Cuaj precision molding txheej txheem ntawm zirconia ceramics

Cuaj precision molding txheej txheem ntawm zirconia ceramics
Cov txheej txheem molding plays lub luag haujlwm txuas hauv tag nrho cov txheej txheem kev npaj ntawm cov ntaub ntawv ceramic, thiab yog tus yuam sij kom ntseeg tau tias kev ua tau zoo thiab kev tsim rov ua dua ntawm cov khoom siv ceramic thiab cov khoom siv.
Nrog rau txoj kev loj hlob ntawm tib neeg, txoj kev siv tes kneading ib txwm siv, lub log txoj kev, txoj kev grouting, thiab lwm yam ntawm cov tsoos ceramics tsis tuaj yeem ua tau raws li cov kev xav tau ntawm cov neeg niaj hnub no rau kev tsim khoom thiab kev ua kom zoo dua qub, yog li cov txheej txheem molding tshiab tau yug los.ZrO2 cov ntaub ntawv zoo ceramic tau dav siv hauv 9 hom kev molding hauv qab no (2 hom kev qhuav thiab 7 hom kev ntub dej):

1. Qhuav molding

1.1 Qhuav nias

Qhuav nias siv lub siab los nias cov hmoov ceramic rau hauv ib qho ntawm lub cev.Nws cov ntsiab lus yog tias nyob rau hauv qhov kev txiav txim ntawm sab nraud quab yuam, cov hmoov hmoov mus rau ib leeg nyob rau hauv pwm, thiab ruaj khov ua ke los ntawm kev sib txhuam sab hauv kom tswj tau ib qho zoo.Lub ntsiab tsis xws luag ntawm lub cev qhuav-nias ntsuab yog spallation, uas yog vim muaj kev sib txhuam sab hauv ntawm cov hmoov thiab kev sib txhuam ntawm cov hmoov thiab cov pwm phab ntsa, uas ua rau lub siab poob hauv lub cev.

Qhov zoo ntawm cov xovxwm qhuav yog qhov loj ntawm lub cev ntsuab yog qhov tseeb, kev ua haujlwm yooj yim, thiab nws yooj yim rau kev paub txog kev ua haujlwm;cov ntsiab lus ntawm noo noo thiab binder nyob rau hauv ntsuab qhuav nias yog tsawg, thiab qhuav thiab firing shrinkage yog me me.Nws yog tsuas yog siv los tsim cov khoom nrog cov duab yooj yim, thiab qhov sib piv me me.Tus nqi tsim khoom ntau ntxiv los ntawm pwm hnav yog qhov tsis zoo ntawm cov xovxwm qhuav.

1.2 Isostatic nias

Isostatic nias yog ib txoj kev tsim tshwj xeeb tsim los ntawm kev siv tshuaj qhuav qhuav.Nws siv cov kua xa tawm siab los siv lub siab sib npaug rau cov hmoov hauv cov pwm elastic los ntawm txhua qhov kev qhia.Vim yog qhov sib xws ntawm lub siab sab hauv ntawm cov kua, cov hmoov bears tib lub siab nyob rau hauv tag nrho cov lus qhia, yog li qhov sib txawv ntawm qhov ntom ntawm lub cev ntsuab yuav zam tau.

Isostatic nias yog muab faib ua lub hnab ntub isostatic nias thiab qhuav hnab isostatic nias.Lub hnab ntub dej isostatic nias tuaj yeem tsim cov khoom nrog cov duab nyuaj, tab sis nws tuaj yeem ua haujlwm tsis tu ncua.Lub hnab qhuav isostatic nias tuaj yeem paub tsis siv neeg txuas ntxiv ua haujlwm, tab sis tsuas yog tuaj yeem tsim cov khoom nrog cov duab yooj yim xws li square, puag ncig, thiab tubular hla ntu.ISostatic nias tuaj yeem tau txais ib qho kev hnav khaub ncaws thiab lub cev ua kom nruj thiab cov khoom siv hluav taws xob tsis zoo, thiab nws tsuas yog tsim nyog rau cov khoom siv nrog tshwj xeeb kev xav tau.

