Ceramik
Alumina seramiiki bụ ụdị ihe eji eme ihe na-eguzogide, ihe na-emebi emebi na ike dị elu. Iji na-etolite uka mmepụta na izute chọrọ nke mgbe ngwaahịa anya, obere egweri ego na mfe ezi egweri, ọ dị oké mkpa ịhọrọ akpụ usoro nke nkụ pressing.Compression ịkpụzi na-achọ na oghere bụ a ntụ ntụ na a ụfọdụ gradation, na obere mmiri na binder.Ya mere, na slurry nke ogbe mgbe bọl-egwe ọka na ezi nchikota ga-mma ga-adị elu nke a mịrị amị na powdered granul den. Ịgba ahịhịa granulation aghọọla usoro bụ isi maka mmepụta nke ceramics ụlọ na ceramics ọhụrụ. The ntụ ntụ nke a kwadebere site na usoro a nwere ezigbo mmiri mmiri, akụkụ ụfọdụ nke nnukwu na obere ahụ, na ezigbo njupụta njupụta. Ya mere, ịgba ihicha bụ ụzọ kachasị dị irè iji kwadebe ntụ ntụ akọrọ.
Ịkpọsa mmiri bụ usoro nke atomized ihe mmiri mmiri (gụnyere slurry) wee gbanwee ka ọ bụrụ ihe ntụ ntụ akọrọ na ikpo ọkụ na-ekpo ọkụ. The ihe na-atomized n'ime kemgwucha ọma spherical fogdrops, n'ihi fogdrops dị nnọọ mma na ruru nke elu ebe na olu bụ nnọọ nnukwu, mmiri ngwa ngwa evaporates, na ihicha na granulation Filiks na-agwụ agwụ n'otu ntabi anya. The urughuru size, mmiri ọdịnaya na nnukwu njupụta nke ihe nwere ike ịchịkwa site ukpụhọde ihicha ọrụ parameters. Spherical ntụ ntụ na edo àgwà na ezi repeatability nwere ike na-emepụta site n'ịkpa ịgba ihicha technology, si otú shortening mmepụta usoro nke ntụ ntụ, ikwado akpaka na-aga n'ihu mmepụta, na ịbụ ihe irè usoro maka nnukwu-ọnụ ọgụgụ nkwadebe nke ọma alumina seramiiki akọrọ ntụ ntụ ihe.
2.1.1 Nkwadebe nke Slurry
The mbụ na klas ulo oru alumina na a ịdị ọcha nke 99% na-kwukwara na banyere 5% nke mgbakwunye iji kwadebe 95% poselin ihe, na bọl-egwe ọka na-rụrụ dị ka ruru nke ihe onwunwe: bọl: mmiri = 1: 2: 1, na ihe nkedo, deflocculant na kwesịrị ekwesị ego nke mmiri na-agbakwunyere iji kwadebe anụ nkwusioru slurry kwesịrị ekwesị, na ikwu na-ekpebi ihe dị mfe na-eme ka a na-eme ihe n'ụzọ ziri ezi. ụdị na usoro onunu ogwu nke deflocculant.
2.1.2 ịgbasa ihicha usoro
Usoro usoro nchịkwa isi na usoro ihicha ịgba bụ: a). The outlet okpomọkụ nke dryer.Generally achịkwa na 110 ℃.b). N'ime dayameta nke nozzle.Jiri 0.16mm ma ọ bụ 0.8mm orifice efere. c), Cyclone separator nrụgide dị iche, njikwa na 220Pa.
2.1.3 Arụmọrụ Nyocha nke ntụ ntụ mgbe fesa ihicha
A ga-eduzi mkpebi nke mmiri dị ka usoro mmiri mmiri seramiiki nkịtị si dị. Ihe ahụmorphology na urughuru nha ka a na-ahụ site na microscope. A na-anwale ihe omimi na nnukwu njupụta nke ntụ ntụ dị ka ụkpụrụ nyocha ASTM si dị maka mmiri mmiri na nnukwu njupụta nke ntụ ntụ ígwè. Usoro bụ: n'okpuru ọnọdụ nke enweghị ịma jijiji, 50g ntụ ntụ (nke ziri ezi na 0. 01g) na-agafe n'olu olu iko nke nwere dayameta nke 6mm na ogologo 3mm maka mmiri mmiri ya; N'okpuru ọnọdụ nke enweghị vibration, ntụ ntụ na-agafe otu iko iko wee daba n'ime akpa 25mm dị elu site na otu iko iko. Njupụta na-adịghị eme mkpọtụ bụ njupụta nkwakọ ngwaahịa rụrụ arụ.
