Njira zisanu ndi zinayi zoumbira molondola za zirconia ceramics

Njira zisanu ndi zinayi zoumbira molondola za zirconia ceramics
Njira yopangira zinthu zadothi imagwira ntchito yolumikizirana pakukonzekera zipangizo zadothi, ndipo ndiyo njira yofunika kwambiri yotsimikizira kuti zinthu zadothi ndi zigawo zake zikugwira ntchito bwino komanso kuti zinthu ndi zinthu zina zadothi ndi zogwiritsidwa ntchito zibwerezedwenso.
Ndi chitukuko cha anthu, njira yachikhalidwe yopangira mawilo, njira yopangira mawilo, njira yopangira ma grouting, ndi zina zotero za zoumba zachikhalidwe sizingakwaniritse zosowa za anthu amakono popanga ndi kukonza, kotero njira yatsopano yopangira ma ceramic idabadwa. ZrO2 fine ceramic tools zimagwiritsidwa ntchito kwambiri mu mitundu 9 iyi ya njira zopangira ma creating (mitundu iwiri ya njira zouma ndi mitundu 7 ya njira zonyowa):

1. Kuumba kouma

1.1 Kukanikiza kouma

Kukanikiza kouma kumagwiritsa ntchito kukanikiza ufa wa ceramic kuti ukhale mawonekedwe enaake a thupi. Chofunika kwambiri ndichakuti, pansi pa mphamvu yakunja, tinthu ta ufa timayandikirana mu nkhungu, ndipo timagwirizanitsidwa mwamphamvu ndi kukangana kwamkati kuti tisunge mawonekedwe enaake. Vuto lalikulu m'matupi obiriwira ouma ndi kufalikira kwa madzi, komwe kumachitika chifukwa cha kukangana kwamkati pakati pa ufa ndi kukangana pakati pa ufa ndi khoma la nkhungu, zomwe zimapangitsa kuti kupanikizika kuchepe mkati mwa thupi.

Ubwino wa kukanikiza kouma ndi wakuti kukula kwa thupi lobiriwira ndi kolondola, ntchito yake ndi yosavuta, ndipo ndikosavuta kugwiritsa ntchito makina; kuchuluka kwa chinyezi ndi chomangira mu kukanikiza kouma kobiriwira kumakhala kochepa, ndipo kuuma ndi kuwotcha kumakhala kochepa. Amagwiritsidwa ntchito makamaka popanga zinthu zokhala ndi mawonekedwe osavuta, ndipo chiŵerengero cha mbali yake ndi chochepa. Kuwonjezeka kwa mtengo wopanga chifukwa cha kuwonongeka kwa nkhungu ndi vuto la kukanikiza kouma.

1.2 Kukanikiza kwa isostatic

Kukanikiza kwa isostatic ndi njira yapadera yopangira yomwe idapangidwa pogwiritsa ntchito njira yachikhalidwe yokanikiza youma. Imagwiritsa ntchito mphamvu yotumizira madzi kuti ikani mphamvu mofanana ku ufa womwe uli mkati mwa nkhungu yosalala kuchokera mbali zonse. Chifukwa cha kusinthasintha kwa mphamvu yamkati ya madzi, ufawo umakhala ndi mphamvu yomweyo mbali zonse, kotero kusiyana kwa kuchuluka kwa thupi lobiriwira kumatha kupewedwa.

Kukanikiza kwa isostatic kumagawidwa m'magulu awiri: kukanikiza kwa isostatic thumba lonyowa ndi kukanikiza kwa isostatic thumba louma. Kukanikiza kwa isostatic thumba lonyowa kumatha kupanga zinthu zokhala ndi mawonekedwe ovuta, koma kumatha kugwira ntchito nthawi ndi nthawi. Kukanikiza kwa isostatic thumba louma kumatha kugwira ntchito yokha mosalekeza, koma kumatha kupanga zinthu zokhala ndi mawonekedwe osavuta monga sikweya, ozungulira, ndi machubu. Kukanikiza kwa isostatic kumatha kupeza thupi lobiriwira lofanana komanso lolimba, lokhala ndi kuchepera pang'ono kwa moto ndi kuchepera kofanana mbali zonse, koma zidazo ndi zovuta komanso zodula, ndipo magwiridwe antchito opanga si okwera mtengo kwambiri, ndipo ndizoyenera kupanga zipangizo zokhala ndi zofunikira zapadera.

