0102 ib0304 ib05
Advanced ceramic khoom siv rau kev siv hnyav
2021-05-26
Tsis muaj kev txhais cov kev pabcuam raug cai. Nws tuaj yeem suav hais tias yog xa mus rau tus nqi siab ntawm kev hloov lub valve lossis cov haujlwm ua haujlwm uas txo cov peev txheej ua haujlwm. Lub ntiaj teb no yuav tsum tau txo cov txheej txheem tsim cov nqi txhawm rau txhim kho cov txiaj ntsig ntawm txhua qhov kev koom tes hauv kev pabcuam hnyav. Cov no muaj xws li roj thiab roj, petrochemicals mus rau nuclear fais fab thiab lub zog tsim, ntxhia ua thiab mining. Designers thiab engineers tab tom sim ua kom tiav lub hom phiaj no nyob rau hauv ntau txoj kev. Txoj kev tsim nyog tshaj plaws yog txhawm rau nce sijhawm thiab ua haujlwm tau zoo los ntawm kev tswj cov txheej txheem tsis zoo (xws li kev kaw haujlwm zoo thiab kev tswj xyuas kom zoo). Kev txhim kho kev nyab xeeb kuj tseem ua lub luag haujlwm tseem ceeb, vim tias txo tus lej ntawm kev hloov pauv tuaj yeem ua rau muaj kev nyab xeeb ntau dua. Tsis tas li ntawd, lub tuam txhab tab tom ua haujlwm los txo cov khoom siv (nrog rau cov twj tso kua mis thiab cov li qub) cov khoom muag thiab yuav tsum tau muab pov tseg. Nyob rau tib lub sijhawm, cov tswv tsev cia siab tias yuav muaj nyiaj ntau los ntawm lawv cov cuab tam. Yog li ntawd, muaj peev xwm ua tau ntau dua yuav ua rau tsawg dua (tab sis txoj kab uas hla loj dua) cov kav dej thiab cov khoom siv thiab cov twj paj nruag tsawg dua rau tib cov khoom ntws. Qhov no qhia tau hais tias, ntxiv rau qhov yuav tsum tau siv cov khoom siv loj dua rau cov kav dej dav dav, nws tseem yuav tsum tau ua kom ntev ntev rau qhov chaw hnyav kom txo tau cov kev pabcuam hauv kev pabcuam thiab kev hloov pauv. Cheebtsam suav nrog li qub thiab cov pob valve yuav tsum muaj zog kom haum rau qhov xav tau daim ntawv thov, tab sis lawv kuj tseem tuaj yeem ua rau lawv lub neej ntev. Txawm li cas los xij, qhov teeb meem tseem ceeb ntawm cov ntawv thov feem ntau yog cov khoom hlau tau mus txog lawv qhov kev txwv. Qhov no qhia tau hais tias cov neeg tsim qauv yuav nrhiav lwm txoj hauv kev rau cov ntaub ntawv tsis yog xim hlau hauv cov ntawv thov, tshwj xeeb tshaj yog cov ntaub ntawv ceramic. Cov yam ntxwv uas yuav tsum tau ua haujlwm rau cov khoom siv hauv cov xwm txheej hnyav xws li thermal shock resistance, corrosion resistance, fatigue resistance, hardness, zog, thiab toughness. Resilience yog ib qho tseem ceeb parameter, vim hais tias cov khoom uas tsis tshua muaj resilient tuaj yeem ua tsis tau zoo. Lub toughness ntawm cov ntaub ntawv ceramic yog txhais raws li kev tiv thaiv tawg propagation. Qee qhov xwm txheej, nws tuaj yeem ntsuas tau siv cov txheej txheem indentation kom tau txais txiaj ntsig zoo siab. Kev siv cov kab hluav taws xob ib sab tuaj yeem muab cov txiaj ntsig ntsuas qhov tseeb. Lub zog muaj feem xyuam nrog kev ua kom tawv, tab sis hais txog ib qho chaw uas cov khoom puas tsuaj puas tsuaj thaum muaj kev ntxhov siab. Nws yog feem ntau hu ua "modulus ntawm rupture" thiab tau los ntawm kev ntsuas peb-point los yog plaub-point dabtsi yog khoov lub zog ntawm ib tug pas ntsuas. Tus nqi ntawm qhov kev xeem peb-point yog 1% siab dua tus nqi ntawm qhov kev xeem plaub-point. Txawm hais tias muaj ntau qhov ntsuas suav nrog Rockwell hardness tester thiab Vickers hardness tester tuaj yeem siv los ntsuas qhov nyuaj, Vickers microhardness nplai yog qhov tsim