Ceramics
Alumina ceramic imhando yekusapfeka, inodzivirira corrosion uye yakakwirira-simba receramic material.Inoshandiswa zvakanyanya uye parizvino ndiyo inonyanya kushandiswa chikamu chepamusoro-tembiricha structural ceramics. Kuti ugadzire kugadzirwa kwakawanda uye kusangana nezvinodiwa zvechigadzirwa chenguva dzose, diki diki kugaya uye nyore kugaya zvakanaka, zvinonyanya kukosha kusarudza nzira yekugadzira yekuomesa yakaoma. Compression molding inoda kuti iyo isina chinhu ihupfu ine imwe gradation, ine hunyoro hushoma uye binder. Naizvozvo, slurry yebatch mushure mekugaya bhora uye kupwanya kwakanaka kunofanira kuomeswa uye kuputika kwehupfu negranulated zviri nani. Kupfapfaidza kuomeswa granulation yave nzira yekutanga yekugadzirwa kwechivako chekeramics uye itsva ceramics.Upfu hwakagadzirwa nenzira iyi ine fluidity yakanaka, imwe chikamu chezvikamu zvakakura uye zviduku, uye yakanaka yakawanda density.Naizvozvo, kupfapfaidza kuomesa ndiyo nzira yakanakisisa yekugadzirira yakaoma yakatsikirirwa poda.
Kupfapfaidza kuomesa inzira iyo zvinhu zvemvura (kusanganisira slurry) zvinogadziriswa atomi uye zvozoshandurwa kuita hupfu hwakaoma munzvimbo inopisa yekuomesa. Zvishandiso zvacho zvinoiswa maatomu kuita akanyanya kunaka spherical fogdrops, nekuda kwefogdrops yakanaka kwazvo uye chiyero chenzvimbo kusvika kuhuwandu hwakakura kwazvo, hunyoro hunokurumidza kubuda, uye kuomesa uye granulation maitiro anopedzwa nekukasira. Iyo particle size, hunyoro hwemukati uye kuwanda density yemidziyo inogona kudzorwa nekugadzirisa kuomesa mashandiro eparameter. Spherical poda ine yunifomu yemhando uye yakanaka kudzokororwa inogona kugadzirwa nekutora pfapfaidzo yekuomesa tekinoroji, nokudaro kupfupisa kugadzirwa kwehupfu, kufambisa otomatiki uye kuenderera kugadzirwa, uye kuva nzira inoshanda kune yakakura-mwero kugadzirira kweakanaka alumina zvedongo yakaoma upfu zvinhu.
2.1.1 Kugadzirira kweSlurry
Iyo yekutanga-kirasi yeindasitiri alumina ine kuchena kwe99% inowedzerwa neinenge 5% yezvinowedzera kugadzirira 95% porcelain zvinhu, uye bhora kugaya kunoitwa zvinoenderana nereshiyo yezvinhu: bhora: mvura = 1: 2: 1, uye binder, deflocculant uye yakakodzera huwandu hwemvura inowedzerwa kugadzirira yakagadzika kuturika kuyerera kwakaringana slurry slurry. zvemukati, mhando uye dosage ye deflocculant.
2.1.2 Kupfapfaidza nzira yekuomesa
Iyo huru yekudzora maitiro maparamendi mukupfapfaidza kuomesa maitiro ndeaya: a). The outlet tembiricha of dryer.Generally controlled at 110℃.b). Inner dhayamita yemhuno.Shandisa 0.16mm kana 0. 8mm orifice plate. c), Cyclone separator pressure difference, control pa220Pa.
2.1.3 Kuongororwa Kwekuita kweUpfu mushure mekupfapfaidza Kuomesa
Unyoro kutsunga ichaitwa maererano zvakajairika zvedongo mwando kutsunga nzira.The particlemorphology uye particle size zvakaonekwa ne microscope.The fluidity uye hukuru hukuru hwehupfu hunoedzwa maererano neASTM yekuedza mitemo yemvura uye hukuru hukuru hwehupfu hwesimbi. Nzira yacho ndeiyi: pasi pemamiriro ekusava nekudengenyeka, 50g poda (yakarurama kusvika 0. 01g) inopfuura nemugoro wegirazi wefurani ine dhayamita ye6mm uye kureba kwe3mm nokuda kwemvura yaro;Pasi pemamiriro ekusava nekudengenyeka, hupfu hunopfuura nemufurairi yegirazi imwe chete uye inowira mumudziyo 25mm yakakwirira kubva kune imwechete girasi funnel. The non-vibrating density ndiyo loose packing density.
