IiCeramics
I-alumina i-ceramic luhlobo lwe-ceramic engagugiyo, i-corrosion-resistant kunye ne-high-high-high-power-high-power-ceramic material.Isetyenziswa ngokubanzi kwaye ngoku ilona didi lusetyenziswa kakhulu kwi-high-temperature structural ceramics. Ukuze wenze imveliso yobuninzi kwaye uhlangabezane neemfuno zembonakalo yemveliso eqhelekileyo, isixa esincinci sokusila kunye nokusila okulula, kubaluleke kakhulu ukukhetha indlela yokwenza i-dry pressing.I-compression molding ifuna ukuba i-blank yi-powder kunye ne-gradation ethile, kunye nokufuma okuncinci kunye ne-binder.Ngoko ke, i-slurry ye-batch emva kokugaya ibhola kunye nokutyumza okulungileyo kufuneka kufumaneke phezulu kunye nomgubo we-granulated ngcono kunye nomgubo we-granulated. Ukutshiza ukomisa i-granulation ibe yindlela esisiseko yokuvelisa i-ceramics yokwakha kunye ne-ceramics entsha.I-powder elungiselelwe yile nkqubo ine-fluidity enhle, umlinganiselo othile wamasuntswana amakhulu kunye namancinci, kunye nobuninzi be-bulk density.Ngoko ke, ukutshiza ukutshiza yeyona ndlela isebenzayo yokulungiselela umgubo ocolileyo owomileyo.
Ukomisa ukutshiza yinkqubo apho izinto ezingamanzi (kubandakanya udaka) zenziwe iatom kwaye ziguqulwe zibe ngumgubo owomileyo kwindawo eshushu yokomisa. Iimathiriyeli zenziwa iathomu ibe ngamathontsi amhlophe angqukuva alunge kakhulu, ngenxa yamathontsi enkungu alungile kakhulu kwaye umlinganiselo wommandla womhlaba ukuya kumthamo mkhulu kakhulu, ukufuma kubaba ngumphunga ngokukhawuleza, kwaye iinkqubo zokomisa kunye negranulation zigqitywa ngephanyazo. Ubungakanani bamasuntswana, ubumanzi kunye nobuninzi bezinto eziphathekayo bunokulawulwa ngokulungelelanisa iiparamitha zokusebenza zokumisa. Umgubo weSpherical onomgangatho ofanayo kunye nokuphindaphinda okuhle kunokuveliswa ngokwamkela iteknoloji yokutshiza yokutshiza, ngaloo ndlela icuthe inkqubo yokuvelisa umgubo, iququzelele imveliso ezenzekelayo kunye neqhubekayo, kwaye ibe yindlela esebenzayo yokulungiselela ubungakanani obukhulu be-alumina eludongeni eyomileyo yomgubo.
2.1.1 Ukulungiswa koLudaka
I-alumina ye-industrial yodidi lokuqala kunye nokucoceka kwe-99% yongezwa malunga ne-5% yezongezo ukulungiselela i-95% ye-porcelain impahla, kunye nokugaya ibhola kuqhutyelwa ngokomlinganiselo wezinto eziphathekayo: ibhola: amanzi = 1: 2: 1, kunye ne-binder, i-deflocculant kunye nesixa esifanelekileyo samanzi songezwa ukulungiselela ukumiswa okuzinzileyo kwe-slurry yokulinganisa ukunqunyulwa kwe-slurry elula. umxholo, uhlobo kunye nomthamo we-deflocculant.
2.1.2 Inkqubo yokutshiza yokomisa
Iiparamitha zenkqubo yokulawula eziphambili kwinkqubo yokumisa isitshizi zezi: a). Iqondo lobushushu lokuphuma kwesomisi. Ngokubanzi lilawulwa kwi-110℃.b). I-diameter yangaphakathi yomlomo.Sebenzisa i-0.16mm okanye i-0. 8mm ipleyiti ye-orifice. c), i-Cyclone isahlukanisi umahluko woxinzelelo, ulawulo kwi-220Pa.