nyog rau cov khoom siv ceramic siab heev. Lub hardness hloov pauv nyob rau hauv kev faib ua feem rau qhov hnav tsis kam ntawm cov khoom. Nyob rau hauv li qub kev khiav hauj lwm nyob rau hauv ib tug cyclic yam, qaug zog yog lub ntsiab kev txhawj xeeb vim lub nruam qhib thiab kaw ntawm lub valve. Kev qaug zog yog qhov pib ntawm lub zog. Tshaj li qhov pib no, cov khoom siv feem ntau ua tsis tau qis dua nws lub zog khoov ib txwm. Corrosion kuj nyob ntawm qhov chaw ua haujlwm thiab qhov nruab nrab uas muaj cov khoom siv. Ntxiv rau "hydrothermal degradation", ntau cov ntaub ntawv ceramic zoo tshaj rau cov hlau hauv daim teb no, thiab qee cov ntaub ntawv zirconia yuav raug "hydrothermal degradation" tom qab raug rau qhov kub thiab txias. Lub geometry, thermal expansion coefficient, thermal conductivity, toughness thiab lub zog ntawm cov khoom raug cuam tshuam los ntawm thermal shock. Qhov chaw no yog qhov tsim nyog rau cov thermal conductivity thiab toughness, yog li cov khoom siv hlau tuaj yeem ua haujlwm zoo. Txawm li cas los xij, kev nce qib hauv cov ntaub ntawv ceramic tam sim no muab cov qib siab ntawm thermal shock resistance. Advanced ceramics tau siv ntau xyoo thiab nrov ntawm cov neeg ua haujlwm kev ntseeg siab, cov kws tsim khoom cog thiab cov neeg tsim lub valve uas xav tau kev ua haujlwm siab thiab tus nqi siab. Raws li kev thov tshwj xeeb, nws yog qhov tsim nyog rau cov formulations sib txawv hauv ntau yam kev lag luam. Txawm li cas los xij, plaub lub ceramics siab heev yog qhov tseem ceeb hauv kev tswj xyuas cov li qub, suav nrog silicon carbide (SiC), silicon nitride (Si3N4), alumina thiab zirconia. Cov ntaub ntawv ntawm lub valve thiab lub pob valve raug xaiv raws li cov kev thov tshwj xeeb. Lub valve siv ob hom tseem ceeb ntawm zirconia, uas muaj tib lub thermal expansion coefficient thiab nruj li steel. Magnesium oxide ib feem stabilized zirconia (Mg-PSZ) muaj lub siab tshaj plaws thermal shock tsis kam thiab toughness, thaum yttria tetragonal zirconia polycrystalline (Y-TZP) yog ib qho nyuaj, tab sis yog susceptible rau hydrothermal degradation. Silicon nitride (Si3N4) muaj cov qauv sib txawv. Gas siab sintered silicon nitride (GPPSN) yog cov khoom siv feem ntau siv rau li qub thiab valve Cheebtsam. Ntxiv rau nws qhov nruab nrab toughness, nws kuj muaj siab hardness thiab lub zog, zoo heev thermal shock kuj thiab thermal stability. Tsis tas li ntawd, nyob rau hauv qhov chaw kub kub, Si3N4 tuaj yeem hloov zirconia los tiv thaiv hydrothermal degradation. Nrog rau kev siv nyiaj nruj dua, tus neeg xav tau tuaj yeem xaiv los ntawm SiC lossis alumina. Ob leeg cov ntaub ntawv muaj siab hardness, tab sis tsis nyuaj tshaj zirconia los yog silicon nitride. Qhov no qhia tau hais tias cov khoom siv tau zoo heev rau kev siv cov khoom siv zoo li qub, xws li liner liners thiab lub rooj zaum valve, tsis yog lub pob valve lossis cov discs uas muaj kev ntxhov siab ntau dua. Piv nrog rau cov khoom siv hlau siv hauv kev thov valve (xws li ferrochrome (CrFe), tungsten carbide, Hastelloy thiab Stellite), cov khoom siv ceramic siab muaj qis dua thiab lub zog zoo sib xws. Cov ntawv thov kev pabcuam suav nrog kev siv cov khoom siv teb, xws li npauj npaim li qub, trunnions, ntab pob li qub thiab cov dej ntws. Nyob rau hauv xws li daim ntaub ntawv, Si3N4 thiab zirconia muaj thermal shock resistance, toughness thiab