2. Kev ntub dej

2.1 Kev sib tw
Cov txheej txheem grouting molding zoo ib yam li daim kab xev casting, qhov txawv yog tias cov txheej txheem molding suav nrog cov txheej txheem ntawm lub cev qhuav dej thiab cov txheej txheem tshuaj coagulation.Lub cev lub cev qhuav dej tshem tawm cov dej hauv slurry los ntawm capillary kev ua ntawm cov ntxeem tau gypsum pwm.Lub Ca2+ tsim los ntawm kev sib cais ntawm qhov chaw CaSO4 nce lub zog ionic ntawm slurry, uas ua rau flocculation ntawm slurry.
Nyob rau hauv qhov kev txiav txim ntawm lub cev lub cev qhuav dej thiab tshuaj coagulation, cov ceramic hmoov hais yog tso rau ntawm phab ntsa gypsum.Grouting yog tsim nyog rau kev npaj ntawm loj-scale ceramic qhov chaw nrog cov duab complex, tab sis qhov zoo ntawm lub cev ntsuab, nrog rau cov duab, ntom, lub zog, thiab lwm yam, tsis zoo, kev siv zog ntawm cov neeg ua haujlwm siab, thiab nws tsis haum. rau kev ua haujlwm automated.

2.2 Kub tuag casting
Kub tuag casting yog sib tov ceramic hmoov nrog binder (paraffin) ntawm qhov kub kub (60 ~ 100 ℃) kom tau slurry rau kub tuag casting.Lub slurry yog txhaj rau hauv cov pwm hlau nyob rau hauv qhov kev txiav txim ntawm compressed cua, thiab lub siab yog tswj.Ua kom txias, demoulding kom tau txais ib qho wax dawb paug, cov wax dawb paug yog dewaxed nyob rau hauv kev tiv thaiv ntawm ib tug inert hmoov kom tau ib tug ntsuab lub cev, thiab lub cev ntsuab yog sintered nyob rau hauv high kub los ua porcelain.

Lub cev ntsuab tsim los ntawm kub tuag casting muaj qhov ntev, cov qauv hauv nruab nrab, tsis tshua muaj pwm hnav thiab ua haujlwm siab, thiab tsim nyog rau ntau yam khoom siv raw.Qhov kub ntawm cov quav ciab slurry thiab pwm yuav tsum tau tswj nruj me ntsis, txwv tsis pub nws yuav ua rau hauv kev txhaj tshuaj lossis deformation, yog li nws tsis tsim nyog rau kev tsim cov khoom loj, thiab ob-kauj ruam kev tua hluav taws yog qhov nyuaj thiab kev siv hluav taws xob ntau.

2.3 Daim kab xev casting
Daim kab xev casting yog ua kom tiav cov hmoov ceramic nrog ntau cov organic binders, plasticizers, dispersants, thiab lwm yam kom tau txais cov kua nplaum uas ntws tawm, ntxiv cov slurry rau lub plhaw ntawm lub tshuab casting, thiab siv cov scraper los tswj cov tuab.Nws ntws tawm mus rau txoj siv conveyor los ntawm kev pub noj nozzle, thiab zaj duab xis dawb paug tau txais tom qab ziab.

Cov txheej txheem no tsim nyog rau kev npaj cov ntaub ntawv zaj duab xis.Txhawm rau kom tau txais kev hloov pauv zoo dua, cov khoom lag luam ntau ntxiv yog ntxiv, thiab cov txheej txheem yuav tsum tau tswj nruj me ntsis, txwv tsis pub nws yuav yooj yim ua rau tsis xws luag xws li tev, streaks, tsis tshua muaj zog zaj duab xis los yog nyuaj tev.Cov organic teeb meem uas siv yog tshuaj lom thiab yuav ua rau ib puag ncig muaj kuab paug, thiab lub cev tsis muaj tshuaj lom lossis tsis muaj tshuaj lom yuav tsum tau siv ntau li ntau tau los txo cov pa phem ib puag ncig.

2.4 Gel txhaj tshuaj molding
Gel txhaj tshuaj molding tshuab yog cov txheej txheem tshiab colloidal sai prototyping thawj zaug tsim los ntawm cov kws tshawb fawb ntawm Oak Ridge National Laboratory thaum xyoo 1990s.Ntawm nws cov tub ntxhais yog siv cov organic monomer kev daws teeb meem uas polymerize rau hauv siab-zog, tom qab txuas cov polymer-solvent gels.