3.1.1 Kugadzirira slurry
Uchishandisa pfapfaidzo yekuomesa granulation maitiro, kugadzirira kwe slurry kiyi yakakosha. Solid content, fineness uye fluidity yematope zvinokanganisa zvakananga kubuda uye saizi yehupfu hwakaoma.
Nemhaka yokuti hupfu hwemhando iyi yealuminium porcelain haibereki, zvakakosha kuti uwedzere huwandu hwakakodzera hwebhainda kuti uvandudze kuumba kushanda kwechinhu chisina chinhu.Inowanzo shandiswa organic zvinhu zvakadai sedextrin, polyvinyl alcohol, carboxymethylcellulose, polystyrene, etc.Polyvinyl alcohol (PVA), mvura-soluble binder, yakasarudzwa mune iyi inonzwisisika kushanduka kwehunyoro hunyoro huchava hunyoro hunokosha. kukanganisa maitiro ehupfu hwakaoma.
Polyvinyl doro rine marudzi mazhinji akasiyana, madhigirii akasiyana ehydrolysis uye dhigirii repolymerization, izvo zvinozokanganisa kupfapfaidza kuomesa maitiro. Yayo general hydrolysis dhigirii uye polymerization degree inozokanganisa iyo yekupfapfaidza kuomesa maitiro. Chiyero chayo chinowanzoita 014 - 015wt.Kuwedzerwa kwezvizhinji kuchaita kuti spray granulation powder iite yakaoma yakaoma yakaoma powder particles kudzivirira zvimedu kubva pakuremara panguva yekutsikirira.Kana iyo particle maitiro asingagoni kubviswa panguva yekudzvinyirira, izvi zvinokanganisa zvichachengetwa mumuviri wakasvibirira uye hazvigoni kubviswa mushure mekupfura, izvo zvichakanganisa kunaka kwechigadzirwa chekupedzisira. Binder yekuwedzera yakawandisa simba rakasvibira rinowedzera kurasikirwa kwekushanda. Kuedza kunoratidza kuti kana huwandu hwakakodzera hwebhainda hwawedzerwa, chikamu chegirini billet chinoonekwa pasi pe microscope. Zvinogona kuonekwa kuti kana kudzvinyirirwa kunowedzera kubva ku3Mpa kusvika ku6Mpa, chikamu chinowedzerwa zvakanaka, uye kune nhamba shomanana yezvikamu zvakatenderera. Kana kudzvinyirirwa kuri 9Mpa, chikamu chacho chakatsetseka, uye hapana chaizvo zvidimbu zvakatenderera, asi kudzvanywa kwepamusoro kunotungamira kune stratification yegirinhi billet.PVA inovhurwa panenge 200 ℃.
Tanga kupisa, uye kunyura panenge 360 ℃. Kuti uparadze iyo organic binder uye kunyorovesa billet zvimedu, gadzira iyo yemvura interlayer pakati pezvimedu, kunatsiridza plasticity yebillet, kuderedza kupesana pakati pezvimedu uye kupesana pakati pezvigadzirwa uye mold, kusimudzira kuwedzera kwe density yeiyo yakatsikirirwa billet uye kugovera kwakaringana kwepurasitiki, wedzera huwandu hwakakodzera hwepurasitiki, kudzvanywa kwepurasitiki. anoshandiswa glycerin, ethyl oxalic acid, nezvimwewo.
Nemhaka yokuti binder is an organic macromolecular polymer, nzira yekuwedzera binder mu slurry yakakoshawo zvikuru.Ndiyo yakanakisisa yekuwedzera bhainda rakagadzirirwa mumatope eunifomu nezvinodiwa zvakasimba.Nenzira iyi, iyo isina kunyungudutswa uye isina kupararira zvinhu zvehupenyu zvinogona kudziviswa kuti zviunzwe mu slurry, uye kukanganisa kunokwanisika kunowedzera. bhora kugaya kana kubvongodza. Mhepo yakaputirwa mudonhwe iri muhupfu hwakaoma, izvo zvinoita kuti zvimedu zvakaoma zvive mhango uye zvinoderedza huwandu hwehuwandu. Kuti ugadzirise dambudziko iri, defoamers inogona kuwedzerwa.
Nekuda kwezvehupfumi uye zvehunyanzvi zvinodiwa, yakakwirira yakasimba yemukati inodiwa.Sezvo simba rekugadzira remuomesi richireva kuyerera kwemvura paawa, iyo slurry ine yakakwirira yakasimba yemukati ichawedzera zvakanyanya kuoma kwehupfu. Kana iyo yakasimba yemukati ichiwedzera kubva pa50% kusvika 75%, kubuda kweiyo dryer kuchawedzera kaviri.