2. Kunyowa

2.1 Kukonza Magulu
Njira yopangira grouting ndi yofanana ndi kuponyera tepi, kusiyana kwake ndikuti njira yopangira ikuphatikizapo njira yochotsera madzi m'thupi ndi njira yolumikizirana ndi mankhwala. Kuchotsa madzi m'thupi kumachotsa madzi omwe ali mu slurry kudzera mu capillary action ya gypsum mold yokhala ndi porous. Ca2+ yopangidwa ndi kusungunuka kwa pamwamba pa CaSO4 imawonjezera mphamvu ya ionic ya slurry, zomwe zimapangitsa kuti slurry ifalikire.
Pogwiritsa ntchito madzi m'thupi komanso kuuma kwa mankhwala, tinthu ta ufa wa ceramic timayikidwa pakhoma la gypsum nkhungu. Kulumikiza ndi koyenera kukonzekera zigawo zazikulu za ceramic zokhala ndi mawonekedwe ovuta, koma mtundu wa thupi lobiriwira, kuphatikizapo mawonekedwe, kuchulukana, mphamvu, ndi zina zotero, ndi wochepa, mphamvu ya antchito ndi yayikulu, ndipo si yoyenera kugwira ntchito zokha.

2.2 Kuponya kotentha
Kuthira madzi otentha (hot die casting) ndiko kusakaniza ufa wa ceramic ndi binder (paraffin) pa kutentha kwakukulu (60~100℃) kuti mupeze slurry kuti muthire madzi otentha. Slurry imalowetsedwa mu nkhungu yachitsulo pogwiritsa ntchito mpweya wopanikizika, ndipo kupanikizika kumasungidwa. Kuziziritsa, kuchotsa slurry kuti sera ikhale yopanda kanthu, sera yopanda kanthu imachotsedwa ndi madzi pansi pa chitetezo cha ufa wosagwira ntchito kuti ipeze thupi lobiriwira, ndipo thupi lobiriwira limasunthidwa pa kutentha kwakukulu kuti likhale porcelain.

Thupi lobiriwira lopangidwa ndi hot die casting lili ndi miyeso yeniyeni, kapangidwe kake ka mkati kamene kali kofanana, kusawonongeka kwa nkhungu pang'ono komanso kupanga bwino kwambiri, ndipo ndi loyenera zipangizo zosiyanasiyana zopangira. Kutentha kwa sera ndi nkhungu kuyenera kulamulidwa mosamala, apo ayi kungayambitse jakisoni kapena kusintha, kotero sikoyenera kupanga zigawo zazikulu, ndipo njira yopangira zinthu ziwiri ndi yovuta ndipo mphamvu zimagwiritsidwa ntchito kwambiri.

2.3 Kuponya tepi
Kuponya tepi ndi kusakaniza ufa wa ceramic ndi zinthu zambiri zomangira zachilengedwe, mapulasitiki, zotulutsira madzi, ndi zina zotero kuti mupeze slurry yolimba yoyenda, kuwonjezera slurry ku hopper ya makina oponyera, ndikugwiritsa ntchito chokokera kuti muwongolere makulidwe. Imatuluka kupita ku lamba wotumizira kudzera mu nozzle yodyetsera, ndipo filimu yopanda kanthu imapezeka ikauma.

Njirayi ndi yoyenera pokonzekera zinthu zopangidwa ndi filimu. Kuti zinthu zikhale zosavuta kuzisintha, zinthu zambiri zachilengedwe zimawonjezedwa, ndipo magawo a njirayo amafunika kuyendetsedwa mosamala, apo ayi zingayambitse zolakwika monga kupukuta, mizere, mphamvu yochepa ya filimu kapena kupukuta kovuta. Zinthu zachilengedwe zomwe zimagwiritsidwa ntchito ndi poizoni ndipo zimayambitsa kuipitsa chilengedwe, ndipo njira yopanda poizoni kapena yopanda poizoni iyenera kugwiritsidwa ntchito momwe zingathere kuti ichepetse kuipitsa chilengedwe.

2.4 Kuumba jakisoni wa gel
Ukadaulo wopangira jekeseni wa gel ndi njira yatsopano yopangira jekeseni mwachangu ya colloidal yomwe idapangidwa koyamba ndi ofufuza ku Oak Ridge National Laboratory kumayambiriro kwa zaka za m'ma 1990. Pakati pake pali kugwiritsa ntchito njira za organic monomer zomwe zimapangitsa kuti jekeseni zikhale ma gels amphamvu kwambiri, olumikizidwa mbali zonse.