lub zog, thiab tuaj yeem hloov mus rau qhov chaw xav tau tshaj plaws. Vim lub hardness thiab corrosion kuj ntawm cov khoom, kev pab cuam lub neej ntawm cov khoom yog ob peb zaug ntawm cov hlau tivthaiv. Lwm cov txiaj ntsig muaj xws li cov yam ntxwv ua haujlwm ntawm lub neej ntawm lub valve, tshwj xeeb tshaj yog nyob rau hauv cov cheeb tsam uas muaj peev xwm txiav tawm thiab tswj tau. Qhov no tau tshwm sim nyob rau hauv rooj plaub ntawm 65mm (2.6 nti) valve kynar / RTFE pob thiab liner raug rau 98% sulfuric acid ntxiv rau ilmenite, lub ilmenite tau hloov mus rau titanium oxide pigment. Qhov xwm txheej corrosive ntawm cov xov xwm txhais tau hais tias lub neej ntawm cov khoom no tuaj yeem ntev li rau lub lis piam. Txawm li cas los xij, kev siv lub voj voos kheej kheej (tus tswv ntawm magnesium oxide ib feem stabilized zirconia (Mg-PSZ)) tsim los ntawm Nilcra™ (Daim duab 1) muaj qhov zoo heev hardness thiab corrosion kuj thiab tau muab rau peb xyoos. Kev pabcuam cuam tshuam, yam tsis muaj qhov pom kev hnav thiab tsim kua muag. Nyob rau hauv linear li qub (xws li lub kaum sab xis li qub, throttle li qub los yog lub ntiaj teb li qub), vim "lub rooj nyuaj" cov yam ntxwv ntawm cov khoom, zirconia thiab silicon nitride yog haum rau ob lub valve plugs thiab valve rooj. Ib yam li ntawd, alumina tuaj yeem siv rau hauv qee yam hauv ob sab phlu thiab tawb. Los ntawm lub pob sib txuam ntawm lub nplhaib lub rooj zaum, qhov siab ntawm kev sib khi tuaj yeem ua tiav. Rau cov tub ntxhais valve, suav nrog spool valve, inlet thiab qhov hluav taws xob lossis valve lub cev bushing, ib qho ntawm plaub lub ntsiab lus ceramic tuaj yeem siv tau raws li daim ntawv thov. Lub siab hardness thiab corrosion kuj ntawm cov khoom tau ua pov thawj tias muaj txiaj ntsig zoo ntawm cov khoom lag luam thiab kev pabcuam lub neej. Siv lub DN150 npauj npaim valve siv hauv Australian bauxite refinery ua piv txwv. Cov ntsiab lus silica siab nyob rau hauv nruab nrab ua rau cov qib siab hnav ntawm lub valve bushings. Lub liner thiab valve disc siv thawj zaug yog ua los ntawm 28% CrFe alloy thiab kav tsuas yog yim mus rau kaum lub lis piam. Txawm li cas los xij, vim yog kev qhia txog li qub ua los ntawm Nilcra ™ zirconia (Daim duab 2), lub neej kev pabcuam tau nce mus txog 70 lub lis piam. Vim nws toughness thiab lub zog, ceramics ua hauj lwm zoo nyob rau hauv feem ntau daim ntawv thov valve. Txawm li cas los xij, nws yog lawv qhov hardness thiab corrosion kuj uas pab txuas lub neej ntawm lub valve. Nyob rau hauv tas li ntawd, qhov no txo tus nqi ntawm tag nrho lub neej voj voog los ntawm kev txo downtime rau hloov qhov chaw, txo kev ua hauj lwm peev thiab cov khoom muag, tsawg tsawg ntawm phau ntawv tuav, thiab txhim khu kev ruaj ntseg los ntawm txo cov to. Tau ntev, daim ntawv thov ntawm cov khoom siv ceramic nyob rau hauv high-pressure li qub tau yog ib qho ntawm cov kev txhawj xeeb tseem ceeb, vim tias cov li qub no raug rau siab axial lossis torsional loads. Txawm li cas los xij, cov neeg ua si loj hauv daim teb no tab tom tsim lub pob valve tsim uas txhim kho kev muaj sia nyob ntawm kev ua kom lub zog. Lwm qhov kev txwv loj yog qhov loj. Qhov loj ntawm lub rooj zaum loj tshaj plaws thiab lub pob valve loj tshaj plaws (Daim duab 3) ua los ntawm magnesia ib nrab stabilized zirconia yog DN500 thiab DN250, feem. Txawm li cas los xij, feem ntau tam