Kudzika kwakasimba kwemukati ndicho chikonzero chikuru chekugadzirwa kwehollow particles.Pakuoma, mvura inoenda pamusoro pedonhwe uye inotakura zvimedu zvakasimba, izvo zvinoita kuti chikamu chemukati chedonhwe ive negomba; kana yakaderera permeability elastic firimu inoumbwa yakatenderedza kudonhedza, nekuda kweiyo yakaderera evaporation kukurumidza, tembiricha yedonhwe inowedzera, uye mvura inoputika kubva mukati mechikamu, izvo zvinoita kuti donhwe riwedzere. Muzviitiko zviviri izvi, bhora chimiro chezvimedu chichaparadzwa, uye buri annular kana apuro rakaumbwa kana pear rakaumbwa zvimedu zvichagadzirwa, izvo zvinoderedza hupfu hwehupfu hwakaoma uye hupfu hwakaoma. zvemukati zvinogona kuderedza
Muchidimbu kuomeswa kwemaitiro, kudzikisira kwekuomeswa kunogona kuderedza kuwanda kwekunamira kunotamirwa kune chidimbu chepamusoro pamwe chete nemvura, kuitira kudzivirira kuti iyo binder yakasungirirwa pachikamu chepamusoro inopfuura yepakati, kuitira kuti zvimedu zvive nenzvimbo yakaoma, uye zvimedu hazvikanganise nekupwanya mukutsikirira nekuumba, kuitira kuderedza huwandu hwemuviri webillet. Nokudaro, kuti uwane hupfu hwakaoma hwepamusoro, hutsika hwakasimba hwe slurry hunofanira kuwedzerwa.
Iyo slurry inoshandiswa pakupfapfaidza kuomeswa inofanira kunge ine fluidity yakakwana uye hunyoro hushoma sezvinobvira.Kana viscosity ye slurry yakaderedzwa nekuunza mvura yakawanda, kwete chete kushandiswa kwesimba kwekuomeswa kunowedzera, asiwo kuwanda kwehuwandu hwechigadzirwa kunoderedzwa.Naizvozvo, zvakakosha kuderedza viscosity ye slurry nerubatsiro rwecoagulant, maduku maduku akaomeswa kana maduku akaomeswa. inogona kuonekwa secolloidal dispersion system.Dzidziso yecolloidal stability inoratidza kuti kune masimba maviri ari kushanda pazvikamu zvakaturika: van der Waals force (Coulomb force) uye electrostatic repulsion force. Kana simba racho richinyanya giravhiti, agglomeration uye flocculation ichaitika.Iyo yose inogona simba (VT) yekudyidzana pakati pezvimedu zvine chokuita nedaro razvo, panguva iyo VT pane imwe nguva ndiyo uwandu hwesimba rinokwevera VA uye repulsive energy VR.Apo VT pakati pezvimedu zvinopa huwandu hwepamusoro hwakanaka hunogona simba, iyo ndiyo imwe hurongwa hwekudzikisa, iyo inonzi depoly inopiwa. sisitimu ndiyo iyo mabasa anodzora VR: iyo yepamusoro charge yezvimedu uye ukobvu hwekaviri emagetsi layers.Kukora kwebilayer kunopesana nesquare root yevalence bond uye kusungirirwa kweiyo equilibrium ion.Double layer compression inogona kuderedza chinogona kuvharira che flocculation, saka iyo valence bond uye kusungirirwa kunodiwa kune yakaderera dhizaini. HCI, HNO3, NaOH, (CH) 3noh (quaternary amine), GA, nezvimwewo.
Nokuti mvura-based slurry ye95 alumina ceramic powder haina kwazvakarerekera uye alkalescent, akawanda coagulants ane yakanaka diluting effect pane imwe ceramic slurry inorasikirwa nebasa rayo.Naizvozvo, zvakaoma zvikuru kugadzirira slurry nepamusoro yakasimba uye yakanaka fluidity.The barren alumina slurry, iyo ndeye amphoteric oxide, ine zvakasiyana-siyana zveadhidhi uye disociation maitiro akasiyana-siyana e-dissociation maitiro e-dissociation. micelle kuumbwa uye chimiro. Iyo pH kukosha kwe slurry ichakanganisa zvakananga dhigirii rekuparadzanisa uye adsorption, zvichikonzera shanduko ye ζ inogona uye inoenderana flocculation kana dissociation.
