Zotsatira za sintering pa katundu wa zirconia ceramics

Zotsatira za sintering pa katundu wa zirconia ceramics

Monga mtundu wa zinthu za ceramic, zirconium ili ndi mphamvu zambiri, kuuma kwakukulu, kukana kwabwino, asidi ndi alkali kukana, kukana kutentha kwakukulu ndi zina zabwino kwambiri. Kuphatikiza pa kugwiritsidwa ntchito kwambiri m'mafakitale, ndi chitukuko champhamvu chamakampani opanga mano m'zaka zaposachedwa, zirconia ceramics zakhala zida zopangira mano ndipo zidakopa chidwi cha ofufuza ambiri.

Kuchita kwa zirconia ceramics kudzakhudzidwa ndi zinthu zambiri, lero tikukamba za zotsatira za sintering pazinthu zina za zirconia ceramics.

Sintering njira

The chikhalidwe sintering njira ndi kutenthetsa thupi kudzera cheza kutentha, conduction kutentha, kutentha convection, kotero kuti kutentha kuchokera pamwamba zirconia kwa mkati, koma matenthedwe madutsidwe wa zirconia ndi woipa kuposa aluminiyamu ndi zipangizo zina zadothi. Pofuna kupewa kusweka chifukwa cha kupsinjika kwa matenthedwe, kuthamanga kwachikhalidwe kumakhala pang'onopang'ono ndipo nthawi yayitali, yomwe imapangitsa kuti kupanga kwa zirconia kukhala kwanthawi yayitali ndipo mtengo wake umakhala wokwera. M'zaka zaposachedwa, kuwongolera umisiri processing wa zirconia, kufupikitsa nthawi processing, kuchepetsa mtengo kupanga, ndi kupereka mkulu ntchito mano zirconia ceramic zipangizo akhala cholinga cha kafukufuku, ndi mayikirowevu sintering mosakayikira zingamuthandize sintering njira.

Zapezeka kuti microwave sintering ndi mpweya kuthamanga sintering alibe kusiyana kwakukulu pa chikoka cha theka permeability ndi kuvala kukana. Chifukwa chake ndi chakuti kachulukidwe wa zirconia wopezedwa ndi microwave sintering ndi wofanana ndi sintering wamba, ndipo onse ndi wandiweyani sintering, koma ubwino wa mayikirowevu sintering ndi otsika sintering kutentha, mofulumira liwiro ndi yochepa sintering nthawi. Komabe, kutentha kwa kutentha kwa mpweya kumachepa, nthawi yopuma ndi yaitali, ndipo nthawi yonse yopuma imakhala pafupifupi 6-11h. Poyerekeza ndi sintering wamba, microwave sintering ndi njira yatsopano yopangira sintering, yomwe ili ndi ubwino wa nthawi yaifupi ya sintering, kuyendetsa bwino kwambiri komanso kupulumutsa mphamvu, ndipo imatha kusintha microstructure ya ceramics.

Akatswiri ena amakhulupiriranso kuti zirconia pambuyo mayikirowevu sintering akhoza kukhalabe metastable tequartet gawo, mwina chifukwa mayikirowevu mofulumira Kutentha akhoza kukwaniritsa kachulukidwe mofulumira zinthu pa kutentha m'munsi, kukula kwa njere ndi ang'onoang'ono ndi yunifolomu kuposa amene wamba kuthamanga sintering, m'munsi kuposa. gawo lofunikira lakusintha kwa t-ZrO2, lomwe limathandizira kuti zisungidwe momwe zingathere m'malo osasunthika kutentha, kuwongolera mphamvu ndi kulimba kwa ceramic. zipangizo.

Pawiri sintering ndondomeko

Zirconia za ceramic za sintered zitha kukonzedwa ndi zida zodulira za emery chifukwa cha kuuma kwakukulu ndi mphamvu, ndipo mtengo wake ndi wokwera komanso nthawi yayitali. Pofuna kuthetsa mavuto omwe ali pamwambawa, nthawi zina zirconia zadothi zidzagwiritsidwa ntchito kawiri pa sintering, pambuyo pa mapangidwe a thupi la ceramic ndi sintering yoyamba, CAD / CAM amplification Machining ndi mawonekedwe omwe mukufuna, ndiyeno sintering mpaka kutentha komaliza. zakuthupi kwathunthu wandiweyani.

Iwo anapeza kuti awiri sintering njira adzasintha sintering kinetics wa zirconia zadothi, ndipo adzakhala ndi zotsatira zina pa kachulukidwe sintering, mawotchi katundu ndi microstructure wa zirconia zadothi. The makina katundu wa machinable zirconia ceramics sintered kamodzi wandiweyani ndi bwino kuposa sintered kawiri. Mphamvu yopindika ya biaxial ndi kulimba kwa ming'alu ya zirconia za ceramic zomwe zimapindika kamodzi ndizokwera kuposa zomwe zidayikidwa kawiri. Njira yothyoka ya ceramic sintered zirconia ceramics ndi transgranular/intergranular, ndipo kugunda kwa crack ndikolunjika. Mapangidwe othyoka a zirconia ceramics osweka kawiri amakhala osweka pang'onopang'ono, ndipo ming'aluyo imakhala yowawa kwambiri. Makhalidwe amtundu wa fracture wophatikizika ndiabwino kuposa mawonekedwe osavuta a intergranular fracture.

Sintering vacuum

Zirconia ayenera sintered mu vakuyumu chilengedwe, mu sintering ndondomeko adzabala ambiri thovu, ndi mu vakuyumu chilengedwe, thovu n'zosavuta kutulutsa ku sungunuka mkhalidwe wa porcelain thupi, kusintha osalimba zirconia, potero kuonjezera theka-permeability ndi makina katundu zirconia.

Kutentha kwa kutentha

Mu njira ya sintering ya zirconia, kuti mupeze ntchito yabwino ndi zotsatira zoyembekezeredwa, kutentha kwapansi kuyenera kutengedwa. Kutentha kwapamwamba kumapangitsa kutentha kwa mkati kwa zirconia kukhala kosagwirizana pamene kufika kutentha komaliza kwa sintering, zomwe zimatsogolera ku maonekedwe a ming'alu ndi mapangidwe a pores. Zotsatira zimasonyeza kuti ndi kuwonjezeka kwa kutentha kwa kutentha, nthawi ya crystallization ya zirconia crystals imafupikitsidwa, mpweya pakati pa makhiristo sungathe kutulutsidwa, ndipo porosity mkati mwa zirconia crystals imawonjezeka pang'ono. Ndi kuwonjezeka kwa kutentha kwa kutentha, gawo laling'ono la monoclinic crystal gawo limayamba kukhalapo mu gawo la tetragonal la zirconia, zomwe zidzakhudza makina. Pa nthawi yomweyi, ndi kuwonjezeka kwa kutentha kwa kutentha, mbewuzo zidzakhala polarized, ndiko kuti, kukhalapo kwa mbewu zazikulu ndi zazing'ono zimakhala zosavuta. Kutentha kwapang'onopang'ono kumathandizira kupanga mbewu zambiri zofananira, zomwe zimawonjezera semipermeability ya zirconia.