Tukwane na musamman yana nufin nau'in tukwane tare da kayan aikin injiniya na musamman, na zahiri ko sinadarai, albarkatun da ake amfani da su da fasahar samarwa da ake buƙata sun sha bamban da yumbu na yau da kullun da haɓakawa. Dangane da halaye da amfani, ana iya raba tukwane na musamman zuwa nau'i biyu: tukwane na tsari da yumbu na aiki. Daga cikin su, tsarin tukwane yana nufin yumbu waɗanda za a iya amfani da su azaman kayan aikin injiniya, waɗanda gabaɗaya suna da ƙarfi mai ƙarfi, tsayin daka, babban ƙarfin roba, juriya mai girma, juriya na sawa, juriya na lalata, juriya iskar shaka, juriya ta thermal da sauran halaye.
Akwai nau'ikan tukwane iri-iri da yawa, fa'idodi da rashin amfani, kuma jagorar aikace-aikacen fa'ida da rashin amfani sun bambanta, daga cikinsu akwai "silinkin nitride yumbura" saboda ma'auni na aiki a kowane fanni, an san shi da mafi kyawun ingantaccen aiki a ciki. iyali ceramics na tsarin, kuma yana da kewayon aikace-aikace da yawa.
Amfanin silicon nitride yumbura
Silicon nitride (Si3N4) za a iya raba zuwa covalent bond mahadi, tare da [SiN4] 4-tetrahedron a matsayin tsarin naúrar. Ana iya ganin takamaiman matsayi na nitrogen da silicon atom daga wannan hoton da ke ƙasa, silicon yana tsakiyar tetrahedron, kuma matsayi na tetrahedron huɗu yana mamaye da ƙwayoyin nitrogen, sannan kowane tetrahedron uku yana raba zarra guda ɗaya, koyaushe. fadada cikin sarari mai girma uku. A ƙarshe, an kafa tsarin hanyar sadarwa. Yawancin kaddarorin silicon nitride suna da alaƙa da wannan tsarin tetrahedral.
Akwai nau'ikan siliki guda uku na siliki nitride, waɗanda sune α, β da γ matakan, waɗanda α da β matakan sune mafi yawan nau'ikan silicon nitride. Saboda atom ɗin nitrogen suna da ƙarfi sosai, silicon nitride yana da ƙarfi mai ƙarfi, ƙarfi mai ƙarfi da juriya mai zafi, kuma taurin zai iya kaiwa HRA91 ~ 93; Kyakkyawan thermal rigidity, zai iya tsayayya da babban zafin jiki na 1300 ~ 1400 ℃; Smallaramin halayen sinadarai tare da carbon da abubuwan ƙarfe suna haifar da ƙarancin ƙima; Yana da mai mai da kansa don haka yana da tsayayya da sawa; Juriya na lalata yana da ƙarfi, ban da hydrofluoric acid, ba ya amsawa tare da sauran inorganic acid, babban zafin jiki kuma yana da juriya na iskar shaka; Har ila yau yana da kyakkyawan juriya na zafin zafi, sanyaya mai kaifi a cikin iska sannan kaifi mai zafi ba zai rushe ba; Creep na silicon nitride yumbura yana raguwa a babban zafin jiki, kuma jinkirin nakasar filastik ƙarami ne ƙarƙashin aikin babban zafin jiki da ƙayyadaddun kaya.
Bugu da kari, silicon nitride tukwane kuma suna da babban takamaiman ƙarfi, yanayin takamaiman yanayi, haɓakar haɓakar thermal, kyawawan kaddarorin lantarki da sauran fa'idodi, don haka yana da ƙimar aikace-aikacen musamman a cikin matsanancin yanayi kamar babban zafin jiki, babban saurin gudu, watsa labarai mai ƙarfi mai lalata, da ƙari. ana la'akari da kasancewa ɗaya daga cikin mafi kyawun kayan aikin yumbu don haɓakawa da aikace-aikacen, kuma sau da yawa ya zama zaɓi na farko a yawancin aikace-aikacen da ke buƙatar gwadawa.
Lokacin aikawa: Agusta-15-2023