Lub slurry ntawm ceramic hmoov yaj nyob rau hauv ib qho kev daws ntawm cov organic monomers yog cam khwb cia rau hauv pwm, thiab cov monomer sib tov polymerizes los ua ib feem gelled.Txij li cov tom qab txuas nrog polymer-cov kuab tshuaj muaj tsuas yog 10% -20% (cov feem ntau) polymer, nws yooj yim tshem tawm cov kuab tshuaj los ntawm cov gel los ntawm cov kauj ruam kom qhuav.Nyob rau tib lub sijhawm, vim yog kev sib txuas ntawm cov polymers, cov polymers tsis tuaj yeem txav nrog cov kuab tshuaj thaum lub sijhawm ziab.

Txoj kev no tuaj yeem siv los tsim cov khoom siv ib-theem thiab cov khoom sib xyaw ua ke, uas tuaj yeem tsim cov duab puab, quasi-net-qhov loj me ntawm cov khoom siv ceramic, thiab nws lub zog ntsuab yog siab li 20-30Mpa lossis ntau dua, uas tuaj yeem rov ua dua.Qhov teeb meem tseem ceeb ntawm txoj kev no yog qhov shrinkage tus nqi ntawm lub embryo lub cev yog siab heev thaum lub sij hawm densification txheej txheem, uas yooj yim ua rau lub deformation ntawm lub embryo lub cev;qee cov organic monomers muaj oxygen inhibition, uas ua rau saum npoo tev thiab poob;vim qhov kub-induced organic monomer polymerization txheej txheem, ua rau kub shaving ua rau lub hav zoov ntawm kev ntxhov siab nyob rau hauv, uas ua rau lub blanks yuav tawg thiab hais txog.

2.5 Direct solidification txhaj tshuaj molding
Direct solidification txhaj tshuaj molding yog lub tshuab moulding tsim los ntawm ETH Zurich: cov dej hnyav, cov hmoov av ceramic thiab cov organic additives tau sib xyaw ua ke los tsim electrostatically ruaj khov, qis-viscosity, siab-khoom-cov ntsiab lus slurry, uas tuaj yeem hloov pauv los ntawm kev ntxiv Slurry pH lossis tshuaj lom neeg. uas nce electrolyte concentration, ces cov slurry yog txhaj rau hauv cov pwm uas tsis yog-porous.

Tswj kev nce qib ntawm cov tshuaj tiv thaiv tshuaj thaum lub sijhawm ua haujlwm.Cov tshuaj tiv thaiv ua ntej txhaj tshuaj molding yog nqa tawm maj mam, viscosity ntawm slurry yog khaws cia tsawg, thiab cov tshuaj tiv thaiv yog nrawm dua tom qab txhaj tshuaj molding, slurry solidifies, thiab cov kua slurry hloov mus rau hauv lub cev khoom.Lub cev ntsuab tau txais cov khoom siv zoo thiab lub zog tuaj yeem ncav cuag 5kPa.Lub cev ntsuab yog demolded, qhuav thiab sintered los ua ib feem ntawm cov duab uas xav tau.

Nws cov txiaj ntsig yog tias nws tsis tas yuav tsum tau lossis tsuas yog xav tau ib qho me me ntawm cov organic hauv lub cev (tsawg dua 1%), lub zog ntsuab tsis tas yuav muaj kev sib tw, cov txheeb ze lub zog yog qhov siab (55% ~ 70%), thiab nws tuaj yeem tsim qhov loj-loj thiab nyuaj-zoo li cov khoom siv ceramic.Nws qhov tsis zoo yog tias cov khoom siv ntxiv yog kim, thiab roj feem ntau tso tawm thaum lub sij hawm cov tshuaj tiv thaiv.

2.6 Txhaj tshuaj molding
Txhaj tshuaj molding tau ntev tau siv nyob rau hauv molding ntawm cov khoom yas thiab molding ntawm hlau pwm.Cov txheej txheem no siv qhov ntsuas kub qis ntawm thermoplastic organics lossis kub kub curing ntawm thermosetting organics.Cov hmoov thiab cov khoom siv organic sib xyaw ua ke hauv cov khoom sib xyaw tshwj xeeb, thiab tom qab ntawd txhaj rau hauv pwm nyob rau hauv siab siab (txog rau pua pua MPa).Vim lub siab loj molding, qhov tau txais qhov khoob muaj qhov ntev, siab smoothness thiab compact qauv;kev siv cov cuab yeej tshwj xeeb molding zoo heev txhim kho kev tsim khoom.