3.1.1 Nkwadebe nke slurry
Iji usoro ihicha granulation spray, nkwadebe nke slurry bụ isi ihe dị mkpa. Ọdịnaya siri ike, ịdị mma na mmiri mmiri nke apịtị ga-emetụta nsonaazụ na nha nha nke ntụ ntụ.
N'ihi na ntụ ntụ nke a na ụdị alumina poselin bụ aga, ọ dị mkpa ka ịgbakwunye a kwesịrị ekwesị ego nke ihe nkedo ka mma na-akpụ arụmọrụ nke blank.Commonly ji organic bekee dị ka dextrin, polyvinyl mmanya, carboxymethylcellulose, polystyrene, etc.Polyvinyl mmanya (PVA), a mmiri-soluble ihe nkedo, a na-ahọrọ nke ukwuu na-enwe mmetụta dị nro nke iru mmiri na nke a nnwale. Njirimara nke ntụ ntụ akọrọ.
Polyvinyl mmanya nwere ọtụtụ ụdị dị iche iche, ogo dị iche iche nke hydrolysis na ogo polymerization, nke ga-emetụta usoro ihicha ịgba. Ogo ogo hydrolysis n'ozuzu ya na ogo polymerization ga-emetụta usoro ihicha ịgba. Usoro ọgwụgwọ ya na-abụkarị 014 - 015wt% .Mgbakwunye nke ukwuu ga-eme ka ntụ ntụ granulation na-eme ka ọkpụkpụ siri ike na-eme ka ọkpụkpụ na-eme ka ọkpụkpụ na-eme ka ọ ghara imebi n'oge pressing.Ọ bụrụ na a pụghị ikpochapụ àgwà ndị ahụ n'oge ịpị, a ga-echekwa ntụpọ ndị a n'ime ahụ na-acha akwụkwọ ndụ na enweghị ike ikpochapụ mgbe agbapụ, nke ga-emetụta àgwà nke ngwaahịa ikpeazụ. Ihe mgbakwunye mgbakwunye obere ike akwụkwọ ndụ akwụkwọ ndụ ga-abawanye mfu ọrụ. Nnwale ahụ na-egosi na mgbe agbakwunyere ihe nkedo kwesịrị ekwesị, a na-ahụ akụkụ nke billet green n'okpuru microscope. Enwere ike ịhụ na mgbe a na-abawanye nrụgide site na 3Mpa ruo 6Mpa, akụkụ ahụ na-abawanye nke ọma, ma enwere obere ọnụọgụ nke gburugburu. Mgbe nrụgide bụ 9Mpa, ngalaba ahụ dị nro, na enweghị isi ihe dị iche iche, mana nrụgide dị elu ga-eduga na stratification nke akwụkwọ ndụ akwụkwọ ndụ billet. PVA na-emeghe na ihe dịka 200 ℃.
Malite na-ere ọkụ, na igbapu na ihe dị ka 360 ℃. Iji igbari organic ihe nchikota na mmiri na billet ahụ, na-etolite mmiri mmiri interlayer n'etiti ahụ, melite plasticity nke billet, belata esemokwu n'etiti ahụ na esemokwu n'etiti ihe na ebu, na-akwalite njupụta njupụta nke pịa billet na ihe nkesa nke plastic na-ejikarị eme ihe, na-agbakwụnye nkesa nke plastik kwesịrị ekwesị. glycerin, ethyl oxalic acid, wdg.
N'ihi na ihe nkedo ahụ bụ polymer macromolecular macromolecular, usoro nke ịgbakwunye ihe nkedo n'ime slurry dịkwa oke mkpa. Ọ bụ ihe kachasị mma iji tinye ihe nkedo a kwadebere n'ime apịtị edo na ọdịnaya siri ike achọrọ. N'ụzọ dị otú a, a na-ezere ihe ndị na-adịghị edozi na nke a na-agbasaghị ka a na-ebute n'ime slurry, na ntụpọ ndị nwere ike ime mgbe a na-agbapụ bọlbụ nwere ike belata ngwa ngwa. na-akpali akpali. Ikuku a na-etinye n'ime droplet dị na ntụ ntụ akọrọ, nke na-eme ka ihe ndị ahụ na-ekpo ọkụ na-ekpo ọkụ ma na-ebelata ụda olu. Iji dozie nsogbu a, enwere ike ịgbakwunye defoamers.
