Ukukhethwa kwe-silica sol coating kuzothinta ngqo ubulukhuni obungaphezulu kanye nokunemba kobukhulu be-dimensionalukukhishwa kwezimali. I-silica sol coatings ngokuvamile ingakhetha ngokuqondile i-silica sol enengxenye enkulu ye-silica engu-30%. Inqubo yokumboza ilula futhi ukusebenza kulula. Ngesikhathi esifanayo, igobolondo lokubunjwa lokubunjwa elikhiqizwa ngokusebenzisa i-coating linamandla amakhulu, futhi umjikelezo wokwenza igobolondo nawo ungafinyezwa.
I-silica sol iyisibopho esivamile esisekelwe emanzini esine-silicic acid colloid structure. Kuyisixazululo se-polymer colloidal lapho izinhlayiya ze-silica ezihlakazeke kakhulu zincibilika emanzini. Izinhlayiya ze-colloidal ziyindilinga futhi zinobubanzi obungu-6-100 nm. Iinqubo yokutshala imaliukwenza igobolondo inqubo gelling. Kunezici eziningi ezithonya i-gelation, ikakhulukazi i-electrolyte, i-pH, ukugxila kwe-sol kanye nezinga lokushisa. Kunezinhlobo eziningi zama-silica sols ezithengiswayo, futhi esetshenziswa kakhulu i-alkaline silica sol enokuqukethwe kwe-silica okungama-30%. Inqubo yokwenza igobolondo le-silica sol ilula. Inqubo ngayinye inezinqubo ezintathu: ukumboza, ukuhlanganisa, nokomisa. Inqubo ngayinye iphindaphindiwe izikhathi eziningi ukuze uthole igobolondo le-multilayer lobukhulu obudingekayo.
Ngokuvamile kunezindlela ezimbili zokukhiqiza i-silica sol: ukushintshaniswa kwe-ion kanye nokuchithwa. Indlela yokushintshanisa i-ion ibhekisela ekushintshanisweni kwe-ion yengilazi yamanzi ehlanjululwe ukususa ama-ion e-sodium nokunye ukungcola. Khona-ke isisombululo siyahlungwa, sishiswe futhi sigxilwe ekumineni okuthile ukuze kutholakale i-silica sol. Indlela yokuhlakaza ibhekisela ekusebenziseni i-silicon ehlanzekile yezimboni (ingxenye enkulu ye-silicon ≥ 97%) njengento eluhlaza, futhi ngaphansi kwesenzo se-catalyst, incibilika ngokuqondile emanzini ngemva kokushisisa. Ngemuva kwalokho, isisombululo siyahlungwa ukuze kutholwe i-silica sol.
Izinhlaka Zobuchwepheshe ze-Silica Sol Zokusakaza Kwezimali | ||||||||
| Cha. | Ukwakheka Kwekhemikhali (ingxenye enkulu, %) | Izakhiwo Zomzimba | Abanye | |||||
| SiO2 | Na2O | Ukuminyana (g/cm3) | pH | I-Kinematic Viscosity (mm2/s) | Usayizi we-SiO2 Particl (nm) | Ukubukeka | Isigaba Sokumisa | |
| 1 | 24-28 | ≤ 0.3 | 1.15 - 1.19 | 9.0 - 9.5 | ≤ 6 | 7-15 | nge-invory noma umbala oluhlaza okhanyayo, ngaphandle kokungcola | ≥ unyaka ongu-1 |
| 2 | 29-31 | ≤ 0.5 | 1.20 - 1.22 | 9.0 - 10 | ≤8 | 9-20 | ≥ unyaka ongu-1 | |
I-castings etholwe inqubo yokwenza igobolondo le-silica sol inobukhulu obuphansi obuphezulu, ukunemba okuphezulu kobukhulu kanye nomjikelezo omude wokwenza amagobolondo. Le nqubo isetshenziswa kakhulu ekukhipheni ama-alloys amelana nokushisa okuphezulu, izinsimbi ezikwazi ukumelana nokushisa, izinsimbi ezingenasici, izinsimbi ze-carbon, ama-alloys aphansi, ama-alloys e-aluminium nama-alloys ethusi.
Ukunemba kwe-silica sol elahlekile inqubo yokufaka utshalomali kwe-wax ifaneleka ukukhiqizwa okuphindaphindekayo kwezingxenye zomumo wenetha kusuka ezinhlobonhlobo zezinsimbi nama-alloys asebenzayo. Nakuba ngokuvamile isetshenziselwa ukulingisa okuncane, le nqubo isetshenziselwe ukukhiqiza amafreyimu eminyango yendiza ephelele, enensimbi efika ku-500 kgs kanye nokusakazwa kwe-aluminium kufika ku-50 kgs. Uma kuqhathaniswa nezinye izinqubo zokulingisa ezifana ne-die casting noma ukwenza isihlabathi, kungaba inqubo ebizayo. Kodwa-ke, izakhi ezingakhiqizwa kusetshenziswa ukufakwa kwe-investimenti zingahlanganisa amakhonsathi ayinkimbinkimbi, futhi ezimeni eziningi izingxenye ziphonswa eduze komumo wengqikithi, ngakho-ke zidinga ukusetshenzwa kabusha okuncane noma zingasasebenzi lapho kwasakazwa.