sim no specifiers nyiam siv ceramics los ua qhov chaw uas nws qhov ntev tsis tshaj qhov ntev. Txawm hais tias cov ntaub ntawv ceramic tam sim no tau raug pov thawj tias yog qhov kev xaiv tsim nyog, tseem muaj qee cov lus qhia yooj yim uas yuav tsum tau ua raws li txhawm rau ua kom lawv qhov ua tau zoo. Cov khoom siv ceramic yuav tsum tau siv ua ntej tsuas yog xav tau los txo cov nqi. Ob sab hauv thiab sab nraud yuav tsum zam cov ces kaum ntse thiab kev ntxhov siab. Txhua qhov muaj peev xwm thermal expansion mismatch yuav tsum tau txiav txim siab thaum lub sij hawm tsim. Txhawm rau txo qhov kev ntxhov siab ntawm hoop, nws yog ib qho tsim nyog yuav tsum khaws cov ceramic sab nraud es tsis yog sab hauv. Thaum kawg, qhov kev xav tau ntawm geometric tolerances thiab nto tiav yuav tsum tau ua tib zoo xav txog, vim tias cov kev kam rau siab no tuaj yeem ua rau cov nqi tsis tsim nyog. Los ntawm kev ua raws li cov lus qhia no thiab cov kev coj ua zoo tshaj plaws hauv kev xaiv cov ntaub ntawv thiab kev sib koom tes nrog cov neeg muag khoom txij thaum pib ntawm txoj haujlwm, kev daws teeb meem zoo tshaj plaws tuaj yeem ua tiav rau txhua daim ntawv thov kev pabcuam. Cov ntaub ntawv no tau txais, tshuaj xyuas thiab hloov kho los ntawm cov ntaub ntawv muab los ntawm Morgan Advanced Materials. Morgan Advanced Materials-Technical Ceramics. (Lub Kaum Ib Hlis 28, 2019). Advanced ceramic cov ntaub ntawv tsim nyog rau kev pabcuam loj. AZoM. Tau txais los ntawm https://www.azom.com/article.aspx?ArticleID=12305 nyob rau lub Tsib Hlis 26, 2021. Morgan Advanced Materials-Technical Ceramics. "Cov khoom siv ceramic siab heev rau kev siv kev pabcuam loj". AZoM. Peb Hlis 26, 2021. Morgan Advanced Materials-Technical Ceramics. "Advanced ceramic cov ntaub ntawv rau cov ntawv thov kev pabcuam loj". AZoM. https://www.azom.com/article.aspx?ArticleID=12305. (Tau txais lub Tsib Hlis 26, 2021). Morgan Advanced Materials-Technical Ceramics. 2019. Cov khoom siv ceramic zoo tsim nyog rau kev siv cov kev pabcuam loj. AZoM, saib lub Tsib Hlis 26, 2021, https://www.azom.com/article.aspx? ArticleID = 12305. AZoM tham nrog Associate Professors Arda Gozen, George thiab Joan Berry los ntawm Washington State University. Arda yog ib feem ntawm pab pawg ntawm ntau lub koom haum mob siab rau tsim scaffolds ntawm engineered cov ntaub so ntswg los ntawm kev coj tus yam ntxwv ntawm tib neeg cov ntaub so ntswg. Hauv kev xam phaj no, AZoM tau tham nrog Dr. Tim Nunney thiab Dr. Adam Bushell ntawm Thermo Fisher Scientific txog Nexsa G2 qhov kev ntsuam xyuas saum npoo av. Hauv kev xam phaj no, AZoM thiab Dr. Juan Araneda, tus thawj coj ntawm kev siv tshuaj lom neeg ntawm Nanalysis, tau tham txog kev siv ntau ntxiv thiab kev siv hluav taws xob ntawm NMR thiab yuav ua li cas pab kev tsom xam ntawm lithium deposits. Leco's GDS850 glow discharge spectrometer tuaj yeem siv los txheeb xyuas ntau yam khoom siv hlau. Nws kuj muab qhov ntau qhov tob profileing ntawm cov khoom. Nws muaj ntau yam ntawm 120-800 nm thiab muaj ntau yam. Hardinge® T series tig cov chaw thiab SUPER-PRECISION® T series tig cov chaw tau lees paub cov thawj coj hauv kev lag luam hauv ultra-precision thiab nyuaj tig daim ntawv thov. Peb siv cov ncuav qab zib los txhim kho koj qhov kev paub. Los ntawm txuas ntxiv mus saib lub vev xaib no, koj pom zoo rau peb siv cov ncuav qab zib. Xav paub ntxiv.