Nyob rau xyoo 1970s thiab thaum ntxov 1980s, cov txheej txheem txhaj tshuaj molding tau siv rau molding ntawm ceramic qhov chaw.Cov txheej txheem no paub txog cov yas molding ntawm cov ntaub ntawv tsis zoo los ntawm kev ntxiv ntau cov organic teeb meem, uas yog cov txheej txheem ceramic yas molding.Hauv kev txhaj tshuaj molding tshuab, ntxiv rau kev siv cov thermoplastic organics (xws li polyethylene, polystyrene), thermosetting organics (xws li epoxy resin, phenolic resin), los yog dej-soluble polymers ua lub ntsiab binder, nws yog ib qho tsim nyog yuav tau ntxiv qee qhov ntau ntawm cov txheej txheem. cov khoom siv xws li cov khoom siv yas, cov roj nplaum thiab cov khoom sib txuas los txhim kho cov dej ntws ntawm cov ceramic txhaj tshuaj raug tshem tawm thiab xyuas kom zoo ntawm lub cev txhaj tshuaj molded.

Cov txheej txheem txhaj tshuaj molding muaj qhov zoo ntawm qib siab ntawm automation thiab meej qhov loj ntawm molding dawb paug.Txawm li cas los xij, cov ntsiab lus ntawm cov organic hauv lub cev ntsuab ntawm kev txhaj tshuaj molded ceramic feem yog siab li 50vol%.Nws yuav siv sij hawm ntev, txawm tias ob peb hnub mus rau kaum ob hnub, txhawm rau tshem tawm cov organic tshuaj hauv cov txheej txheem sintering tom ntej, thiab nws yooj yim los ua qhov tsis zoo.

2.7 Colloidal txhaj tshuaj molding
Txhawm rau daws cov teeb meem ntawm qhov loj ntawm cov organic teeb meem ntxiv thiab qhov nyuaj ntawm kev tshem tawm cov teeb meem hauv cov txheej txheem txhaj tshuaj molding ib txwm, Tsinghua University muaj tswv yim tsim cov txheej txheem tshiab rau colloidal txhaj tshuaj molding ntawm ceramics, thiab nws tus kheej tsim ib qho kev txhaj tshuaj colloidal molding qauv. kom paub qhov kev txhaj tshuaj ntawm barren ceramic slurry.tsim.

Lub tswv yim yooj yim yog muab cov colloidal molding nrog kev txhaj tshuaj molding, siv cov cuab yeej siv tshuaj thiab cov cuab yeej kho tshiab los ntawm cov txheej txheem colloidal in-site solidification molding.Cov txheej txheem tshiab no siv tsawg dua 4wt.% ntawm cov organic teeb meem.Ib qho me me ntawm cov organic monomers lossis cov organic sib txuas hauv cov dej-raws li kev ncua yog siv los ua kom cov polymerization ntawm cov organic monomers sai sai tom qab txhaj tshuaj rau hauv pwm los tsim cov pob txha pob txha, uas sib npaug ntawm cov hmoov ceramic.Ntawm lawv, tsis tsuas yog lub sij hawm ntawm degumming yog heev luv luv, tab sis kuj muaj peev xwm ntawm cracking ntawm degumming yog heev txo.

Muaj qhov sib txawv loj ntawm kev txhaj tshuaj molding ntawm ceramics thiab colloidal molding.Qhov sib txawv tseem ceeb yog qhov qub yog nyob rau hauv qeb ntawm cov yas molding, thiab tom kawg belongs rau slurry molding, uas yog, slurry tsis muaj plasticity thiab yog cov khoom siv barren.Vim hais tias cov slurry tsis muaj plasticity nyob rau hauv colloidal molding, ib txwm lub tswv yim ntawm ceramic txhaj molding tsis tuaj yeem saws.Yog tias colloidal molding tau ua ke nrog kev txhaj tshuaj molding, colloidal txhaj tshuaj molding ntawm cov ntaub ntawv ceramic yog pom tau los ntawm kev siv cov cuab yeej siv tshuaj thiab cov cuab yeej kho tshiab los ntawm cov txheej txheem colloidal in-site molding.

Cov txheej txheem tshiab ntawm colloidal txhaj tshuaj molding ntawm ceramics yog txawv los ntawm cov colloidal molding thiab tsoos txhaj tshuaj molding.Qhov kom zoo dua ntawm qib siab ntawm molding automation yog qhov zoo sublimation ntawm cov txheej txheem colloidal molding, uas yuav dhau los ua kev cia siab rau kev lag luam ntawm high-tech ceramics.