Alumina slurry ine kukosha kwepamusoro kwezvakanaka uye zvisina kunaka ζ zvinogona mu acid kana alkaline medium.Panguva ino, viscosity ye slurry iri mumutengo wakaderera wehurumende ye de coagulation, asi kana slurry iri mumamiriro asina kwaakarerekera, viscosity yayo inowedzera, uye flocculation inoitika.Inowanikwa kuti iyo fluidity ye slurry inovandudza hukuru hwehuputi hwehuputi hunoita kuti huve hwakanyanya. inoderedzwa nekuwedzera demulsifier yakakodzera, kuitira kuti viscosity yayo isvike pedyo nemvura. Iyo fluidity yemvura yakayerwa neyakareruka viscometer masekonzi matatu / 100 ml, uye fluidity ye slurry masekonzi mana / 100 ml. iyo viscosity ye slurry yakaderedzwa, kuitira kuti zvinyorwa zvakasimba mu slurry zviwedzere kusvika ku 60%, uye kutakura kwakagadzikana kunogona kuumbwa.Sezvo simba rekugadzira remuomesi rinoreva kubuda kwemvura neawa, saka kumiswa.
3.1.2 Kudzora maparamendi makuru mukupfapfaidza nzira yekuomesa
Mhepo yekuyerera kwemhepo mushongwe yekuomesa inokanganisa nguva yekuomesa, nguva yekuchengetedza, mvura yakasara uye kunamatira kwemadziro emadonhwe.Mukuedza uku, iyo droplet air mixing process inosanganiswa kuyerera, ndiko kuti, gasi rinopisa rinopinda mushongwe yekuomesa kubva kumusoro, uye iyo atomizing nozzle inoiswa pazasi peiyo shongwe yekuomesa, ichigadzira donho remhepo inosanganiswa neparabola, uye inodonhedza tsime remhepo. countercurrent, uye kana donho richisvika kumusoro kwekurohwa, rinova kuyerera kwemvura uye kupfapfaidza muchimiro chekoni. Hurefu hwenguva dzose yekuomesa nhanho yekuomesa zvinoenderana nehunyoro hwemudonhwe, viscosity yematope, tembiricha uye hunyoro hwemhepo yakaoma. Muganhu C kubva padanho rekuomeswa rinogara riripo kusvika padanho rekuomeswa rinodaidzwa kuti yakakosha. Panguva ino, pamusoro pechidonhwe hachichakwanisa kuchengetedza nzvimbo yakazadzwa nekufamba kwemvura, Nekuderera kwehuwandu hwekubuda kwemhepo, tembiricha yemadonhwe inowedzera, uye pamusoro pemadonhwe panzvimbo D inozara, ichiita dhizaini yakaoma goko. Evaporation inoenda mukati, uye mwero wekuoma unoramba uchiderera. Kuwedzera kubviswa kwemvura kunoenderana nekunyorova kwemvura yegomba rakaoma. Naizvozvo, zvinodikanwa kudzora maitiro ekushanda anonzwisisika.
Hunyoro hwehupfu hwakaoma hunonyanya kutariswa netembiricha yekubuda kwemushini wekupfapfaidza. Hunyoro hunokanganisa kuwanda kwehupfu uye kuyerera kwehupfu hwakaoma, uye hunoona kunaka kweyakadzvanywa isina chinhu.PVA inonzwa nekunyorova. Pasi pemamiriro akasiyana ehunyoro hwehunyoro, huwandu hwakafanana hwePVA hunogona kukonzera kuomarara kwakasiyana kwepasi pevhu rakaoma zvimedu, izvo zvinoita kuti kutsunga kwekumanikidza kuchinjike uye kunaka kwekugadzira kusagadzikana panguva yekutsikirira. Naizvozvo, tembiricha yekubuda inofanira kunyatsodzorwa kuti ive nechokwadi chekunyorova kwehupfu hwakaoma. Kazhinji, kutonhora kwekubuda kunofanira kudzorwa pa 110 ℃, uye kupisa kwemukati kunofanira kugadziriswa maererano.The inlet tembiricha haisi kupfuura 400 ℃, inowanzodzorwa inenge inenge 380 ℃.Kana kupisa kwemukati kwakanyanya, kupisa kwemhepo inopisa pamusoro peshongwe kuchapisa. Kana mhute inodonha ichikwira kusvika pakakwirira uye inosangana nemhepo yakanyanyisa, nokuda kwehupfu yeceramic ine binder, mhedzisiro yebhainda ichaderedzwa, uye pakupedzisira kushanda kwehupfu hwakaoma huchakanganiswa.Chechipiri, kana tembiricha yekupinza yakakwira zvakanyanya, hupenyu hwesevhisi hwehita huchakanganisika, uye ganda rehita rinodonha uye ropinda mushongwe yekuomesa nemhepo inopisa uye bvisa tembiricha yehupfu, bvisa tembiricha yehupfu. zvakatemerwa, tembiricha yekubuda inogonawo kugadziridzwa nekudzvanywa kwepombi yekudyisa, mutsauko wekumanikidza wedutu separator, iyo yakasimba yemukati slurry nezvimwe zvinhu.