N'ihi aku na uba na nkà na ụzụ chọrọ, elu siri ike ọdịnaya chọrọ. Dị ka mmepụta ike nke draya na-ezo aka na evaporation mmiri kwa elekere, slurry na elu siri ike ọdịnaya ga-budata dịkwuo akọrọ ntụ mmepụta. Mgbe ọdịnaya siri ike na-abawanye site na 50% ruo 75%, mmepụta nke draya ga-abawanye ugboro abụọ.
Ọdịnaya siri ike dị ala bụ isi ihe mere e ji emepụta ihe ndị na-adịghị ahụkebe. N'ime usoro ihicha, mmiri na-akwaga n'elu mmiri ahụ ma na-ebu ihe siri ike, nke na-eme ka akụkụ dị n'ime nke ntanye ahụ ghara; ma ọ bụrụ na a na-emepụta ihe nkiri dị ala nke na-agbanwe agbanwe na gburugburu droplet, n'ihi obere ikuku evaporation, okpomọkụ nke droplet na-abawanye, na mmiri na-esi n'ime ime ahụ pụta, nke na-eme ka ọkpụkpụ na-egbuke egbuke. ọdịnaya siri ike nwere ike ibelata
Na nkenke ihicha usoro, Mbelata ihicha usoro nwere ike ibelata ego nke nrapado bufee na urughuru elu tinyere mmiri, nke mere na iji zere na ihe nkedo ịta na urughuru elu dị ukwuu karịa n'etiti, nke mere na ahụ nwere a siri ike elu, na ahụ adịghị deform na-egwepịa n'ime usoro nke ịpị na-akpụ, ka iji belata ahụ uka nke billet. Ya mere, iji nweta ntụ ntụ akọrọ dị elu, ihe siri ike nke slurry ga-abawanye.
Ọ bụrụ na slurry nke a na-eji ihicha ihicha kwesịrị inwe mmiri mmiri zuru ezu na obere mmiri dị ka o kwere mee. Ọ bụrụ na a na-ebelata viscosity nke slurry site n'iwebata mmiri ndị ọzọ, ọ bụghị nanị na ike oriri nke ihicha na-abawanye, kamakwa nnukwu njupụta nke ngwaahịa na-ebelata. ahụ, nke nwere ike na-ewere dị ka a colloidal mgbasa usoro. Ozizi nke colloidal kwụsie ike na-egosi na e nwere abụọ agha na-eme ihe nkwusioru ahụ: van der Waals Force (Coulomb Force) na electrostatic repulsion ike. Ọ bụrụ na ike bụ tumadi ike ndọda, agglomeration na flocculation ga-eme.The ngụkọta ike ike (VT) nke mmekọrịta n'etiti ahụ na-metụtara ha anya, n'oge nke VT n'oge ụfọdụ bụ nchikota nke ike ndọda VA na-asọ oyi ike VR.When VT n'etiti ahụ na-egosi kacha mma ike ike, ọ bụ usoro nke a na-eme ka usoro nke a suspension bụ nkwụsi ike nke a na-enye usoro nke a suspension VA. Ọrụ ndị ahụ na-achịkwa VR: ụgwọ dị elu nke ihe ndị dị n'elu na ọkpụrụkpụ nke okpukpu abụọ nke eletriki eletrik. The ọkpụrụkpụ nke bilayer bụ inversely proportional ka square mgbọrọgwụ nke valence bond na ịta nke equilibrium.Double oyi akwa mkpakọ nwere ike ibelata nwere ihe mgbochi nke flocculation, ya mere valence bond na ịta nke equilibrium ion na ala ngwọta na-achọrọ NOCI3. NaOH, (CH) 3noh (quaternary amine), GA, wdg.
N'ihi na mmiri nke dabeere na slurry nke 95 alumina seramiiki ntụ ntụ na-anọpụ iche na alkalescent, ọtụtụ coagulants nke nwere mmetụta dị mma diluting mmetụta na ndị ọzọ seramiiki slurry na-efunahụ ha ọrụ.Ya mere, ọ na-esi nnọọ ike ịkwadebe slurry na elu siri ike ọdịnaya na ezi fluidity.The aga alumina slurry, nke bụ nke alumina alumina slurry, nke bụ nke amphote, nwere dị iche iche acid disso oxidation usoro. ọnọdụ dissociation nke dị iche iche mielle mejupụtara na Ọdịdị. Uru pH nke slurry ga-emetụta kpọmkwem ogo nke dissociation na adsorption, na-ebute mgbanwe nke ζ nwere ike na flocculation ma ọ bụ dissociation kwekọrọ.