Dothi la ufa wa ceramic wosungunuka mu yankho la ma monomers achilengedwe limaponyedwa mu chikombole, ndipo chisakanizo cha monomer chimapanga polymer kuti chipange gawo lokhala ndi gelled. Popeza polymer-solvent yolumikizidwa mbali zonse ili ndi 10%–20% (mass fraction) polymer yokha, n'zosavuta kuchotsa solvent kuchokera ku gawo la gel pochita kuuma. Nthawi yomweyo, chifukwa cha kulumikizana kwa ma polima mbali zonse, ma polima sangasunthe ndi solvent panthawi youma.

Njirayi ingagwiritsidwe ntchito popanga zigawo za ceramic za gawo limodzi komanso zophatikizika, zomwe zimatha kupanga zigawo za ceramic zooneka ngati zovuta, zooneka ngati neti, ndipo mphamvu yake yobiriwira ndi yokwera kufika pa 20-30Mpa kapena kuposerapo, zomwe zitha kukonzedwanso. Vuto lalikulu la njira iyi ndikuti kuchuluka kwa thupi la mluza kumakhala kwakukulu panthawi yowonjezereka, zomwe zimapangitsa kuti thupi la mluza lisinthe mosavuta; ma monomers ena achilengedwe ali ndi choletsa cha okosijeni, chomwe chimapangitsa kuti pamwamba pake patseguke ndikugwa; chifukwa cha njira yopangira polymerization ya monomer yachilengedwe yomwe imachitika chifukwa cha kutentha, zomwe zimapangitsa kuti kumeta kutentha kumabweretsa kupsinjika kwamkati, komwe kumapangitsa kuti malo obisika asweke ndi zina zotero.

2.5 Kuumba jakisoni wolimbitsa mwachindunji
Kuyika jakisoni mwachindunji ndi ukadaulo wopangira ulusi womwe unapangidwa ndi ETH Zurich: madzi osungunula, ufa wa ceramic ndi zowonjezera zachilengedwe zimasakanizidwa mokwanira kuti zipange slurry yokhazikika, yotsika, komanso yolimba kwambiri, yomwe ingasinthidwe powonjezera Slurry pH kapena mankhwala omwe amawonjezera kuchuluka kwa electrolyte, kenako slurry imalowetsedwa mu nkhungu yopanda mabowo.

Yang'anirani kupita patsogolo kwa zochita za mankhwala panthawiyi. Kuchitapo kanthu musanapange jekeseni kumachitika pang'onopang'ono, kukhuthala kwa slurry kumakhala kochepa, ndipo kuchitapo kanthu kumawonjezeka pambuyo popanga jekeseni, slurry imauma, ndipo slurry yamadzimadzi imasandulika kukhala thupi lolimba. Thupi lobiriwira lomwe lapezeka lili ndi mphamvu zabwino zamakaniko ndipo mphamvu imatha kufika 5kPa. Thupi lobiriwira limachotsedwa, kuumitsidwa ndikusiyidwa kuti lipange gawo la ceramic la mawonekedwe omwe mukufuna.

Ubwino wake ndi wakuti sichifunikira kapena chimangofunika zowonjezera zochepa zachilengedwe (zosakwana 1%), thupi lobiriwira siliyenera kuchotsedwa mafuta, thupi lobiriwira ndi lofanana, kuchuluka kwake ndi kwakukulu (55% ~ 70%), ndipo limatha kupanga zigawo zazikulu komanso zooneka ngati ceramic. Vuto lake ndilakuti zowonjezerazo ndi zodula, ndipo mpweya nthawi zambiri umatulutsidwa panthawi yochitapo kanthu.

2.6 Kuumba jakisoni
Kuumba jakisoni kwakhala kukugwiritsidwa ntchito kwa nthawi yayitali popanga zinthu zapulasitiki komanso kupanga nkhungu zachitsulo. Njirayi imagwiritsa ntchito kuuma kwa thermoplastic organics kutentha kochepa kapena kuuma kwa thermosetting organics kutentha kwambiri. Ufa ndi chonyamulira cha organic zimasakanizidwa mu chipangizo chapadera chosakaniza, kenako zimalowetsedwa mu nkhungu pansi pa kupanikizika kwakukulu (makumi mpaka mazana a MPa). Chifukwa cha kupanikizika kwakukulu kwa kuumba, malo opanda kanthu omwe apezeka ali ndi miyeso yeniyeni, kusalala kwambiri komanso kapangidwe kakang'ono; kugwiritsa ntchito zida zapadera zopangira nkhungu kumathandizira kwambiri kupanga bwino.