Musiyano wemutsindo wedutu separator.Musiyano wekumanikidza wedutu separator yakakura, iyo inowedzera tembiricha yekubuda, kuwedzera kuunganidzwa kwezvimedu zvakanaka uye kuderedza goho remuomesi.
3.1.3 Hunhu hwepfapfaidzo hupfu hwakaomeswa
Iyo fluidity uye kurongedza density yealumina ceramic poda yakagadzirwa nepfapfaidzo yekuomesa nzira inowanzova nani pane iyo yakagadzirirwa neyakajairwa maitiro. Iyo poda yemanyorero granulation haigone kuyerera kuburikidza neanoona mudziyo pasina kudedera, uye hupfu hwespray granulation hunogona kuita izvi zvizere. Tichitaura kune iyo ASTM chiyero chekuyedza simbi poda fluidity uye kuwanda kwehuwandu, Iyo yakawanda density uye fluidity yezvimedu zvakawanikwa nekupfapfaidza kuomesa pasi pemamiriro akasiyana emukati emvura akayerwa. Ona Tafura 1.
Tafura 1 yakasununguka density uye fluidity ye spray yakaomeswa poda
Tafura 1 Hupfu density uye kuyerera mwero
| Hunyoro (%) | 1.0 | 1.6 | 2.0 | 2.2 | 4.0 |
| Density yekusimba (g/cm3) | 1.15 | 1.14 | 1.16 | 1.18 | 1.15 |
| Liquidity (s) | 5.3 | 4.7 | 4.6 | 4.9 | 4.5 |
Hunyoro hwehupfu hwekupfapfaidza hupfu hwakaomeswa hunowanzodzorwa pa1 - 3%. Panguva ino, iyo fluidity yehupfu yakanaka, iyo inogona kusangana nezvinodiwa zvekumanikidza kuumba.
DG1 ndiko kuwanda kwehupfu hwakagadzirwa nemaoko, uye DG2 ndiko kuwanda kwehupfu hwekupfapfaidza granulation.
Ruoko rwegranulated poda inogadzirwa nebhora kugaya, kuomesa, sieving uye granulation.
Tafura 2 density yehupfu dzakatsikirirwa dzakagadzirwa nemanual granulation uye spray granulation
Tafura 2 Green Body's density
| Pressure (MPA) | 4 | 6 | 8 | 10 | 12 | 14 |
| DG1 (g/cm3) | 2.32 | 2.32 | 2.32 | 2.33 | 2.36 | 2.4 |
| DG2 (g/cm3) | 2.36 | 2.46 | 2.53 | 2.56 | 2.59 | 2.59 |
Iyo particle size uye morphology yehupfu zvakaonekwa ne microscope.Inogona kuonekwa kuti zvimedu zvinenge zvakasimba zvakasimba spherical, zvine chimiro chakajeka uye nzvimbo yakatsetseka. Zvimwe zvimedu zvakaumbwa neapuro, pear rakaumbwa kana bhiriji, zvichiverengera 3% yehuwandu. The particle size distribution is sezvinotevera: the maximum particle size is 200 μ m (< 1%), the small particle size is 20 μ m (munhu oga), zvidimbu zvizhinji zvinenge 100 μ m (50%), uye zvimedu zvakawanda zvinenge 50 μ m (20%). Hupfu hunobudiswa nekupfapfaidza kuomesa is sintered pa 165 dhigirii / 165 dhigirii pa 165 cm.3.
(1) 95 alumina slurry ine 60% yakasimba yemukati inogona kuwanikwa nekushandisa PVA sebhainda, ichiwedzera coagulant yakakodzera uye lubricant.
(2) zvine musoro kudzora kwekupfapfaidza kuomeswa kwekushanda paramita inogona kuwana yakakodzera yakaoma poda.
(3) nekutora pfapfaidzo yekuomesa maitiro, 95 alumina poda, iyo inokodzera kuwanda yakaoma kudzvanya maitiro, inogona kugadzirwa. Loose density yaro inenge 1. 1g/cm3uye sintering density i3170g/cm3.