Alumina slurry nwere uru kachasị mma na nke na-adịghị mma ζ nwere ike na acid ma ọ bụ alkaline medium. N'oge a, viscosity nke slurry dị na ala kachasị ala nke steeti de coagulation, ebe mgbe slurry dị na ọnọdụ na-anọpụ iche, viscosity ya na-abawanye, na flocculation na-apụta. na-agbakwunye demulsifier kwesịrị ekwesị, nke mere na uru viscosity ya dị nso na mmiri. Mmiri nke mmiri a tụrụ site na viscometer dị mfe bụ 3 sekọnd / 100 ml, na fluidity nke slurry bụ 4 sekọnd / 100 ml. a na-ebelata viscosity nke slurry, nke mere na ọdịnaya siri ike dị na slurry nwere ike ịbawanye ruo 60%, a pụkwara ịmepụta nkwakọ ngwaahịa kwụsiri ike. Dị ka ike mmepụta nke draya na-ezo aka na evaporation nke mmiri kwa elekere, ya mere nkwụsịtụ.
3.1.2 Control nke isi parameters na ịgba ihicha usoro
Usoro ikuku ikuku na ụlọ elu ihicha na-emetụta oge ihicha, oge njigide, mmiri fọdụrụ na mgbidi ịrapara nke ụmụ irighiri mmiri. N'ime nnwale a, usoro ngwakọta ikuku droplet na-agwakọta eruba, ya bụ, gas na-ekpo ọkụ na-abanye n'ụlọ elu ihicha site n'elu, na atomizing nozzle na-arụnyere na ala nke ihicha ụlọ elu, na-akpụ isi iyi mmiri, na droplet bụ parabocurt counter bụ parabocurt. Droplet ahụ rutere n'elu ọrịa strok, ọ na-aghọ ihe mgbada na-agbada ma na-agbaba n'ime ọdịdị conical. Ozugbo droplet na-abanye n'ụlọ elu ihicha, n'oge na-adịghị anya, ọ ga-eru ọsọ ọsọ nke ihicha ma banye n'ọsọ ihicha ọsọ mgbe niile. Ogologo oge ikpo ọkụ na-agba ọsọ mgbe niile na-adabere na mmiri ọdịnaya nke droplet, viscosity nke apịtị, okpomọkụ na iru mmiri nke ikuku akọrọ. A na-akpọ ókèala C site na ogbo ihicha ọsọ mgbe niile ruo n'oge ihicha ngwa ngwa. N'oge a, elu nke droplet enweghị ike ịnọgide na-enwe ọnọdụ jujuru site na mbugharị nke mmiri, na mbelata nke evaporation ọnụego, okpomọkụ nke ụmụ irighiri mmiri na-abawanye, na elu nke ụmụ irighiri mmiri na ebe D na-ejupụta, na-akpụ a oyi akwa nke siri ike shei. Evaporation na-aga n'ime ime, ọnụ ọgụgụ ihicha na-aga n'ihu na-agbada. Mwepụ ọzọ nke mmiri na-ejikọta ya na mmiri mmiri nke shei siri ike. Ya mere, ọ dị mkpa ijikwa usoro ọrụ ezi uche dị na ya.
The mmiri ọdịnaya nke akọrọ ntụ ntụ na-tumadi kpebisiri ike site tinyekwa okpomọkụ nke ịgba dryer.The mmiri ọdịnaya emetụta nnukwu njupụta na fluidity nke akọrọ ntụ ntụ, na-ekpebi àgwà enwe blank.PVA bụ mmetụta iru mmiri. N'okpuru ọnọdụ dị iche iche nke mmiri mmiri, otu ego nke PVA nwere ike ime ka ike dị iche iche nke elu oyi akwa nke akọrọ ntụ ntụ, nke na-eme ka mkpebi nke nrụgide na-agbanwe na àgwà mmepụta na-ejighị n'aka n'oge usoro ịpị. Ya mere, a ga-achịkwa nke ọma na okpomọkụ na-apụ apụ iji hụ na mmiri dị n'ime ntụ ntụ. N'ozuzu, a ga-achịkwa okpomọkụ na-ekpo ọkụ na 110 ℃, na ntinye okpomọkụ kwesịrị imezi ya otú ahụ. The mbata okpomọkụ abụghị ihe karịrị 400 ℃, n'ozuzu na-achịkwa na banyere 380 ℃. Ọ bụrụ na mbata okpomọkụ dị oke elu, okpomọkụ ikuku na-ekpo ọkụ n'elu ụlọ elu ahụ ga-ekpo ọkụ. Mgbe alụlụ dara na-ebili ruo n'ókè kasị elu ma na-ezute overheated ikuku, n'ihi na seramiiki ntụ ntụ nwere ihe nkedo, mmetụta nke binder ga-ebelata, na n'ikpeazụ, ịpị arụmọrụ nke akọrọ ntụ ntụ ga-emetụta. a na-ekpebisi ike, a pụkwara imezi ọnọdụ okpomọkụ na-apụ apụ site na nrụgide nke mgbapụta nri, ọdịiche nrụgide nke cyclone separator, ọdịnaya siri ike nke slurry na ihe ndị ọzọ.
