm feem ntau muaj yog:

RauStainless hlau, ntau cov qib siab feem ntauHauv qab no 0.1%, uas yog qhov zoo tsis - pacous nyob rau hauv cov ntsiab lus ntsiab lus. Qhov no yog vim li cas cov hlau uas stainless hlau tuaj yeem tuav lub siab, tiv thaiv kev nkag mus rau cov kua dej txawm tias tom qab siv.

1.5 Porosity thiab nws cov nyhuv ntawm cov khoom khoom

Porosity tseem cuam tshuam cov khoom siv ua tau zoo. Qhov siab dua porosity, txo qis lub zog thiab durability-} Tab sis cov siab dua permeability. Cia peb saib lub ntsab lug sib raug zoo no:

Yog li, hauv stainless hlau, minimizing porosity txhais tau tiasKev ntseeg siab rau kev ntseeg tau thiab kev nyiam huv{{0 {}} ob ntawm nws cov kev txhais tau zoo.

1.6 Porosity hauv cov khoom txhua hnub thiab cov hlau stainless

Yuav kom nkag siab li cas tsis muaj li cas stainless hlau yog, piv nws nrog ntau ntxeem thiab tsis {{{0} {{0} pack paj ntaub ntawv:

Qhov kev sib piv ntawm cov hlau loj uas tsis muaj hlauTshwj xeeb qhov ceev thiab tsis - porous qauv, Rivaled tsuas yog los ntawm iav - Tsis tau muab cov tshuab ua kom zoo dua qub.

1.7 Vim li cas cov neeg ua yeeb yam teeb meem hauv kev siv daim ntawv thov engineering

Porosity ncaj qha cuam tshuam rau kev ua tau zoo hauv kev lag luam xws li:

Aerospace:Cov hlau ntxaij hlau tuaj yeem ua tsis tau raws li qhov siab cycling.

Khoom Noj & Haus:Cov chaw ntxeem tau ntxiab microbes thiab kom muaj kev huv huv.

Kho Mob:Porosity nyob rau hauv kev yield tuaj yeem ua rau muaj kev kis tus kab mob lossis muaj kev nkees.

Pom:Kev tswj cov ntxeem tau muaj txiaj ntsig zoo rau kev xaiv permeability.

Yog li, kev nkag siab thiab tswj cov hws yog lub plawv ntawm cov ntaub ntawv niaj hnub tsim tawm. Stainless hlau nyob ze - xoom portosity ua rau nws abenchmark rau kev nyiam huv thiab ntseeg tau, tshwj xeeb tshaj yog nyob rau hauv sectors uas yuav tsum tsis huv thiab corrosion - ib cheeb tsam.

1.8 Qhov kev sib raug zoo ntawm porosity thiab corrosion

Porosity nce thaj tsam thaj chaw uas corrosion tuaj yeem pib. Nyob rau hauv carbon steels lossis nrum Irons, cuab noo noo lossis chloride ions hauv pores accelate xeb ceev tus xeb. Stainless hlau, ntawm qhov tod tes, tshuav nws corrosion tiv tausnws tsis - porous porous latrix thiab tiv thaiv cov chromium oxide zaj duab xis, uas ntsaws ruaj ruaj txawm tias micro - tsis xws luag.

Uas sib xyaw ua ke ntawmQuav + PassivationPiav qhia yog vim li cas stainless hlau ntxhov ntxhov hauv harsh tubrog nkoj, tshuaj lom neeg, thiab kev lag luam kev nyab xeeb.

Kawm ntxiv:Nkag siab hlau mesh nyob rau hauv cov ntawv thov txhua hnub