2.1.3 Ukuhlolwa kokusebenza komgubo emva kokutshiza ngokuFafaza
Ukumiselwa kokufuma kuya kwenziwa ngokweendlela eziqhelekileyo zokumisela ukufuma kweceramic. Isuntswanai-morphology kunye nobukhulu be-particle size yabonwa nge-microscope.I-fluidity kunye ne-bulk density of powder ivavanywa ngokwemigangatho yovavanyo ye-ASTM yobuninzi kunye nobuninzi be-powder yensimbi. Indlela yile: phantsi kwemeko yokungangcangcazeli, i-50g powder (echanekile ukuya kwi-0. 01g) idlula kwintamo yefestile yeglasi enobubanzi obuyi-6mm kunye nobude obuyi-3mm ngenxa yobuninzi bayo;Ngaphantsi kwemeko yokungangcangcazeli, umgubo udlula kwifuneli yeglasi efanayo kwaye iwele kwisitya esingama-25mm ukuphakama ukusuka kwifunnel efanayo yeglasi. Ubuninzi obungashukumiyo bubunzima bokupakisha obukhululekile.
3.1.1 Ukulungiswa kodaka
Ukusebenzisa inkqubo yokumisa i-spray granulation, ukulungiswa kwe-slurry yinto ebalulekileyo. Umxholo oqinileyo, u-fineness kunye ne-fluidity yodaka luya kuchaphazela ngokuthe ngqo umveliso kunye nobukhulu beqhekeza lomgubo owomileyo.
Ngenxa yokuba umgubo wolu hlobo alumina porcelain ludlolo, kuyimfuneko ukongeza isixa esifanelekileyo isibophelelo ukuphucula ukusebenza blank.Ezisetyenziswa ngokuqhelekileyo izinto eziphilayo ezifana dextrin, polyvinyl utywala, carboxymethylcellulose, polystyrene, etc.Polyvinyl alcohol (PVA), i-binder enyibilikayo emanzini, yakhethwa kulo mfuniselo we-humidity ye-humidity. zichaphazela iimpawu zomgubo owomileyo.
Utywala bePolyvinyl buneentlobo ezininzi ezahlukeneyo, amanqanaba ahlukeneyo e-hydrolysis kunye neqondo le-polymerization, eliya kuchaphazela inkqubo yokumisa isitshizi. Isidanga sayo se-hydrolysis ngokubanzi kunye nesidanga se-polymerization siya kuchaphazela inkqubo yokutshiza yokumisa. I-dosage yayo ngokuqhelekileyo i-014 - 015wt. Ukongezwa kobuninzi kakhulu kuya kubangela ukuba i-spray granulation powder yenze iinqununu ezinzima ezinomileyo ukuze zithintele amaqhekeza ekukhubazekeni ngexesha lokucinezela. Ukongezwa kweBinder kuncinci kakhulu amandla aluhlaza kuya konyusa ilahleko yokusebenza. Uvavanyo lubonisa ukuba xa ubungakanani obufanelekileyo be-binder bongezwa, icandelo le-billet eluhlaza libonwa phantsi kwe-microscope. Kuyabonakala ukuba xa uxinzelelo lunyukile ukusuka kwi-3Mpa ukuya kwi-6Mpa, icandelo linyuswa ngokufanelekileyo, kwaye kukho inani elincinci leengqungquthela ze-spherical. Xa uxinzelelo luyi-9Mpa, icandelo ligudile, kwaye akukho masuntswana angqukuva, kodwa uxinzelelo oluphezulu luya kukhokelela ekuhluthweni kwe-billet.PVA eluhlaza ivulwa malunga ne-200 ℃
Qala ukutshisa, kwaye ukhuphe malunga ne-360 ℃. Ukuze unyibilikise i-binder yezinto eziphilayo kwaye umanzise amasuntswana e-billet, yenza i-interlayer yolwelo phakathi kwamasuntswana, uphucule i-plastiki ye-billet, unciphise ukungqubuzana phakathi kwamasuntswana kunye nokungqubuzana phakathi kwezixhobo kunye nokubumba, ukukhuthaza ukwanda koxinaniso lwe-billet ecinezelweyo kunye nokusabalalisa okuqhelekileyo kweplastiki kunye nokusabalalisa okuqhelekileyo kweplastiki. ezisetyenziswayo yi glycerin, ethyl oxalic acid, njl.