Ọdịiche nrụgide nke separator cyclone. Ihe dị iche iche nke nrụgide nke ikuku cyclone dị ukwuu, nke ga-eme ka ọnọdụ okpomọkụ dịkwuo elu, na-amụba nchịkọta nke ihe dị mma ma belata mkpụrụ nke draya.
3.1.3 Njirimara nke ịgba Fikiere ntụ ntụ
Mmiri mmiri na njupụta nke alumina seramiiki ntụ ntụ nke a kwadebere site na usoro ịgbasa mmiri na-adịkarị mma karịa nke a kwadebere site na usoro mbụ. Uzuzu nke granulation akwụkwọ ntuziaka enweghị ike ịgbaba site na ngwaọrụ nchọpụta na-enweghị ịma jijiji, na ntụ ntụ nke granulation spray nwere ike ime nke a kpamkpam. N'ịtụ aka na ọkọlọtọ ASTM maka ịnwale mmiri ntụ ntụ metal na njupụta buru ibu, a tụrụ nnukwu njupụta na mmiri nke ihe enwetara site na ihicha mmiri n'okpuru ọnọdụ ọdịnaya mmiri dị iche iche. Lee tebụl 1.
Isiokwu 1 rụrụ njupụta na fluidity nke ịgba Fikiere ntụ ntụ
Isiokwu 1 Njupụta ntụ ntụ na ọnụego eruba
| Ọdịnaya mmiri (%) | 1.0 | 1.6 | 2.0 | 2.2 | 4.0 |
| Njupụta nke mkpirisi (g/cm3) | 1.15 | 1.14 | 1.16 | 1.18 | 1.15 |
| Mmiri (s) | 5.3 | 4.7 | 4.6 | 4.9 | 4.5 |
A na-achịkwa ọdịnaya mmiri nke ntụ ntụ mịrị amị na 1-3%. N'oge a, mmiri mmiri nke ntụ ntụ dị mma, nke nwere ike izute ihe achọrọ nke ịpị ịkpụzi.
DG1 bụ njupụta nke ntụ ntụ granulation ejiri aka mee, na DG2 bụ njupụta nke ntụ ntụ maka granulation spray.
A na-eji ntụ ọka granulated aka akwado ya site na-egwe ọka, ihicha, sieving na granulation.
Tebụl 2 njupụta nke ntụ ntụ ndị a na-etinye n'ahụ kpụrụ site na granulation ntuziaka na ịgba granulation
Tebụl 2 Njupụta Green ahụ
| Nrụgide (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 |
The urughuru size na morphology nke ntụ ntụ e hụrụ site microscope.It nwere ike hụrụ na ahụ bụ ihu ọma siri ike spherical, na doro anya interface na-eji ire ụtọ elu. Akụkụ ụfọdụ bụ ụdị apụl, ube ube ma ọ bụ bridged, na-aza 3% nke mkpokọta. The urughuru size nkesa bụ dị ka ndị a: kacha urughuru size bụ 200 μ m (< 1%), nke kacha nta urughuru size bụ 20 μ m (otu n'otu), ọtụtụ irighiri ihe dị ka 100 μ m (50%), na ọtụtụ ahụ bụ ihe dị ka 50 μ m (20%). The ntụ ntụ na-emepụta site spraying bụ sintered na 3 165 cm.3.
(1) Enwere ike nweta 95 alumina slurry nwere 60% siri ike site na iji PVA dị ka ihe nkedo, na-agbakwunye coagulant kwesịrị ekwesị na mmanu mmanu.
(2) ezi uche akara nke ịgba ihicha ọrụ parameters nwere ike nweta ezigbo akọrọ ntụ ntụ.
(3) site na ịnakwere ịgba ihicha usoro, 95 alumina ntụ ntụ, nke kwesịrị ekwesị maka nnukwu nkụchi usoro, nwere ike mepụta. Njupụta ya rụrụ arụ bụ ihe dịka 1.1g / cm3na njupụta sintering bụ 3170g / cm3.