Izingxenye eziyinhloko ze-wax coating yenqubo yokutshala imali yilezi:
Isendlalelo esingaphezulu se-silika enamathelayo. Ingaqinisekisa amandla ongqimba olungaphezulu futhi iqinisekise ukuthi ungqimba lwangaphezulu aluqhekeki;
I-Refractory. Ngokuvamile i-high-purity zirconium powder ukuze kuqinisekiswe ukuthi ukumboza kune-refractoriness eyanele futhi akuphenduli ngamakhemikhali ngensimbi encibilikisiwe.
Okokugcoba. I-surfactant. Ngenxa yokuthi i-silica sol coating iyinalethi esekelwe emanzini, ukumanzisa phakathi kwayo nesikhunta se-wax kubi, futhi umphumela wokumboza nokulenga awulungile. Ngakho-ke, kuyadingeka ukwengeza i-ejenti yokumanzisa ukuthuthukisa ukugqoka nokusebenza kokulenga.
I-Defoamer. Iphinde ibe yi-surfactant enhloso yayo iwukuqeda amabhamuza omoya ku-ejenti yokumanzisa.
Isicwengisisi sokusanhlamvu. Ingaqinisekisa ukucolisiswa okusanhlamvu kwe-castings futhi ithuthukise izakhiwo zemishini ye-castings.
Amanye ama-appendages:i-ejenti emisiwe, inkomba yokomisa, i-ejenti yokukhululwa okuqhubekayo, njll.
Ukukhetha okulungile kwengxenye yengxenye ngayinye ku-silica sol coating kuyisihluthulelo sokuqinisekisa ikhwalithi ye-coating. Izingxenye ezimbili eziyisisekelo kakhulu zokumboza ama-refractories nama-binder. Isilinganiso phakathi kwalokhu okubili isilinganiso sempushana-kuya-soketshezi lwento enamathelayo. Isilinganiso se-powder-to-liquid sopende sinethonya elikhulu ekusebenzeni kopende kanye negobolondo, okuzogcina kuthinte ikhwalithi yokukhipha. Uma isilinganiso se-powder-to-liquid se-coating siphansi kakhulu, i-coating ngeke ibe minyene ngokwanele futhi kuyoba nama-voids amaningi kakhulu, okuzokwenza ubuso be-casting bube nzima. Ngaphezu kwalokho, isilinganiso esiphansi kakhulu se-powder-to-liquid sizokwandisa ukuthambekela kokuqhekeka kwe-coating, futhi amandla egobolondo azoba aphansi, okuzogcina kubangele ukuvuza kwensimbi encibilikisiwe ngesikhathi sokubunjwa. Ngakolunye uhlangothi, uma isilinganiso se-powder-to-liquid siphezulu kakhulu, i-coating izoba mkhulu kakhulu futhi i-fluidity izoba mpofu, okwenza kube nzima ukuthola i-coating enobukhulu obufanayo kanye nobukhulu obufanele.
Ukulungiswa kokugqoka kuyingxenye ebalulekile yokuqinisekisa ikhwalithi yegobolondo. Lapho wenza ukugqoka, izingxenye kufanele zihlakazwe ngokufanayo futhi zixutshwe ngokugcwele futhi zimanziswe omunye nomunye. Imishini esetshenziselwa ukwakheka kopende, inani lezengezo kanye nesikhathi sokunyakazisa kuzothinta ikhwalithi yopende. Isitolo sethu sokutshala imali sisebenzisa izixube eziqhubekayo. Ukuze kuqinisekiswe ikhwalithi yokugqoka, lapho zonke izingxenye zokugqoka ziyizinto ezintsha ezisanda kufakwa, ukugqoka kufanele kushukunyiswe isikhathi eside ngokwanele.
Ukulawulwa kwezakhiwo ze-silica sol coatings kuyisinyathelo esibalulekile sokulawula ikhwalithi. I-viscosity, ukuminyana, izinga lokushisa le-ambient, njll. kapende kufanele kulinganiswe okungenani kathathu ngosuku, futhi kufanele kulawulwe ngaphakathi kwebanga elimisiwe nganoma yisiphi isikhathi.
Isikhathi sokuthumela: Jul-25-2022