Ngenxa yokuba i-binder i-organic macromolecular polymer, indlela yokongeza i-binder kwi-slurry nayo ibaluleke kakhulu.Yona nto ibhetele yokongeza i-binder elungiselelwe kwi-uniform yodaka kunye nomxholo oqinileyo ofunekayo.Ngale ndlela, izinto eziphilayo ezinganyibilikiyo nezingaxutywanga zingaphetshwa ukuba ziziswe kwi-slurry, kwaye iziphene ezinokuthi zifakwe kwi-slurry enokwenzeka, emva kokuba i-binder ifakwe lula, emva kokuba i-binder ifakwe lula. ibhola yokugaya okanye ukuvuselela. Umoya ofakwe kwi-droplet kwi-powder eyomileyo, eyenza amaqhekeza omileyo angabikho kwaye anciphise ubuninzi bomthamo. Ukuze kulungiswe le ngxaki, i-defoamers inokongezwa.
Ngenxa yeemfuno zezoqoqosho kunye nezobuchwephesha, umxholo ophezulu oqinileyo uyafuneka.Njengoko amandla okuvelisa i-dryer abhekisela kumanzi aphuma evaporation ngeyure, i-slurry enomxholo ophezulu oqinileyo iya kwandisa kakhulu imveliso yomgubo owomileyo. Xa umxholo oqinileyo unyuka ukusuka kwi-50% ukuya kwi-75%, imveliso yesomisi iya kwanda ngamaxesha amabini.
Isiqulatho esisezantsi esiqinileyo sesona sizathu siphambili sokubunjwa kweengqungquthela ezingenanto.Kwinkqubo yokomisa, amanzi afudukela kumphezulu we-droplet kwaye aphethe iincinci eziqinileyo, okwenza inxalenye yangaphakathi ye-droplet ihobe; ukuba ifilimu e-elastiki ephantsi yokufikelela iphantsi yenziwa malunga ne-droplet, ngenxa yesantya esiphantsi sokuphefumula, ubushushu be-droplet buyanda, kwaye amanzi aphuphuma kwindawo engaphakathi, eyenza i-droplet bulge. Kuzo zombini iimeko, i-ball shape of particles iya kutshatyalaliswa, kwaye i-annular evulekileyo okanye i-apile emile okanye i-pear shaped particles iya kuveliswa, eya kunciphisa i-bulkity ye-powder eyomileyo. umxholo unokunciphisa
Kwinkqubo yokumisa okufutshane, ukucuthwa kwenkqubo yokomisa kunokunciphisa inani le-adhesive edluliselwe kwi-particle surface kunye namanzi, ukuze ugweme ukuba i-binder concentration kwi-particle surface inkulu kunombindi, ukwenzela ukuba amasuntswana anomhlaba onzima, kwaye amasuntswana angakhubeki kwaye atyumke kwinkqubo yokucinezela kunye nokwenza, ukuze kuncitshiswe ubunzima bomzimba we-billet. Ngoko ke, ukuze ufumane umgangatho ophezulu owomileyo, umxholo oqinileyo we-slurry kufuneka unyuswe.