Kumapeto kwa zaka za m'ma 1970 ndi kumayambiriro kwa zaka za m'ma 1980, njira yopangira jekeseni inagwiritsidwa ntchito popanga zinthu zadothi. Njirayi imapangitsa kuti pulasitiki ipange zinthu zopanda kanthu powonjezera zinthu zambiri zachilengedwe, zomwe ndi njira yodziwika bwino yopangira pulasitiki yadothi. Mu ukadaulo wopangira jekeseni, kuwonjezera pa kugwiritsa ntchito zinthu zachilengedwe za thermoplastic (monga polyethylene, polystyrene), zinthu zachilengedwe zotenthetsera (monga epoxy resin, phenolic resin), kapena ma polima osungunuka m'madzi ngati chomangira chachikulu, ndikofunikira kuwonjezera zinthu zina zothandizira monga mapulasitiki, mafuta odzola ndi zinthu zolumikizira kuti ziwongolere kusinthasintha kwa jekeseni yadothi ndikuwonetsetsa kuti thupi lopangidwa ndi jekeseni lili bwino.

Njira yopangira jekeseni ili ndi ubwino wa kuchuluka kwa zochita zokha komanso kukula kolondola kwa malo opanda kanthu opangira jekeseni. Komabe, kuchuluka kwa zinthu zachilengedwe zomwe zili m'thupi lobiriwira la zinthu zopangidwa ndi jekeseni ndi 50vol%. Zimatenga nthawi yayitali, ngakhale masiku angapo mpaka masiku ambiri, kuti zichotse zinthu zachilengedwezi pakapita nthawi, ndipo n'zosavuta kuyambitsa zolakwika zabwino.

2.7 Kuumba jakisoni wa Colloidal
Pofuna kuthetsa mavuto a kuchuluka kwa zinthu zachilengedwe zomwe zawonjezeredwa komanso zovuta zothetsa mavuto omwe amabwera chifukwa cha njira yachikhalidwe yopangira jekeseni, Yunivesite ya Tsinghua mwaluso idapereka njira yatsopano yopangira jekeseni ya colloidal ya zoumba, ndipo idapanga payokha chitsanzo chopangira jekeseni ya colloidal kuti ipange jekeseni ya ceramic yopanda kanthu.

Lingaliro loyambira ndikuphatikiza kupanga ma colloidal ndi kupanga ma injection, pogwiritsa ntchito zida zopangira jakisoni ndi ukadaulo watsopano wochiritsa womwe umaperekedwa ndi njira yopangira ma colloidal in-situ solidification. Njira yatsopanoyi imagwiritsa ntchito zinthu zosakwana 4wt.% za organic matter. Kuchuluka pang'ono kwa ma monomers achilengedwe kapena mankhwala achilengedwe omwe ali mumadzi osungunuka amagwiritsidwa ntchito kuyambitsa mwachangu polymerization ya ma monomers achilengedwe atalowetsedwa mu nkhungu kuti apange mafupa a organic network, omwe amakulunga ufa wa ceramic mofanana. Pakati pawo, nthawi yochotsa ma ceramic imachepetsedwa kwambiri, komanso kuthekera kwa kusweka kwa kuchotsa ma diski kumachepa kwambiri.

Pali kusiyana kwakukulu pakati pa kupanga zinthu za ceramic ndi kupanga zinthu za colloidal. Kusiyana kwakukulu ndikuti koyamba kuli m'gulu la kupanga zinthu za pulasitiki, ndipo komaliza kuli m'kupanga zinthu za slurry, ndiko kuti, slurry ilibe plasticity ndipo ndi chinthu chopanda kanthu. Chifukwa slurry ilibe plasticity mu kupanga zinthu za colloidal, lingaliro lachikhalidwe la kupanga zinthu za ceramic silingagwiritsidwe ntchito. Ngati kupanga zinthu za colloidal kuphatikizidwa ndi kupanga zinthu za jekeseni, kupanga zinthu za colloidal pogwiritsa ntchito zipangizo za ceramic kumachitika pogwiritsa ntchito zipangizo za jekeseni ndi ukadaulo watsopano wochiritsa womwe umaperekedwa ndi njira ya kupanga zinthu za colloidal.

Njira yatsopano yopangira zinthu zadothi pogwiritsa ntchito colloidal ndi yosiyana ndi kupanga zinthu zadothi pogwiritsa ntchito colloidal ndi kupanga zinthu zadothi pogwiritsa ntchito njira yachikhalidwe yopangira zinthu. Ubwino wa kupanga zinthu zadothi pogwiritsa ntchito njira yopangira zinthu zadothi pogwiritsa ntchito colloidal, yomwe idzakhala chiyembekezo cha kukula kwa mafakitale a zinthu zadothi pogwiritsa ntchito ukadaulo wapamwamba.