I-slurry esetyenziselwa ukomisa isitshizi kufuneka ibe ne-fluidity eyaneleyo kunye nokufuma okuncinci kangangoko kunokwenzeka.Ukuba i-viscosity ye-slurry iyancitshiswa ngokuzisa amanzi amaninzi, kungekhona nje ukusetyenziswa kwamandla okomisa kunyuswa, kodwa kunye nobuninzi bemveliso buyancipha. inokuthi ithathwe njengenkqubo ye-colloidal dispersion.Ithiyori yokuzinza kwe-colloidal ibonisa ukuba kukho amandla amabini asebenza kumasuntswana amisiweyo: i-van der Waals force (i-Coulomb force) kunye ne-electrostatic repulsion force. Ukuba amandla ubukhulu becala, i-agglomeration kunye ne-flocculation iyakwenzeka.Itotali yamandla anokubakho (VT) yentsebenziswano phakathi kwamasuntswana anxulumene nomgama wabo, ngexesha apho i-VT ngaxa lithile sisimbuku samandla omxhuzulane we-VA kunye ne-repulsive energy VR.Xa i-VT phakathi kwamasuntswana inikezela ubuninzi bamandla afanelekileyo, yinkqubo ethile ye-depoly. inkqubo yileyo misebenzi ilawula i-VR: intlawulo yomphezulu wamasuntswana kunye nobukhulu bemigangatho yombane ephindwe kabini. Ubukhulu bebilayer buhambelana ngokungafaniyo nengcambu yesikwele sebhondi ye-valence kunye noxinaniso lwe-ion equilibrium. Ukunyanzeliswa kwe-double layer kunokunciphisa umqobo onokuthi uthintele i-flocculation, ngoko i-valence bond kunye nokugxininiswa kwe-valence kunye nokuxininisa okufunekayo kwi-equilibrium equilibrium . HCI, HNO3, NaOH, (CH) 3noh (quaternary amine), GA, njl.
Ngenxa yokuba udaka olusekelwe emanzini lwe-95 alumina yomgubo weceramic lungathathi hlangothi kunye ne-alkalescent, i-coagulants ezininzi ezinefuthe elihle lokuhlanjululwa kwezinye i-ceramic slurry zilahlekelwa umsebenzi wazo.Ngoko ke, kunzima kakhulu ukulungiselela i-slurry enomxholo ophezulu oqinileyo kunye ne-fluidity enhle. ukuqulunqwa kwe-micelle kunye nesakhiwo. Ixabiso le-pH le-slurry liya kuchaphazela ngokuthe ngqo iqondo lokuqhawula kunye ne-adsorption, okukhokelela kutshintsho lwe-ζ enokwenzeka kunye ne-flocculation ehambelanayo okanye i-dissociation.
I-alumina slurry inexabiso eliphezulu lezinto ezintle kunye ezimbi ζ ezinokubakho kwi-asidi okanye i-alkaline medium.Ngeli xesha, i-viscosity ye-slurry iphantsi kwexabiso le-decoagulation, ngelixa xa i-slurry ikwimeko engathathi hlangothi, i-viscosity yayo iyanda, kwaye i-flocculation iyenzeka. iyancipha ngokudibanisa i-demulsifier efanelekileyo, ukuze ixabiso layo le-viscosity lisondele kumanzi. I-fluidity yamanzi elinganiswa ne-viscometer elula yimizuzwana emi-3 / 100 ml, kunye no-fluidity ye-slurry yimizuzwana emi-4 / 100 ml. i-viscosity ye-slurry iyancitshiswa, ukwenzela ukuba umxholo oqinileyo kwi-slurry unganyuswa ukuya kwi-60%, kwaye ukupakisha okuzinzile kunokwakheka.Njengoko amandla okuvelisa i-dryer abhekisela ku-evaporation yamanzi ngeyure, ngoko ukumiswa.
3.1.2 Ukulawulwa kweeparamitha eziphambili kwinkqubo yokutshiza yokumisa
Iphethini yokuhamba komoya kwinqaba yokumisa ichaphazela ixesha lokumisa, ixesha lokugcinwa, amanzi aseleyo kunye nodonga olunamathele. Kulo mvavanyo, inkqubo yokuxuba umoya we-droplet ixutywe, oko kukuthi, igesi eshushu ingena kwinqaba yokumisa ukusuka phezulu, kwaye i-nozzle ye-atomizing ifakwe phantsi kombhobho wokomisa, ukwenza i-droplet droplet ixube, kunye ne-droplet ye-droplet mix, kunye ne-droplet ye-spray. i-countercurrent, kwaye xa i-droplet ifikelela phezulu kwi-stroke, iba yi-downstream flow and spray in shape conical. Ngokukhawuleza xa i-droplet ingena kwinqaba yokomisa, ngokukhawuleza iya kufikelela kwisantya esiphezulu sokumisa kwaye ingene kwinqanaba lokumisa ngokukhawuleza. Ubude benqanaba lokumisa isantya esingaguqukiyo buxhomekeke kumswakama wethontsi, i-viscosity yodaka, ubushushu kunye nokufuma komoya owomileyo. Umda wenqanaba C ukusuka kwinqanaba lokumisa ngokukhawuleza ukuya kwinqanaba lokumisa ngokukhawuleza libizwa ngokuba yindawo ebalulekileyo. Ngeli xesha, umphezulu wethontsi awunakuphinda ulondoloze imeko ehluthisiweyo ngokufuduka kwamanzi, Ngokuhla kwesantya sokuphuma komphunga, ubushushu bamathontsi buyanda, kwaye umphezulu wamathontsi kwindawo D ugcwele, wenza umaleko weqokobhe eliqinileyo. I-evaporation ihamba ngaphakathi, kwaye izinga lokumisa liyaqhubeka liyancipha. Ukupheliswa okungaphezulu kwamanzi kuhambelana nokunyameka komswakama wegobolondo elinzima.Ngoko ke, kuyimfuneko ukulawula iiparitha zokusebenza ezifanelekileyo.
Isiqulatho sokufuma somgubo owomileyo simiselwa ubukhulu becala liqondo lobushushu lokuphuma kwesomiso sokutshiza. Isiqulatho sokufuma sichaphazela ukuxinana kwesambuku kunye nobumanzi bomgubo owomileyo, kwaye simisela umgangatho we-blank.PVA ecinezelweyo inobuntununtunu. Ngaphantsi kweemeko ezahlukeneyo zomswakama womswakama, umlinganiselo ofanayo we-PVA unokubangela ubunzima obuhlukeneyo bomgangatho ophezulu we-powder particles eyomileyo, eyenza ukuzimisela ukunyanzeliswa koxinzelelo kunye nomgangatho wokuvelisa ungaqiniseki ngexesha lenkqubo yokucinezela. Ngoko ke, iqondo lokushisa lokuphuma kufuneka lilawulwe ngokungqongqo ukuze kuqinisekiswe ukufuma komgubo owomileyo. Ngokuqhelekileyo, ukushisa okuphumayo kufuneka kulawulwe kwi-110 ℃, kwaye iqondo lokushisa lokungena kufuneka lilungelelaniswe ngokufanelekileyo.Iqondo lokushisa lokungena alikho ngaphezu kwe-400 ℃, ngokuqhelekileyo lilawulwa malunga ne-380 ℃.Ukuba ukushisa kwe-inlet kuphezulu kakhulu, iqondo lokushisa lomoya oshushu phezulu kwinqaba liya kudlula. Xa inkungu ihla iye phezulu kwaye idibana nomoya oshushu kakhulu, ngenxa yomgubo we-ceramic oqulethe i-binder, umphumo we-binder uya kuncitshiswa, kwaye ekugqibeleni umsebenzi ocinezelayo womgubo owomileyo uya kuchaphazeleka. zizimisele ngokusisiseko, ubushushu bokuphuma bunokulungelelaniswa noxinzelelo lwempompo yokutya, umahluko woxinzelelo lwesahluli se-cyclone, umxholo oqinileyo we-slurry kunye nezinye izinto.
Ukwahlukana koxinzelelo lwe-cyclone separator.Umehluko woxinzelelo lwe-cyclone separator inkulu, eya kwandisa ukushisa kwe-outlet, ukwandisa ukuqokelelwa kweengqungquthela ezintle kunye nokunciphisa isivuno sesomisi.
3.1.3 Iimpawu zesitshizi somgubo omisiweyo
Ubuninzi be-fluidity kunye nokupakishwa komgubo we-alumina ceramic olungiselelwe yindlela yokutshiza yokumisa ngokuqhelekileyo kungcono kunezo zilungiswe yinkqubo eqhelekileyo. I-powder ye-granulation ye-manual ayikwazi ukuhamba ngesixhobo sokubona ngaphandle kokungcangcazela, kwaye umgubo we-spray granulation unokukwenza oku ngokupheleleyo. Ngokubhekiselele kumgangatho we-ASTM wokuvavanya ubumanzi bomgubo wesinyithi kunye nokuxinana kwesambuku, ukuxinana kwesambuku kunye nolwelo lwamasuntswana afunyenwe ngokomiswa ngesitshizi phantsi kweemeko ezahlukeneyo zomxholo wamanzi alinganisiwe. Jonga kwiTheyibhile 1.
Itheyibhile yoku-1 yoxinaniso kunye nobumanzi bomgubo wokutshiza owomileyo
Itheyibhile 1 Ubuninzi bePowder kunye nesantya sokuhamba
| Umxholo wokufuma (%) | 1.0 | 1.6 | 2.0 | 2.2 | 4.0 |
| Ukuxinana kokuqina (g/cm3) | 1.15 | 1.14 | 1.16 | 1.18 | 1.15 |
| Umbane (s) | 5.3 | 4.7 | 4.6 | 4.9 | 4.5 |
Isiqulatho sokufuma somgubo wokutshiza owomileyo silawulwa ngokubanzi kwi-1 - 3%. Ngeli xesha, i-fluidity ye powder ilungile, enokuthi ihlangabezane neemfuno zokucofa ukubumba.
I-DG1 yingxinano yomgubo wegranulation eyenziwe ngesandla, kwaye i-DG2 yingxinano yomgubo wokutshiza.
I-powder granulated yesandla ilungiswa ngokugaya ibhola, ukomiswa, ukuhluzwa kunye negranulation.
Ubuninzi beTheyibhile yesi-2 yee powders ezicinezelweyo ezenziwe ngegranulation ngesandla kunye ne-spray granulation
Itheyibhile 2 Ubuninzi boMzimba oHlaza
| Uxinzelelo (MPA) | 4 | 6 | 8 | 10 | 12 | 14 |
| I-DG1 (g/cm3) | 2.32 | 2.32 | 2.32 | 2.33 | 2.36 | 2.4 |
| I-DG2 (g/cm3) | 2.36 | 2.46 | 2.53 | 2.56 | 2.59 | 2.59 |
Ubungakanani be-particle kunye ne-morphology ye-powder yabonwa nge-microscope.Ingabonwa ukuba iinqununu ziyi-spherical eqinile, kunye ne-interface ecacileyo kunye ne-smooth surface. Amanye amasuntswana amile okweapile, amile okwepere okanye adityanisiwe, athatha i-3% yetotali. Ukuhanjiswa kobungakanani bamasuntswana ngolu hlobo lulandelayo: ubungakanani besuntswana eliphezulu lingama-200 μ m (<1%), ubuncinci besayizi yesuntswana yi-20 μ m (umntu), amasuntswana amaninzi amalunga ne-100 μ m (50%), kwaye uninzi lwamasuntswana lumalunga ne-50 μ m (20%).3.
(1) I-95 ye-alumina slurry ene-60% umxholo oqinileyo unokufumaneka ngokusebenzisa i-PVA njenge-binder, yongeza i-coagulant efanelekileyo kunye ne-lubricant.
(2) ulawulo olufanelekileyo lweeparamitha zokusebenza zokutshiza unokufumana umgubo owomileyo.
(3) ngokwamkela inkqubo yokumisa isitshizi, i-95 ye-alumina powder, efanele inkqubo yokucinezela isambuku esomileyo, inokuveliswa. Ubuninzi bayo obukhululekile bu malunga ne-1. 1g / cm3kwaye ingxinano ye-sintering yi-3170g / cm3.
